СИСТЕМА УТИЛИЗАЦИИ ЭНЕРГИИ УГЛЯ С ПОМОЩЬЮ СВЕРХПРОВОДЯЩЕЙ ПЕРЕДАЧИ ЭЛЕКТРОЭНЕРГИИ

Изобретение относится к области электротехники, в частности к системе утилизации энергии угля, и содержит средство генерирования тепловой электроэнергии для преобразования энергии угля в угольном месторождении, находящемся в отдаленном от конечного потребителя месте, в электрическую энергию путем генерирования тепловой электроэнергии вблизи угольного месторождения, нагрузку переменного тока у конечного потребителя, сеть передачи/распределения переменного тока и средство передачи электроэнергии для передачи электрической энергии от средства генерирования тепловой электроэнергии вблизи угольного месторождения на сеть передачи/распределения. Средство передачи электроэнергии состоит из комбинации сверхпроводящей системы передачи электроэнергии постоянного тока с малыми потерями при передаче с использованием сверхпроводящего силового кабеля и обычной сети передачи/распределения с нормальной температурой. Техническим результатом изобретения является эффективное использование оборудования для ...

УСТРОЙСТВО ДЛЯ ПЕРЕДАЧИ ПОСТОЯННОГО ТОКА ВЫСОКОГО НАПРЯЖЕНИЯ

Изобретение относится к области электротехники и может быть использовано в устройствах для передачи постоянного тока высокого напряжения. Техническим результатом является обеспечение высокой варьируемости устройства в режимах работы, в частности, для компенсации обусловленных работой отключений. В устройстве для передачи постоянного тока высокого напряжения имеются первый преобразовательный блок (1) и второй преобразовательный блок (4), которые соответственно подключены к магистральной линии (11, 21) и к обратной линии (12, 22). Каждый преобразовательный блок (1, 4) подключен к отдельной независимой обратной линии (12, 22). Обратные линии (12, 22) соединены между собой через полюсную линию (31), причем полюсная линия (31) может прерываться с помощью блока (32) прерывания полюсной линии. 7 з.п. ф-лы, 5 ил.

ДЕТЕКТОР ПОВРЕЖДЕНИЯ ЛИНИИ

Изобретение относится к области электротехники и может быть использовано в системе обнаружения повреждения для обнаружения повреждений линии на электродной линии в системе HVDC. Техническим результатом является повышение надежности системы обнаружения повреждения. Электродная линия содержит первое и второе ответвления, соединенные параллельно. Система обнаружения повреждения содержит первую и вторую схемы генерации импульсов, выполненные с возможностью генерации электрических импульсов в первое и второе ответвления соответственно, а также первое и второе устройства измерения тока, выполненные с возможностью генерации сигналов, указывающих электрические сигналы, имеющие место в первой и второй линиях ввода соответственно. Возможность независимой генерации электрических импульсов в первое и второе ответвления соответственно, а также независимой регистрации первой и второй структур сигнала, представляющих электрические сигналы на первой и второй линиях ввода соответственно, повышает информационное ...

УСТРОЙСТВО ДЛЯ ГИБКОЙ ПЕРЕДАЧИ ЭНЕРГИИ И ДЛЯ УСТРАНЕНИЯ ОБЛЕДЕНЕНИЯ ВЫСОКОВОЛЬТНОЙ ЛИНИИ С ПОМОЩЬЮ ПОСТОЯННОГО ТОКА

Использование: в области электротехники. Технический результат - улучшение режима регулирования реактора с одновременным устранением нечетных гармоник. Устройство (1) имеет число фаз, соответствующее числу фаз высоковольтной линии, при этом каждая фаза имеет, по меньшей мере, одну индуктивность (6) и одну вентильную схему (10), включенную последовательно каждой индуктивности (6), вентильная схема (10) с помощью узловой точки (11) соединена с присоединением переменного тока и имеет первую ветвь (14) цепи тока с первым мощным полупроводниковым вентилем (12) и вторую ветвь (15) - с вторым мощным полупроводниковым вентилем (13), при этом мощные полупроводниковые вентили (12, 13) включены противоположно друг другу относительно узловой точки (11), первая и вторая ветвь (15) цепи тока предназначены для соединения с помощью, по меньшей мере, одного переключателя (16, 17) нулевой точки с нулевой точкой (18) реактора с тиристорным управлением, нулевая точка (18) соединена с нулевой точкой средства ...

УСТРОЙСТВО ДЛЯ РЕЗЕРВИРОВАННОГО ЭНЕРГОСНАБЖЕНИЯ ПО МЕНЬШЕЙ МЕРЕ ОДНОЙ НАГРУЗКИ

Использование: в области электротехники. Технический результат заключается в повышении надежности. Устройство для резервированного энергоснабжения по меньшей мере одной нагрузки (14) с первым вентильным преобразователем электроэнергии (2), который через первый вывод (7) является соединяемым с первой сетью переменного напряжения (8), вторым вентильным преобразователем электроэнергии (3), который через второй вывод (11) является соединяемым со второй сетью переменного напряжения (12), и промежуточным звеном напряжения постоянного тока (4), которое на стороне постоянного напряжения соединяет первый вентильный преобразователь электроэнергии (2) со вторым вентильным преобразователем электроэнергии (3), которым является возможно резервированное энергоснабжение, промежуточное звено напряжения постоянного тока (4) содержит по меньшей мере один вывод нагрузки для энергоснабжения нагрузки (14). 2 н. и 16 з.п. ф-лы, 7 ил.

СИСТЕМА ЭЛЕКТРОПЕРЕДАЧИ И СПОСОБ УПРАВЛЕНИЯ ЕЮ

Использование: в области электротехники. Технический результат заключается в повышении надежности. Система электропередачи содержит электрическую подстанцию-выпрямитель (2) и электрическую подстанцию-инвертор (3), каждая из которых имеет последовательное соединение, по меньшей мере, двух преобразователей (6-9). Параллельно с каждым преобразователем соединен обходной выключатель (12-15). Устройство (22-25) управления выполнено с возможностью деблокировки блокированного преобразователя путем начала управления им с большим углом запаздывания и постепенного уменьшения угла запаздывания до тех пор, пока весь постоянный ток не потечет через этот преобразователь, и последующего управления упомянутым обходным выключателем для размыкания при нулевом токе и для останова работы упомянутого преобразователя путем управления им с постепенно увеличивающимся углом запаздывания до тех пор, пока напряжение на этом преобразователе не станет нулевым, и для последующего управления преобразователем, подлежащим ...

СИСТЕМА ДЛЯ ОТБОРА ЭЛЕКТРОЭНЕРГИИ ОТ ВЫСОКОВОЛЬТНОЙ ЛИНИИ ПЕРЕДАЧИ ПОСТОЯННОГО ТОКА

Использование: в энергетике. Сущность: в высоковольтную линию передачи постоянного тока включен последовательно первый преобразователь, преобразующий постоянный ток в переменный. Его выход подключен к первичной обмотке первого трансформатора, вторичная обмотка которого подключена к второму преобразователю, к которому подключена вторичная сеть постоянного тока. К вторичной сети постоянного тока подключен третий преобразователь, преобразующий постоянный ток в переменный ток для местной сети. Система отбора электроэнергии от линии передачи постоянного тока в местную сеть позволяет отбирать небольшие количества энергии от мощных сетей постоянного тока относительно недорого. 6 з.п. ф-лы, 4 ил.

СПОСОБ И УСТРОЙСТВО УПРАВЛЕНИЯ ГИБРИДНОЙ СИСТЕМОЙ ПЕРЕДАЧИ ПОСТОЯННОГО ТОКА

Использование: в области электротехники. Технический результат – обеспечение эффективного управления напряжением и током гибридной системы электропередачи постоянного тока, не допуская перебоев в электропередаче. Способ управления гибридной системой электропередачи постоянного тока включает в себя: регулировку общего количества вставленных подмодулей модульного многоуровневого преобразователя и полярности выходного уровня вставленных подмодулей в режиме реального времени под напряжение постоянного тока выпрямительной подстанции на другом конце или регулировку общего количества вставленных подмодулей модульного многоуровневого преобразователя и полярности выходного уровня вставленных подмодулей в режиме реального времени под величину постоянного тока или мощность постоянного тока; регулировку общего количества вставленных подмодулей модульного многоуровневого преобразователя и полярности выходного уровня вставленных подмодулей в режиме реального времени под величину постоянного тока и напряжение ...

ПОДХОДЯЩЕЕ ДЛЯ ДВУХЦЕПНЫХ ЛИНИЙ УСТРОЙСТВО ПРОДОЛЬНОЙ КОМПЕНСАЦИИ

Изобретение относится к области электротехники. Раскрывается сущность подходящего для двухцепных линий устройства продольной компенсации. Устройство содержит один последовательный трансформатор и один преобразователь. Один преобразователь и двухцепные линии электропередачи соответственно подключены к трем обмоткам одного последовательного трансформатора. В решении, представленном в настоящей заявке, устройство может быть установлено самостоятельно в системе передачи электроэнергии для использования в качестве статического синхронного продольного компенсатора, а также может использоваться в качестве компонента единого регулятора потоков мощности, трансформируемого статического компенсатора, межлинейного регулятора потоков мощности и единого регулятора качества электроэнергии для последовательного подключения к устройству системы передачи электроэнергии. Технический результат заключается в возможности сэкономить емкость преобразователя, повысить эффективность применения устройства продольной ...

СИСТЕМА ЭНЕРГОСНАБЖЕНИЯ (ВАРИАНТЫ)

Изобретение относится к области электротехники и может быть использовано для эксплуатации скважин насосными установками для энергоснабжения электроэнергией удаленное электрическое устройство. Система энергоснабжения содержит преобразователь переменного напряжения в постоянное напряжение, соединенный с источником переменного напряжения для преобразования переменного напряжения в высокое постоянное напряжение на первом пункте. Преобразователь переменного напряжения в постоянное напряжение содержит множество компонентов преобразователя переменного напряжения в постоянное напряжение, которые на входе соединены параллельно с источником переменного напряжения и которые на выходе соединены последовательно с электрическим проводником. Электрический проводник проходит к множеству преобразователей напряжения на удаленном пункте, входы которых соединены последовательно с электрическим проводником, а выходы выдают соответствующие напряжения на электрическое устройство. 3 н. и 50 з.п. ф-лы, 36 ил.

КОНТРОЛЬ ПЕРЕДАЧИ ПОСТОЯННОГО ТОКА ВЫСОКОГО НАПРЯЖЕНИЯ

Использование: в области электротехники. Технический результат - повышение быстродействия распознавания неисправностей по постоянному току. Согласно способу задают пороговое значение (L1) силы тока для силы тока (I1, I2) передачи постоянного тока высокого напряжения, по меньшей мере одну длину интервала (T1, T2) для временных интервалов и для каждой заданной длины интервала (T1, T2) пороговое значение (L2, L3) изменения для определяемого по временным интервалам длины интервала (T1, T2) изменения силы тока силы тока (I1, I2). Для каждого полюса (7, 8) передачи постоянного тока высокого напряжения определяют силу тока (I1, I2) и для каждой заданной длины интервала (T1, T2) определяют изменение силы тока силы тока (I1, I2), определяемое по временным интервалам длины интервала (T1, T2). Делают вывод о неисправности по постоянному току, если величина силы тока (I1, I2) по меньшей мере одного полюса (7, 8) больше, чем пороговое значение (L1) силы тока, или для длины интервала (T1, T2) величина ...

ПРЕОБРАЗОВАТЕЛЬНАЯ ПОДСТАНЦИЯ

... 1. Преобразовательная подстанция для соединения системы переменного тока (AC) с линией (3) передачи постоянного тока высокого напряжения (HVDC), содержащая, по меньшей мере, два преобразователя (8, 9), установленных в отдельных залах (40, 41, 60, 61) преобразовательных вентилей и имеющих каждый сторону постоянного тока (DC) для соединения с упомянутой линией передачи и AC сторону, соединенную с упомянутой AC системой (6), упомянутая преобразовательная подстанция содержит установку управления, выполненную с возможностью управления работой упомянутых преобразователей, средство для обеспечения преобразователей питанием собственных нужд, а также средство для управления общими условиями работы преобразователей, такими как охлаждение его компонентов, отличающаяся тем, что упомянутая установка управления содержит отдельное устройство (49, 50) управления для управления каждым преобразователем преобразовательной подстанции, что подстанция имеет отдельное средство (71-74) для обеспечения каждого ...

СПОСОБ ЭКСПЛУАТАЦИИ ВЕТРЯНОГО ПАРКА

Использование: в области электротехники. Технический результат – обеспечение поддержания сети электроснабжения ветряными парками при изменении поведения сети электроснабжения. Изобретение касается способа эксплуатации ветроэнергетической установки (100) или ветряного парка (112) с несколькими ветроэнергетическими установками (100) для обмена электрической мощности между ветряным парком и сетью электроснабжения, при этом каждая ветроэнергетическая установка (100) имеет одно или несколько устройств подачи питания (808, 810), и ветроэнергетическая установка (100) или соответственно ветряной парк (112) соединены через точку сетевого подключения (118) с сетью электроснабжения (120), и мощность обменивается через точку сетевого подключения (118), при этом одно или несколько устройств подачи питания (808, 810) работают как формирующие напряжение блоки (808) и одно или несколько устройств подачи питания (808, 810) работают как формирующие ток блоки (810), при этом, в частности, предусмотрено, чтобы ...

СИЛОВАЯ КАБЕЛЬНАЯ ЛИНИЯ

... 1. Силовая кабельная линия, характеризующаяся: силовым кабелем для осуществления передачи и распределения постоянного тока; блоком наложения переменного тока для наложения переменной составляющей тока на упомянутый силовой кабель; и ответвляющим блоком электропитания для отбора мощности, наведенной наложенной переменной составляющей тока, из упомянутого кабеля. 2. Силовая кабельная линия по п.1, отличающаяся тем, что упомянутый силовой кабель представляет собой сверхпроводящий кабель. 3. Силовая кабельная линия по п.2, отличающаяся тем, что сверхпроводящий кабель имеет первый сверхпроводящий слой и второй сверхпроводящий слой, расположенные коаксиально через электроизолирующий слой, предусмотренный на внешней периферии первого сверхпроводящего слоя, и упомянутый ответвляющий блок электропитания предусмотрен на участке разделения, где первый сверхпроводящий слой и второй сверхпроводящий слой расположены не коаксиально в блоке соединения кабелей. 4. Силовая кабельная линия по любому из пп ...

СПОСОБ ПЕРЕКЛЮЧЕНИЯ С ПАССИВНОГО СЕКЦИОНИРОВАНИЯ НА ПОДКЛЮЧЕНИЕ К ЭНЕРГОСИСТЕМЕ

СИСТЕМА ПЕРЕДАЧИ

... 1. Система передачи HVDC (высокого напряжения на постоянном токе), содержащая на одном конце двухполюсной линии (3) передачи HVDC преобразовательную станцию (2) для соединения упомянутой линии передачи с системой (6) переменного тока, причем упомянутая станция содержит два преобразователя (8, 9), каждый из которых имеет сторону постоянного тока соединенную с одной стороны, с соответствующим из двух полюсов (104, 105) упомянутой линии передачи с высоким потенциалом и, с другой стороны с шиной (111, 112) нейтрали для этого полюса контура (10) нейтрали постоянного тока, общего для преобразователей и имеющей нулевой потенциал за счет заземления, и каждый упомянутый преобразователь имеет сторону переменного тока соединенную с упомянутой системой переменного тока, причем упомянутый контур нейтрали постоянного тока имеет элемент, соединяющий с электродными линиями (191-193), и контур снабжен первыми выключателями постоянного тока, позволяющими размыкать первую токовую цепь (130) от шины нейтрали ...

СПОСОБ БЛОКИРОВАНИЯ ПЕРЕХОДА НЕСКОЛЬКИХ ИНВЕРТОРНЫХ ЭЛЕКТРИЧЕСКИХ СТАНЦИЙ В РЕЖИМ ПАССИВНОГО УПРАВЛЕНИЯ В СОСТОЯНИИ СЕКЦИОНИРОВАНИЯ

УСТРОЙСТВО УПРАВЛЕНИЯ ПОСЛЕДОВАТЕЛЬНЫМИ КЛАПАНАМИ ДЛЯ ПЕРЕДАЧИ МОЩНОСТИ ПОСТОЯННОГО ТОКА ВЫСОКОГО НАПРЯЖЕНИЯ

УСТРОЙСТВО ДЛЯ ПРЕОБРАЗОВАНИЯ ЭЛЕКТРИЧЕСКОГО ПАРАМЕТРА, ИМЕЮЩЕЕ РЕАКТОР С НУЛЕВОЙ ТОЧКОЙ

... 1. Устройство (1) для преобразования электрического параметра в области передачи и распределения электроэнергиис преобразователем (2), переключаемым между сетью (11) переменного напряжения и контуром (7) постоянного напряжения, который имеет силовые полупроводниковые вентили (3), которые располагаются между выводом (4) переменного напряжения и выводом (5, 6) постоянного напряжения, причем каждый силовой полупроводниковый вентиль (3) включает в себя последовательную схему из биполярных подмодулей (8), которые имеют соответственно накопитель энергии и силовую полупроводниковую схему, ис блоком (9) сетевого подключения, соединенным с выводом (4) переменного напряжения для соединения с сетью (11) переменного напряжения,отличающееся посредствомреактора (14) с нулевой точкой, соединенного с точкой (13) потенциала между блоком (9) сетевого подключения и преобразователем (2), имеющего дроссельные катушки (15), соединенные с заземленной нулевой точкой (16), причем дроссельные катушки (15) выполнены ...

СИСТЕМА И СПОСОБ ПРЕОБРАЗОВАНИЯ ЭЛЕКТРИЧЕСКОЙ ЭНЕРГИИ ДЛЯ ВОЗОБНОВЛЯЕМЫХ ИСТОЧНИКОВ ЭНЕРГИИ

... 1. Система преобразования электрической энергии, включающая:первый преобразователь электрической энергии, имеющий вход и выход, при этом первый преобразователь электрической энергии сконфигурирован для приема электрической энергии в первой форме на упомянутом входе и для обеспечения напряжения постоянного тока заранее заданной величины на упомянутом выходе;второй преобразователь электрической энергии, имеющий вход и выход, при этом второй преобразователь электрической энергии сконфигурирован для приема упомянутого напряжения постоянного тока заранее заданной величины на упомянутом входе и для обеспечения напряжения переменного тока на упомянутом выходе;шину постоянного тока, включенную между выходом первого преобразователя электрической энергии и входом второго преобразователя электрической энергии, при этом шина постоянного тока сконфигурирована для передачи напряжения постоянного тока заранее заданной величины; иустройство для накопления энергии, функционально соединенное с упомянутой ...

КОНФИГУРАЦИИ МОДУЛЬНОЙ МНОГОУРОВНЕВОЙ ПОДВОДНОЙ ЭНЕРГЕТИЧЕСКОЙ УСТАНОВКИ

... 1. Энергоснабжающая установка (10), содержащая источник (20) питания переменного тока, выполненный с возможностью подачи электроэнергии к одному или нескольким токоприемникам переменного тока через шину (14) передачи постоянного тока, которая содержит посылающий конец и принимающий конец, причем посылающий конец присоединен к одному набору модульных преобразователей (12) электроэнергии, выполненных с конфигурацией многоуровневого модульного преобразователя электроэнергии, а принимающий конец присоединен к другому набору модульных преобразователей (13) электроэнергии, выполненных с конфигурацией многоуровневого модульного преобразователя электроэнергии, при этом конфигурация указанного многоуровневого модульного преобразователя электроэнергии на принимающем конце симметрична конфигурации указанного многоуровневого модульного преобразователя электроэнергии на посылающем конце. ! 2. Энергоснабжающая установка (10) по п.1, в которой один или несколько токоприемников переменного тока непосредственно ...

STROMRICHTERKUPPLUNG MIT EINER SPANNUNGSAUSGLEICHSSCHALTUNG

ZUSTANDSSIGNALBILDUNG ZUR ANZEIGE DES UEBERGANGES IN DIE BETRIEBSART "BYPASS" BEI EINER EINRICHTUNG ZUR HOCHSPANNUNGSGLEICHSTROMUEBERTRAGUNG.

The bypass condition signal formation for HV DC transmission uses detection of the current regulator transformer currents (Iry, Isy, Ity, Ird, Isd, Itd) on the current regulator side, which are weighted by different weighting factors before summation. The summation value has no zero range during the normal commutation sequence with the bypass condition signal supplied when the sum current is zero after a given time interval from interruption of the normal commutation sequence. This time interval is at least equal to the commutation of the DC current (Ig) by the selected thyristor valves. Pref. all the weighting/actors are different but all have the same sign.

HGUE-KRAFTWERKSTATION MIT MASCHINENTRANSFORMATOR

VERFAHREN UND VORRICHTUNG ZUR ERMITTLUNG VON ORDNUNGSZAHLEN VON NICHTCHARAKTERISTISCHEN OBERSCHWINGUNGSSTRÖMEN UND DEREN KOMPENSATION

Gleichstrom-Hochspannungs-UEbertragungssystem

STEUEREINRICHTUNG FÜR AKTIVE FILTER UND VERFAHREN ZUR OBERWELLENVERÄNDERUNG IN EINEM BIPOLAREN GLEICHSTROMZWISCHENKREIS

Windenergiepark

REGELUNGSANORDNUNG FUER EINE HGUE-ANLAGE MIT ENERGIE-RUECKWAERTSSPEISUNG

STEUER- UND VERSORGUNGSSYSTEM

Anordnung zum selbsttaetigen Abschalten von Gleichstromhochspannungsleitungen

Elektrisches Verteilnetz sowie Verfahren zum Betreiben eines elektrischen Verteilnetzes

Elektrisches Versorgungsnetz mit einem Verteilnetz und zumindest zwei Strängen eines Wechselstrom-Mittelspannungsnetzes, wobei die Stränge des Wechselstrom-Mittelspannungsnetzes über jeweils einen Transformator mit dem Verteilnetz verbunden sind. Ein Leistungsausgleich ist besonders dann möglich, wenn zwischen den Strängen des Wechselstrom-Mittelspannungsnetzes eine direkte Gleichspannungsverbindung gebildet ist.

Verfahren und Einrichtung zum Betriebe eines Drehfeldinduktionsumformers als Netzkupplungsmaschine zwischen zwei auch mit eigenen Energiequellen ausgestatteten Wechselstromnetzen annaehernd gleicher Frequenz

EINE WANDLERVORRICHTUNG UND EIN VERFAHREN ZUR STEUERUNG DERSELBEN

HOCHSPANNUNGSGLEICHSTROMÜBERTRAGUNGSSYSTEM

Fault protection for voltage source converters

High Voltage Direct Current Power Transmission Plant

... 1,194,463. H.V.D.C. power transmission. ALLMANNA SVENSKA ELEKTRISKA A.B. 28 June, 1968, No. 30835/68. Heading H2F. In a H.V.D.C. transmission system, the rectifying station 1 employs uncontrolled rectifiers and has an automatic voltage regulator on the A.C. side so as to feed a constant voltage to the D.C. transmission line 3 whilst the inverting station 2 uses controlled rectifiers to give automatic control of current or power. As described, the rectifying station 1 may use series-parallel arrangements of semi-conductor diodes 12, supplied from an alternator 14 via a transformer 11. Automatic regulation of the D.C. on line 3 is achieved by a device 16 which controls the field of the alternator 14 and/or the tappings on transformer 11. The current at the receiving end 2 is monitored by a transductor 26 and compared with a reference 28 so as to adjust the delay angle of the mercury arc or thyristor rectifiers and thus to control the current or power in line 3. A further transductor 41 operates ...

HVDC convertor control

Improvements in high voltage d.c. transmission systems

... 1,095,014. Converting. ALLMANNA SVENSKA ELEKTRISKA A.B. April 14, 1965 [April 20, 1964], No. 15971/65. Heading H2F. In a H.V.D.C. transmission system two or more rectifier stations supply two or more converter stations connected by two parallel transmission lines. Normally the two lines are joined by a switch (12) (Figs. 1 and 3, not shown, for single pole and double pole lines respectively). If one of a number of series converters at a station develops a fault, the faulty converter is by-passed and one converter at a station of the opposite kind (rectifying or inverting) is also by-passed. The connections to the parallel lines are rearranged so that the unaffected converters are connected by the other line working at reduced voltage.

Voltage source converter and control thereof

A voltage source converter (VSC) 200, especially for use in High Voltage Direct Current (HVDC) power distribution/transmission, has at least one phase limb having a high-side DC terminal DC+, a low-side DC terminal DC- and an AC terminal 202. A voltage wave-shaper 204 provides a selectively variable voltage level Vws. Each phase limb also has a switch arrangement SU1, SU2, SL1, SL2 operable to provide at least first and second switch states. In the first switch state the low-side DC terminal is electrically connected to the AC terminal via a first path that includes the voltage wave-shaper. In the second switch state the high-side DC terminal is electrically connected to the AC terminal via a second path that includes the voltage wave-shaper. The voltage wave-shaper may comprise a chain-link circuit including a series of cells 104b, each having an energy storage element, such as a capacitor, 107 and a cell switch arrangement 105 operable to selectively connect the energy storage element ...

Converter

A converter 30, particularly a bidirectional converter for a HVDC power transmission network, comprises at least one limb connected between first and second DC terminals 32,34. Each limb includes a phase element 36 having a plurality of switching elements 40 and at least one AC terminal for connection to an AC network 50. The plurality of switching elements are switchable to selectively interconnect a DC side 58 voltage of the phase element and an AC side voltage, where each switching element has forward and reverse voltage blocking capabilities. At least one DC side sub-converter 38,39, operable as a voltage synthesiser, is connected to the DC side of the phase element. The converter further includes a controller 60 to selectively control the switching of the switching elements of the phase element to control the operation of the DC side sub-converter of each limb as a voltage synthesiser. The controller also controls the switching of the switching elements of the phase elements to provide ...

Fault protection for voltage source converters

This application describes methods and apparatus for fault protection of voltage source converters (VSCs), especially VSCs including a plurality of cells arranged as a chain-link circuit such as may be used for HVDC. An apparatus 200 for use in a voltage source converter has first and second cell terminals 104a, 104b, an energy storage element (such as a capacitor) 101 and a plurality of switches 102a, 102b configured such that first and second cell terminals can be selectively connected in a path that includes the energy storage element 101 or a path that bypasses the energy storage element. To provide the fault protection the apparatus also includes one or more surge protection devices 201 in parallel with at least one of said plurality of switches and said energy storage element. Each surge protection device 201 comprises a gas discharge tube in series with a metal oxide varistor.

Circuit Arrangement for the Automatic Balancing of Pre-Set Current Values which can be Varied Arbitrarily.

... 1,165,584. High voltage D.C. systems. LICENTIA PATENT - VERWALTUNGS G.m.b.H. 17 Feb., 1967 [18 Feb., 1966], No. 7619/67. Heading H2F. [Also in Division G3] In an arrangement such as a high voltage D.C. transmission system including a plurality of input current sources, e.g. E 1 , E 2 , E 3 , each producing a respective output current, e.g. A 1 , A 2 , A 3 in which it is desired to maintain the sum of the output currents at a predetermined fixed value despite arbitrary variations in any one of the individual output currents, there is provided a control circuit which automatically balances the currents in the arrangement to achieve the desired object. As shown, the control circuit comprises summing networks 1, 2, 3, which receive one input from the sources E 1 , E 2 ; the outputs of the summing networks constitute the output currents A 1 , A 2 , A 3 and these outputs are also applied to an adder 4 (Fig. 6, not shown), which compares the sum of the outputs with a desired value set by a device ...

Bipolar DC power transmission scheme

Method and apparatus for fault prediction of sub-module in flexible direct current transmission converter valve

Method and apparatus for fault prediction of a sub-module in a flexible direct current transmission converter valve by: determining if sub-module is in a charging or discharging state according to topology of sub-module and direction of collected bridge arm current, in connection with control instruction for the sub-module, the control instruction including switching in, switching out and blocking; determining a voltage rising or reducing rate according to the magnitude of current and capacitance of the sub-module or according to loss and capacitance of the sub-module; predicting a voltage after a pre-set time; comparing the actual voltage measured after the pre-set time and the predicted voltage to determine if a fault occurs. The voltage reducing rate may be determined according to the magnitude of the current and the capacitance of the sub-module if the sub-module is in a fast-discharging state, or according to the loss and capacitance if the sub-module is in a slow-discharging state ...

IMPROVEMENTS IN STATIC ELECTRIC CONVERTERS

... 1,270,310. Static converter control systems. ALLMANNA SVENSKA ELEKTRISKA A.B. 28 Aug., 1969 [29 Aug., 1968], No. 42789/69. Heading H2F. Relates to a rapid re-starting arrangement for a static converter 1 (Fig. 1) connected between an A.C. system and an HVDC transmission line, after it has been blocked by a blocking device 12 (e.g. part of a protection means for the D.C. line 4), the arrangement ensuring rapid increase in the D.C. voltage without overvoltage and including means whereby after blocking is removed an increased signal is applied temporarily to the input of a control amplifier 5 controlling a pulse delay angle control unit 6 and control pulse generator 7 thereby to reduce the control pulse delay angle. Blocking.-The maximum output voltage from amplifier 5 causes minimum delay angle and maximum positive direct voltage output from the converter. Minimum output from the amplifier gives maximum control angle i.e. towards 180 degrees. The blocking device 12 thus operates on the input ...

DC POWER TRANSMISSION SYSTEM CONNECTED BETWEEN AN AC SUPPLY AND AN AC LOAD

... 1,240,931. Static converter systems. COMPAGNIE GENERALE D'ELECTRICITE. 15 Jan., 1969 [16 Jan., 1968], No. 2499/69. Heading H2F. A two-pole D.C. transmission line linking two A.C. networks, has a 3-phase, 6-rectifier cell Graetz bridge at each end (Fig. 1, not shown) and identical control arrangements (Fig. 2) for each bridge whereby one functions as an invertor and the other as a rectifier according to the desired direction of energy transmission. The control arrangement calculates the necessary firing angles taking into account essential factors such as the "rectifier limiting striking instant "-defined as the minimum delay from the theoretical zero-going positive passage of a rectifier element and the instant it can be fired with safety; also the "inverter limiting striking instant "-defined as the angle separating the firing of a given rectifier element from the instant when a conducting rectifier element passes through zero-i.e. the supplement of the min. angle of advance. Control arrangement ...

Means for controlling static converters in a high voltage dc transmission system

... 813,989. Automatic control systems for D.C. power transmission; converting. ALLMANNA SVENSKA ELEKTRISKA A.B. Sept. 6, 1955 [Sept. 7, 1954], No. 25493/55. Classes 38 (2) and 38 (4). In a high voltage D.C. power transmission system between one or more rectifier stations and one or more inverter stations in which at least one of the stations automatically regulates the transmission voltage and at least one of the other stations automatically regulates its D.C. voltage in such a manner that a " controlled quantity " is held at a predetermined value, the regulators at both stations are additionally controlled to oppose changes in the line current. This reduces current surges due to system faults until protective gear has had time to operate. The " controlled quantity " shown is the frequency of the receiving A.C. network; but it is said that it might be the D.C. power transmitted, the D.C. current transmitted or the transmission voltage, and it may, Fig. 4 (not shown), or it may not, Figs. 2 ...

Improvements in or relating to converters

METHOD FOR STARTING UP A CONVERTER-STATION OF A HIGH-VOLTAGE DC TRANSMISSION SYSTEM

A DC transformer/reactor.

The present invention relates to a DC transformer/reactor comprising a magnetic circuit, wherein the magnetic circuit comprises magnetic core and at least one winding. The winding comprises at least one current-carrying conductor. Each winding comprises also i insulation system, which comprises on the one hand at least two semiconducting layers, wherein each layer constitutes substantially ; equipotential surface, and on the other hand between them is arranged a solid insulation.

Electromagnetic device.

An electromagnetic device comprises a magnetic field generating electrical circuit including a winding (1) having at least one electrical conductor (2). The winding comprises a solid insulation (4) surrounded by outer and inner layers (3, 5) serving for equalization of potential and having semi conducting properties. Said at least one electrical conductor (2) is arranged interiorly of the inner semiconducting layer (3). The invention also relates to methods for electric field control and production of a magnetic circuit as well as use of a cable for obtaining a winding.

Improved DC bus regulator

Transformer/reactor.

The present invention relates to a power transformer/reactor (14, 15, 16) for high voltages, comprising at least one winding having at least one current-carrying conductor. The winding comprises a solid insulation (7) surrounded by outer and inner layers (8, 6) serving for equalization of potential and having semiconducting properties. The layers (6. 8) and the insulation (7) adhere along essentially the whole of its contact surfaces. Said conductor is arranged interiorly of the inner semiconducting layer (6). The outer layer (8) is connected to ground or otherwise relatively low potential. Said solid insulation in the windings constitutes substantially the total electrical insulation in the power transformer/reactor.

Electromagnetic device

A dc transformer reactor

Transformer/reactor

Power supply system for radio base station

Improved DC bus regulator.

Subsea electrical architectures

RULE ARRANGEMENT FOR THE REGULATION OF THE EFFECT AND REACTIVE POWER BEHAVIOR OF A HIGH VOLTAGE - DIRECT CURRENT TRANSMISSION PLANT (HGUE PLANT)

HIGH VOLTAGE DIRECT CURRENT TRANSMISSION - CLOSE COUPLING PLANT

PROCEDURE AND ARRANGEMENT FOR THE REVERSAL OF THE ENERGY FLOW OF A DIRECT CURRENT ENERGY TRANSMISSION SYSTEM

RULE PROCEDURE FOR TWO THREE-PHASE CURRENT SUPPLY A CONNECTION HIGH VOLTAGE DIRECT CURRENT TRANSMISSION.

TO USE PROCEDURE FOR THE CONTROLLING OF A STATIC CONVERTER IN A HGUE SYSTEM AND CONVERTER WITH CONTROL AROUND THIS PROCEDURE.

DIRECT CURRENT CLOSE COUPLING.

Direct current force transfer between a number of static inverter act ions

High-voltage direct-current transmission device

A power apparatus for a high voltage electrical power system

The invention relates to a power apparatus (1) for a high voltage electrical power system (19), the power apparatus comprising a voltage source converter (2) and a high voltage dc power source (3) comprising one or more strings (4a, 4b, 4c) including a plurality of dc power source members (20a-e) connected in series, and switches (9), (11, 13) configured to connect and disconnect said strings, where said switches are solid-state switches, each string is subdivided into a plurality of dc power source units (8, 10, 12), each dc power source unit including a plurality of dc power source members connected in series and each dc power source unit is provided with one of said solid-state switches configured to connect and disconnect the dc power source unit, and that all solid-state switches in the string are arranged so that they are turned on and off simultaneously.

Device for supplying electrical energy from a plurality of strings of photovoltaic modules to a power grid

I n a device (1) for supplying electrical energy from a plurality of strings (2) of photovoltaic modules (3) to a power grid (4), which comprises a connection terminal (7) for each string (2) of the plurality of strings (2), each connection terminal (7) comprising over-current protection means including a power switch (9) for selectively disconnecting the respective string (2), and a central insulation monitoring unit (15) providing an insulation status of the entire plurality of strings (2); the power switch (9) of each over-current protection means is an all-pole disconnecting power switch (9) which can be opened and closed by a controller (11 -13) via a motor in response to the insulation status provided by the central insulation monitoring unit (15) to select and selectively disconnect a string having an insulation failure, and to further supply electrical energy from the remaining strings (2) of the plurality of strings (2) having no insulation failure.

An electrical power conversion system and method

A system (20) and method for electrical power conversion is described. The system (20) is intended for use in converting a high voltage DC power output from a turbine generator to an AC power signal that is suitable for connecting to an AC power grid. The system (20) utilises a mechanical coupling (27) between a synchronous motor (26) driving a synchronous generator (28) in order to provide isolation, as well as allowing for control of the real power output by the system.

DC-AC inverter assembly, in particular solar cell inverter

The invention relates to a DC-AC inverter assembly, in particular a solar cell inverter of a photovoltaic plant, comprising a semiconductor bridge circuit and characterized in that a DC chopper controller is provided for creating half-waves of an AC voltage on the output side and the bridge circuit is connected downstream of the DC chopper controller and acts as pole changer on the half-waves.

Distribution system for electrical power

Relay protection method and device against LC parallel circuit detuning faults

A relay protection method against LC parallel circuit detuning faults comprises the steps of: a relay protection device samples a current of a parallel LC, that is, a reactor and a capacitor, and samples a total current flowing through the whole LC; convert the current of the reactor into a current of an equivalent capacitor; calculate amplitudes of the current of the equivalent capacitor and a current of a realistic capacitor, and calculate an amplitude of the total current flowing through the LC; calculate a current amplitude ratio of the equivalent capacitor to the realistic capacitor; and when the amplitude of the total current flowing through the LC is large enough, send an alarm signal or a trip signal by delay and output an idle contact of a trip relay if the current ratio exceeds a preset upper and lower limit range. Also provided is a corresponding relay protection device. The relay protection method and device against LC parallel circuit detuning faults can improve stability of ...

Power conversion device

The purpose of the present invention is to provide a technology for increasing the voltage of a direct current link without increasing the power allotted by a power buffer circuit. In the present invention, a discharge duty (dc) which is a duty conducted by a switch (Sc) employs a value ((Vm/Vc)cos ...

Wind farm with DC voltage network

The invention relates to a wind farm for generating electrical energy from wind, comprising at least two wind turbines for generating the electrical energy and a common infeed device for feeding the generated electrical energy, or part thereof, into an electrical supply grid, wherein the wind turbines are connected to the infeed device via an electrical DC voltage network in order for electrical energy generated by the respective wind turbine to be conducted to the infeed device by means of electrical direct current.

System for very long subsea step-out transmission of electric DC power

The invention provides a system for operation of electric power subsea loads supplied through a long subsea step out cable, particularly high electric power subsea loads, distinctive in that the system comprises a high voltage direct current (HVDC) transmission subsea step out cable, the cable is connected to a HVDC source in a near end and to a HVDC motor in a far subsea end.

SYSTEM AND METHOD FOR TRANSMITTING ELECTRIC POWER INTO A BORE

A system for transmitting electric power into a bore hole, the system comprising an electric transmission line (7) extending through the bore hole between an electric power source (1) and a receiving station (3), wherein the receiving station includes frequency increasing means (10) for increasing the frequency of the electric current supplied through the electric transmission line, voltage converter means (11) for changing the voltage of the electric current supplied to it via the frequency increasing means, connecting means for supplying the frequency-increased electric current to the voltage converter means, and means for connecting an electric load to the receiving station.

HVDC FLOATING CURRENT ORDER SYSTEM

CONVERTER WITH ACTIVE FAULT CURRENT LIMITATION

A voltage source converter (20) for high voltage DC power transmission that is connectable, in use, between a DC network (22) and another electrical network (24) to interconnect the DC network (22) and the other electrical network (24). The voltage source converter (20) comprises a converter unit (26) to convert power flowing between the DC network (22) and the other electrical network (24) and at least one fault unit (28). The or each fault unit (28) includes at least one fault module (30) having a voltage source (36) that is operable, in the event of a short circuit in a DC network (22) connected to the voltage source converter (20), to produce a voltage that acts to reduce current flowing through the voltage source converter (20) and the short circuit.

DEVICE FOR SUPPLYING ELECTRICAL ENERGY FROM A PLURALITY OF STRINGS OF PHOTOVOLTAIC MODULES TO A POWER GRID

I n a device (1) for supplying electrical energy from a plurality of strings (2) of photovoltaic modules (3) to a power grid (4), which comprises a connection terminal (7) for each string (2) of the plurality of strings (2), each connection terminal (7) comprising over-current protection means including a power switch (9) for selectively disconnecting the respective string (2), and a central insulation monitoring unit (15) providing an insulation status of the entire plurality of strings (2); the power switch (9) of each over-current protection means is an all-pole disconnecting power switch (9) which can be opened and closed by a controller (11 -13) via a motor in response to the insulation status provided by the central insulation monitoring unit (15) to select and selectively disconnect a string having an insulation failure, and to further supply electrical energy from the remaining strings (2) of the plurality of strings (2) having no insulation failure.

POWER CONVERSION SYSTEMS

In a general aspect, a power conversion system includes a power converter, a transformer, and a voltage adjustment device. The power converter is configured to receive a variable DC power generated by a power generation device and to convert the received DC power to AC power at a first voltage. The transformer is configured to receive the AC power from the power converter and to deliver AC power at a second voltage to a utility power network. The voltage adjustment device is configured to adjust the first voltage to a target value determined on the basis of a voltage of the DC power.

REDUCING PHOTOVOLTAIC ARRAY VOLTAGE DURING INVERTER RE-ENABLEMENT

An apparatus for harvesting solar power includes a photovoltaic array for generating a DC voltage; a discharge circuit for causing the DC voltage to decay from a first value to a second value; and an inverter circuit for transforming an output voltage from the discharge circuit into an AC voltage.

LINE FAULT DETECTOR

The present invention relates to a fault detection system for detection of line faults on an electrode line in an HVDC system wherein the electrode line comprises a first and second branch connected in parallel. The fault detection system comprises a first and second pulse generation circuit arranged to generate electrical pulses onto the first and second branches, respectively, as well as first and second current measurement devices arranged to generate signals indicative of electrical signals occurring in first and second injection lines, respectively. The possibility of independent generation of electrical pulses onto the first and second branches, respectively, as well as the independent registration of first and second signal patterns representing electrical signals on the first and second injection lines, respectively, increases the information content in the collected data, thereby facilitating for a more reliable analysis of whether or not a fault is present on the electrode line ...

POWER CONVERSION SYSTEM AND METHOD

A power conversion system includes a power transformer for receiving AC power at a first voltage from an input side and for delivering AC power at a second voltage to an output side. A power converter is also included in the power conversion system wherein the power converter includes an input side converter on the input side and an output side converter on the output side coupled through a plurality of DC links. A converter controller in the power converter provides control signals to the input side converter and the output side converter for regulating an active power and a reactive power flow through the power converter. Each of the input side converters and the output side converters includes at least two power converter transformers coupled between respective power converter bridges coupled to the plurality of DC links and the input side or to the plurality of DC links and the output side.

METHOD AND SYSTEM FOR CONTROLLING AN AC-DC CONVERTER SYSTEM

In control of an AC-DC converter system including AC-DC converters (1A, 1B) having respective AC terminals connected to AC power systems (6A, 6B) and having respective DC terminals connected to each other, a fault in the AC power systems is detected, and upon occurrence of a fault in any of the AC power systems, the DC current of the AC-DC converter which is connected to the sound AC power system is adjusted in such a manner as to maintain the AC voltage of the AC-DC converter which is connected to the sound AC power system at a desired value.

PULSE WIDTH MODULATION HIGH VOLTAGE DIRECT CURRENT TRANSMISSION SYSTEM AND CONVERTER

A converter for interconnecting two electric networks to transmit electric power from one network to the other, each network being coupled to a respective power generator station. The converter, having an AC side and a DC side, includes a bridge of semiconductor switches with gate turn-off capability coupled to a control system to produce a bridge voltage waveform having a fundamental Fourier component at the frequency of the electric network coupled to the AC side of the converter. The control system includes three inputs for receiving reference signals allowing to control the frequency, the amplitude and the phase angle of the fundamental Fourier component with respect to the alternating voltage of the network coupled to the AC side of the converter. Through appropriate feedback loops, the converter may be used to maintain at a predetermined level the power flowing therethrough or to keep at a preset value the voltage across the DC terminals of the converter and, in both cases, to maintain ...

METHOD FOR CONTROLLING OPERATING CONDITIONS OF D.C. TRANSMISSION LINE AND CONTROL DEVICE FOR EFFECTING SAME

METHOD FOR CONTROLLING OPERATING CONDITIONS OF D.C. TRANSMISSION LINE AND CONTROL DEVICE FOR EFFECTING SAME According to the invention, the method for controlling operating conditions of a d.c. transmission line consists in maintaining a predetermined current value at a first substation by controlling voltage at that substation, while at a second substation voltage is controlled to maintain an extreme value of a certain controlled variable dependent on the operating conditions at said second substation and formed as a function of parameters which, when reaching an extreme value, ensures a maximum possible voltage at that substation, while maintaining the predetermined current value. The method is effected with the aid of a control device comprising a controlled variable former, an adder, an automatic controlled variable optimizer and a control action discriminator.

VOLTAGE-MEASURING DEVICE FOR CONTROLLING THE RECTIFIERS OF CURRENT-CONVERTERS IN HIGH- VOLTAGE DIRECT-CURRENT TRANSMISSION SYSTEMS

In a device for establishing a phase-correct representation of a high alternating voltage from a mains, for the purpose of controlling mainsoperated rectifiers (valves) of a current-converter-connected to the mains through a current-converter-transformer, in a high-voltage direct-current trans-mission system, an auxiliary winding is provided in the current-converter-trans-former.

HIGH VOLTAGE DIRECT CURRENT TRANSMISSION APPARATUS

A high voltage direct current transmission apparatus having a DC carrying line provided with a DC cable. The transmission apparatus includes voltage-limiting members connected to the DC carrying line and comprising surge diverters and diodes interconnected so that the limiting voltage level is higher for a line voltage of one of the positive and negative polarities than for a line voltage of the opposite polarity, and so that for both polarities of the line voltage, the limiting level is different from zero.

METHOD FOR STARTING UP A CONVERTER STATION OF A HIGH VOLTAGE DC TRANSMISSION SYSTEM

To start up a converter station of a high-voltage d.c. transmission system, the station being initially not connected to any functioning three-phase system, the active power required is drawn from the d.c. side of the converter station, and the reactive power required is drawn from an independent reactive power source. The latter is initially run up to the a.c. operating voltage and frequency, whereupon the controllable rectifier elements of the converter station are triggered. During run-up, converter losses may be made up by an active power source on the a.c. side e.g. a Diesel stand-by generator. The converter station can then be used to transmit power from a network to start a generating plant associated with the converter station, after which the generating plant can feed the network through the converter station. The converter station may be part of a HVDC transmission network, or of an internal HVDC block of a generating plant.

DC POWER TRANSMISSION

DC POWER TRANSMISSION A DC transmission system including at least one rectifier and one inverter station, between which operating information is communicated, responds to a failure in the communication by reducing maximum voltage of one of the stations to allow another station to become, or remain, current controlling. Typically, the current margin is also transferred and a current order is established as the margin plus some selected value.

REGULATING MODE SELECTOR SCHEME FOR AN ELECTRIC POWER CONVERTER

CONVERTER CONTROL APPARATUS FOR PARALLEL CONNECTED MULTI-TERMINAL DIRECT CURRENT SYSTEM

POWER CONVERSION EQUIPMENT

DC POWER TRANSMISSION CONTROL

METHOD OF TAKING A POLE OF A HIGH-VOLTAGE D-C TRANSMISSION STATION OUT OF SERVICE

Method of and Apparatus for Connecting a Photovoltaic Device to an AC Power Grid

A method of connecting a photovoltaic device to an AC power grid through an inverter includes monitoring a DC voltage at an input of an inverter, and activating the inverter when the monitored DC voltage exceeds a first predetermined threshold. The method further includes synchronizing an output voltage of the inverter with a grid voltage, connecting an output of the inverter to the AC power grid upon synchronization if the monitored DC voltage exceeds a second predetermined threshold, and deactivating the inverter if a detected power being fed through the inverter falls below a predetermined power threshold while maintaining the connection between the output of the inverter and the AC power grid. Lastly, the method includes disconnecting the output of the deactivated inverter from the grid if the monitored DC voltage falls below a third predetermined threshold. Further, an apparatus that performs such functionality is also provided.

Facility for forming lithium ion cells

A facility for forming lithium ion cells 1 preferably comprises an object support for the lithium ion cells 1 to be formed, and a forming system which contains an electrical circuit having an AD/DC converter unit 3, with multiple DC outputs 4, as needed, to which the lithium ion cells may be connected in an electrically conductive manner. To allow energy-optimized forming in this manner, a battery management system 6 is connected to each of the DC outputs 5, and is connectable to at least one lithium ion cell 1.

Coordinated control of multi-terminal hvdc systems

Multi-terminal HVDC systems and control methods therefore are disclosed. Methods for controlling multi-terminal HVDC systems having a plurality of converter stations may include receiving a plurality of measurements from a plurality of measurement units disposed on the HVDC system, identifying from the measurements a disruption within the HVDC system, monitoring the measurements to identify a steady-state disrupted condition for the HVDC system, calculating a new set point for at least one of the plurality of converter stations, which new set point may be based on the steady-state disrupted condition and the measurements, and transmitting the new set point to the at least one of the plurality of converter stations. In some examples, the HVDC systems may include an HVDC grid interconnecting the plurality of converter stations and a controller communicatively linked to the plurality of measurement units and the plurality of converter stations.

Power supply and power control circuitry

A power supply can include a storage component or a storage unit including a capacitive element. In an embodiment, the power supply can include an electrical energy storage unit, a transformer, switching elements, and a pulse width modulation unit. In a particular embodiment, the power supply can be configured to provide an output voltage different from the voltage supplied by the electrical energy power storage unit. In another embodiment, the power supply can include storage components having electrodes connect to different printed circuit boards. In still another embodiment, the power supply can include an output anode, an output cathode, and an input electrode connected to the storage component. In a further embodiment, the power supply circuitry can include a transformer, switching elements, a pulse width modulation unit, and an output control units coupled to an output electrode, the pulse width modulation unit, or any combination thereof.

DC-AC Inverter Assembly, in Particular Solar Cell Inverter

A DC-AC inverter assembly, in particular a solar cell inverter of a photovoltaic plant, is disclosed. The inverter includes a semiconductor bridge circuit and wherein a DC chopper controller is provided for creating half-waves of an AC voltage on the output side and the bridge circuit is connected downstream of the DC chopper controller and acts as pole changer on the half-waves.

Connecting a Photovoltaic Array at a High Open Circuit Voltage

For connecting a PV array via an inverter to an AC power grid, at first a DC link at the input side of the inverter is pre-charged from the AC power grid. A link voltage of the DC link is adjusted to a pre-set value with the inverter connected to the AC power grid, the pre-set value being lower than an open circuit voltage of the PV array, and then the PV array at its open circuit voltage is directly connected to the DC link, while the link voltage is continuously adjusted to the pre-set value.

DC Power Source For A High Voltage Power Apparatus

A dc power source for a high voltage power apparatus, the dc power source including one or more strings including a plurality of dc power source units connected in series, and switches configured to connect and disconnect said strings. The switches are solid-state switches distributed among the power source units of each string, and all solid-state switches in the string are arranged so that they are turned on and off simultaneously. Each switch is connected in parallel with a first controllable semiconductor in a first direction and connected in parallel with a second controllable semiconductor in a second direction which is opposite to the first direction, and the dc power source includes a control unit configured to bypass a failed switch by triggering the forward biased of the first or second controllable semiconductor connected to the failed switch in case a fault in the switch is detected.

Method and apparatus for controlling a dc-transmission link

A method for controlling a DC-transmission link for transmitting electric power from a power production unit connected to an AC-DC converter at a first side of the DC-transmission link to a utility grid connected to a DC-AC converter at a second side of the DC-transmission link is provided. The method includes: obtaining a DC voltage signal indicative of a DC voltage at the DC transmission link; controlling the AC-DC converter such that an AC voltage at an AC side of the AC-DC converter is adjusted based on the DC voltage signal. Further, an apparatus for controlling a DC-transmission link is provided.

WIRE CONNECTING METHOD AND CONVERTER STATION FOR ULTRA-HIGH VOLTAGE DIRECT CURRENT POWER TRANSMISSION, AND ULTRA-HIGH VOLTAGE DIRECT CURRENT POWER TRANSMISSION SYSTEM

Connection methods for UHVDC transmission at rectification side and at inversion side, UHV converter stations at rectification side and at inversion side, and an UHVDC transmission system are disclosed. The present invention employs a manner of multiple drop points to solve the problem of poor security stability of electric grid caused by feeding a large amount of power via one point. 1. A connection method for UHVDC transmission at rectification side , comprising:setting an UHV HV converter station at rectification side and an UHV LV converter station at rectification side respectively;said UHV LV converter station at rectification side receiving a first AC power from a first power source collection point, converting said first AC power into a first low voltage DC power and inputting it into said UHV HV converter station at rectification side;said UHV HV converter station at rectification side receiving a second AC power from a second power source collection point and said first low voltage DC power, rectifying said second AC power and superimposing it with said first low voltage DC power to generate a first UHVDC power and outputting the first UHVDC power via an UHV DC transmission line.2. The method according to claim 1 , wherein claim 1 ,said UHV HV converter station at rectification side comprises two HV valve halls with different polarities;said UHV LV converter station at rectification side comprises two LV valve halls with different polarities.3. The method according to claim 2 , whereinsaid two HV valve halls with different polarities are located at different locations and/or said two LV valve halls with different polarities are located at different locations.4. A connection method for UHVDC transmission at inversion side claim 2 , comprising:setting an UHV HV converter station at inversion side and an UHV LV converter station at inversion side respectively;said UHV HV converter station at inversion side inputting a first UHVDC power via an UHVDC ...

HYBRID 2-LEVEL AND MULTILEVEL HVDC CONVERTER

A voltage source converter is used in high voltage direct current power transmission and reactive power compensation. The voltage source converter comprises first and second DC terminals for connection in use to a DC network, three phase elements and at least one auxiliary converter connected between the first and second DC terminals, each phase element including a plurality of primary switching elements and at least one AC terminal for connection in use to a respective phase of a multi-phase AC network, the plurality of primary switching elements being controllable in use to facilitate power conversion between the AC and DC networks, the or each auxiliary converter being operable in use to act as a waveform synthesizer to modify a first DC voltage presented to the DC network so as to minimise ripple in the DC voltage. 1. A voltage source converter for use in high voltage direct current power transmission and reactive power compensation , the voltage source converter comprising:first and second DC terminals for connection in use to a DC network,three phase elements and three auxiliary converters connected between the first and second DC terminals,each phase element including two parallel connected strings of series connected primary switching elements, the mid-points between each string of series-connected primary switching elements defining AC terminals for connection in use to a respective phase of an AC network,each auxiliary converter being connected in parallel with a respective one of the phase elements to define a single-phase converter limb and the three single-phase converter limbs being mounted and connected in series to the first and second DC terminals to define a two-terminal DC network for three-phase power transmission;the primary switching elements being controllable in use to facilitate power conversion between the AC and DC networks,each auxiliary converter being operable in use to act as a waveform synthesizer to modify a first DC voltage ...

METHOD OF CONTROLLING THE POWER INPUT TO A HVDC TRANSMISSION LINK

Disclosed is a method of controlling the power input to a HVDC transmission link, which HVDC transmission link is connected to an AC power plant via a first voltage source converter and to AC grid via a second voltage source converter, which method includes using the second voltage source converter to perform voltage control of the HVDC transmission link during a no-fault mode of operation of the grid; monitoring a HVDC transmission link parameter to detect an unbalanced fault; and using the first voltage source converter to regulate the output of the AC power plant on the basis of the monitored HVDC transmission link parameter in the event of an unbalanced fault. Also described are a control module for controlling the power input to a HVDC transmission link; a voltage source converter for a power plant; and a power generation and transmission arrangement. 1. A method of controlling the power input to a high-voltage direct-current (HVDC) transmission link , the HVDC transmission link is connected to an alternating-current (AC) power plant via a first voltage source converter and to an AC grid via a second voltage source converter , the method comprising:performing voltage control of the HVDC transmission link during a no-fault mode of operation of the grid via the second voltage source converter;monitoring a HVDC transmission link parameter to detect an unbalanced fault; andregulating the output of the AC power plant via the first voltage source converter in the event of an unbalanced fault, which is on the basis of the monitored HVDC transmission link parameter.2. The method according to claim 1 ,wherein the unbalanced fault is detected when the monitored HVDC transmission link parameter exceeds a predefined threshold value.3. The method according to claim 1 ,wherein the monitored HVDC transmission link parameter comprises a HVDC transmission link voltage.4. The method according to claim 1 ,wherein the regulating the output of the AC power plant comprises providing ...

NEUTRAL POINT CLAMPED CONVERTER CONTROL SYSTEMS AND METHODS

A control system includes first and second fundamental control units for generating first and second fundamental commands, and a compensation control unit. The compensation control unit includes first and second calculation elements and a comparator for comparing first and second modulation indexes. When the first modulation index is less than the second modulation index, the first calculation element generates a first source-side compensation command. When the first source-side compensation command is not sufficient to balance the neutral point voltage, the first calculation element further generates a first line-side compensating command. When the first modulation index is greater than the second modulation index, the second calculation element generates a second line-side compensation command. When the second line-side compensation command is not sufficient to balance the neutral point voltage, the second calculation element further generates a second source-side compensating command. 1. A control system for providing commands to a source-side converter and a line-side converter of a power conversion system for balancing a neutral point voltage on a DC link between the source-side converter and the line-side converter , the control system comprising:a first fundamental control unit configured to generate a first fundamental command to implement fundamental power conversion operation for the source-side converter;a second fundamental control unit configured to generate a second fundamental command to implement fundamental power conversion operation for the line-side converter; and a comparator configured to compare a first modulation index of the source-side converter and a second modulation index of the line-side converter;', 'a first calculation element configured to, when the first modulation index is less than the second modulation index, receive a fundamental compensation command and generate a first source-side compensation command for injection into the ...

POWER CONVERTER AND INTEGRATED DC CHOKE THEREFOR

A power conversion system and a DC link choke therefore are presented, in which a continuous core structure is provided with first and second legs around which four or more windings are located, with one or more shunt structures providing a magnetic flux path between intermediate portions of the first and second legs. 1. A power conversion system , comprising:a rectifier operative to provide DC output power at a rectifier DC output;an inverter comprising an inverter DC input, and operative to provide AC output power to a load; and a core structure comprising: a first leg including first and second ends and an intermediate portion disposed between the first and second ends, a second leg including first and second ends and an intermediate portion disposed between the first and second ends, a third leg extending between the first ends of the first and second legs, and a fourth leg extending between the second ends of the first and second legs,', 'at least one shunt providing a magnetic flux path between the intermediate portions of the first and second legs,', 'a first winding forming a first coil coupled between the rectifier DC output and the inverter DC input, the first winding forming at least one turn around the first leg between the intermediate portion and the first end of the first leg, a second winding forming a second coil coupled between the rectifier DC output and the inverter DC input, the second winding forming at least one turn around the first leg between the intermediate portion and the second end of the first leg,', 'a third winding forming a third coil coupled between the rectifier DC output and the inverter DC input, the third winding forming at least one turn around the second leg between the intermediate portion and the first end of the second leg, and', 'a fourth winding forming a fourth coil coupled between the rectifier DC output and the inverter DC input, the fourth winding forming at least one turn around the second leg between the ...

Imputed dc link (idcl) cell based power converters and control thereof

Power flow controllers based on Imputed DC Link (IDCL) cells are provided. The IDCL cell is a self-contained power electronic building block (PEBB). The IDCL cell may be stacked in series and parallel to achieve power flow control at higher voltage and current levels. Each IDCL cell may comprise a gate drive, a voltage sharing module, and a thermal management component in order to facilitate easy integration of the cell into a variety of applications. By providing direct AC conversion, the IDCL cell based AC/AC converters reduce device count, eliminate the use of electrolytic capacitors that have life and reliability issues, and improve system efficiency compared with similarly rated back-to-back inverter system.

CONVERTER FOR HVDC TRANSMISSION AND REACTIVE POWER COMPENSATION

A power electronic converter for use in high voltage direct current power transmission and reactive power compensation comprises a plurality of switching elements interconnecting in use a DC network and one or more AC networks, the plurality of switching elements being controllable in use to facilitate power conversion between the AC and DC networks, wherein in use, the plurality of switching elements are controllable to form one or more short circuits within the power electronic converter so as to define one or more primary current flow paths, the or each primary current flow path including a respective one of the AC networks and the power electronic converter and bypassing the DC network. 1. A power electronic converter for use in high voltage direct current power transmission and reactive power compensation comprising a plurality of switching elements interconnecting in use a DC network and one or more AC networks , the plurality of switching elements being controlled in use to form one or more short circuits within the power electronic converter so as to define one or more primary current flow path including a respective one of the AC networks and the power electronic converter and bypassing the DC network , characterized in that the switching elements are forming at least one phase element including two-parallel-connected sets of series-connected switching elements to interconnect in use an AC voltage and a DC voltage , a junction between the series-connected switching elements of each set of series-connected switching elements defining an AC terminal for connection to the AC network , wherein an auxiliary converter is connected in parallel or in series with the or each phase element , the auxiliary converter acting as a waveform synthesizer to modify a DC voltage presented to the DC side of the or each phase element , the auxiliary converter and the phase element thus forming a single phase converter-limb.2. (canceled)3. (canceled)4. (canceled)5. (canceled)6. ...

VOLTAGE BALANCING OF SYMMETRIC HVDC MONOPOLE TRANSMISSION LINES AFTER EARTH FAULTS

A voltage balancing unit for a symmetric monopole high voltage direct current (HVDC) transmission line interconnecting two voltage source converters (VSCs), the transmission line including first arresters having a first switching impulse protective level (SIPL) is provided. The voltage balancing unit includes a pair of second arresters having a second SIPL which is less than the first SIPL, and a switching device being arranged for temporarily connecting, in the event of a voltage unbalance on the transmission line, the first arresters between either pole and ground. A voltage unbalance on the transmission line may be removed by temporarily connecting second arresters, with a significantly lower SIPL than the first arresters, for limiting the pole voltage to a level close to the normal voltage. Further, a method of voltage balancing is provided. Voltage unbalances may arise as a consequence of lightning induced earth faults. 1. A voltage balancing unit for a symmetric monopole high voltage direct current , HVDC , transmission line being arranged for interconnecting a first voltage source converter , VSC , and a second VSC , the transmission line comprising:a first pole and a second pole, and two pairs of first arresters, a first pair being arranged at a first end of the transmission line and a second pair being arranged at a second end of the transmission line, a first arrester of either pair being connected between the first pole and ground and a second arrester of either pair being connected between the second pole and ground, the first arresters having a first switching impulse protective level, SIPL,the voltage balancing unit is arranged to perform voltage balancing for a voltage unbalance caused by an earth fault and comprises:a pair of second arresters having a second SIPL which is less than the first SIPL, andswitching means being arranged for:connecting, through being closed after the earth fault has been cleared and in response to determining that the ...

Electricity storage apparatus for controlling power consumption and method therefor

A method for controlling power consumption by an electricity storage apparatus is provided. The method includes receiving, from a utilizing side, an inquiry request signal for inquiring whether power supply from the electricity storage apparatus is possible, inquiring an amount of charged power from the electricity storage apparatus compared to a capacity of the electricity storage apparatus, comparing a required amount of power, which is included in the inquiry request signal, with the amount of charged power, and based on the comparison result, determining an amount of power to supply to the utilizing side and whether to switch to an operation mode of supplying the amount of power to the utilizing side, and upon determining to switch to the operation mode, checking an amount of available supply power in accordance with the operation mode, and transmitting information about the checked amount of available supply power to the utilizing side.

Subsea Electrical System Having Subsea Penetrator with Integral Current Sensor

A system and method for coupling electrical power subsea. The system comprises a subsea penetrator to seal an opening around a conductor extending through a partition or enclosure. The subsea penetrator comprises an integral current sensor operable to produce a signal representative of current through the conductor. The penetrator comprises a boot configured to seal the opening through which the conductor extends. The current sensor may be disposed within the boot.

CASCADED CONVERTER STATION AND CASCADED MULTI-TERMINAL HVDC POWER TRANSMISSION SYSTEM

A cascade converter station and a multi-end cascade high-voltage direct current (HVDC) power transmission system. The converter station includes a low-voltage end converter station () and a high-voltage end converter station (). The high-voltage end converter station () is connected in series with the low-voltage end converter station () through a medium-voltage direct current (DC) power transmission line () and connected to a HVDC power transmission line (). With the cascade converter station and the multi-end cascade HVDC power transmission system, HVDC power transmission can be achieved in a flexible, reliable and economical manner. 1. A cascaded converter station used in cascaded multi-terminal HVDC power transmission , comprising:a low-voltage end converter station having a positive side and a negative side, each of which comprising:a converter transformer coupled to a first alternating current (AC) network;a converter valve coupled to the converter transformer for realizing DC/AC conversion; andsmoothing reactors provided on both ends of the converter valve; anda high-voltage end converter station, which is connected in series to the low-voltage end converter station through a middle-voltage DC power transmission line, and is connected to a high-voltage DC power transmission line, wherein the high-voltage end converter station comprises a positive side and a negative side, each of which comprising:a converter transformer coupled to a second alternating current (AC) network;a converter valve coupled to the converter transformer for realizing DC/AC conversion; andsmoothing reactors provided on both ends of the converter valve;wherein a grounding line coupled to a grounding electrode and a metal return line coupled between a positive line and a negative line are provided in the low-voltage end converter station.2. The cascaded converter station according to claim 1 , wherein in each of the low-voltage end converter station and the high-voltage end converter ...

Multi-level converter, and inverter having the same and solar power supply apparatus having the same

There are provided a multi-level converter capable of outputting power having various voltage levels with respect to a single input power supply by using a simple circuit, an inverter having the same, and a solar power supply apparatus having the same. The multi-level converter includes a first buck-boost unit having a first power switch switching an input power supply and outputting a first power having a voltage level varied according to switching of the first power switch; a bypass unit outputting a second power having a voltage level of the input power supply; and a second buck-boost unit having a second power switch switching the input power supply and outputting a third power having a voltage level varied according to switching of the second power switch.

Multi-level converter, and inverter having the same and solar power supply apparatus having the same

There is provided a multi-level converter capable of a multi-level converter capable of outputting power having various voltage levels by using a simple circuit with respect to a single input power supply, an inverter having the same, and a solar power supply apparatus having the same. The present invention provides a multi-level converter including a first buck-boost unit having a single power switch switching an input power supply and outputting a first power having a voltage level varied according to the switching of the power switch, a bypass unit outputting a second power having a voltage level of the input power supply, and a second buck-boost unit sharing the power switch with the first buck-boost unit and outputting a third power having a voltage level varied according to the switching of the power switch; an inverter having the same; and a solar power supply apparatus having the same.

POWER TRANSMISSION SYSTEMS

An offshore wind farm includes a plurality of wind turbines connected to an onshore converter station by means of a distributed power transmission system. The power transmission system includes a series of offshore converter platforms distributed within the wind farm. Each converter platform includes a busbar carrying an ac voltage for the converter platform and to which the wind turbines are connected. Each converter platform also includes one or more converter transformers connected to the busbar and a series of one or more converter modules. The power transmission system includes dc transmission lines which deliver generated power back to the onshore converter station. 1. A power transmission system comprising a busbar carrying an ac voltage for the converter platform and connectable to one or more devices,', 'one or more converter transformers connected to the busbar, and', 'a series of one or more converter modules each converter module having ac terminals connected to a respective one of the converter transformers, and first and second dc terminals;, 'a series of two or more converter platforms distributed within an area, each converter platform includingwherein for the first converter platform in the series the first dc terminal of the first converter module in the series is connected to a first dc transmission line;wherein for each converter platform apart from the last converter platform in the series the second dc terminal of the last converter module in the series is connected to the first dc terminal of the first converter module in the series of the next converter platform in the series by means of a dc connection line; andwherein for the last converter platform in the series the second dc terminal of the last converter module in the series is connected to a second dc transmission line.2. The power transmission system according to claim 1 , wherein each converter platform includes two or more converter transformers and a series of two or more converter ...

POWER SUPPLY METHOD AND APPARATUS

Embodiments of the present invention disclose a power supply method, including: rectifying a second alternating current, and converting the second alternating current into a second high voltage direct current; when the second high voltage direct current is abnormal, inputting a third high voltage direct current to a DC/DC module; when the second high voltage direct current is normal, inputting the second high voltage direct current to the DC/DC module; and converting, by the DC/DC module, the second high voltage direct current or the third high voltage direct current into a low voltage direct current for outputting. 1. A power module , comprising a rectifier module , a selecting module , and a DC/DC (Direct Current/Direct Current) module , wherein:the rectifier module is configured to rectify an input second alternating current, and convert the second alternating current into a second high voltage direct current for outputting;the selecting module is connected to channels for inputting two high voltage direct currents to the DC/DC module, wherein the two high voltage direct currents comprise the second high voltage direct current and a third high voltage direct current;the selecting module is configured to: when it is detected that the second high voltage direct current is normal, connect a channel for inputting the second high voltage direct current to the DC/DC module and disconnect a channel for inputting the third high voltage direct current to the DC/DC module; when it is detected that the second high voltage direct current is abnormal, connect the channel for inputting the third high voltage direct current to the DC/DC module and disconnect the channel for inputting the second high voltage direct current to the DC/DC module; andthe DC/DC module is configured to convert the input second high voltage direct current or the third high voltage direct current into a low voltage direct current, and output the low voltage direct current to a load for use.2. The power ...

Modular multilevel converter using asymmetry

A power electronic converter assembly is provided having a multi-level converter, a plurality of phase elements and a controller to switch the multi-level converter. The multi-level converter includes a plurality of AC terminals and is operable to generate an AC phase voltage (V A , V B , V C ) at each AC terminal. The plurality of phase elements define a star connection in which a first end of each phase element is connected to a common junction. Each AC terminal is connected in series with a second end of a respective phase element of the star connection. The controller can switch the multi-level converter to modulate the plurality of AC phase voltages (V A , V B , V C ) to define a set of asymmetrical voltage vectors so as to synthesise a non-zero neutral point voltage at the common junction of the star connection, the non-zero neutral point voltage and each AC phase voltage (V A , V B , V C ) defining a line-to-neutral voltage across each phase element, the line-to-neutral voltages being equal in magnitude and displaced at equidistant phase angles.

MODULAR MULTI-LEVEL CONVERTER AND METHOD OF CONTROLLING VOLTAGE BALANCING OF MODULAR MULTI-LEVEL CONVERTER

A method of controlling voltage balancing of a modular multi-level converter is provided. The method includes receiving state information on each of n sub modules in an arm module, grouping the n sub modules into m sub module groups, receiving first state information on each of sub modules in a first one of the m sub module groups, among the state information on each of the n sum modules, receiving second state information on each of sub modules not included in the first sub module group, among state information on each of the n sum modules previously stored in a memory, controlling switching of a sub module by using the first state information and the second state information, and updating the memory with the first state information. 1. A method of controlling voltage balancing of a modular multi-level converter , the method comprising:receiving, by an input unit, state information on each of n sub modules in an arm module;grouping, by the input unit, the n sub modules into m sub module groups;receiving, by a determination unit, first state information on each of sub modules in a first one of the m sub module groups, among the received state information on each of the n sum modules;receiving, by the determination unit, second state information on each of sub modules not included in the first sub module group, among state information on each of the n sum modules previously stored in a memory;controlling, by the determination unit, switching of a sub module by using the first state information and the second state information; andupdating, by the determination unit, the memory with the first state information.2. The method according to claim 1 , wherein each of the first and second state information comprises on/off state information and a sub module voltage.3. The method according to claim 2 , further comprising calculating weight information on each of the n sub modules based on the state information on each of the n sub modules.4. The method according to claim 3 , ...

POWER PLANT

A power plant contains an internal AC voltage grid, electrical energy generation units which are connected to the internal AC voltage grid, and a HVDC transmission device, which is connected to the internal AC voltage grid, is connectable to an external AC voltage grid via a DC link and enables energy transmission from the internal AC voltage grid in the direction of the external AC voltage grid. The energy generation units feed their power into the internal AC voltage grid via a power electronics converter. The energy generation units each have a synchronization device, which is suitable for regulating the generation of the output voltage of the respective energy generation unit such that the phase angle of the output voltage has a setpoint phase angle, which is preset to the respective energy generation unit, with respect to a synchronization signal applied on the input side. 115-. (canceled)16. A power plant , comprising:an internal AC voltage grid;a multiplicity of electrical energy generation units being connected to said internal AC voltage grid, said electrical energy generation units each having at least one of a power electronics converter or a double-fed asynchronous machine with a stator and a rotor;at least one HVDC transmission device connected to said internal AC voltage grid, and being connectable to an external AC voltage grid via a DC link, said at least one HVDC transmission device enables energy transmission from said internal AC voltage grid in a direction of the external AC voltage grid;said energy generation units either feed power into said internal AC voltage grid via said power electronics converter, or feed the power into said internal AC voltage grid via said stator of said double-fed asynchronous machine, said rotor of said double-fed asynchronous machine is fed via said power electronics converter; andeach of said energy generation units having a synchronization device suitable for regulating a generation of an output voltage of a ...

POWER SUPPLY METHOD AND APPARATUS

Embodiments of the present invention disclose a power supply method, including: rectifying a second alternating current, and converting the second alternating current into a second high voltage direct current; when the second high voltage direct current is abnormal, inputting a third high voltage direct current to a DC/DC module; when the second high voltage direct current is normal, inputting the second high voltage direct current to the DC/DC module; and converting, by the DC/DC module, the second high voltage direct current or the third high voltage direct current into a low voltage direct current for outputting. 1. A power module , comprising a rectifier module , a selecting module , and a DC/DC (Direct Current/Direct Current) module , wherein:the rectifier module is configured to rectify an input second alternating current, and convert the second alternating current into a second high voltage direct current for outputting;the selecting module is connected to channels for inputting two high voltage direct currents to the DC/DC module, wherein the two high voltage direct currents comprise the second high voltage direct current and a third high voltage direct current;the selecting module is configured to: when it is detected that the second high voltage direct current is normal, connect a channel for inputting the second high voltage direct current to the DC/DC module and disconnect a channel for inputting the third high voltage direct current to the DC/DC module; when it is detected that the second high voltage direct current is abnormal, connect the channel for inputting the third high voltage direct current to the DC/DC module and disconnect the channel for inputting the second high voltage direct current to the DC/DC module; andthe DC/DC module is configured to convert the input second high voltage direct current or the third high voltage direct current into a low voltage direct current, and output the low voltage direct current to a load for use.2. The power ...

HIGH VOLTAGE DIRECT CURRENT POWER TRANSMISSION SERIES VALVE GROUP CONTROL DEVICE

A high voltage direct current power transmission series valve group control device, is used for regulating a series circuit having two or more valve groups provided with controllable power semiconductors respectively. Each valve group is provided with a current regulation unit and a voltage regulation unit. The current regulation unit controls a direct current current flowing through a valve group corresponding thereto, and the voltage regulation unit controls a voltage across two ends of a valve group corresponding thereto. One valve group is selected from the series valve group as a master control valve group, while the others are taken as slave control valve groups. The master control valve group selects a trigger angle output by the current regulation unit to control same, and the slave control valve group selects a trigger angle obtained after the trigger angle transmitted from the master control valve group and an output value of the voltage regulation unit pass through a subtractor to control same. 1. A high voltage direct current power transmission series valve group control device , configured to regulate a high voltage direct current power transmission device having two or more valve groups that are connected in series and controllable power semiconductors respectively , whereineach valve group is provided with a current regulation unit and a voltage regulation unit, the current regulation unit is configured to control a direct current flowing through a valve group corresponding to the current regulation unit, and the voltage regulation unit is configured to control a voltage across two ends of a valve group corresponding to the voltage regulation unit; one valve group is selected from the series valve group as a master control valve group, and the others are taken as slave control valve groups; the master control valve group selects a trigger angle output by the current regulation unit to control same, the master control valve group is controlled by ...

Method for controlling power grid frequency of multiple energy storage systems, and system therefor

The present invention relates to a power management system (PMS) for multiple energy storage systems (ESS) that is for integrated management of the system having multiple ESS for controlling a frequency and having a hierarchical control structure. The PMS for ESS comprises: a plurality of ESS; a local management system (LMS) for managing one or more ESS of the plurality of ESS for each local unit; an ESS Controller (ESSC) for general management of the LMS, judging a state of the LMS and determining an output value of one or more ESS in the LMS, and transmitting the determined output value to the respective ESS; and a PMS for general management of the entire system comprising the plurality of ESS, the LMS and the ESSC, judging the state of the entire system and participating in a power grid frequency control market through a grid operator contract, controlling the output of the LMS, and adjusting a control parameter for output control.

MVDC LINK-POWERED BATTERY CHARGERS AND OPERATION THEREOF

One embodiment is a system comprising a medium voltage direct current (MVDC) link electrically coupling a first AC-DC converter and a second AC-DC converter. The first AC-DC converter is electrically coupled with a first alternating current (AC) feeder. The second AC-DC converter electrically coupled with a second AC feeder. A battery charger electrically coupled with the MVDC link via a converterless connection. A first electronic controller is operatively coupled with the first AC-DC converter. A second electronic controller is operatively coupled with the second AC-DC converter. During operation of the battery charger to charge a battery the first electronic controller is configured to control power flow between the first AC feeder and the second AC feeder and the second electronic controller is configured to control the voltage of the MVDC link. 1. A system comprising:a medium voltage direct current (MVDC) link electrically coupling a first AC-DC converter and a second AC-DC converter, the first AC-DC converter coupled with first distribution voltage alternating current (DVAC) power system circuitry, the second AC-DC converter coupled with second DVAC power system circuitry;a battery charger providing a converterless electrical connection between the MVDC link and a battery connector;a first electronic controller operatively coupled with the first AC-DC converter; anda second electronic controller operatively coupled with the second AC-DC converter;wherein during operation of the battery charger to charge a battery electrically coupled with the battery charger the first electronic controller is configured to control active power flow between the first DVAC power system circuitry and the second DVAC power system circuitry and the second electronic controller is configured to control voltage of the MVDC link to charge the battery.2. The system of wherein the first electronic controller and the second electronic controller operate concurrently and independently ...

POWER SUPPLY FOR SUBMODULE CONTROLLER OF MMC CONVERTER

A power supply for a submodule controller of an MMC converter, which supplies driving power to a submodule controller of an MMC connected to an HVDC system. The power supply includes: a bridge circuit unit including an energy storage unit storing a DC voltage of a series-connected submodule of the MMC converter, and multiple power semiconductor devices connected in parallel to the energy storage unit in a bridge form; a first resistor unit connected in parallel to the energy storage unit, and configured with at least one series-connected resistor; a second resistor unit connected in series to the first resistor unit; a switch unit connected in parallel to the first resistor unit; and a DC/DC converter converting a voltage output from output terminals formed in both ends of the second resistor unit into a low voltage, and supplying the same to the submodule controller. 1. A power supply for a submodule controller of an MMC converter , the power supply comprising:a bridge circuit unit including an energy storage unit storing a DC voltage of a series-connected submodule of the MMC converter, and multiple power semiconductor devices connected in parallel to the energy storage unit in a bridge form;a first resistor unit connected in parallel to the energy storage unit, and configured with at least one series-connected resistor;a second resistor unit connected in series to the first resistor unit;a switch unit connected in parallel to the first resistor unit; anda DC/DC converter converting a voltage output from output terminals formed in both ends of the second resistor unit into a low voltage, and supplying the same to the submodule controller.2. The power supply of claim 1 , wherein when a voltage detected in the energy storage unit is equal to or smaller than a preset voltage claim 1 , the switch unit is turned on so as to form a bypass circuit in the first resistor unit.3. A power supply for a submodule controller of an MMC converter claim 1 , the power supply ...

GROUNDING ARRANGEMENT FOR A VOLTAGE SOURCE CONVERTER

A grounding arrangement for a Voltage Source Converter (VSC) in a power transmission system is provided. The VSC comprises at least one converter branch () comprising at least one module (-), each module comprising a plurality of serially connected sub-modules (-) that can be controllably switched to generate a controlled voltage across the module (-) and each module including a first sub- module (24) at one end thereof and a last sub-module () at an opposite end thereof. Each sub-module (-) includes a first terminal (), a second terminal (), an energy storage element () and a switching arrangement (), wherein at least one of the first () or second terminals () is coupled to a terminal of the energy storage unit (). A first terminal () of the first sub-module () of a module () at one end of the converter branch () is configured to be connected to earth potential on or after shutdown of the converter, and a second terminal () of the last sub-module () of the module (N) at the opposite end of the converter branch () is configured to be connected to earth potential on or after shutdown of the converter. A grounding arrangement () comprising a plurality of switch units (42) is provided, each switch unit () associated with one of the plurality of sub-modules (-) of each module (22-22) and configured to connect the first () and second () terminals of the associated sub-module (24-24) on remote activation of the grounding arrangement (), following connection to earth potential of the first () and last sub-modules () of the converter branch (). 117-. (canceled)18. A voltage source converter (VSC) for use in a power transmission system , the VSC comprising:at least one converter branch comprising at least one module, each module comprising a plurality of serially connected sub-modules that can be controllably switched to generate a controlled voltage across the module and each module including a first sub-module at one end thereof and a last sub-module at an opposite end ...

DEMAND RESPONSE IMPLEMENTED IN AN INFRASTRUCTURE HAVING A DC LINK

A system for regulating electrical energy transfer over a pathway including a DC link () is provided. The system is configured for computing a rate of electrical energy flow through the DC link at least in part on a basis of a state of balance between power generation and a load determined from frecuency measurement () and for adjusting the rate of electrical energy flow through the DC link. An electrical vehicle charger is provided that includes a power input for connection to an AC power distribution network and a power output for connection to an electric vehicle, and is configured for determining a rate of electrical energy flow through the power output by using as a factor a state of balance between power generation and load in an AC power distribution network to which the power input connects. A method for regulating electrical energy transfer over a pathway including a DC link is also provided. 126.-. (canceled)27. A system for regulating an electrical energy transfer over a pathway including a DC link established between a first AC power distribution network and a second AC power distribution network , comprising: i. receive at an input data related to a characteristic of an electrical energy distributed in the first AC power distribution network and conveying a state of balance in the first AC power distribution network, between power generation and load,', 'ii. process the data and in response to detection of a state of imbalance between the power generation and load in the first AC power distribution network, compute a reduced rate of electrical energy flow through the DC link, from the first AC power distribution network to the second AC power distribution network, at least in part on a basis of a magnitude of the state of imbalance between power generation and load in the first AC power distribution network, wherein the state of imbalance is characterized by an under frequency condition in the first AC power distribution network,, 'a. a machine-readable ...

COMMUTATION FAILURE PREDICTION METHOD, DEVICE AND STORAGE MEDIUM BASED ON ENERGY ACCUMULATION FEATURES OF INVERTER

The disclosure discloses a commutation failure prediction method, device and storage medium based on energy accumulation features of inverter. The method includes the following steps: collecting instantaneous values of three-phase valve side current and calculating the derivatives of the three-phase valve side current according to the instantaneous values of three-phase valve side current; the derivative includes positive, negative and zero states; according to the derivatives of the three-phase valve side current, determining the locations of incoming valve and ongoing valve; based on the valve side current of the incoming valve and ongoing valve, calculating energy accumulation features of the 12-pulse inverter; predicting whether the commutation failure from the incoming valve to the ongoing valve will happen according to the states of the derivatives of the three-phase valve side current and the energy accumulation features of the 12-pulse inverter. 1. A commutation failure prediction method based on energy accumulation features of inverter , wherein the inverter is a 12-pulse inverter; the method comprising:collecting instantaneous values of three-phase valve side current and calculating derivatives of the three-phase valve side current according to the instantaneous values of three-phase valve side current, the derivative includes three states: positive, negative and zero;determining locations of incoming valve and ongoing valve in the 12-pulse inverter according to the derivatives of the three-phase valve side current; calculating energy accumulation features of the 12-pulse inverter based on the valve side current of the incoming valve and ongoing valve, the energy accumulation features include real-time energy difference and limit energy difference;predicting whether the commutation failure from the incoming valve to the ongoing valve will happen according to the states of the derivatives of the three-phase valve side current and the energy accumulation ...

POWER NETWORK MONITORING SYSTEM AND METHOD

Power network monitoring systems are presented. In some embodiments, the system includes a master device installed in at least one substation among the plurality of substations, and slave devices installed in remaining substations except from the substation in which the master device is installed. Each of the slave devices may include a first PMU configured to measure data such as reactive/active power, magnitudes and phase angles of a voltage and current of the substation in which the slave device is installed. The master device may analyze data transmitted from each of the slave devices, may generate a command for taking action of a corresponding slave device based on an analyzed result, and may transmit the generated command to the corresponding slave device. 1. A power network monitoring system that monitors a plurality of substations , the power network monitoring system comprising:a master device configured to be installed in at least one substation among a plurality of substations; anda plurality of slave devices configured to be installed in the plurality of substations except from the substation in which the master device is installed, a first phasor measurement unit (PMU) configured to measure data of the substation in which the slave device is installed; and', 'a first communication unit configured to transmit the data measured by the first PMU to the master device,', 'wherein the master device is configured to analyze the data transmitted from each of the slave devices, generate a command for taking action of a corresponding slave device based on the analyzed data, and transmit the generated command to the corresponding slave device., 'wherein each of the slave devices comprises2. The power network monitoring system according to claim 1 , wherein the data or command is transmitted and/or received between the master device and the corresponding slave device by using at least one of: a communication cable or a wireless communication.3. The power network ...

CONTROL CIRCUIT

The present disclosure relates to control circuits. One circuit includes first and second primary terminals for connection to first and second power transmission lines and a current transmission path extending between the primary terminals and having current transmission path portions separated by a third primary terminal. A first current transmission path portion includes at least one primary switching element connected in series between the first and third primary terminals, the second current transmission path portion includes an energy conversion block connected between the second and third primary terminals, and the energy conversion block includes at least one primary energy conversion element for removing energy from the power transmission lines. The control circuit further includes a converter limb connected across the second and third primary terminals that includes an auxiliary converter. The control circuit further includes a control unit which controls the auxiliary converter to selectively provide a voltage source. 1. A control circuit comprising:first and second primary terminals for respective connection to first and second power transmission lines;a current transmission path extending between the first and second primary terminals and having first and second current transmission path portions separated by a third primary terminal, the first current transmission path portion including at least one primary switching element connected in series between the first and third primary terminals, the second current transmission path portion including an energy conversion block connected between the second and third primary terminals, the energy conversion block including at least one primary energy conversion element for removing energy from the power transmission lines;a converter limb connected across the second and third primary terminals, the converter limb including an auxiliary converter; anda control unit which controls the auxiliary converter to ...

A METHOD OF CLEARING A FAULT IN A HVDC ELECTRICAL NETWORK

A method of clearing a fault in a high voltage DC electrical network, including power converters interconnected by a DC power transmission, comprising: detecting a fault in the DC power transmission and reconfiguring each power converter to a fault blocking mode drinving the DC fault current towards zero; locating the fault and isolating a faulty portion from a healthy remaining portion; reconfiguring one of the power converters designated as a re-energising power converter from the fault blocking to re-energise the healthy remaining portion; and detecting a rise in the voltage level in the healthy remaining portion above a threshold level and reconfiguring the remaining power converter connected with the healthy remaining portion from the fault blocking to the normal power transmission. 1. A method of clearing a fault in a high voltage DC electrical network including at least three power converters interconnected by at least a first DC power transmission medium , the method comprising:detecting a fault in the first DC power transmission medium and in response reconfiguring each power converter from a normal power transmission mode to a fault blocking mode to drive the resulting DC fault current flowing in the first DC power transmission medium towards zero;locating the fault in the first DC power transmission medium and isolating a faulty portion of the first DC power transmission medium from a healthy remaining portion of the first DC power transmission medium;reconfiguring at least one of the power converters designated as a re-energising power converter from the fault blocking mode to a re-energising mode to re-energise the healthy remaining portion of the first DC power transmission medium; anddetecting a rise in the voltage level in the healthy remaining portion of the first DC power transmission medium above a first threshold level and in response reconfiguring the or each remaining power converter connected with the healthy remaining portion of the first DC ...

CONTROL CIRCUIT

A control circuit is provided, including first and second terminals for connection to an electrical network; a current transmission path extending between the first and second terminals, the current transmission path including first and second current transmission path portions, the first and second current transmission path portions being arranged to permit a current flowing, in use, between the first and second terminals and through the first current transmission path portion to bypass the second current transmission path portion and to permit a current flowing, in use, between the first and second terminals and through the second current transmission path portion to bypass the first current transmission path portion; and a controller configured to selectively remove the or each energy storage device from the respective current transmission path portion to cause current to flow from the electrical network through the current transmission path and the or each energy conversion element. 1. A control circuit comprising:first and second terminals for connection to an electrical network;a current transmission path extending between the first and second terminals, the current transmission path including first and second current transmission path portions, the first and second current transmission path portions being arranged to permit a current flowing, in use, between the first and second terminals and through the first current transmission path portion to bypass the second current transmission path portion and to permit a current flowing, in use, between the first and second terminals and through the second current transmission path portion to bypass the first current transmission path portion, each current transmission path portion including a respective converter, each converter including at least one module, each module including at least one energy storage device, the current transmission path further including at least one energy conversion element; anda ...

Electrical assembly

There is provided an electrical assembly for use in an electrical system. The electrical assembly comprises a DC path. The DC path includes: a DC power transmission medium; and a current commutation device, the current commutation device including a switching element and an energy absorbing element, the switching element arranged to permit a current flowing, in use, through the DC path to flow through the switching element and at the same time bypass the energy absorbing element, wherein the electrical assembly further includes a control unit programmed to selectively control the switching of the switching element to commutate the current directly from the switching element to the energy absorbing element in order to increase the resultant voltage drop caused by the flow of direct current through the DC path in which the current commutation device is connected and thereby oppose the flow of the current through the DC path.

POWER DISTRIBUTION NETWORK

A power system and method of operating the power system includes a first power source and a second power source arranged in a series, a first electrical load and a second electrical load arranged in series with first and second power sources, and a set of bypass current paths independently associated with at least a subset of the first power source, the second power source, the first electrical load, and the second electrical load. 1. A power system comprising:a first power source and a second power source arranged in a series;a first electrical load and a second electrical load arranged in series with first and second power sources; anda set of bypass current paths independently associated with at least a subset of the first power source, the second power source, the first electrical load, and the second electrical load, and wherein the set of bypass current paths are selectably enabled to allow current to bypass a pair of components comprising at least one of the first power source and the second power source, and at least one of the first electrical load and the second electrical load.2. The power system of wherein the set of bypass current paths are arranged in parallel with the respective at least a subset of first power source claim 1 , the second power source claim 1 , the first electrical load claim 1 , and the second electrical load.3. The power system of wherein the set of bypass current paths are independently associated with each of the first power source claim 1 , the second power source claim 1 , the first electrical load claim 1 , and the second electrical load.4. The power system of claim 1 , further including a set of first switchable elements associated with the set of bypass current paths and in series with the respective first power source claim 1 , the second power source claim 1 , the first electrical load claim 1 , or the second electrical load.5. The power system of wherein the set of bypass current paths include a respective in-line set of ...

VOLTAGE SOURCE CONVERTER

A voltage source converter includes DC terminals for connection to a DC network, a plurality of converter limbs between the DC terminals, and a controller. Each converter limb includes first and second limb portions separated by a respective AC terminal, the AC terminal of each converter limb connecting to a multi-phase AC network. Each limb portion extends between a corresponding DC terminal and AC terminal. Each limb portion including a valve having switching element(s) and energy storage device(s), the switching element being switchable to selectively insert the energy storage device into the limb portion and bypass the energy storage device to control a voltage across that valve. The controller is programmed to control the switching of valves to form a current circulation path including the limb portions corresponding to the selected valves, the AC phases connected to the limb portions corresponding to the selected valves, and the DC network. 1. A voltage source converter comprising:first and second DC terminals for connection to a DC network; anda plurality of converter limbs, each converter limb extending between the first and second DC terminals, each converter limb including first and second limb portions separated by a respective AC terminal, the AC terminal of each converter limb for connection to a respective AC phase of a multi-phase AC network, each first limb portion extending between the corresponding first DC terminal and AC terminal, each second limb portion extending between the corresponding second DC terminal and AC terminal, each limb portion including a respective valve, each valve including at least one switching element and at least one energy storage device, the or each switching element of each valve being switchable to selectively insert the or each corresponding energy storage device into the corresponding limb portion and bypass the or each corresponding energy storage device in order to control a voltage across that valve; anda ...

Power Control System and Control Device

A power control system includes: a first AC/DC converter; a second AC/DC converter; a first switch connected between a first transmission line of a first power system having a first system frequency and the first AC/DC converter; a second switch connected between the first transmission line and the second AC/DC converter; a third switch connected between a second transmission line of a second power system having a second system frequency and the first AC/DC converter; a fourth switch connected between the second transmission line and the second AC/DC converter; a fifth switch connected between the first AC/DC converter and the second AC/DC converter; and a control device. When the first and second AC/DC converters are caused to operate as AC/DC converters in a BTB (Back to Back) method, the control device controls at least the fifth switch to be in a closed state.

Control device and power control system

A control device for controlling a power source connected to an alternating-current (AC) power system includes: a frequency control unit that controls a frequency of the power source operating in a constant-voltage constant-frequency control scheme; a power calculation unit that calculates, when the frequency control unit varies a frequency of the power source, a variation of an effective power output from the power source; an arithmetic unit that calculates a frequency characteristics constant of the AC power system, based on a variation of the frequency of the power source and the variation of the effective power output from the power source; and a selection unit that selects a control scheme for the power source, based on the frequency characteristics constant of the AC power system.

High-voltage direct current transmission path

A high-voltage direction current transmission path includes at least one or two or more lines. Along at least one of the lines, at least one tapping/feeding point is provided at which at least one group of electrolytic cell stacks can be connected directly by a thyristor switching arrangement. The thyristor switching arrangement of each group of electrolytic cell stacks includes a power thyristor, a bypass thyristor and an emergency shutoff element switched in parallel to the power thyristor in a bypass line.

ELECTRIC POWER GENERATION CONTROL DEVICE, ELECTRIC POWER CONVERTER CONTROL DEVICE, ELECTRIC POWER GENERATION CONTROL METHOD AND PROGRAM

The present electric power generation control device includes: an event detection unit which detects an event attributable to a deterioration in the balance between a torque input to a generator and an effective power output by the generator, the deterioration being caused by a reduction in a set value of the effective power received from the generator by an electric power converter when the electric power converter has detected a failure necessitating interruption of electric power transmission from the generator by a direct-current (DC) power transmission unit, the DC power transmission unit transmitting DC power, the electric power converter connecting a generator to the DC power transmission unit; and a torque command reduction unit which causes a reduction in a torque command to a motor when the event detection unit has detected the event attributable to the deterioration in the balance, the motor outputting the torque input to the generator. 1. An electric power generation control device , comprising:an event detection unit which detects an event attributable to a deterioration in the balance between a torque input to a generator and an effective power output by the generator, the deterioration being caused by a reduction in a set value of the effective power received from the generator by an electric power converter when the electric power converter has detected a failure necessitating interruption of electric power transmission from the generator by a direct-current (DC) power transmission unit, the DC power transmission unit transmitting DC power, the electric power converter connecting the generator to the DC power transmission unit; anda torque command reduction unit which causes a reduction in a torque command to a motor when the event detection unit has detected the event attributable to the deterioration in the balance, the motor outputting the torque input to the generator.2. The electric power generation control device according to claim 1 , wherein ...

Buck Boost Converter Cell for MMC

The present disclosure relates to a converter cell () for an MMC. The cell comprises a primary energy storage (C), an inductor (Lf), and a secondary energy storage (C); and first and second converter valves (T, T). The secondary energy storage (C) is connected in series with the first converter valve (T1), and together with said first converter valve in parallel with the inductor (L), and the primary energy storage (C) is connected in series with the second converter valve (T), and together with said second converter valve (T) in parallel with the inductor (L). 110.-. (canceled)11. A converter cell for a modular multilevel converter , the cell consisting of:a primary energy storage;an inductor;a secondary energy storage, the primary energy storage, the inductor and the secondary energy storage all connected in parallel with each other between two terminals of the cell;a first converter valve comprising a first semiconductor switch and a first antiparallel diode, wherein the secondary energy storage is connected in series with the first converter valve, and together with the first converter valve in parallel with the inductor; anda second converter valve comprising a second semiconductor switch and a second antiparallel diode, the second semiconductor switch able to conduct electrical current in the same direction as the first semiconductor switch when switched to a conducting state, wherein the primary energy storage is connected in series with the second converter valve, and together with the second converter valve in parallel with the inductor; when the first semiconductor switch is switched to conducting and the second semiconductor switch is switched to non-conducting, a current is allowed to flow from the secondary energy storage to the inductor, charging the inductor, via the first semiconductor switch, after which;', 'when both the first semiconductor switch and the second semiconductor switch are switched to non-conducting, a current is allowed to flow from ...

Power Converter and Power Conversion System

A power converter that performs power conversion between a DC line and an AC system includes a power conversion circuit including a plurality of submodules connected in series with each other, and a controller to control each of the plurality of submodules. Each submodule includes a switching circuit and a capacitor connected in parallel with the switching circuit. When a circuit breaker provided between the AC system and the power conversion circuit is opened, the controller drives the switching circuit of at least one submodule of the plurality of submodules such that the capacitor of the at least one submodule is discharged via a discharge circuit connected to the DC line. 1. A power converter that performs power conversion between a DC line and an AC system , the power converter comprising:a power conversion circuit including a plurality of submodules connected in series with each other; anda controller to control each of the plurality of submodules, whereineach of the plurality of submodules includes a switching circuit and a capacitor connected in parallel with the switching circuit, andwhen a circuit breaker provided between the AC system and the power conversion circuit is opened, the controller drives the switching circuit of at least one submodule of the plurality of submodules such that the capacitor of the at least one submodule is discharged via a discharge circuit connected to the DC line,wherein the switching circuit includes a switching element and a thyristor connected in parallel with the switching element, andthe controller drives the thyristor of the at least one submodule to discharge the capacitor of the at least one submodule via the discharge circuit.2. The power converter according to claim 1 , wherein the controller sets a number of the at least one submodule such that a sum of output voltages of the respective submodules is less than a threshold.3. The power converter according to claim 1 , wherein the controller sets a number of the at ...

OPERATING A MULTILEVEL CONVERTER

A method of operating a multilevel converter having multiple phase modules, each with three phase module branches. In a first switching position, a switching device of each phase module connects an alternating voltage connection of the phase module to a first connection point between a first phase module branch and a third phase module branch. In a second switching position, the switching device connects the alternating voltage connection to a second connection point between the third phase module branch and a second phase module branch. In the method, circulating currents of the multilevel converter are controlled in accordance with total energy variables and differential energy variables of the phase modules to balance the energy between the phase module branches. 110-. (canceled)11. A method of operating a multilevel converter , the method comprising:providing the multilevel converter with a plurality of phase modules that are connected in parallel with one another between a first DC voltage connection and a second DC voltage connection of the multilevel converter,each of the phase modules having a plurality of modules each with at least two electronic switching elements and an electrical energy storage device;each of the phase modules having a first phase module branch, which is connected to the first DC voltage connection, a second phase module branch, which is connected to the second DC voltage connection, a third phase module branch, which connects the first phase module branch with the second phase module branch, and a switching device having a first switching position that connects an AC voltage connection of the phase module to a first connecting point between the first phase module branch and the third phase module branch and a second switching position that connects the AC voltage connection to a second connecting point between the third phase module branch and the second phase module branch;and the method further comprising:determining for each of the ...

FAULT PROTECTION FOR VOLTAGE SOURCE CONVERTERS

Fault protection of a voltage source converter is provided. An apparatus has a chain-link circuit in series with a director switch. The chain-link circuit includes cells including an energy storage element and cell switching elements connected with anti-parallel diodes. Each cell switching element has a cell switching element controller. The director switch includes director switch units, each having a director switching element and a director switch unit controller. Each cell switching element controller monitors for a fault current and turns-off its associated cell switching element and reports a fault event to a fault controller. Each director switch unit controller monitors for a fault current and reports a fault event to the fault controller but the director switch unit control keeps its associated director switching element turned-on. The fault controller monitors for reports of fault events to order the cell switching elements of at least some of the cells to turn-off. 1. An apparatus for a voltage source converter comprising:a chain-link circuit in series with a director switch; anda fault controller;wherein the chain-link circuit comprises a plurality of cells, each cell comprising an energy storage element and a plurality of cell switching elements connected with antiparallel diodes, the cell switching elements being configured such that the energy storage element can be selectively connected in series between terminals of the cell or bypassed;wherein each cell switching element has an associated cell switching element controller;wherein the director switch comprises a plurality of director switch units, each director switch unit comprising a director switching element and a director switch unit controller;wherein each cell switching element controller is configured to monitor for a fault current and, in the event a fault current is detected, to turn-off its associated cell switching element and report a fault event to the fault controller;wherein each ...

METHOD FOR CONTROLLING AN ELECTRICAL TRANSMISSION LINK INCLUDING A DIRECT CURRENT HIGH VOLTAGE LINE

The invention relates to a method for controlling an electrical transmission link () between first and second AC voltage buses () comprising a high-voltage DC line (), first and second AC/DC converters () connected to the high-voltage DC line (), comprising: 1. A method for controlling an electrical transmission link between first and second AC voltage buses connected respectively to first and second AC voltage areas of an electrical transmission grid , the transmission link comprising a high-voltage DC line , a first AC/DC converter connected firstly to the first bus and secondly to the high-voltage DC line , and a second AC/DC converter connected firstly to the second bus and secondly to the high-voltage DC line , the method comprising:retrieving a setpoint active power value (Pdc0) applied to the first or to the second converter;retrieving the instantaneous values V1 and V2 of the voltages on the first and second buses, respectively; {'br': None, 'i': Pdc=ΔPdc', '+ΔPdc, 'sub': s', 'a, 'Δ'}, 'wherein the setpoint active power of the first or of the second converter is modified by a value including a term ΔPdc, so as to impose new dynamics on the grid including the first and second areas, where{'sub': 's', 'claim-text': {'br': None, 'i': 'Pdc', 'sub': 'a', 'Δ=λδ*(δref−δ)'}, 'Where ΔPdcis a synchronization termwhere δ=δ1−δ2 is the phase offset between the voltages of the first and second buses for the retrieved instantaneous values, δ1 is the angle of the voltage on the first bus, δ2 is the angle of the voltage on the second bus, δref is an initial phase offset value between the voltages of the first and second buses, λδ is an amplification gain;{'sub': 'a', 'claim-text': {'br': None, 'i': 'Pdc', 'sub': 'a', 'Δ=λω*(ω1−ω2)'}, 'where ΔPdcis a damping term{'b': 1', '2, 'where ω1 is the electrical angular frequency of the area , ω2 is the electrical angular frequency of the area , λω is an amplification gain.'}2. The control method as claimed in claim 1 , wherein the ...

Method for designing multiple tuned filter in high voltage direct current system

A method for designing a multiple tuned filter (MTF) in a high voltage direct current (HVDC) system includes setting an input parameter constituting the MTF; setting a resonance frequency of the MTF; extracting at least one LC combination case constituting the MTF on the basis of the input parameter and the resonance frequency; performing optimization for harmonic reduction on the LC combination case; and extracting an LC combination case determined based on a result obtained by performing the optimization.

ELECTRIC UNIT FOR A PUMPED-STORAGE POWER PLANT

A pumped-storage power plant, such as an electric unit can include a frequency converter and a rotating electric synchronous machine, the machine being provided in a cavern. The frequency converter can include at least two elements which can be used as inverters or as rectifiers according to the operating mode of the machine, for example during the operation of the motor or during the operation of the generator. The machine-side element can be provided within the cavern, and the network-side element can be provided outside of the cavern. 1. An electric unit for a pumped-storage power plant , connectable to an electric grid and comprising:a machine hall having a rotating electric synchronous machine; anda frequency converter,wherein the synchronous machine is configured for connection to a water turbine and/or a water pump; andwherein the frequency converter has a machine-side electrical element and a grid-side electrical element, which electrical elements are connected to one another, with one electrical element being operable as a rectifier and one electric element being operable as an inverter, depending on an operation of the synchronous machine, whereinthe machine-side electrical element is provided within the machine hall and is connected to a stator of the machine, and the grid-side electrical element is provided outside the machine hall and is electrically connected to the machine-side element via a DC link.2. The electric unit as claimed in claim 1 , wherein the machine hall is a cavern.3. The electric unit as claimed in claim 1 , comprising:a generator transformer and/or a filter, which are provided outside the machine hall.4. The electric unit as claimed in claim 1 , wherein the electric elements of the frequency converter are each configured for inductive generator operation claim 1 , capacitive generator operation claim 1 , inductive motor operation or capacitive motor operation.5. The electric unit as claimed in claim 1 , wherein the frequency converter ...

DATA CONTROL SYSTEM

Disclosed embodiments relate to a data control system. In some embodiments, the data control system includes a transmission module configured to add synchronization signal information to data included in a first data stream to generate a second data stream, and a plurality of control modules configured to receive the second data stream from the transmission module. In some embodiments, the data includes power information. 1. A data control system , comprising:a transmission module configured to add synchronization signal information to data included in a first data stream to generate a second data stream; anda plurality of control modules configured to receive the second data stream from the transmission module,wherein the data comprises power information.2. The data control system according to claim 1 , wherein the transmission module comprises:at least one global positioning system (GPS) reception unit configured to receive the first data stream;a control unit connected to the at least one GPS reception unit and configured to extract the data from the received first data stream and generate the second data stream comprising the extracted data and the synchronization signal information; anda plurality of transmission units connected to the control unit and configured to transmit the second data stream to the plurality of control modules.3. The data control system according to claim 2 , wherein the first data stream is collected from a yard or a field to be transmitted.4. The data control system according to claim 2 , wherein the second data stream is separately generated and transmitted to the plurality of control modules.5. The data control system according to claim 2 , wherein the second data stream is generated once and simultaneously transmitted to the plurality of control modules.6. The data control system according to claim 2 , wherein the transmission module further comprises a server configured to receive the synchronization signal information or transmit ...

DEMAND RESPONSE IMPLEMENTED IN AN INFRASTRUCTURE HAVING A DC LINK

A system for regulating electrical energy transfer over a pathway including a DC link () is provided. The system is configured for computing a rate of electrical energy flow through the DC link at least in part on a basis of a state of balance between power generation and a load determined from frequency measurement () and for adjusting the rate of electrical energy flow through the DC link. An electrical vehicle charger is provided that includes a power input for connection to an AC power distribution network and a power output for connection to an electric vehicle, and is configured for determining a rate of electrical energy flow through the power output by using as a factor a state of balance between power generation and load in an AC power distribution network to which the power input connects. A method for regulating electrical energy transfer over a pathway including a DC link is also provided. 1. A system for regulating electrical energy transfer over a pathway including a DC link , the system comprising a data processing device , including:a. a machine readable storage encoded with non-transitory software for execution by a CPU, the software being configured for computing a rate of electrical energy flow through the DC link at least in part on a basis of a state of balance between power generation and load in an AC power distribution network to which the pathway connects;b. an output for generating a control signal for adjusting the rate of electrical energy flow through the DC link according to the computed rate.2. A system as defined in claim 1 , wherein the AC power distribution network supplies electrical energy flowing through the pathway and the DC link.3. A system as defined in claim 2 , wherein the data processing device includes an input for receiving frequency information from the AC power distribution network.4. A system as defined in claim 3 , wherein the data processing device adapts the control signal to reduce the rate of electrical energy ...

VOLTAGE SOURCE CONVERTER AND CONTROL THEREOF

Methods and apparatus for hard switching of Alternate-Arm-Converter voltage source converters. Such voltage source converters have a phase limb with a high and low side converter arm connecting an AC terminal to a high and low side DC terminal, respectively comprising a chain-link circuit in series with a director switch. Each chain-link circuit comprises series connected cells that can be switched to generate a controlled voltage across the chain-link circuit. In embodiments, a controller turns-off the director switch of a converter arm that is conducting current in response to a hard-switching request for a first phase limb. In response to a hard-switching request, the controller controls the chain-link circuits of the first phase limb at any point in a phase cycle to control: a DC voltage across the director switch; and/or the current flowing through the director switch to a predetermined level before turning the director switch off. 1. A voltage source converter comprising:at least one phase limb comprising a high side converter arm connecting an AC terminal to a high side DC terminal and a low side converter arm connecting the AC terminal to a low side DC terminal;wherein each of the converter arms comprises a chain-link circuit in series with a director switch;wherein each chain-link circuit comprises a plurality of series connected cells that can be controllably switched to generate a controlled voltage across the chain-link circuit; anda controller configured to turn-off the director switch of a converter arm that is conducting current in response to a hard-switching request for a first phase limb;wherein, in response to a hard-switching request, the controller is configured to control the chain-link circuits of the first phase limb at any point in a phase cycle to control at least one of: a DC voltage across the director switch; and the current flowing through the director switch to a predetermined level before turning the director switch off.2. A voltage ...

METHOD FOR FAULT PROTECTION IN HVDC GRID, HVDC NODE OF HVDC GRID, AND HVDC GRID SYSTEM

The present invention concerns a node of an HVDC grid composed of HVDC nodes and of a plurality of links interconnecting the HVDC nodes, each HVDC node being interconnected to at least one HVDC node of the HVDC grid by a link composed of conductive cables for high voltage direct current transportation and one optical fiber, at least one HVDC node being interconnected to at least two HVDC nodes, each HVDC node comprising, for each link connecting the HVDC node to the at least one other HVDC node, a link module comprising a fault sensing device, a breaker, and an optical transceiver for communicating through the optical fiber of the link. 18-. (canceled)10. The method according to claim 9 , characterized in that the method further comprises:transferring, if a second breaker disabling request has been received by the first link module, a third breaker disabling request, through the optical transceivers of the second link modules.11. The method according to claim 9 , characterised in that the second link modules continuously transfer the first breaker disabling request until the effective isolation of the link by the first link module.12. The method according to claim 9 , characterised in that the checking if a second breaker disabling request has been received by the first link module consists in checking if the second breaker disabling request is still being received by the first link module.13. The method according to claim 11 , characterised in that the checking if a second breaker disabling request has been received by the first link module consists in checking if the second breaker disabling request is still being received by the first link module.14. The method according to claim 9 , characterised in that the method further comprises the activating a timer of a predetermined duration when the first breaker disabling request is received by the first link module claim 9 , and the checking if a second breaker disabling request is received by the first link module ...

SYSTEM FOR ROBOTIC 3D PRINTING

A robotic 3D printing system has a six degree of freedom (DOF) robot () that holds the platform () on which the 3D pad () is built on. The system uses the dexterity of the 6 DOF robot to move and rotate rue platform relative to the 3D printing head (), which deposits the material on the platform. The system allows the part build in 3D directly with a simple printing head and depositing the material along the gravity direction. The 3D printing head is held by another robot () or robots. The robot movement can be calibrated to improve the accuracy and efficiency for high precision 3D part printing. 1. A system for printing a 3D part on a platform comprising:a first robot for holding and moving said platform; andat least one second robot having attached thereto a 3D printing head positioned and movable by said second robot to print said 3D part on said platform when said first robot moves said platform relative to said printing head.2. The system of further wherein said at least one second robot comprises at least one or more other robots located adjacent to said at least one second robot claim 1 , said one or more other robots also having attached thereto an associated one of one or more 3D printing heads positioned and movable by each of said one or more other robots to print said 3D part on said platform when said first robot moves said platform relative to said at least one second robot and said associated one or said printing heads attached to said one or more other robots.3. The system of further comprising at least one or more other robots located adjacent said first robot for holding and inserting into a predetermined location on said 3D part an associated one of one or more pre-manufactured parts.4. The system of further comprising at least one or more other robots located adjacent said first robot for holding an associated one of one or more tools for performing work on said 3D part.5. A system for printing a 3D part on a platform comprising:a first robot for ...

POWER TRANSMISSION VIA A BIPOLAR HIGH-VOLTAGE DC TRANSMISSION LINK

A converter station has two line-commutated converters for energy transmission via a bipolar high voltage direct current transmission line. In a first operating mode of the converter station the two converters are electrically connected in an anti-parallel circuit to the same pole of the high voltage direct current transmission link and one of the converters is operated as a rectifier and the other converter is operated as an inverter in an network. In a second operating mode the two converters are connected to different poles of the high voltage direct current transmission link and both converters are operated as either rectifiers or inverters in the AC network. In both operating modes a station active power exchanged between the converter station and the AC network is controlled by active power specifications for converter active powers which are exchanged between the converters and the AC network. 115-. (canceled)16. A method of operating a converter station having two line-commutated converters for power transmission via a bipolar high-voltage DC transmission link , the method comprising:in a first mode of operation, electrically connecting the two converters to one pole of the high-voltage DC transmission link in an antiparallel connection, and operating one of the converters as a rectifier on an AC grid and operating another of the converters as an inverter on the AC grid;in a second mode of operation, connecting the two converters to different poles of the high-voltage DC transmission link and operating both converters either as rectifiers or as inverters on the AC grid;in the first and second modes of operation, controlling a station real power exchanged between the converter station and the AC grid by real power stipulations for converter real powers exchanged between the two converters and the AC grid; andprescribing a threshold value for the station real power and operating the converter station in the first mode of operation for station real powers below ...

Apparatus and method for supplying hybrid power of offshore plant

A power supply apparatus of an offshore plant comprises: an AC/DC converter converting alternating current produced from a generator into direct current and supplying the direct current to a DC bus; a power load connected to the DC bus so as to regenerate power; a first DC/DC converter connected to the DC bus; a second DC/DC converter connected to the DC bus; a first power storage unit connected to the first DC/DC converter and storing power when a voltage of the DC bus is maintained at a level of a first threshold value or higher for a first time period; and a first resistance unit connected to the second DC/DC converter and consuming power when the voltage of the DC bus is maintained at the level of the first threshold value or higher for a second time period. The second time period is longer than the first time period.

High-power conversion system

A high-power conversion system includes a switching circuit and at least one reactor, the at least one reactor being electrically connected to the switching circuit, and the core of the at least one reactor being electrically connected to a potential point of the high-power conversion system.

FAULT LEVEL ESTIMATION METHOD FOR POWER CONVERTERS

A method for fault level estimation for a power converter quickly after a fault clearing event includes a step of providing a training dataset with an input variable set and a corresponding system fault level output variable. The method further includes a step of deducing a hypothesis function based on the training dataset and estimating the system fault level quickly after the fault clearing event using the hypothesis function. The hypothesis function is deduced either using a neural network computational model or using a multivariate polynomial regression approach. The estimated fault level can then be used to adjust the controller parameters of the power converter. 115-. (canceled)16. A method for system fault level estimation for a power converter quickly after a fault clearing event , the method comprising the following steps:providing a training dataset having an input variable set and a corresponding system fault level output variable;deducing a hypothesis function based on the training dataset;estimating the system fault level after the fault clearing event using the hypothesis function.17. The method according to claim 16 , further comprising a step of adjusting controller parameters of the power converter based on the system fault level estimation.18. The method according to claim 16 , which comprises deriving the input variable set from voltage measurements and reactive power exchange measurements after the fault clearing event.19. The method according to claim 16 , which comprises detecting the fault clearing event by an under-voltage condition.20. The method according to claim 18 , which comprises effecting the voltage measurements and the reactive power exchange measurements at a bus bar connected to the power converter.21. The method according to claim 16 , wherein the step of deducing the hypothesis function comprises using a neural network computational model.22. The method according to claim 18 , which comprises conducting the voltage measurements ...

Modular Power Center

A modular and adaptable power system may be used to provide electrical power connections in an industrial work site, such as a mine. The system provides a plug-and-play interchangeable output module that can be quickly and easily disconnected from and reconnected to a separate and independent input/feed-through module. This allows a user to daisy chain multiple input/feed-through modules together, thereby greatly reducing setup time. Output modules can be quickly disconnected and relocated and returned to previous locations and reconnected. 1. A modular power system for distributing electrical power from a power supply to one or more work sites that are remote from the power supply , the modular power system comprising: a first housing having a base portion;', 'an input connector attached to the first housing, the input connector for receiving a supply voltage from the power supply; and', 'a feed-through connector attached to the first housing, the feed-through connector in electrical communication with the input connector, such that the supply voltage is present at the feed-through connector when the input connector receives the supply voltage from the power supply; and, 'an input/feed-through module comprising a second housing having a base portion configured to mechanically align with, receive, and attach to the base portion of the first housing;', 'a conductor configured to connect to and receive the supply voltage from the input/feed-through module when the output module is attached to the input/feed-through module;', 'a first transformer disposed within the second housing and in electrical communication with the conductor, the first transformer for receiving and stepping down the supply voltage to a first output voltage that is less than the supply voltage; and', 'a plurality of first electrical receptacles attached to the second housing that are in electrical communication with the first transformer, the plurality of first electrical receptacles for providing ...

Relay protection method and apparatus against lc parallel circuit detuning faults

A relay protection method against LC parallel circuit detuning faults comprises the steps of: a relay protection device samples a current of a parallel LC, that is, a reactor and a capacitor, and samples a total current flowing through the whole LC; convert the current of the reactor into a current of an equivalent capacitor; calculate amplitudes of the current of the equivalent capacitor and a current of a realistic capacitor and calculate an amplitude of the total current flowing through the LC; calculate a current amplitude ratio of the equivalent capacitor to the realistic capacitor; and when the amplitude of the total current flowing through the LC is large enough, send an alarm signal or a trip after a setting time delay if the current ratio exceeds a preset upper and lower limit range. Also provided is a corresponding relay protection device.

Hybrid capacitor bank for a power conversion assembly

A power conversion assembly includes a power converter having a plurality of switching devices, a power source electrically coupled to the power converter, and a direct current (DC) filter circuit bridging the power converter and the power source. The DC filter circuit includes a DC link having a positive rail, a negative rail, and a capacitor bank. The capacitor bank includes a first set of capacitors being a first type of capacitors and a second set of capacitors being a different, second type of capacitors. Each capacitor in the first set of capacitors is positioned closer to a respective switching device of the plurality of switching devices than a corresponding capacitor of the second set of capacitors to minimize impedance between each capacitor in the first set of capacitors and the respective switching device such that a majority of ripple current from the plurality of switching devices passes through the first set of capacitors.

POWER CONVERSION DEVICE AND POWER SYSTEM

A power conversion device which is connected between an electric generation grid and a demand area grid and performs power conversion includes: a power converter which is connected to an electric generation grid and which converts AC power received from the electric generation grid to DC power and transmits the DC power via DC bus; and a control device for controlling the power converter. The control device includes a detection unit for detecting DC current of the DC bus, and a protection control unit for performing protection control for suppressing an amount of power received from the electric generation grid, on the basis of variation in the DC current, thereby continuing operation in the case of disturbance in the demand area grid. 1. A power conversion device comprising:a power converter which is connected to an electric generation grid and which converts AC power received from the electric generation grid to DC power and transmits the DC power via DC bus; anda control device for controlling the power converter, wherein a detection unit for detecting DC current of the DC bus,', 'an AC voltage control unit for causing AC voltage at a power reception end of the power converter serving as voltage of the electric generation grid, to follow an AC voltage command,', 'a DC current control unit for causing the DC current to follow a DC current command, and', 'a protection control unit for performing protection control for suppressing an amount of power received from the electric generation grid, by decreasing an amplitude of the AC voltage command, on the basis of variation in the DC current, and, 'the control device includes'}the control device generates an output voltage command for the power converter on the basis of output of the AC voltage control unit and output of the DC current control unit.2. The power conversion device according to claim 1 , whereinthe control device generates instantaneous voltage reduction in the connected electric generation grid by the ...

Method And Apparatus For Controlling Hybrid Direct-Current Transmission System

A method and apparatus for controlling a hybrid direct-current (DC) transmission system. The method comprises: adjusting the total number of inserted sub-modules of a modular multi-level converter and the polarity of an output level of the inserted sub-modules in real time, according to a DC voltage of a rectifier station at other end; or adjusting the total number of inserted sub-modules of a modular multi-level converter and the polarity of an output level of the inserted sub-modules in real time, according to the magnitude of a DC current or DC power; or adjusting the total number of inserted sub-modules of a modular multi-level converter and the polarity of an output level of the inserted sub-modules in real time, according to both the magnitude of the DC current and the DC voltage of the rectifier station at the other end. The method can effectively control the DC voltage and the direct current of a hybrid DC transmission system, avoiding the power transmitting breakdown. 1. A method for controlling a hybrid direct-current (DC) transmission system , characterized in that , comprising: adjusting , by the hybrid direct-current transmission system according to a DC voltage of a rectifier station at other end , a total number of inserted sub-modules of a modular multi-level converter and a polarity of an output level of the inserted sub-modules in real time; oradjusting, by the hybrid direct-current transmission system according to a magnitude of a DC current or DC power, the total number of the inserted sub-modules of the modular multi-level converter and the polarity of the output level of the inserted sub-modules in real time; oradjusting, by the hybrid direct-current transmission system according to both the magnitude of the DC current and the DC voltage of the rectifier station at the other end, the total number of the inserted sub-modules of the modular multi-level converter and the polarity of the output level of the inserted sub-modules in real time.2. The ...

High Voltage Energy Harvesting and Conversion Renewable Energy Utility Size Electric Power Systems and Visual Monitoring and Control Systems

A renewable energy, utility-size electric power system is provided with a high voltage, renewable energy harvesting network connected by a direct current link to a centralized grid synchronized multiphase regulated current source inverter system. The harvesting network includes distributed renewable energy power optimizers and transmitters that control delivery of renewable energy to the grid synchronized multiphase regulated current source inverter system. A visual immersion monitoring and control system can be provided for a three dimensional, visually oriented, virtual reality display, and command and control environment.

Systems, methods, and devices for bipolar high voltage direct current electrical power distribution

Systems, methods and devices for aircraft power distribution include a bipolar high voltage direct current source component; an electrical loading component capable of drawing electrical power from the bipolar high voltage direct current source component; a set of switching components configured to selectively couple power from the bipolar high voltage DC source component to the electrical loading; and a transient suppression component. The transient suppression component is configured to limit current flowing through the first or the second subset of the set of switching components when the first and the second subsets are not in the same state.

CONVERTER

A power electronic converter, for use in high voltage direct current power transmission and reactive power compensation, comprises at least one converter limb including first and second terminals being connectable to a DC network and a third terminal, the or each converter limb defining first and second limb portions connected in series between the third terminal and a respective one of the first and second terminals, each limb portion including a chain-link converter, each chain-link converter including a plurality of modules connected in series, each module including at least one primary switching element connected to at least one energy storage device, each converter limb being controllable to selectively define a circulation path carrying an AC circulation current for presentation to the DC network to minimise DC ripple in a DC voltage presented to the DC network. 1. A power electronic converter , for use in high voltage direct current power transmission and reactive power compensation , comprising at least one converter limb including first and second terminals being connectable to a DC network and a third terminal , the or each converter limb defining first and second limb portions connected in series between the third terminal and a respective one of the first and second terminals , each limb portion including a chain-link converter , each chain-link converter including a plurality of modules connected in series , each module including at least one primary switching element connected to at least one energy storage device , each converter limb being controllable to selectively define a circulation path carrying an AC circulation current for presentation to the DC network to minimise DC ripple in a DC voltage presented to the DC network.2. A power electronic converter according to claim 1 , wherein each limb portion further includes at least one secondary switching element connected in series with the chain-link converter claim 1 , the at least one secondary ...

ELECTRIC POWER CONVERSION DEVICE

A power conversion device includes M number of DC/DC converters, first-side terminals of the DC/DC converters are connected so that common current flows between both positive and negative terminals of first DC terminals of the power conversion device, and second-side terminals thereof are connected so that common current flows between both positive and negative terminals of second DC terminals of the power conversion device. The power conversion device further includes M-1 number of auxiliary converters each connected between two DC/DC converters and performing DC/DC conversion. The DC/DC converters control voltages of the second-side terminals and input voltage of the power conversion device. Each auxiliary converter controls voltages of the first-side terminals of the two DC/DC converters so as to be equalized. 1. A power conversion device comprising:a power conversion unit including M number of DC/DC converters between first DC terminals and second DC terminals each pair of which is composed of both positive and negative terminals, where M is two or greater, the power conversion unit performing power transmission between the first DC terminals and the second DC terminals; anda controller for controlling the power conversion unit, whereinthe power conversion unit further includes one or more balancing circuits each connected between two of the DC/DC converters and balancing powers of the two DC/DC converters,in the M number of DC/DC converters, one of input and output thereof is defined as a first side and the other one is defined as a second side, first-side terminals of the DC/DC converters are connected so that current flows in common between both positive and negative terminals of the first DC terminals, and second-side terminals of the DC/DC converters are connected so that current flows in common between both positive and negative terminals of the second DC terminals, andeach balancing circuit is connected between two pairs of the first-side terminals of the ...

RIPPLE CONTROL AND OPTIMISATION IN A POWER TRANSMISSION NETWORK

There is disclosed a controller () for a power electronic network element () of a power transmission network (), wherein the controller () is configured to vary a control parameter of the network element () which at least partly determines a ripple profile in a transmission line of the network. The controller () is configured to vary the control parameter between at least a first value and second value to cause the ripple profile in the transmission line to change; and the controller is configured to vary the control parameter periodically or in response to a signal indicating a threshold temperature at a hotspot location along the transmission line. A method of optimising control parameters for a power transmission network () is also disclosed. 115-. (canceled)16. A controller for a power electronic network element of a power transmission network , wherein the controller is configured to vary a control parameter of the network element which at least partly determines a ripple profile in a transmission line of the network , wherein the controller is configured to vary the control parameter between at least a first value and second value to cause the ripple profile in the transmission line to change; and wherein the controller is configured to vary the control parameter periodically or in response to a signal indicating a threshold temperature at a hotspot location along the transmission line.17. The controller according to claim 16 , wherein the control parameter is selected from the group comprising:a switching frequency of the power electronic network element; andan apparent impedance parameter which determines the apparent impedance of the network element.18. A power transmission network comprising a power transmission line claim 16 , a power electronic network element for controlling power transmission through the power transmission line claim 16 , and a controller for varying a control parameter of the network element claim 16 , the controller configured to ...

APPARATUS AND METHOD OF MEASURING DATA IN HIGH VOLTAGE DIRECT CURRENT SYSTEM

A data measurement device in a high voltage direct current (HVDC) system is provided. The data measurement device includes: a power measurement unit measuring pieces of power related data; and a control unit determining measurement times at which the pieces of power related data are measured respectively, and performing control based on pieces of power related data having a same measurement time among the pieces of power related data. 1. A data measurement device in a high voltage direct current (HVDC) system , the data measurement device comprising:a power measurement unit measuring pieces of power related data; anda control unit determining measurement times at which the pieces of power related data are measured respectively, and performing control based on pieces of power related data having a same measurement time among the pieces of power related data.2. The data measurement device according to claim 1 , wherein the control performed by the control unit comprises at least one of operation control of a switching device comprising a circuit breaker claim 1 , power control increasing or decreasing an amount of transmission power claim 1 , and voltage control controlling DC and AC voltages.3. The data measurement device according to claim 1 , wherein the control unit controls the power measurement unit to enable information on the measurement time to be tagged to each of the pieces of power related data.4. The data measurement device according to claim 1 , further comprising a signal transmission and conversion unit that converts the pieces of power related data into control operation data for performing the control to transmit the control operation data to the control unit.5. The data measurement device according to claim 4 , wherein the control unit predicts the measurement time from a time at which conversion into the control operation data is completed claim 4 , in a case where it is difficult to determine the measurement time.6. The data measurement device ...

Method and system for architecture, control, and protection systems of modular stacked direct current subsea power system

A high-voltage DC (HVDC) power system and a method of controlling and protecting the HVDC power system includes a plurality of sending-end (SE) modules coupled in electrical series and a plurality of receiving-end (RE) power converter modules electrically coupled to said plurality of SE modules, the RE modules coupled in a switchyard configuration, the switchyard configuration including a plurality of load branches coupled together in electrical series, each load branch including a branch bypass switch configured to bypass load current around an associated load branch, and a branch protection system.

Extending the life of a compromised umbilical

A method of using an umbilical between a surface location and an underwater location of an underwater fluid extraction well system is provided. The umbilical includes an electrical power conductor configured to transmit electrical power at a first frequency from a source at the surface location to the underwater location. The method comprises detecting that the umbilical has been compromised by the ingress of water. In response thereto, the method comprises converting electrical power from the source to electrical power at a second frequency, wherein the second frequency is lower than the first frequency or DC electrical power; transmitting the electrical power at the second frequency or DC electrical power to the underwater location via the conductor; and converting, at the underwater location, the electrical power at the second frequency or DC electrical power to electrical power at a frequency used by the underwater equipment of the well system.

HIGH VOLTAGE DIRECT CURRENT (HVDC) CONVERTER SYSTEM AND METHOD OF OPERATING THE SAME

A high voltage direct current (HVDC) converter system includes at least one line commutated converter (LCC) and at least one current controlled converter (CCC). The at least one LCC and the at least one CCC are coupled in parallel to at least one alternating current (AC) conduit and are coupled in series to at least one direct current (DC) conduit. The at least one LCC is configured to convert a plurality of AC voltages and currents to a regulated DC voltage of one of positive and negative polarity and a DC current transmitted in only one direction. The at least one current controlled converter (CCC) is configured to convert a plurality of AC voltages and currents to a regulated DC voltage of one of positive and negative polarity and a DC current transmitted in one of two directions. 1. A high voltage direct current (HVDC) converter system comprising:at least one line commutated converter (LCC) configured to convert a plurality of alternating current (AC) voltages and currents to a regulated direct current (DC) voltage of one of positive and negative polarity and a DC current transmitted in only one direction; andat least one current controlled converter (CCC) configured to convert a plurality of AC voltages and currents to a regulated DC voltage of one of positive and negative polarity and a DC current transmitted in one of two directions, wherein said at least one LCC and said at least one CCC are coupled in parallel to at least one AC conduit and are coupled in series to at least one DC conduit;wherein said at least one LCC is coupled in parallel to at least one switch device and wherein said at least one CCC and said at least one switch device at least partially define a black start current transmission path.2. The HVDC converter system in accordance with claim 1 , wherein said at least one LCC and said at least one CCC define at least one of at least one HVDC rectifier device and at least one HVDC inverter device.3. The HVDC converter system in accordance with ...

HVDC CONVERTER WITH NEUTRAL-POINT CONNECTED ZERO-SEQUENCE DUMP RESISTOR

A power electronic converter ()is for use in high voltage direct current power transmission and reactive power compensation, the power electronic converter () including three phase elements () defining a star connection () and a converter unit () including first and second DC terminals () for connection in use to a DC network (56) and three AC terminals (), the converter unit () including a plurality of switching elements () controllable in use to facilitate power conversion between the AC and DC networks (), the power electronic converter () further including a third DC terminal () connected between the first and second DC terminals (), the third DC terminal () being connected to a common junction () of the star connection () to define an auxiliary connection (), the auxiliary connection () including at least one dump resistor () connected between the common junction () and the third DC terminal (), wherein the switching elements () of the converter unit () are controllable in use to modify a phase voltage at each AC terminal () to include a triplen harmonic voltage component so as to dissipate real power in the or each dump resistor () at a triplen harmonic frequency. 13030323840303450525654545832367074445678505278403682844078707434. A power electronic converter () for use in high voltage direct current power transmission and reactive power compensation , the power electronic converter () including three phase elements () defining a star connection in which a first end () of each phase element is connected to a common junction () , the power electronic converter () further including a converter unit () including first and second DC terminals ( , ) for connection in use to a DC network () and three AC terminals () , each AC terminal () being connected in series with a second end () of a respective phase element () of the star connection () , the converter unit including a plurality of switching elements ( , ) controllable in use to facilitate power conversion ...

RELATING TO POWER CONVERTERS

In the field of high voltage direct current (HVDC) power transmission networks there is a need for an improved power converter. 110-. (canceled)11. A power converter , for use in a HVDC power transmission network , comprising first and second DC terminals for connection in use to a DC network and between which extends at least one converter limb , the or each converter limb including first and second limb portions separated by an AC terminal for connection in use to an AC network , each limb portion including a switching valve , and the power converter including a controller programmed to control switching of the switching valves to control the flow of a converter current (I) through the power converter and thereby in-use transfer power between the power converter and the AC network ,the power transferred between the power converter and the AC network having an active component and a reactive component, andthe controller being further programmed in use to:{'sub': 'max', '(i) prioritize to a first extent the transfer of reactive power between the power converter and the AC network during a first operating condition, when the AC voltage (V) of the AC network lies outside a desired operating range, by allowing up to a first amount of the converter current (I) to be a reactive current; and'}{'sub': 'max', '(ii) prioritize to a second extent, less than the first extent, the transfer of reactive power between the power converter and the AC network during a second operating condition, when the AC voltage (V) of the AC network lies within the desired operating range, by limiting the amount of converter current (I) that can be a reactive current to a second amount, less than the first amount, the second amount being determined according to a measured operating frequency of the AC network.'}12. The power converter according to wherein the controller is programmed to determine the second amount of converter current (I) that can be a reactive current by reducing the first ...

CONVERTER

A voltage source converter includes a converter limb having limb portions separated by an AC terminal and extending between DC terminals, each limb portion including a primary switching element to switch the limb portion into and out of circuit. The converter further includes an auxiliary limb. The primary switching element of each limb portion is switchable to switch the auxiliary limb into and out of circuit with the corresponding limb portion. The converter further includes a control unit to, in one mode, inject a circulation current that flows in one direction in one of the limb portions and minimize a current flowing in the opposite direction in that limb portion. Each primary switching element switches the respective limb portion into or out of circuit following the minimization of the limb portion current by the circulation current. 1. A voltage source converter comprising:a converter limb extending between first and second DC terminals and having first and second limb portions separated by an AC terminal, the first and second DC terminals being connectable to a DC electrical network and the AC terminal being connectable to an AC electrical network, each limb portion including a primary switching element, the primary switching element of each limb portion being switchable to switch the corresponding limb portion into and out of circuit between the corresponding DC terminal and the AC terminal to control the configuration of an AC voltage at the AC terminal;an auxiliary limb including an auxiliary converter, the auxiliary converter including at least one auxiliary switching element, the auxiliary limb being connected to the AC terminal, the primary switching element of each limb portion being switchable to switch the auxiliary limb into and out of circuit with the corresponding limb portion and thereby switch the auxiliary limb into and out of circuit with the corresponding DC terminal; anda control unit to selectively control the switching of the or each ...

CONTROL OF VOLTAGE SOURCE CONVERTERS

A method and apparatus for controlling a fault blocking voltage source converter apparatus which is, in use, connected to an AC system and a DC system for power transmission, in the event of a DC side interruption operating the voltage source converter apparatus after identification of a need for a DC side interruption based on a voltage order, so as to extract at least some electrical energy stored in the connected DC system to the voltage source converter apparatus. 1. A method of controlling a fault blocking voltage source converter apparatus which is , in use , connected to an AC system and a DC system for power transmission , the method comprising , in the event of a DC side interruption:operating the voltage source converter apparatus after identification of a need for a DC side interruption based on a voltage order; and,extracting at least some electrical energy stored in the connected DC system to the voltage source converter apparatus.2. The method as claimed in wherein said voltage order is based on DC current flow to transfer at least some of the electrical energy stored in the connected DC system to the connected AC system.3. The method as claimed in comprising generating the voltage order with a polarity that is opposite to the polarity of DC current flow.4. The method as claimed in comprising controlling the magnitude of the voltage order based on the magnitude of the DC current flow.5. The method as claimed in wherein the magnitude of the voltage order varies at least one of continuously or in a step-wise fashion with the magnitude of DC current between a maximum allowable positive voltage order and a maximum allowable negative voltage order.6. The method as claimed in comprising controlling the magnitude of the voltage order so as to decrease over time from a value substantially equal to a monitored DC terminal voltage.7. The method as claimed in wherein the magnitude of the voltage order is decreased at a rate such that a current flow in the DC ...

CONTROL DEVICE FOR DISTRIBUTED POWER SUPPLY SYSTEM, DISTRIBUTED POWER SUPPLY SYSTEM, AND CONTROL PROGRAM OF DISTRIBUTED POWER SUPPLY SYSTEM

A control device () of a distributed power supply system () which includes a plurality of power supply groups () having at least one wind turbine generator (); and a rectifier () which is provided corresponding to each of the power supply groups (), and rectifies AC power to DC power, so that the DC power rectified by the rectifier () is collected to transmit the electric power, comprises a grouping section groups the power supply groups () into at least two groups (); a phase command generation section generates phase commands different from one another for each group () to output to the power supply groups () belonging to the respective groups (), and generates the same phase command to output to the wind turbine generators () belonging to the same group (); and a transmission section transmits the generated phase command to the wind turbine generators (). 1. A control device of a distributed power supply system which includes a plurality of power supply groups having at least one distributed power supply , and a rectifier which is provided corresponding to each of the power supply groups , and rectifies AC power of the distributed power supply to DC power , so that the DC power rectified by the rectifier is collected to transmit the electric power ,the control device comprising:a grouping device that groups the plurality of power supply groups into at least two groups;a phase command generation device that generates phase commands different from one another for each group to output to the power supply groups belonging to the respective groups, and generates the same phase command to output to the distributed power supplies in the power supply groups belonging to the same group; anda transmission device that transmits the phase command generated by the phase command generation device to the distributed power supplies of the power supply groups.2. The control device of a distributed power supply system according to claim 1 , whereinthe transmission device transmits ...

Controlling multiple plasma processes

A power converter is capable to convert an electrical input power into a bipolar output power and to deliver the bipolar output power to at least two independent plasma processing chambers. The power converter includes a power input port for connection to an electrical power delivering grid, at least two power output ports each for connection to one of the plasma processing chambers, and a controller configured to control the power converter to deliver the bipolar output power to the power output ports, using at least one of control parameters including power, voltage, current, excitation frequency, and threshold for protective measures. The controller includes a virtual power supply for each power output port, and each virtual power supply includes a separate complete set of all fixed and time varying parameters and internal states associated with the operation of the individual power output port.

IMPROVEMENTS IN OR RELATING TO POWER TRANSMISSION NETWORKS

In the field of high voltage direct current (HVDC) power transmission there is provided a power converter assembly () comprising a line-commutated power converter () that is configured to transfer power from a DC network () to a corresponding receiving AC network (). The power converter assembly () also includes a control unit which is operatively associated with the line-commutated power converter () and is programmed, in response to the receiving AC network () exhibiting a reduced AC voltage (V, V, V), to cause a reduction in the operating DC voltage (V) of the line-commutated power converter () by the DC network (). 1. A power converter assembly for use in a high voltage direct current (HVDC) power transmission network , comprising:a line-commutated power converter configured to transfer power from a DC network to a corresponding receiving AC network; and{'sub': a', 'b', 'c', 'DC, 'a control unit operatively associated with the line-commutated power converter, the control unit being programmed, in response to the receiving AC network exhibiting a reduced AC voltage (V, V, V), to cause a reduction in the operating DC voltage (V) of the line-commutated power converter.'}2. A power converter assembly according to wherein the control unit is programmed to cause a reduction in the operating DC voltage (V) of the line-commutated power converter to prevent subsequent commutation failures occurring within the line-commutated power converter.3. A power converter assembly according to wherein the control unit is programmed to cause a reduction in the operating DC voltage (V) of the line-commutated converter which is proportional to the reduction in the AC voltage (V claim 1 , V claim 1 , V) in the corresponding receiving AC network.4. A power converter assembly according to wherein the control unit is programmed to take into account one or more of the following when causing a reduction in the operating DC voltage (V) of the line-commutated power converter:{'sub': 'DC', 'a ...

INTERCONNECTION EQUIPMENT FOR A HIGH-VOLTAGE DC GRID

An item of interconnection equipment for a high-voltage DC grid includes first and second terminals for connection to first and second lines of a high-voltage DC grid, a third terminal for connection to a local station or a line of the high-voltage grid, a node connected to the first to third terminals, a first superconductor current limiter and a first controlled switch connected in series between the first terminal and the node, a second superconductor current limiter and a second controlled switch connected in series between the second terminal and the node, a third superconductor current limiter and a third controlled switch connected in series between the third terminal and the node, and a current injector configured to inject an electrical current into the node. 110-. (canceled)11. An apparatus comprising an item of interconnection equipment for a high-voltage direct-current network , wherein said item of interconnection equipment comprises first , second , and third terminals , a node , a first current limiter , a second current limiter , a third current limiter , first , second and third controlled switches , and a current injector , wherein said first and second terminals are configured for connection to first and second lines of a high-voltage direct-current network , wherein said third terminal is configured for connection to a local station or to a line of the high-voltage network , wherein said node is connected to said first to third terminals , wherein said first current limiter and said first controlled switch are connected in series between said first terminal and said node , wherein said second current limiter and said second controlled switch are connected in series between said second terminal and said node , wherein said third current limiter and said third controlled switch are connected in series between said third terminal and said node , wherein said current injector is configured to inject an electrical current into said node upon a voltage ...

Control Feedback Loop Design with Fast Transient Response for Multi-level Converter

Disclosed herein are a system, method and non-transitory program storage device that are intended to provide a control system with quick response for a multi-level power converter. The control system may regulate an output voltage of the power converter based on one or more feedback signals. The feedback signals may be generated based on a differential between the output voltage and a reference voltage. The control system may further include one or more feed-forward signals representative of either the output voltage or transients of the output voltage. The control system may further include one or more switches in parallel with the one or more capacitors to selectively enable and/or disable direct feed-forward and capacitive feed-forward responsive to the output voltage at different levels.

START-UP OF HVDC NETWORKS

A method and apparatus for controlling a voltage source converter to energise a DC link. A voltage order generating module generates a voltage order for controlling the voltage source converter to generate a DC voltage on the DC link. An oscillation damping module monitors the DC current flow to determine an indication of current oscillation and the voltage order is based on a voltage reference signal which is modulated by the indication of current oscillation to provide oscillation damping. 1. A method of controlling a voltage source converter to energise a DC link comprising:controlling the voltage source converter to generate a DC voltage on the DC link based on a voltage order; andmonitoring DC current flow to determine an indication of current oscillation;wherein the voltage order is based on a voltage reference signal which is modulated by said indication of current oscillation to provide oscillation damping.2. The method as claimed in wherein the indication of current oscillation is determined by filtering a signal indicative of DC current flow.3. The method as claimed in wherein filtering the signal indicative of DC current flow comprises applying at least one of a band-pass filter and a high-pass filter.4. The method as claimed in wherein a current controller receives the indication of current oscillation and determines a damping control signal for modulating said voltage reference signal.5. The method as claimed in wherein the value of the damping control signal is controlled so as not to exceed a predetermined limit.6. The method as claimed in wherein the predetermined limit varies over time.7. The method as claimed in wherein the voltage reference signal is a time varying voltage reference signal.8. The method as claimed in wherein the time varying voltage reference signal comprises a ramp signal.9. The method as claimed in wherein the ramp signal ramps from an initial value corresponding to the voltage of the DC link when the voltage source converter is ...

METHOD FOR CONTROLLING AN UNINTERRUPTABLE POWER SUPPLY

The disclosure relates to a method for controlling an uninterruptable power supply and a respective computer program. The uninterruptable power supply comprises a grid connection, a grid switch connected to the grid connection, a rectifier and an inverter interconnected via a DC link, an energy storage connected to the DC link, a load connection, to which the inverter is connected, and a bypass switch, which is connected in parallel to the rectifier, the DC link and the inverter between the grid switch and the load connection, wherein the grid switch is a mechanical switch and the bypass switch is a semiconductor switch. 1. A method for controlling an uninterruptable power supply ,wherein the uninterruptable power supply comprises a grid connection, a grid switch connected to the grid connection, a rectifier and an inverter interconnected via a DC link, an energy storage connected to the DC link, a load connection, to which the inverter is connected, and a bypass switch, which is connected in parallel to the rectifier, the DC link and the inverter between the grid switch and the load connection;wherein the grid switch is a mechanical switch and the bypass switch is a semiconductor switch; in a normal operation mode in which the bypass switch is opened, the grid switch is closed, the uninterruptable power supply is connected to a grid via the grid connection and connected to a load via the load connection, operating the rectifier in a rectifying mode, in which an AC current from the grid is converted to a DC current supplied to the DC link and operating the inverter to convert the DC current from the DC link into an AC current supplied to the load;', 'upon receiving a fault signal, which signals an electrical fault concerning at least one of the load and the grid, sending a disconnect signal to the grid switch to open the grid switch and disconnect the uninterruptable power supply from the grid; and', 'upon receiving a confirmation signal from the grid switch, which ...

SUBMODULES OF MMC CONVERTER

Proposed is a submodule of an MMC converter configured to stably supply power to a submodule controller controlling the submodule of an MMC converter. The submodule includes: an energy storage part storing electric energy therein; a plurality of switching elements connected in parallel to the energy storage part to have a shape of a bridge; a plurality of serially-connected resistors connected in parallel to the energy storage part; a plurality of DC-DC converters connected in parallel to a resistor of the plurality of resistors; a power switching part operating to select and output one voltage of voltages output from the plurality of DC-DC converters and a plurality of voltages input from outside; and a submodule controller operating with the voltage output by the power switching part so as to control switching operations of the plurality of switching elements. 1. A submodule of an MMC converter , the submodule comprising:an energy storage part for storing electric energy therein;a plurality of switching elements connected in parallel to the energy storage part to have a shape of a bridge;a plurality of serially-connected resistors connected in parallel to the energy storage part;a plurality of DC-DC converters connected in parallel to a resistor of the plurality of resistors;a power switching part for operating to select and output one voltage of voltages output from the plurality of DC-DC converters and a plurality of voltages input from outside; anda submodule controller for operating with the voltage output by the power switching part so as to control switching operations of the plurality of switching elements.2. The submodule of claim 1 , wherein the power switching part selects one voltage of the voltages output from the plurality of DC-DC converters and the plurality of voltages input from the outside according to a preset priority and outputs the selected voltage to the submodule controller.3. The submodule of claim 1 , wherein at least one charging cell is ...

COMMUNICATIONS NETWORK FOR COMMUNICATION BETWEEN A CONTROL UNIT AND A POWER ELECTRONICS ELEMENT

A communications network for communication between at least one power electronics element and at least one control unit is disclosed. At least one transmit/receive unit of the communications network is configured to receive at least one signal from an upstream direction, and evaluate if the at least one signal is correctly received. In case the at least one signal is correctly received, the at least one transmit/receive unit is configured to forward, in an allocated first time slot, the at least one signal to a plurality of transmit/receive units in a downstream direction, and receive, in an allocated second time slot, a plurality of signals from the plurality of transmit/receive units as a response of the forwarded at least one signal. 116-. (canceled)17. A communications network in a High Voltage Direct Current , HVDC , power system for communication between at least one control unit and a plurality of power electronics elements comprised in the HVDC power system , wherein the at least one control unit is configured to control the plurality of power electronics elements by means of transmitting at least one signal to the plurality of power electronics elements , wherein the communications network further comprises:at least one array of at least one transmit/receive unit configured to, in an upstream direction from the plurality of power electronics elements to the at least one control unit and in a downstream direction from the at least control unit to the plurality of power electronics elements, receive at least one signal transmitted over the communications network in the downstream or upstream direction, and transmit the received at least one signal over the communications network in the downstream or upstream direction, respectively, wherein the at least one transmit/receive unit is further configured to:receive at least one signal from an upstream direction, and evaluate if the at least one signal is correctly received, andin case the at least one signal is ...

Power Flow Control Device for Controlling the Distribution of Currents in a Mesh Network

A power flow control device intended to be used in a mesh network. The device includes a first voltage source connected between a first terminal (B1) and a third terminal (B3). A second voltage source is connected between a second terminal (B2) and the third terminal (B3). A current source is connected alternately to the first voltage source and the second voltage source and configured to ensure a transfer of energy between the first voltage source and the second voltage source. A switching means is arranged to allow the current source to be connected alternately in parallel with the first voltage source or in parallel with the second current source.

ELECTRICAL ASSEMBLY

An electrical assembly includes a power converter having first and second DC terminals which are connectable to a DC electrical network. The power converter also includes converter limbs connected between the first and second DC terminals. Each converter limb includes an AC terminal that is connectable to a respective AC phase of a multi-phase AC electrical network. Each converter limb also includes limb portions, each connected between a corresponding AC terminal and a respective one of the first and second DC terminals. Each limb portion includes switching element(s). The electrical assembly includes a single grounding circuit having a reactor configured to provide a current path for alternating current with a high impedance to ground and a current path for direct current with a low impedance to ground. The grounding circuit is arranged so that only one of the AC phases is connected to ground via the grounding circuit. 1. An electrical assembly comprising:a power converter including:first and second DC terminals connectable to a DC electrical network;a plurality of converter limbs connected between the first and second DC terminals, each converter limb including:a respective AC terminal connectable to a respective AC phase of a multi-phase AC electrical network; andfirst and second limb portions, each limb portion connected between the corresponding AC terminal and a respective one of the first and second DC terminals, each limb portion including at least one switching element;wherein the electrical assembly includes a single grounding circuit that includes a reactor configured to provide a current path for alternating current with a high impedance to ground and a current path for direct current with a low impedance to ground, the grounding circuit being arranged so that only one of the AC phases is connected to ground via the grounding circuit.2. An electrical assembly according to claim 1 , wherein the grounding circuit further includes a resistor connected with ...

OVERLOAD CURRENT LIMITING METHOD FOR VOLTAGE SOURCE CONVERTER

According to the overload current limiting method for a voltage source converter, when a pole control system receives a water-cooling overload current limiting instruction, an active and reactive instruction are changed at the same time according to a specified slope, so that an absolute value of an arm current of the converter decreases in a fixed slope, and can be ensured that active power and reactive power fall to zero at the same time, and a water-cooling load limiting aim of the converter can be achieved by reducing the arm current. After a water-cooling overload power limiting instruction received by the pole control system is cancelled, a current value of the active power and the inactive power remain unchanged. When a water-cooling overload power limiting instruction is received again, decrease continues on the basis of current power values until the power falls to zero. 2. The overload current limiting method for a voltage source converter of claim 1 , wherein a change of the active instruction and a change of the reactive instruction are independent to each other claim 1 , namely claim 1 , an active power and a reactive power decrease at the same time according to the change method; ora power control station does not change a reactive instruction while changes an active instruction, and a reactive instruction of a direct-current (DC) voltage control station is reduced according to the change method.3. The overload current limiting method for a voltage source converter of claim 1 , whereinif an active power control station receives a water-cooling overload current limiting instruction, the active power control station changes instructions according to the change method of the active and reactive instructions;if a DC voltage control station receives the water-cooling overload current limiting instruction, the DC voltage control station sends an instruction for requesting to reduce an active power to a power control station through an inter-station ...

Power flow calculation method and device for ac-dc interconnected power system, storage medium and terminal

Provided are a power flow calculation method and device for an alternating current (AC)-direct current (DC) interconnected power system, a storage medium and terminal. A state of a DC network is calculated according to a control mode of a converter station, and a connection point between the DC network and an AC network is equivalent to a power node; and power flow calculation is performed through a Newton-Raphson method.

IMPROVEMENTS IN OR RELATING TO MONITORING ASSEMBLIES

In the field of monitoring assemblies for gas tube switching devices which is operable in a plurality of different conducting modes, a monitoring assembly includes a monitoring module to distinguish in real time at least one conducting mode from the or each other conducting mode. 114-. (canceled)15. A monitoring assembly , for a gas tube switching device operable in a plurality of different conducting modes , the monitoring assembly comprising a monitoring module to distinguish in real time at least one conducting mode from the or each other conducting mode.16. The monitoring assembly according to wherein the monitoring module in use distinguishes the at least one conducting mode by considering claim 15 , while the switching device is conducting claim 15 , one or more of:an on-state voltage across the switching device;an electromagnetic emission from the switching device; oran operating temperature of the switching device.17. The monitoring assembly according to wherein the monitoring module considers an on-state voltage across the switching device and comprises a voltage monitoring circuit configured to in use provide a monitoring output proportional to the voltage (V) arising across the switching device claim 16 , the voltage monitoring circuit operating in a first mode while the switching device is conducting in which it communicates the whole voltage magnitude (V) arising across the switching device claim 16 , and the voltage monitoring circuit operating in a second mode while the switching device is not conducting in which it truncates at least a portion of the whole voltage magnitude (V) arising across the switching device.18. The monitoring assembly according to wherein the voltage monitoring circuit comprises a voltage divider stage having a monitoring output configured to provide a monitoring output voltage (V) proportional to the voltage (V) arising across the switching device.19. The monitoring assembly according to wherein the voltage divider stage ...

Filter apparatus, a method for filtering harmonics in an electrical power transmission or distribution system, and such a system

A filter apparatus includes at least one filter, each filter being tunable and including at least one capacitor arrangement. The capacitor arrangement includes a plurality of first capacitors, a plurality of second capacitors, and a plurality of switches. Each switch is switchable between a non-conducting mode and a conducting mode. The plurality of second capacitors and the plurality of switches are arranged to connect or disconnect the second capacitors on different potentials in order to tune the filter by adjusting the capacitance of the filter. An electrical power transmission or distribution system includes such a filter apparatus. A method is provided for filtering harmonics in an electrical power transmission or distribution system by means of such a filter apparatus.

RELATING TO POWER TRANSMISSION NETWORKS

In the field of high voltage direct current (HVDC) power transmission networks, there is a need for improvements to allow a single power converter to control individual AC network voltages carried by multiple AC transmission conduits to multiple AC network elements, such as respective wind parks. 113-. (canceled)14. A power transmission network comprising a power converter having first and second DC converter terminals for connection in use to a DC network and an AC converter terminal electrically connected to a plurality of AC transmission conduits each of which is for connection in use to a respective AC network element configured to operate at a respective individual AC network voltage , the power converter including a primary converter controller programmed in use to control the transfer of power through the power converter and thereby between the DC network and the plurality of AC network elements , and the primary converter controller being further programmed in use to control each individual AC network voltage by establishing a virtual voltage representative of the plurality of AC network voltages and altering a single AC converter voltage produced by the power converter at the AC converter terminal to adjust the virtual voltage and thereby adjust each individual AC network voltage.15. The power transmission network according to claim 14 , wherein the primary converter controller is programmed to establish a virtual voltage commensurate with the average of the individual AC network voltages.16. The power transmission network according to claim 14 , wherein the primary converter controller is programmed to establish the virtual voltage in a vector form having real and imaginary parts.17. The power transmission network according to claim 14 , wherein the primary converter controller is additionally programmed to compare the established virtual voltage with a predetermined virtual voltage reference and to alter the AC converter voltage produced by the power ...

STATION BUILDING POWER SUPPLY

A station building power supply includes: a power converter that converts DC power to AC power; a casing that houses the power converter; an AC system circuit that supplies the AC power output from the power converter to electrical apparatus outside the casing; and a filter circuit that applies a high-frequency current generated in the power converter from the AC system circuit to the casing. In the station building power supply, the power converter and the casing are grounded. 1. A station building power supply comprising:a power converter to convert DC power to AC power;a casing housing the power converter;an AC system circuit to supply the AC power output from the power converter to electrical apparatus outside the casing; anda filter circuit to apply a high-frequency current generated in the power converter from the AC system circuit to the casing,wherein the power converter and the casing are grounded.2. The station building power supply according to claim 1 , whereinthe AC system circuit is a three-wire power line, and,in the filter circuit, ends of three high-frequency capacitors on one side are connected by Y-connection, a neutral point is connected to the casing, and ends of the three high-frequency capacitors on the other side are connected to different wires of the three-wire power line from one another.3. The station building power supply according to claim 1 , further comprisingan electromagnetic contactor to open and close a path of the AC system circuit, the electromagnetic contactor being disposed closer to the power converter than a point of contact between the AC system circuit and the filter circuit.4. The station building power supply according to claim 1 , further comprisingan electromagnetic contactor to open and close a path of the AC system circuit, the electromagnetic contactor being disposed closer to the electrical apparatus than a point of contact between the AC system circuit and the filter circuit.5. The station building power supply ...

STATION-HYBRID HIGH VOLTAGE DIRECT CURRENT SYSTEM AND METHOD FOR POWER TRANSMISSION

A high voltage direct current (HVDC) transmission system comprises a first terminal comprising a first voltage source converter (VSC) having a first and second VSC terminals and a first line commutated converter (LCC) having first and second LCC terminals; a second terminal comprising a second VSC having third and fourth VSC terminals and a second LCC having third and fourth LCC terminals; and a transmission line pair comprising a positive transmission line that couples the first VSC terminal and the first LCC terminal of the first VSC and the first LCC, respectively, to the third VSC terminal and the third LCC terminal of the second VSC and the second LCC, respectively, and a second positive line that couples the second VSC terminal and the second LCC terminal of the first VSC and the first LCC, respectively, to the fourth VSC terminal and the fourth LCC terminal of the second VSC and the second LCC, respectively.

MULTILEVEL VALVE FOR VOLTAGE SOURCED CONVERTER TRANSMISSION

A method for transforming electric power from high voltage AC voltage and AC current to high voltage DC voltage and DC current and from high voltage DC voltage and DC current to high voltage AC voltage and AC current. The method includes passing the power through voltage sourced converters whose legs are comprised all or in part with 3 step ladder bridge modules connected in series. 1. A method for transmitting electric power over a high voltage power grid betweenhigh voltage AC and DC network elements, comprising:implementing a voltage sourced converter comprising a plurality of series-connected modules in each leg of the voltage sourced converter, the voltage sourced converter converts high voltage DC to AC by operating the series-connected modules with each module being configured to convert a DC voltage to a three step DC voltage ladder;selectively controlling a switching operation of six subportions in each module by which the module is placed in one of three available operational states;in response to the switching, in a first state, directing current in series from a first subportion to a first capacitor, wherein the voltage across the capacitor establishes a first voltage level across the module, in a second state, directing current from a first subportion through the first capacitor, a second subportion, a second capacitor, and third subportion, wherein the voltage across the first and second capacitors establishes a second voltage level across the module, and in a third state, directing current from the first subportion through a fourth subportion and third subportion without involving the first and second capacitors, which establishes a third voltage level across the module.2. The method of comprising implementing no more than six insulated gate bipolar transistors each with accompanying reverse biased diodes in each module.3. The method of comprising implementing three limbs whereby generating electrical power signals compatible with conventional three ...

POWER TRANSMISSION NETWORK

A power transmission network comprises, an AC electrical system AC transmission link from the AC electrical system to at least one AC-DC converter which includes: an AC connecting point connected to the AC transmission link and a DC connecting point for connection to a DC transmission link and a control system configured to operate each AC-DC converter in an AC voltage control mode as an AC slack bus to control a magnitude and/or a frequency of an AC voltage of the AC transmission link at a or a respective steady-state value and facilitating a power transfer between its connecting points to accommodate power generated or supplied to the AC electrical system. The control system is further configured to operate each first AC-DC converter in a protection mode to protect each AC-DC converter from an overvoltage and/or an overcurrent. 1. A power transmission network comprising: an AC transmission link for AC power transmission from the AC electrical system to at least one first AC-DC converter;', 'at least one first AC-DC converter including: an AC connecting point operably connected to the AC transmission link; and a DC connecting point for connection to a DC transmission link; and', 'a control system configured to operate the or each first AC-DC converter in an AC voltage control mode as an AC slack bus to control a magnitude and/or a frequency of an AC voltage of the AC transmission link at a or a respective steady-state value and thereby facilitate a power transfer between its AC and DC connecting points so as to accommodate a power generated by or supplied to the AC electrical system,', 'wherein the control system is further configured to operate the or each first AC-DC converter in a converter protection mode to regulate the or the respective steady-state value of the magnitude and/or frequency of the AC voltage of the AC transmission link to protect the or each first AC-DC converter from an overvoltage and/or an overcurrent., 'an AC electrical system;'}2. The ...

ELECTRIC SYSTEM ARCHITECTURE FOR A VEHICLE WITH MULTIPLE LOAD CHARACTERISTICS

An electric power system (EPS) may comprise a first power conversion channel and a second power conversion channel connected in parallel with a permanent magnet synchronous machine (PMSM). The first power conversion channel may be suitable for a load having a first electronic characteristic. The second power conversion channel may be suitable for a load having a second electronic characteristic. The first power conversion channel may comprise a first rectifier configured to receive an alternating current (AC) power from the PMSM and rectify the AC power into a first direct current (DC) power, a first buck converter configured to receive the first DC power from the first rectifier and reduce a voltage of the first DC power, and a first output filter configured to filter the first DC power and supply the first DC power to a first load. 1. An electric power system (EPS) , comprising:a permanent magnet synchronous machine (PMSM);a first rectifier configured to receive an alternating current (AC) power from the PMSM and rectify the AC power into a first direct current (DC) power;a first buck converter configured to receive the first DC power from the first rectifier and reduce a voltage of the first DC power; anda first output filter configured to filter the first DC power and supply the first DC power to a first load.2. The EPS of claim 1 , further comprising:a second rectifier coupled in parallel with the first rectifier and configured to receive the AC power and rectify the AC power into a second DC power; anda second buck converter connected in series with the second rectifier.3. The EPS of claim 2 , wherein the first buck converter is connected in series with the first output filter and the second buck converter is connected in series with the first output filter.4. The EPS of claim 3 , further comprising a third current transducer connected between the second buck converter and the first output filter.5. The EPS of claim 2 , further comprising:a third buck ...