NACHWEIS VON STÖRUNGEN IN STARKSTROMLEITUNGEN

METHOD AND CIRCUIT FOR DETECTING AND BREAKING DISTURBING ELECTRIC ARCS

Anordnung zur Erhoehung der Selektivitaet von Schutzeinrichtungen

Anordnung zur Messung des Leistungsueberlastungs-Koeffizienten kapazitiver Verbraucher sowie zum Schutz derselben gegen Leistungsueberlastung

WITH ALTERNATING CURRENT FED PROTECTIVE CIRCUIT, IN PARTICULAR FOR THE COLLECTION OF GROUND FAULTS IN CABLE SYSTEMS

VERFAHREN ZUR ERFASSUNG VON ERDSCHLÜSSEN

PROOF OF DISTURBANCES IN CABLES FOR POWER INSTALLATION

Ground fault relay circuit for the monitoring of a compensated net

PROTECTIVE CIRCUIT AND PROCEDURE FOR A SUPPRESSION SYSTEM AGAINST ELECTROMAGNETIC DISTURBANCES

Erdschlußrelais

Procedure for improving textile material and means for the execution of the procedure

CIRCUIT ANALYZING SYSTEM

1. A circuit analyzing system includes a current transformer for extracting current from a phase or neutral conductor of a three phase line, a filter connected to the output of the current transformer and functioning to substantially trap current at the fundamental frequency while substantially passing currents at various harmonic frequencies thereof, and signal processing circuitry connected to the output of the filter to perform various functions with the harmonic frequency current input thereto. Among these functions, as shown in various preferred embodiments, are measurement of the harmonic signal in RMS and conveyance of the output to a display instrument for a user or utility's convenience in monitoring harmonic frequency circuits, which have become more common with the advent of electronic equipment having internal power supplies such as personal computers, work stations, printers, and the like. Other functions include a user or utility's connecting a demand circuit mechanism to the measured currents (preferably RMS/harmonic frequency currents), and/or using comparator circuitry to sense the measured harmonic frequency currents and, if they exceed a desired level set by the user or utility, to output a signal to a tripping device such as a power contactor or relay which will in turn institute load shedding.

Negative-Sequence Time-Overcurrent Relay

Für die Kurvenform einer elektrischen Grösse empfindliche Relaisanordnung

Erdschlussschutzeinrichtung bei einem Generator, der über einen Transformator auf das Netz arbeitet.

Erdschlussschutzeinrichtung bei mehreren elektrischen Generatoren und Blindleistungsmaschinen.

Elektrische Ueberstromschutzschaltanordnung

Verfahren und Einrichtung für den Selektivschutz elektrischer Leitungen eines Verteilnetzes gegen Erdschlüsse

Schaltungsanordnung zur Erfassung eines Masseschlusses eines Drehstromgenerators

Verfahren zur Erdschlussüberwachung eines kompensierten Netzes

Differentialschutzeinrichtung

Schutzrelaisanordnung insbesondere Überstromrelaisanordnung

Anordnung zur Messung des Leistungsüberlastungskoeffizienten kapazitiver Verbraucher

Verfahren zum Veredeln von Textilien

Procedure for the detection of an error on channels using harmonious ones and a condition transition diagram.

УСТРОЙСТВО ЗАЩИТНОГО ШУНТИРОВАНИЯ ДУГОВЫХ ПЕРЕНАПРЯЖЕНИЙ

Устройство защитного шунтирования дуговых перенапряжений содержит устройство выбора поврежденной фазы, блок автоматики и управления, блок искусственного замыкания на землю, разделительный конденсатор, устройство блокирования шунтирования, резистор, блок контроля эффективности шунтирования, блок защиты, инвертор и фильтр высших гармоник.

Process and device safety of the capacitive receivers against the overload due to the higher harmonics and device of measurement of the coefficient of this overload

CROWBAR CIRCUIT FOR VOLTAGE CUT OFF WITH SERIES AND SHUNT SWITCHABLE MEANS

METHOD AND APPARATUS FOR DETECTING FAULTS IN AN ELECTRIC POWER DISTRIBUTION SYSTEM

Open conductors (18) in an electric power distribution system (10) are detected by sensing the abrupt change in balance of transformer magnetizing current among phases, particularly the third harmonic of the power system frequency. The current is sensed in each phase (34, 36, 38) and the absolute magnitude of the third harmonic current is compared (46) among the phases. When imbalance exceeds a predetermined value, a signal (54) is produced.

Circuit interrupter providing protection and waveform capture for harmonic analysis

A circuit breaker (1) with a digital trip unit (15) has a protection mode (89) and a waveform capture mode (87) of operation. In the protection mode (89), an equivalent sampling technique based upon pairs of samples spaced 90 electrical degrees apart with a pattern of delays between pairs is used to digitize the waveforms in the protected electrical system (3). Synchronous sampling is used in the waveform capture mode (87). The value of each sample is monitored (77, 79) in the waveform capture mode (87) and a transfer is made back to the protection mode (89) if a threshold value indicating an overcurrent condition is exceeded. The percentage total harmonic distortion, and per harmonic distortion for harmonics, up to and including the 27th are sequentially presented on a display (21) on the front panel of the circuit breaker (1) and can be transmitted along with the raw waveform data to a remote processor. ...

METHOD FOR DETECTING LEAKAGE OR FAULT CURRENTS IN AN ELECTRICAL INSTALLATION USING A PROTECTIVE DEVICE PROVIDING AT LEAST DIFFERENTIAL PROTECTION AND SUCH A DEVICE SUITABLE FOR IMPLEMENTING THE METHOD

DISTRIBUTION LINE FAULT DETECTOR AND THRESHOLD DETECTING METHOD

PURPOSE: To detect a threshold accurately on any input waveform by memorizing a peak value to a digital and hold circuit (P&H circuit) every each frequency range. CONSTITUTION: A memory content of a P&H circuit 7 always memorizes the maximum value until a CPU 8 sends out a reset signal. For that reason, the CPU does not be required to take a synchronism with zero point of an input waveform, and the memory content of the P&H circuit 7 can be read out with an optional time and an optional period. Accordingly, the input waveform can be read out non-synchronously, so that a waiting time for the synchronism is not necessary to provide, and a high speed analysis of the input waveform can be performed. Unlike a CR integrating circuit, a threshold detection on any input waveform such as a non-synchronous pulse waveform and the like can be performed accurately. COPYRIGHT: (C)1990,JPO&Japio ...

Anzeigevorrichtung zum selektiven Erkennen einer mit Erdschluss behafteten Zweigleitung eines Hochspannungsnetzes

Method of detecting harmonic distortion

... 1,096,742. Detecting harmonic distortion. POLITECHNIKA SZCZECINSKA. Feb. 3, 1965 [Feb. 3, 1964], No. 4750/65. Heading G1U. Harmonic distortion in a supply is determined by connecting an ammeter in series with a resistive load across the supply, replacing the resistive load by a capacitive one and comparing the two meter readings. The meter is calibrated in terms of current and voltage overload coefficient and the capacitor and resistor preferably have the same impedance at the fundamental frequency.

PROCEDURE AND ARRANGEMENT FOR ERROR RECOGNITION IN STATIC INVERTER PLANTS.

MIT WECHSELSTROM GESPEISTE SCHUTZSCHALTUNG, INSBESONDERS ZUR ERFASSUNG VON ERDSCHLUESSEN IN KABELNETZEN

INVERTER PRICE INCREASE PROCEDURE AND MECHANISM.

WITH ALTERNATING CURRENT FED PROTECTIVE CIRCUIT, IN PARTICULAR FOR THE COLLECTION OF GROUND FAULTS IN CABLE SYSTEMS

A system for monitoring and/or determining conditions at a first side of a transformer

Power grid protection via transformer neutral blocking systems and triggered phase disconnection

A protection circuit is disclosed. The protection circuit includes a direct current (DC) blocking component electrically connected between a neutral of the transformer and a ground, and an overvoltage protection device electrically connected in parallel with the DC blocking component. The overvoltage protection device is constructed to repeatably and reliably provide overvoltage protection in response to a voltage at the transformer neutral above a threshold. The DC blocking component has an impedance below a predetermined value, thereby effectively grounding the neutral of the transformer. The DC blocking component is persistently maintained in connection to the transformer neutral.

Data collection and processing for digital AC power system monitor/analyzer

DETECTING FAULTS IN POWER LINES

A system for detecting a fault in a power line (1) includes, in the power li ne (1), a first circuit (4) capable of attenuating sig- nals within a first frequency band, which is centered on a first frequency, substantially more than it attenuates signals outside the first frequency band, and, a second circuit (5) connected to the power line (1) on one side of the first circuit (4), the second circuit (5) being capable of extracting signals within a second frequency band that includes the first frequency. The relative levels of two signals extracted by the second circuit (5), are detected and signalled, the two signals being at respective frequencies which the first circuit is capable of attenuating by different relative amounts. ...

CONVERTER ARRANGEMENT AND ISOLATION METHOD THEREOF TO PROTECT FROM HARMONIC DISTORTIONS

The invention provides a converter arrangement that couples an AC power system with a DC power system. The converter arrangement includes a converter, a filter and a control unit. The converter is capable of operating as an inverter and a rectifier based on a mode of operation. The filter comprises a line side reactor, a converter side reactor and a capacitor. The control unit controls operation of the converter. Voltage across the line side reactor is monitored to detect harmonic content therein. The measured voltage is compared with one or more preset threshold values to detect a condition where the harmonic content is higher than at least one of the one or more preset threshold values. An open signal for a relay is generated to isolate the converter arrangement when the measured voltage is higher than the at least one preset threshold value.

OVERCURRENT TRIP DEVICE COMPRISING THE DETECTION OF THE WAVEFORM OF A CURRENT TO BE MONITORED

The invention relates to a circuit breaker (1) comprising an overcurrent trip device (4) with a protective module (6), whose long time delay is influenced by the proportion of harmonic waves in the current to be monitored. To control the dependency of the trip delay on the harmonic wave content, the invention is provided with an adjustment device (9), by means of which a user determines the parameters (A) and (B). Parameter (A) is a limiting value for the harmonic wave content of the current. If said limiting value is exceeded, the trip delay is reduced. The degree of dependency of the trip delay on the harmonic wave content is selected by the additional parameter (B).

Apparatus and method to detect a series arc fault of an electrical circuit

HARMONIC RELAY

PROBLEM TO BE SOLVED: To grasp the maximum distortion rate and maximum effective value of basic wave and each harmonic voltage and current in the past by comparing the basic wave current and each harmonic current with the allowable limit of harmonic current of a capacitor facility including a series reactor and making a decision whether an alarm is outputted or not while taking them totally into account. SOLUTION: A harmonic relay 10 comprises a switch 4c, a series reactor 6, a capacitor 7 and other circuits as a capacitor circuit and has a function for normally measuring the harmonic voltage distortion rate and current value and storing the maximum value along with the date and time thereof, and a function for storing the date and time when the harmonic relay 10 delivers an alarm and when it is reset. A basic current and each harmonic current are compared with the allowable limit of harmonic current of a capacitor facility while taking them totally into account and a decision is made whether ...

Verfahren zur Erdschlussueberwachung eines kompensierten Netzes

Schutzschaltung und Verfahren für ein Unterdrückungssystem gegen elektromagnetische Störungen

Verfahren und Vorrichtung zum kontinuierlichen Behandeln von bahnigen Guetern

Relais mit einer von der Kurvenform der zu ueberwachenden elektrischen Groesse abhaengigen Ansprechempfindlichkeit

Procedure and measuring instrument for determining higher the harmonious tension or the river in electrical high voltage systems

PROCEDURE FOR THE COLLECTION OF GROUND FAULTS

COMPENSATION OF SIMPLE FIBER-OPTIC FARADAY EFFECT SENSORS

ELECTRICAL SHORT-CIRCUIT MONITORING ARRANGEMENT

CONTINUOUS UNINTERRUPTABLE AC GROUNDING SYSTEM FOR POWER SYSTEM PROTECTION

A continuous grounding system for use in an alternating current system including a transformer is disclosed. The system includes a switch assembly connected between a transformer neutral of a transformer and a ground, the switch assembly having an open position and a closed position, the open position disrupting the path through the switch assembly between the electrical connection and the transformer neutral, and the closed position establishing a path connecting the electrical connection to the transformer neutral through the switch assembly, wherein in normal operation of the alternating current electrical device the switch assembly remains in a closed position. The system also includes a DC blocking component positioned in parallel with the switch assembly and connected between the transformer neutral and the ground. The system further includes a control circuit configured to control the switch assembly, the control circuit including a sensor configured to actuate the switch assembly ...

NEGATIVE-SEQUENCE TIME-OVERCURRENT RELAY

Disclosed is a negative-sequence time-overcurrent relay for use in a polyphase synchronous rotary electric machine having a main-circuit breaker and an exciting circuit. The negative-sequence time-overcurrent relay comprises first extracting unit for extracting a fundamental-wave component and a harmonic component from a predetermined electric parameter for each phase given to the polyphase synchronous rotary electric machine, second extracting unit for extracting a fundamental-wave negative sequence current for each phase from a fundamental wave for each phase extracted from the first extracting unit, first calculating unit for squaring the fundamental-wave negative sequence current for each phase, extracted by the second extracting unit, for each phase, second calculating unit for squaring the harmonic component for each phase, extracted by the first extracting unit, for each phase, first adding unit for adding phase-by-phase operational outputs from the second calculating unit, multiplying ...

CIRCUIT ANALYZING SYSTEM

1. A circuit analyzing system includes a current transformer for extracting current from a phase or neutral conductor of a three phase line, a filter connected to the output of the current transformer and functioning to substantially trap current at the fundamental frequency while substantially passing currents at various harmonic frequencies thereof, and signal processing circuitry connected to the output of the filter to perform various functions with the harmonic frequency current input thereto. Among these functions, as shown in various preferred embodiments, are measurement of the harmonic signal in RMS and conveyance of the output to a display instrument for a user or utility's convenience in monitoring harmonic frequency circuits, which have become more common with the advent of electronic equipment having internal power supplies such as personal computers, work stations, printers, and the like. Other functions include a user or utility's connecting a demand circuit mechanism to the measured currents (preferably RMS/harmonic frequency currents), and/or using comparator circuitry to sense the measured harmonic frequency currents and, if they exceed a desired level set by the user or utility, to output a signal to a tripping device such as a power contactor or relay which will in turn institute load shedding.

DATA COLLECTION AND PROCESSING FOR DIGITAL AC POWER SYSTEM MONITOR/ANALYZER

A digital monitor/analyzer for an ac electrical power system samples the current and voltage waveforms at a slow rate for performing metering functions, and at a high rate for analyzing harmonic content. Sampling is performed in sampling frames comprising a plurality of repetitions of sampling for a selected number of cycles followed by a delay of a fraction of a cycle. This effects equivalent sampling at a higher rate for slow speed sampling over a frame. High speed sampling is performed over only onerepetition of the selected number of cycles in a frame so that it can be carried out sychronously as required for the harmonic analysis. The high speed sampling rate is an integer multiple of the slow speed rate so that slow speed data can be extracted from the high speed samples for continuous metering. Fourier analysis of the harmonic content of the waveforms is performed on the odd interrupts while all of the other tasks are apportioned out over the even interrupts of a sampling frame.

EARTH PROTECTION DEVICE SENSITIVE TO ARC CURRENTS, TRIP DEVICE AND CIRCUIT BREAKER COMPRISING SUCH A DEVICE

The earth protection device comprises an input to receive a first signal (IG1) representative of an earth fault current, first signal processing means (5), and means (6) for processing protection functions connected to the first signal processing means. The device comprises second signal processing means (12) to process the first signal (IG1) connected between said input and the first signal processing means (5), said second signal processing means supplying to the first signal processing means a second signal (IG2) representative of an earth fault current having on decrease a gradient lower than a preset gradient limiting value (L). The device can be integrated in electronic trip devices or circuit breakers.

Improvements with the static inverters

Apparatus for detecting arcing faults on low-voltage spot networks

A protective relay for detecting power arcing faults on a three-phase electrical power spot network. A phase-to-phase power arc on a spot network produces harmonics on the phase-to-phase voltages, and the phase currents; a phase-to-ground arc produces harmonics on the phase-to-neutral voltages. The protective relay of the present invention monitors one or more of the three phase-to-phase voltages, the three phase-to-neutral voltages, or the three phase currents and indicates a fault based on the harmonic content of those signals.

SYSTEM FOR DISTRIBUTING ELECTRICAL ENERGY

Method and system for power quality protection

A method for power quality protection includes measurement of electrical and nonelectrical parameters, calculation of additional electrical and nonelectrical parameters, comparison of the value of the calculated parameters with maximum allowed values from a power quality perspective, activation of protection mechanisms for transitioning to a safe mode or for isolation from the bus. The systems and methods may prevent equipment failures when out of the spec power quality is present in the distribution bus and may protect the distribution bus from imposing power quality problems due to equipment failures. Because most of the sensors in the systems of the present invention are already used for other control and protection purposes, there may be no reliability degradation. Most of the calculations and the control logic may be performed digitally for improved reliability and flexibility to modify algorithms.

CORONA DISCHARGE DETECTOR IN POWER INSTALLATION

PROBLEM TO BE SOLVED: To make it possible to analyze corona discharge without a stoppage in power, by detecting a position of noise generation and its conditions in corona discharge on the basis of a containing rate of a frequency factor that is twice the power supply frequency in strong and weak factors. SOLUTION: A direction of sound in discharge is discriminated by an acoustic direction detecting unit 10. An acoustic detecting unit 1 is turned to the direction of sound to receive the sound in discharge. The sound is amplified in a first stage amplifier 2, passed through a high-frequency passing filter 3 to remove noises, and amplified again in a second stage amplifier 4. After the sound signal without noises is rectified by a rectifier 5, the sound signal is subjected to envelope detection, and an analog signal as strong and weak factors of the sound is converted into a digital signal by an A/D converter 7. The digital signal is fed to a CPU 8, and fast Fourier transform is carried out ...

СПОСОБ ИМИТАЦИИ ИСКРЕНИЯ В ЭЛЕКТРИЧЕСКОЙ ЦЕПИ И УСТРОЙСТВО ДЛЯ ЕГО ОСУЩЕСТВЛЕНИЯ

Изобретение относится к области пожарной безопасности и электроэнергетике, а именно к способам и устройствам тестирования устройств предупреждения пожара (взрыва) от искрения (дефектная дуга), возникающего в месте нарушения целостности электрической цепи. Технический результат - повышение достоверности оценки уровня опасности контролируемого объекта устройством предупреждения пожара (взрыва, проявления скрытого отказа) от искрения в электрической цепи и (или) от других неисправностей за счет повышения достоверности результата тестирования устройства. Способ базируется на имитации параметров сопротивления искрового промежутка путем имитации высокочастотных составляющих тока искрения, характеризующих образующие и затухающие стадии цикла "возникновение-гашение искры" на границе области нулевых значений тока искрения, и ширины искрового промежутка. Уровень пожаро- взрывобезопасности и безотказности систем оценивается по имитируемому интегральному показателю в зависимости от суммы имитируемых ...

Устройство для защиты электродвигателя от перегрузки

Изобретение относится к-электротехни- ке, а именно к защите электродвигателей от Т перегрузки как при синусоидальном, так и несинусоидальном напряжении питания. Целью изобретения является повышение надежности защиты электродвигателяЧза счет учета влияния дополнительных потерь активной мощности, обусловленных несинусоидальностью напряжения питающей сети. Устройство для защиты электродвигателя от перегрузки состоит из трансформатора датчика тока 1, фильтров основной 2 и высших 3,4 гармоник, квадратирующих блоков 5-7, умножителей 8, 9, суммирующего блока 10, блока 11 сравнения,блока 12 выдержки времени, исполнительного органа 13. Оценка перегрузки электродвигателя осуществляется по суммарным потерям активной мощности от высших гармоник, протекающих в обмотке электродвигателя 2 ил. (Л ...

Устройство защиты турбогенераторов от повышения частоты

Устройство для защиты группы электродвигателей от перегрузки по токам высших гармоник

Изобретение относится к электротехнике, предназначено для защиты электродвигателей от перегрузки, особенно асинхронных электродвигателей многодвигательного электропривода. Целью изобретения является повышение надежности защиты от перегрузки отдельных электродвигателей многодвигательного электропривода. Цель достигается введением в устройство защиты активных полосовых фильтров 8-11, настроенных на частоты высших гармоник, соответствующие заданным уровням перегрузки электродвигателя. 2 з.п. ф-лы, 1 ил.

Fehlerstromschutzsystem.

Monitoring system for protecting a load in a polyphase A C supply

A phase unbalance detecting system that includes also low-voltage detection and wrong-phase-sequence detection. The system can be packaged in a small volume because it is a solid state type that uses a minimum of electronics and does not require transformers for obtaining signals from the several phases of the plural-phase power line but only one transformer for the D.C. power supply circuit for the detection system. The system incorporates means for allowing it to be used at 50 or 60 Hz without separate adjustment, for making it insensitive to noise and harmonics of the power line, and for providing a good estimate of the negative sequence voltage caused by a phase unbalance. It provides external terminals whereby it can be adapted for use at different power line voltages.

Method for detecting earth faults (ground faults)

The proposed invention makes it possible to selectively detect earth faults on outgoers (outgoing connections) in radial power distribution networks, and can be incorporated both in existing installations and in installations that are to be newly constructed. The method according to the invention consists in the fact that the respective amplitude of the harmonics, preferably of the fifth harmonic, of the total current of each outgoer is continually measured, in that the outgoer with the largest harmonic amplitude referring to the other outgoers is determined and indicated as manifesting an earth fault, and that, if appropriate, further outgoers whose harmonic amplitudes are within a predetermined range below the currently largest harmonic amplitude are also indicated as manifesting an earth fault. ...

Low cost apparatus for detecting arcing faults and circuit breaker incorporating same

Protection circuit and method for an electromagnetic interference suppression system

The present invention relates to protection circuit and method for the EMI/RFI suppression system (2) of such a five-conductor electrical system in which the neutral conductor (N) is provided with a bandstoptype filter circuit (2) for the suppression of a harmonic interference current component. According to the invention, on the neutral conductor (N) is placed a current transformer (CT) having over its secondary a resistive branch (R1), and in parallel therewith, a filter branch (5) comprising a bandpass filter (LC) tuned to the fundamental frequency of said neutral-conductor filter circuit (2) and said filter branch (5) having in series with said bandpass filter branch (LC) a switch element (4) suitable for short-circuiting said neutral-conductor filter circuit (2) when current in said filter branch (5) exceeds a preset upper limit level. <IMAGE>

COMPENSATION OF SIMPLE FIBEROPTIC FARADAY EFFECT SENSORS

SYSTEM FOR POWER TRANSFORMER DIFFERENTIAL PROTECTION

Current transformer (CT) secondary currents for the windings of a power transformer are used to produce a differential current. An operating current value is obtained from the differential current value. A restraining current value is obtained from processed winding current values. Second and fourth harmonic values of the differential current are obtained and are summed with a restraining current quantity which is a result of the restraining current multiplied by a slope characteristic factor. If the operating current value is greater than the sum of the restraining current quantity and the second and fourth harmonic values, an output signal is produced which may be used as a trip signal unless it is blocked by selected blocking signals generated by another portion of the system.

CIRCUIT INTERRUPTER PROVIDING PROTECTION AND WAVEFORM CAPTURE FOR HARMONIC ANALYSIS

A circuit breaker with a digital trip unit has a protection mode and a waveform capture mode of operation. In the protection mode, an equivalent sampling technique based upon pairs of samples spaced 90 electrical degrees apart with a pattern of delays between pairs is used to digitize the waveforms in the protected electrical system. Synchronous sampling is used in the waveform capture mode. The value of each sample is monitored in the waveform capture mode and a transfer is made back to the protection mode if a threshold value indicating an overcurrent condition is exceeded. The percentage age total harmonic distortion, and per harmonic distortion for harmonics, up to and including the 27th are sequentially presented on a display on the front panel of the circuit breaker and can be transmitted along with the raw waveform data to a remote processor.

PROTECTION CIRCUIT AND METHOD FOR AN ELECTROMAGNETIC INTERFERENCE SUPPRESSION SYSTEM

The present invention relates to protection circuit and method for the EMI/RFI suppression system (2) of such a five-conductor electrical system in which the neutral conductor (N) is provided with a bandstop-type filter circuit (2) for the suppression of a harmonic interference current component. According to the invention, on the neutral conductor (N) is placed a current transformer (CT) having over its secondary a resistive branch (R1), and in parallel therewith, a filter branch (5) comprising a bandpass filter (LC) tuned to the fundamental frequency of said neutral-conductor filter circuit (2) and said filter branch (5) having in series with said bandpass filter branch (LC) a switch element (4) suitable for short-circuiting said neutral-conductor filter circuit (2) when current in said filter branch (5) exceeds a preset upper limit level.

EARTH PROTECTION DEVICE SENSITIVE TO ARC CURRENTS, TRIP DEVICE AND CIRCUIT BREAKER COMPRISING SUCH A DEVICE

The earth protection device comprises an input to receive a first signal (IG 1) representative of an earth fault current, first signal processing means (5), and means (6) for processing protection functions connected to the first signal processing means. The device comprises second signal processing means (12) to process the first signal (IG1) connected between said input and the first signal processing means (5), said second signal processing means supplying to the first signal processing means a second signal (IG2) representative of an earth fault current having on decrease a gradient lower than a preset gradient limiting value (L). The device can be integrated in electronic trip devices or circuit breakers.

Fault detector device electric

Process and device for the detection of the higher harmonics of the tension and the current in the electric systems and for the protection of electrical equipment against the harmful effects of these higher harmonics

SYSTEM AND METHOD FOR MONITORING AN OPERATING CONDITION OF AN ELECTRICAL DEVICE WHEN IN OPERATION

Disclosed is an electrical condition monitoring system that is connectable to an electrical device for monitoring the electrical device when in operation, wherein: (i) the electrical condition monitoring system includes (a) a sensing arrangement for temporally sensing an electrical supply to and/or from the electrical device and generating corresponding sensed data; (b) a data processing arrangement that is configured to process the sensed data to generate a corresponding temporally-changing Fourier spectrum including signal harmonic components and to process temporal changes in magnitudes and frequencies of the signal harmonic components to generate analysis data; and (ii) a user interface is configured for user entry of input for analyzing the analysis data and the data processing arrangement is configured to analyze the analysis data based on the input to obtain information indicative of operating condition of the electrical device; characterized in that: (iii) the data processing arrangement ...

DETECTING FAULTS IN POWER LINES

A system for detecting a fault in a power line (1) includes, in the power line (1), a first circuit (4) capable of attenuating signals within a first frequency band, which is centered on a first frequency, substantially more than it attenuates signals outside the first frequency band, and, a second circuit (5) connected to the power line (1) on one side of the first circuit (4), the second circuit (5) being capable of extracting signals within a second frequency band that includes the first frequency. The relative levels of two signals extracted by the second circuit (5), are detected and signalled, the two signals being at respective frequencies which the first circuit is capable of attenuating by different relative amounts.

MEASURING INSTRUMENT FOR DISTORTION FACTOR

PURPOSE: To simplify tuning operation and to measure even a low level distortion precisely by connecting filters in cascade connection and by eliminating the tuning operation for one filter. CONSTITUTION: An input signal is inputted to a variable attenuator 13 and an amplifier 14, through a buffer amplifier 12 wherein a fundamental wave is attenuated. The output of the amplifier 14 is inputted to a level meter 18 through a fundamental wave removing circuit 15 and directly or via a variable attenuator 16 and an amplifier 17. In the circuit 15, the input signal is converted in an A/D converter 20, aided by the output of a multiplying circuit 21 to which the output from the variable attenuator 11 is supplied, and the result is stored in a memory circuit 22. The stored value in the memory circuit is read out by the output of a clock pulse generator 23, and inputted to a filter 25 via a D/A converter 24. Thus, the fundamental wave is attenuated. Then, the distortion factor can be obtained from ...

PROTECTING RELAY

DEMAND MONITOR CONTROLLER PROVIDED WITH HIGHER HARMONICS MEASURING FUNCTION

PROBLEM TO BE SOLVED: To provide a demand monitor controller provided with a higher harnomics measuring function which can perform the management and monitor control of the use power of a customer with simple constitution. SOLUTION: A higher harmonics measuring part 1B is annexed to the demand monitor controller 1A which manages the use power of a customer. The higher harmonics measuring part 1B is provided with an alarm contact 1B1 for higher harmonics and a control output contact 1B2. The alarm contact 1B1 and the control output contact 1B2 are operated when higher harmonics occurrence rate gets over a certain value so as to prevent the occurrence of the fault by higher harmonics of the electronic equipment or the power capacitor of a power distribution system. COPYRIGHT: (C)1998,JPO ...

Gegenkomponentenüberstromrelais

An Electrical Fault Detector

1,169,706. Protective arrangements. ENGLISH ELECTRIC CO. Ltd. 26 Sept., 1967 [29 Sept., 1966], No. 43495/66. Heading H2K. [Also in Division G1] A circuit for detecting such faults as distort the waveform of an electrical supply, comprises filters 5, 6 connected to receive a supply signal and to transmit the fundamental and harmonic components respectively to a comparator 7 which provides an output dependent on the relative values of the components. As shown, the comparator 7 comprises two transistor amplifiers T1, T2 arranged in a balanced configuration. The fundamental component is applied through a current transformer CT1 and a rectifier BR1 to the base of the transistor T1 and the harmonic components are applied through a current transformer CT2 and a rectifier BR2 to the base of the transistor T2. The voltage produced across a resistor R3 is indicative of the ratio between the fundamental and harmonic components and is applied to a level detector (not shown). An alarm or control circuit is connected to the level detector. If the supply signal is a current signal it may be applied through a transactor 4 and a thyrector 14, but if this signal is a voltage signal it is derived from a voltage transformer. A time delay circuit may be connected between the level detector and the circuit 12. The circuit may be used to protect against earth faults due to fallen conductors, arcing faults on insulation and earth faults on domestic appliances. It may be used in testing electric cables and capacitors.

A method of communicating between a master unit and monitoring units monitoring an electrical power supply grid

System and method for high resistance ground fault detection and protection in power distribution systems

A system and method for detecting high resistance ground faults in a power distribution system is disclosed. A fault detection and protection system is provided that includes a plurality of current sensors to measure current on the three phase output of the converter-inverter arrangement of the power distribution system and a controller configured to measure the three phase current on the three phase output, extract a fundamental current component for each phase of the three phase output, extract a third harmonic component for each phase of the three phase output, compare the fundamental current component and the third harmonic component extracted from each phase to a first threshold and a second threshold, respectively, and detect a ground fault on a phase of the three phase output based on the comparisons of the fundamental current component and the third harmonic component to the first and second thresholds.

Low cost active power line conditioner

INVERTER CONTROL METHOD AND APPARATUS

INVERTER CONTROL METHOD AND APPARATUS A control for an inverter operable for converting direct voltage and current to alternating voltage and current. The inverter includes a plurality of electrical valves each operable to conduct current in a single direction upon the application of a positive voltage in the forward direction and the receipt of a trigger pulse. The control provides successive trigger pulses for commutating the current between successive valves at predetermined electrical firing angles and includes a voltage-time area calculating circuit for calculating the maximum permissible firing angle which will permit successful commutation. An inverter commutation failure prevention circuit is coupled to the alternating current network for detecting abnormal voltage conditions and for producing a control signal functionally related to any deviation in the alternating voltage from the expected voltage condition. The control is responsive to the control signal for reducing the electrical ...

PROTECTION CIRCUIT AND METHOD FOR AN ELECTROMAGNETIC INTERFERENCE SUPPRESSION SYSTEM

The present invention relates to protection circuit and method for the EMI/RFI suppression system (2) of such a five-conductor electrical system in which the neutral conductor (N) is provided with a bandstop-type filter circuit (2) for the suppression of a harmonic interference current component. According to the invention, on the neutral conductor (N) is placed a current transformer (CT) having over its secondary a resistive branch (R1), and in parallel therewith, a filter branch (5) comprising a bandpass filter (LC) tuned to the fundamental frequency of said neutral-conductor filter circuit (2) and said filter branch (5) having in series with said bandpass filter branch (LC) a switch element (4) suitable for short-circuiting said neutral-conductor filter circuit (2) when current in said filter branch (5) exceeds a preset upper limit level.

Novel passive power harmonic protector

Harmonic protected location

Method for detecting faults of electric network and electric device as well as fire disaster warning facilities

The inventive method for preventing fire in electric circuits and arrangements consists in measuring electric current of a controllable section, in separating a high frequency component therefrom, in amplifying and rectifying a first harmonic signal, in determining a spark current value, in forming the first harmonic signal from a measured current signal range, in measuring short-circuit, and/or overload and/or leak, and/or in measuring the electric circuit voltage, in forming a warning and/or switching off signal of the controllable section. The signal amplitudes and/or other parameters characterizing a spark striking-suppression cycle are measured for determining a spark current. The inventive fire preventing device comprises a unit for forming a signal of first and higher harmonics, a unit for determining a spark current quantity, a unit for measuring short-circuit and/or overload and/or leak currents, and/or electric circuit voltage measuring currents, units for forming a warning and ...

Detector receiving set of electric arcs of defect

SYSTEM AND METHOD FOR USE WITH MICROGRIDS HAVING INVERTER-BASED DISTRIBUTED GENERATORS

A system and method for controlling microgrids composed of inverter-based distributed generation (IBDG) units. This includes a method using multiple IBDGs to inject impedance-modulated harmonic currents during fault conditions, with each IBDG injecting a unique, differentiable harmonic (i.e., non-fundamental) order from neighboring IBDGs. The method also involves using an inverse time-harmonic-current characteristic to detect faults by locally measuring the harmonic currents injected by IBDGs. A harmonic directional overcurrent relay is also used for fault detection. 1. A system for use with a microgrid having a plurality of inverter-based distributed generators , said system comprising:an injection unit embodied in a computer readable medium for providing each one of a plurality of inverters within said microgrid with a corresponding one of a plurality of differentiable harmonic currents upon a fault condition within said microgrid; anda measuring unit embodied in said computer readable medium for providing detection of said harmonic currents;wherein isolation of a faulted section of said microgrid is enabled based upon said harmonic currents detected.2. The system as claimed in claim 1 , wherein a directional unit embodied in said computer readable medium provides said isolation of said faulted section.3. The system as claimed in claim 2 , wherein said directional unit uses a ratio of said harmonic currents measured on both sides of a microprocessor-based relay within each inverter-based distributed generator to locate said faulted section.4. The system as claimed in claim 3 , wherein said harmonic currents are measured local to said microgrid.5. The system as claimed in claim 4 , wherein said plurality of differentiable harmonic currents vary by harmonic orders relative to adjacent ones of said plurality of inverter-based distributed generators along a common feeder.6. The system as claimed in claim 5 , wherein a backup protection unit embodied in said computer ...

FAULT DETECTION AND CIRCUIT INTERRUPTER DEVICES AND SYSTEMS

Arc fault current interrupter electrical devices and systems. An example is an electrical device comprising: a contact configured for electrical connection to a power line; at least one sensor to detect at least voltage signals indicative of the power line; and a processor configured to determine from the detected voltage signals that a series arc fault has occurred. 1. An electrical device comprising:a contact configured for electrical connection to a power line;at least one sensor to detect at least voltage signals indicative of the power line; anda processor configured to determine from the detected voltage signals that a series arc fault has occurred.2. An electrical device as recited in claim 1 , further comprising a solid state switch for in-series electrical connection with the power line claim 1 , the processor further configured to claim 1 , in response to said determining that the series arc fault has occurred on the power line claim 1 , deactivating the solid state switch.3. An electrical device as recited in claim 2 , wherein the solid state switch is a TRIAC.4. An electrical device as recited in claim 1 , wherein the contact is configured for electrical connection to a downstream power line or an electrical outlet.5. An electrical device as recited in claim 4 , wherein said determining comprises the processor determining that the series arc fault has occurred on the downstream power line or a load plugged into the electrical outlet.6. An electrical device as recited in claim 1 , wherein said determining comprises the processor determining that the series arc fault has occurred on the power line.7. An electrical device as recited in claim 1 , further comprising a communication subsystem claim 1 , wherein the processor is configured to claim 1 , in response to said determining that the series arc fault has occurred claim 1 , sending a communication that the series arc fault has occurred.8. An electrical device as recited in claim 1 , wherein the at least ...

ARC FAULT DETECTION DEVICE

An arc fault detection device includes: a first electric line; at least one sensor for monitoring an electric current or voltage spectrum in the first electric line and outputting an analogue HF measurement signal; and an input section connected to the at least one sensor, the input section including: an input bandpass filter connected to the at least one sensor so as to filter the analogue HF measurement signal, a passband of the input bandpass filter having a predeterminable arc-frequency range so as to detect arcing effects; and a sampling mixer connected to the input bandpass filter, the sampling mixer having a sampling frequency lower than twice an upper threshold frequency of the arc-frequency range. 1. An arc fault detection device , comprising:a first electric line;at least one sensor configured to monitor an electric current or voltage spectrum in the first electric line and to output an analogue HF measurement signal; and an input bandpass filter connected to the at least one sensor so as to filter the analogue HF measurement signal, a passband of the input bandpass filter comprising a predeterminable arc-frequency range so as to detect arcing effects; and', 'a sampling mixer connected to the input bandpass filter, the sampling mixer having a sampling frequency lower than twice an upper threshold frequency of the arc-frequency range., 'an input section connected to the at least one sensor, the input section comprising2. The arc fault detection device of claim 1 , wherein an upper cutoff frequency of the input bandpass filter is higher than an upper threshold frequency of the arc-frequency range claim 1 , andwherein the sampling frequency of the sampling mixer is lower than twice the upper cutoff frequency of the bandbass filter.3. The arc fault detection device of claim 1 , wherein the sampling mixer comprises a local oscillator configured to generate a mixing signal with the sampling frequency claim 1 , andwherein the mixing signal generated by the local ...

ARC FAULT DETECTOR

An arc fault detector includes: a first electric line; a sensor for monitoring an electric current or voltage spectrum in the first electric line and outputting a broadband measurement signal as a monitored signal; a minimum detection unit for detecting a minimum signal value of the monitored signal over a broadband measurement range as a detected minimum signal value; and a controller unit connected to an output of the minimum detection unit, the controller unit comparing the detected minimum signal value with a predefined arc pattern, and outputting a trigger signal on a trigger output if the detected minimum signal value matches the arc pattern. 1. An arc fault detector , comprising:a first electric line;a sensor configured to monitor an electric current or voltage spectrum in the first electric line and to output a broadband measurement signal as a monitored signal;a minimum detection unit configured to detect a minimum signal value of the monitored signal over a broadband measurement range as a detected minimum signal value; anda controller unit connected to an output of the minimum detection unit, the controller unit being configured to compare the detected minimum signal value with a predefined arc pattern, and to output a trigger signal on a trigger output based on the detected minimum signal value matching the arc pattern.2. The arc fault detector of claim 1 , wherein the sensor is configured to output the broadband measurement signal with a bandwidth from at least 10 Hz to 10 MHz.3. The arc fault detector of claim 1 , wherein the minimum detection unit is configured to detect the minimum signal value without determination of a frequency of the minimum signal value.4. The arc fault detector of claim 1 , wherein the minimum detection unit comprises a sweep unit claim 1 , which sweep unit is configured to sweep a narrow bandwidth detection window over the broadband measurement range.5. The arc fault detector of claim 4 , wherein the narrow bandwidth detection ...

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.

Power grid protection via transformer neutral blocking systems and triggered phase disconnection

A protection circuit is disclosed. The protection circuit includes a direct current (DC) blocking component electrically connected between a neutral of the transformer and a ground, and an overvoltage protection device electrically connected in parallel with the DC blocking component. The overvoltage protection device is constructed to repeatably and reliably provide overvoltage protection in response to a voltage at the transformer neutral above a threshold. The DC blocking component has an impedance below a predetermined value, thereby effectively grounding the neutral of the transformer. The DC blocking component is persistently maintained in connection to the transformer neutral.

ARC FAULT DETECTOR

An arc fault detector includes slew-rate-detection, envelope-step-detection, and first and second controller units. The slew-rate-detection-unit determines a slew rate of the electric current in the first electric line, comparing the slew rate with a threshold, and outputting a slew-rate-detection-signal on a second output when the determined slew rate is higher than the threshold. The envelope-step-detection-unit determines change of an envelope-value of a predefined frequency band of the broadband measurement signal within a predefined timespan, and outputs an envelope-step-detection-signal on a third output when the change is higher than a threshold change. The first controller-unit, connected to second and third outputs, outputs a second arc-detection-signal on a fourth output when it receives slew-rate and frequency-detection signals within a first detection-window. The second controller-unit, connected to first and fourth outputs, outputs a trigger signal when it receives first and second arc-detection-signals for at least a defined total time within a second detection-window. 1. An arc fault detector , with the arc fault detector comprising:a first electric line;a first sensor configured to: monitor an electric current or voltage spectrum in the first electric line and output a broadband measurement signal,a signal-pattern analyser configured to: compare the broadband measurement signal with at least a first predefined arc pattern, and output a first arc-detection-signal on a first output in a case where the broadband measurement signal matches the arc pattern;a slew-rate-detector configured to: determine a slew rate of the electric current in the first electric line, compare the determined slew rate with a threshold slew rate, and output a slew-rate-detection-signal on a second output in a case where the determined slew rate is higher than the threshold slew rate;an envelope-step-detector configured to determine a change of an envelope-value of at least a ...

Method of identifying when to initiate control sequences

A method and system are provided for transferring a load between a primary power source and a secondary power source. In accordance with the disclosure, a controller senses, via a sensor, an electrical signal providing power from the primary power source to the load. The controller also detects a non-conforming power event by determining that a parameter of the electrical signal is either more or less than a first threshold value. Responsive to the detection of the non-conforming power event, the controller determines a quantity of non-conforming power events that occur during a first time interval. The controller further can compares the determined quantity of non-conforming power events to a second threshold value. Responsive to the determined quantity of non-conforming power events being either greater or lesser than the second threshold value, the controller initiates a control signal, such as a control signal to initiate a load transfer.

Earth leakage circuit breaker

An earth leakage circuit breaker includes a current sensing unit configured to sense current in a circuit, a converter configured to detect a fundamental wave component and a specific harmonic component from the sensed current, the specific harmonic component being one of a plurality of harmonic components, and a controller. The controller is configured to compare a harmonic component ratio with a threshold component ratio, to determine whether the sensed current is abnormal current, and to control cutoff of the circuit according to the result of determination. The harmonic component ratio is a ratio of the specific harmonic component to the fundamental wave component. The converter is configured to convert the sensed current from an analog signal into digital data and to perform Fourier transform with respect to the converted digital data to detect the fundamental wave component and the specific harmonic component.

Arc fault detection system and method and circuit interrupter employing same

A DC arc fault detection module includes a current detecting section having at least one output, wherein the current detecting section is structured to determine whether at least one signal based on a current measured from a DC supply line exceeds at least one corresponding predetermined threshold level and cause the at least one output to indicate that the threshold level has been exceeded. The module also includes a processing device structured to: (i) receive the at least one output, (ii) determine whether an arc fault in the DC electrical system has occurred based on at least the at least one output, (iii) determine an estimation of background noise based on at least one signal indicative of a current on the DC supply line, and (iv) adjust the at least one corresponding predetermined threshold level based on the estimation of background noise.

Abnormality diagnosis device, abnormality diagnosis method, and abnormality diagnosis system

An abnormality diagnosis device includes: a data acquirer to acquire a current waveform and a driving frequency of an electric motor; a storage which stores a combination of a current value of the current waveform and the driving frequency at an identical time by the data acquirer; a data determiner to determine whether or not a current value of the current waveform and the driving frequency as a diagnosis target at an identical time by the data acquisition match the combination stored in the storage; an analyzer to perform frequency analysis for the current waveform determined to be matched by the data determiner, to extract sideband waves, and calculate a spectrum intensity of the sideband waves; and an abnormality diagnosis processor to make a diagnosis that abnormality has occurred, when the spectrum intensity of the sideband waves is equal to or greater than a threshold.

SYSTEM FOR DISTRIBUTING ELECTRICAL ENERGY

The present invention relates to a system for distributing electrical energy, comprising an electricity grid configured to supply electrical energy to end users, characterized in that the grid is operated on a direct voltage. 1. A device for billing energy consumption within a system for distributing electrical energy , the system comprising:an electricty grid configured to supply electrical energy to end users, characterized in that the grid is operated on a direct voltage; the device comprising:a connection for consumption of electrical energy from an electricity grid;a connection for supplying electrical energy to a consumer connection;a connection for data communication with an administrator of the electricity grid;a metering device connected to the connection for consumption and to the connection for data communication and configured to:monitor the amount of electrical energy consumed at the consumption point; andmonitor the moment the electrical energy is consumed;a data processing unit connected to the metering device and to the connection for data communication and configured todetermine, via the connection for data communication, the electric power available for consumption at the connection;determine, via the connection to the metering device, the power consumed; andmake available to an output for data output the amount of the electric power available for consumption at the connection.2. The device as claimed in claim 1 , coupled to a control member which is configured to:set a target value for the consumed electrical energy,consume the target value of electrical energy,supply electrical energy to an energy buffer coupled to the control member when the electrical energy actually consumed by users connected to the control member is less than the target value; anddraw electrical energy from the energy buffer coupled to the control member when the electrical energy actually consumed by users connected to the control member is greater than the target value.3. ...

TRANSFORMER PROTECTION CIRCUIT AND METHOD

Systems and methods for protecting an electrical component in an alternating current system that includes a transformer are disclosed. In one aspect, a circuit includes a switch assembly connected between a transformer neutral of a transformer and a ground and having an open position and a closed position. In normal operation, the switch remains in a closed position. The circuit further includes a DC blocking component positioned in parallel with the switch assembly and connected between the transformer neutral and the ground, a voltage probe connected between the transformer neutral and ground and configured to monitor an instantaneous voltage level at the transformer neutral, and a control circuit configured to control the switch assembly, the control circuit including a sensor configured to actuate the switch assembly to an open position at least upon detection of a harmonic signal in at least one phase of the transformer or a predetermined threshold of DC or quasi DC current between the transformer neutral and the ground. 1. An electrical protection circuit for use in an alternating current system including a transformer , the system comprising:(a) a switch assembly connected between a transformer neutral of a transformer and a ground, the switch assembly having an open position and a closed position, the open position disrupting the path through the switch between the electrical connection and the ground connection, and the closed position establishing a path connecting the electrical connection to the ground connection through the switch assembly, wherein in normal operation the switch remains in a closed position;(b) a DC blocking component positioned in parallel with the switch assembly and connected between the transformer neutral and the ground;(c) a voltage probe connected between the transformer neutral and ground and configured to monitor an instantaneous voltage level at the transformer neutral; and(d) a control circuit configured to control the switch ...

APPARATUS FOR MITIGATION OF ADVERSE EFFECTS OF GEOMAGNETICALLY INDUCED CURRENTS ON TRANSFORMERS

An apparatus for mitigating GIC (geomagnetically induced current) effects through a fuzzy logic controlled variable resistor. Under GIC conditions (or any unbalanced fault current condition), the GIC or unbalanced fault current flows through the neutral of a power transformer. It is detected by the fuzzy logic controller, which sends a signal to a switch to open. The resistor is in the circuit and impedes the flow of current through the neutral, thereby protecting the transformer from getting overheated. 1. A system for mitigating the effects of geomagnetically induced currents or unbalanced fault conditions in a power system , comprising:a fuzzy logic controller in electronic communication with a transformer protection circuit electrically connected to a transformer neutral, wherein variable levels of current flow through the transformer neutral; anda variable resistor in the transformer protection circuit;wherein the fuzzy logic controller is configured to accept as input a deviation in the level of current flow through the transformer neutral, and determine as output a resistance value of the variable resistor based upon said input.2. The system of claim 1 , further comprising a switch with an open position and a closed position claim 1 , wherein said current flow is directed through the variable resistor in the open position.3. The system of claim 1 , wherein the level of current flow results from geomagnetically induced currents in a power system.4. The system of claim 1 , wherein the level of current flow results from unbalanced faults in a power system.5. The system of claim 1 , wherein the resistance of the variable resistor is set at 0 Ohms if there is no current flow through the transformer neutral.6. The system of claim 1 , wherein the resistance of the variable resistor is set from about 100 Ohms to about 730 Ohms claim 1 , with higher resistance levels set for higher levels of current flow through the transformer neutral This application is a ...

High-Impedance Fault Detection Using Coordinated Devices

A conductor-mounted device (CMD) used to signal an intelligent electronic device (IED) of the existence of a fault on a portion of the electric power delivery system is described herein. The CMD may provide a heartbeat signal to the IED. The CMD may provide a fault signal to the IED. The CMD may be powered via a parasitic current draw on the conductor to which it is mounted. An IED may use a fault signal and/or LOC signal from a CMD to coordinate a high-impedance fault detection and/or downed line events. 1. A conductor mounted device , comprising:a clamp assembly to secure the mounting device to a conductor;a current transformer coupled to the conductor to produce a secondary current proportional to a primary current in the conductor;a heartbeat circuit stage to transmit a heartbeat signal indicating that the conductor mounted device is functional;a state determination circuit to determine a state of the conductor;a transmitter configured to transmit the heartbeat signal and the conductor state; anda power supply to receive at least a portion of the secondary current to charge a power store, and supply power to at least the transmitter of the conductor mounted device.2. The system of claim 1 , wherein the current transformer comprises a pole piece that extends from the conductor mounted device proximate the conductor.3. The system of claim 1 , wherein the clamp assembly comprises at least one clamping arm that pivots via a pivot member.4. The system of claim 1 , further comprising:a human machine interface (HMI) oriented toward the ground when the conductor mounted device is mounted to the conductor, the HMI comprising at least one display element.5. The system of claim 1 , wherein the transmitter comprises a wireless RF transmitter claim 1 , and wherein the conductor mounted device further comprises an antenna connected to the transmitter.6. The system of claim 1 , wherein the power store comprises one of a capacitor and a battery claim 1 , and wherein the power ...

ARC PROTECTION SYSTEM AND METHOD TO CONTROL ARC PROTECTION SYSTEM

Provided is an arc protection system in which an arc remover does not operate in a case of a phase-to-phase short circuit fault or a ground/earth fault among arc faults in a distribution panel, the arc protection system including a sensor configured to sense an arc fault of a distribution panel, an arc removing unit configured to ground a fault current, and a control unit connected to the sensor and configured to measure a short circuit current value of the distribution panel, wherein when the arc fault is sensed and the short circuit current value corresponds to a three-phase short circuit current, the control unit drives the arc removing unit, and when the short circuit current value is smaller than the three-phase short circuit current, the control unit does not drive the arc removing unit. 1. An arc protection system comprising:a sensor configured to sense an arc fault of a distribution panel;an arc removing unit configured to ground a fault current; anda control unit connected to the sensor and configured to measure a short circuit current value of the distribution panel,wherein when the arc fault is sensed and the short circuit current value corresponds to a three-phase short circuit current, the control unit drives the arc removing unit, and when the short circuit current value is smaller than the three-phase short circuit current, the control unit does not drive the arc removing unit.2. The arc protection system of claim 1 , further comprising:a circuit breaking unit installed to open or close a circuit of the distribution panel,wherein when the short circuit current value is equal to or greater than a first setting value, the control unit determines that the three-phase short circuit current flows, and when short circuit current value is equal to or greater than a second setting value that is smaller than the first setting value, the control unit opens the circuit breaking unit.3. The arc protection system of claim 2 , wherein the distribution panel ...

包括中性电流传感器的多极闪络故障断路器

提供了用于至少具有承载从源到负载的彼此异相的AC电流的第一和第二线路导线以及公共中性导线的配电系统的故障探测系统。系统包括闪络故障电流传感器，其包括缠绕在中空芯上并耦合到这两个线路导线的线圈，使得在线路导线中的电流在中空芯内部在相反的方向上流动，因而在线圈中引起作为线路导线中的电流的差的函数的输出信号。中性电流传感器产生表示中性导线中的电流的幅值和相方向的输出信号。闪络故障探测电路包括被编程为执行下列操作的处理器：（1）响应于第一输出信号中的变化来分析第二输出信号以确定第一输出信号中的变化是否至少部分地可归因于线间电路中的电流，（2）如果答案是肯定的，则确定用于调节第一输出信号的值的比例因子，以及（3）分析经调节的第一输出信号以确定闪络故障是否出现并响应于探测到闪络故障而产生跳闸信号。

Method and apparatus for detecting high-impedance faults in electrical power systems

The present invention features a method and apparatus for detecting and enabling the clearance of high impedance faults (HIFs) in an electrical transmission or distribution system. Current in at least one phase in a distribution system is monitored in real time by sensors. Analog current signature information is then digitized for processing by a digital computer. Zero crossings are identified and current maxima and minima located. The first derivatives of the maxima and minima are computed and a modified Fast Fourier Transform (FFT) is then performed to convert time domain to frequency domain information. The transformed data is formatted and normalized and then applied to a trained neural network, which provides an output trigger signal when an HIF condition is probable. The trigger signal is made available to either a network administrator for manual intervention, or directly to switchgear to deactivate an affected portion of the network. The inventive method may be practiced using either conventional computer hardware and software or dedicated custom hardware such as a VLSI chip.

Control method of switchboard with built-in image harmonic filter

A control method of a switchboard with a built-in image harmonic filter comprises the steps of: turning on the switching unit to input a zigzag wiring transformer; calculating an image on the N-phase busbar; comparing the image segment and a reference value; when the zero fraction is smaller than the reference value, controlling the switching unit off, applying the maximum applied current to the Peltier module, and applying the maximum voltage to the cooling fan; measuring temperature and noise if the image is not smaller than the reference value; comparing the measured temperature signal and a critical temperature range; when the measured temperature signal is greater than or equal to the critical temperature range, controlling the switching unit off, applying a maximum applied current to the Peltier module, and applying a maximum voltage to the cooling fan; if the measured temperature signal is less than the threshold temperature range, controlling the switching unit on, not applying a current to the Peltier module, and controlling the cooling fan off; if the measured temperature signal is within the threshold temperature range, comparing the measured noise signal with the critical noise range; when checked as a high noise environment, controlling the switching unit off, applying a maximum applied current to the Peltier device, and applying a maximum voltage to the cooling fan; when the low-noise environment is checked, the switching unit maintains ON-controlled, applying a minimum current to the Peltier module, and applying a differential voltage to the cooling fan; and if it exists within the critical noise range, PWM control the switching unit, applying a differential current to the Peltier module, and applying a differential voltage to the cooling fan. Cooling operation can be efficiently controlled.

Current control apparatus of distribution static compensator considering nonlinear load

본 발명은 비선형 부하를 고려한 배전용 정지형 보상기의 전류 제어 장치에 관한 것으로서, 폐루프 제어기인 비례공진 제어부에 반복제어부를 병렬로 연결하여, 지령 전류의 기본파 제어는 비례공진 제어부를 통해 수행하고, 비선형 부하로 인해 생성된 다수의 고조파 제어는 반복제어부를 통해 수행하여, 비선형 부하로 인해 부하 전류에 다수의 고조파가 포함될 때, 기존보다 향상된 전류 제어 성능을 제공할 수 있는 것이다. The present invention relates to a current control device for a stationary compensator for power distribution considering a non-linear load, by connecting a repeating control unit in parallel to the proportional resonance control unit which is a closed loop controller, and the fundamental wave control of the command current is performed through the proportional resonance control unit, The plurality of harmonics control generated by the nonlinear load may be performed through the repeating control unit to provide improved current control performance when the plurality of harmonics are included in the load current due to the nonlinear load. 배전용 정지형 보상기, 전류 제어, 비례공진제어기, 반복제어기, 비선형 부하 Stationary Compensator for Power Distribution, Current Control, Proportional Resonance Controller, Repetitive Controller, Nonlinear Load

Method and device for detecting electric arc

FIELD: electrical engineering.SUBSTANCE: according to the electric arc detection method, the signal samples obtained in parallel for the first, second and third filtrations for the current time window and for another time window are determined. Correlation is determined among the first correlation between the samples selected after the first filtering and determined for the current window, and the samples obtained after the first filtering and defined for the other window, the second correlation between said samples obtained after the second filtering and determined for the current window, and the samples obtained after the second filtering and defined for the other window, third correlation between said samples obtained after the third filtering and determined for the current window, and the samples obtained after the third filtering and defined for the other window. Presence of an electric arc is detected depending, at least on a certain correlation.EFFECT: technical result is increased efficiency of detection of the electric arc.13 cl, 8 dwg РОССИЙСКАЯ ФЕДЕРАЦИЯ (19) RU (11) (13) 2 665 063 C2 (51) МПК H02H 7/00 (2006.01) ФЕДЕРАЛЬНАЯ СЛУЖБА ПО ИНТЕЛЛЕКТУАЛЬНОЙ СОБСТВЕННОСТИ (12) ОПИСАНИЕ ИЗОБРЕТЕНИЯ К ПАТЕНТУ (52) СПК H02H 7/00 (2006.01) (21)(22) Заявка: 2014124392, 16.06.2014 (24) Дата начала отсчета срока действия патента: Дата регистрации: (73) Патентообладатель(и): ШНЕЙДЕР ЭЛЕКТРИК ЭНДЮСТРИ САС (FR) 28.08.2018 (56) Список документов, цитированных в отчете о поиске: US 5602709A, 11.02.1997. US 21.06.2013 FR 1355914 (43) Дата публикации заявки: 27.12.2015 Бюл. № 36 5561605A, 01.10.1996. RU 2633651С1, 20.06.2016. RU 2249827С2, 20.05.2000. 2 6 6 5 0 6 3 R U Адрес для переписки: 129090, Москва, ул. Б. Спасская, 25, строение 3, ООО "Юридическая фирма Городисский и Партнеры" (54) СПОСОБ И УСТРОЙСТВО ОБНАРУЖЕНИЯ ЭЛЕКТРИЧЕСКОЙ ДУГИ (57) Реферат: Использование: в области электротехники. окна, второй корреляции между упомянутыми Технический результат – повышение ...

Electric power distributing board equipped with self diagnosis

The present invention relates to a motor control center, and more specifically, to a motor control center equipped with a self-diagnosis function. The present invention is to provide a power distribution apparatus which is capable of periodically diagnosing an image harmonic filtering characteristic of the power distribution apparatus and lifespan of an image harmonic filter. In order to achieve the above-mentioned objective, a motor control center according to a preferred embodiment of the present invention comprises: an overload protection unit which measures a temperature of an image harmonic filter via a temperature sensor installed on the image harmonic filter, which blocks the image harmonic filter by turning off a switch when the temperature of the image harmonic filter exceeds a preset upper limit temperature, which re-introduces the image harmonic filter by turning on the switch when the temperature of the image harmonic filter is lower than a preset lower limit temperature while the image harmonic filter has been blocked; and a performance evaluation unit which diagnoses performance of the image harmonic filter by using a zero phase sequence component introduced into a commercial power system during a period for which the image harmonic filter has been blocked.

Power distribution system

System for distributing electrical energy

本发明涉及一种用于分送电能的系统，所述系统包括被配置成供给电能到终端用户的电网，其特征在于所述电网以直流电压运行。

Method and system for power quality protection

A method for power quality protection includes measurement of electrical and nonelectrical parameters, calculation of additional electrical and nonelectrical parameters, comparison of the value of the calculated parameters with maximum allowed values from a power quality perspective, activation of protection mechanisms for transitioning to a safe mode or for isolation from the bus. The systems and methods may prevent equipment failures when out of the spec power quality is present in the distribution bus and may protect the distribution bus from imposing power quality problems due to equipment failures. Because most of the sensors in the systems of the present invention are already used for other control and protection purposes, there may be no reliability degradation. Most of the calculations and the control logic may be performed digitally for improved reliability and flexibility to modify algorithms.

Electric fire prevention equipment

본 발명은 전기 선로상의 전류와 전압 신호를 계측하여 단락, 누전, 아크 및 트래킹을 검출하여 전기 화재를 예방할 수 있는 장치에 관한 것으로서, 상기 장치는 전압 센서로부터 선로상의 전압 신호를 검출하는 전압 검출부; 전류 센서로부터 선로상의 전류 신호를 검출하는 전류 검출부; 상기 디지털 변환된 신호로부터 실효값, 지연시간, 고조파, 숄더값 중 어느 하나 이상을 연산하여, 전류의 실효값의 기울기를 기준값과 비교하여 단락 여부를 판단하는 기능, 누설전류를 기준값과 비교하여 누전 여부를 판단하는 기능, 누전 상태에서 고조파 증가율을 기준값과 비교하여 트래킹 발생 여부를 판단하는 기능, 전류의 실효값, 숄더의 폭, 지연시간, 고조파 증가율을 각각의 기준값과 비교하여 아크 발생 여부를 판단하는 기능 중 어느 하나 이상의 기능을 수행하는 신호처리부; 상기 신호처리부의 처리 결과를 표시하는 표시부; 상기 신호처리부의 처리 결과를 원격 전송하는 송신부; 및 단락, 누전, 트래킹, 아크 중 하나 이상 발생시 경보를 발하는 경보부; 를 포함하여 구성되는 것으로, 상기 트래킹 및 아크 발생 여부 판단시 고조파 증가율을 기준값과 비교함에 있어서는 도비치스 함수를 모함수로 하는 웨이블릿 변환을 통해 추출한 고주파 성분의 크기를 기준값과 비교하는 것이 특징이며, 전기 화재의 직접적인 원인이 되는 단락, 누전, 아크 및 트래킹 발생 여부를 사전에 파악할 수 있고 특히 아크 및 트래킹 검출에 있어 다양한 형태의 고조파가 함유된 파형으로부터 정확하고 신속하게 그 특징을 추출하고 이상 여부를 판단할 수 있다는 효과를 가진다. The present invention relates to a device capable of preventing an electric fire by measuring a current and a voltage signal on an electric line to detect a short circuit, a short circuit, an arc, and a tracking. The apparatus includes: a voltage detector for detecting a voltage signal on a line from a voltage sensor; A current detector for detecting a current signal on a line from the current sensor; Calculates one or more of an effective value, a delay time, a harmonic, and a shoulder value from the digitally converted signal, and compares the slope of the effective value of the current with a reference value to determine whether a short circuit occurs; Determination of whether or not tracking occurs by comparing the harmonic growth rate with the reference value in the short-circuit state, and determining the arc occurrence by comparing the effective value of the current, the width of the shoulder, the delay time, and the harmonic growth rate with each reference value. A signal processor for performing any one or more of the following functions; A display unit which displays a processing result of the signal processor; A transmitter for remotely transmitting the processing result of ...

Integrated surge protector for cctv

An integrated surge arrester is provided to facilitate the interlocking with a protector by forming the protector with the surge arrester. A communication line protecting circuit unit is comprised of a first protective circuit(110), a second protective circuit(120) and a third protective circuit(130). A power line protection circuit unit consists of an overcurrent protection circuit(210), a first overvoltage protection circuit(220) and a second overvoltage protection circuit(240). The first overvoltage protection circuit consists of varister variable resistors. An image line protection circuit unit is composed of a first protection circuit(410), a second protection circuit(420) and a third protection circuit(430).

METHOD FOR SECTIONING A HALF-POWERED ELECTRIC POWER DISTRIBUTION LINE WITH A SECTIONER THAT PRESENTS A PERTUBATION, HALF-POWERED ELECTRIC POWER DISTRIBUTION LINE SECTIONER FOR THE SAME AND ELECTRONIC CIRCUIT OF DETECTION OF A CURRENT FAILURE CURRENT

Método para seccionar una línea de media tension que presenta una perturbacion, comprendiendo: a) evaluar una corriente con una bobina detectora; b) convertir la intensidad a diferencia de potencial, transfiriendo la informacion a un microprocesador; c) analizar el perfil de onda mediante un algoritmo para análisis de armonicas por Series de Fourier; y d) determinar el comportamiento del seccionador segun el resultado obtenido en c). El paso d) comprende: no efectuar un conteo si: i) la corriente no sobrepasa un valor prefijado como corriente de falla, o ii) el perfil de onda corresponde a una corriente de ôin rushö, o iii) efectuar un conteo para desconexion si el perfil de onda corresponde a un cortocircuito que supera un valor prefijado como corriente de falla. Dado d) iii), el método comprende e): i) no efectuar el disparo del mecanismo de desconexion si se trata de una falla transitoria; o ii) efectuar la desconexion si se alcanza un numero de conteos prefijado. El método puede comprender adicionalmente en forma simultánea con e) ii), f) enviar una senal de RF a otro/s seccionadores paralelamente conectados en un punto de la línea de distribucion para que se desconecten conjuntamente. Seccionador de líneas de distribucion de energía eléctrica para ramales auxiliares donde la línea principal está protegida por un disyuntor de reposicion automática, que comprende un circuito electronico con un microcontrolador capaz de identificar una corriente de falla permanente de una transitoria, inmunizando el seccionador contra las corrientes de ôin rushö, y dicho circuito electronico. Method for sectioning a medium voltage line that presents a disturbance, comprising: a) evaluating a current with a detector coil; b) convert the intensity to potential difference, transferring the information to a microprocessor; c) analyze the wave profile using an algorithm for harmonic analysis by Fourier Series; and d) determine the behavior of the disconnector according to the result ...

Electric power distributing board equipped with self diagnosis

The present invention relates to a power distribution board, and more specifically, to a power distribution board equipped with a self-diagnosis function. The present invention is to provide a power distribution apparatus which is capable of periodically diagnosing an image harmonic filtering characteristic of the power distribution apparatus and lifespan of an image harmonic filter. In order to achieve the above object, the power distribution board according to a preferred embodiment of the present invention comprises: an overload protection unit which measures the temperature of an image harmonic filter via a temperature sensor installed on the image harmonic filter, which blocks the image harmonic filter by turning off a switch when the temperature of the image harmonic filter exceeds a preset upper limit temperature, which re-introduces the image harmonic filter by turning on the switch when the temperature of the image harmonic filter is lower than a preset lower limit temperature while the image harmonic filter has been blocked; and a performance evaluation unit which diagnoses performance of the image harmonic filter by using a zero phase sequence component introduced into a commercial power system at a time when the image harmonic filter has been blocked.

METHOD AND DEVICE FOR DETECTING ELECTRIC ARC

Method for detecting leakage or fault currents in an electrical installation using a protection device providing at least differential protection and such a device suitable for implementing said method

Procédé de détection de courants de fuite ou de défaut dans une installation électrique à partir d’un appareil de protection assurant au moins une protection différentielle et un tel appareil convenant à la mise en œuvre dudit procédé. La présente invention a pour objet un procédé de détection de courants de fuite ou de défaut dans une installation électrique à partir d’un appareil de protection, ladite installation électrique étant alimentée par un courant circulant dans au moins deux conducteurs d'un réseau alternatif ou continu. Il consiste à détecter une dissymétrie du signal de mesure alternatif entre son alternance, ou demi-période, positive et son alternance, ou demi-période, négative générée par la présence d’harmoniques de rang pair dans ledit signal de mesure alternatif représentatives d’un courant continu relatif à un courant de défaut survenant dans le réseau : soit en déterminant, par analyse fréquentielle du signal de mesure alternatif, une valeur de mesure représentative de l’apparition d’harmoniques de rang pair dans ledit signal de mesure alternatif, puis en comparant ladite valeur de mesure avec un seuil de référence que comprend ladite unité de traitement et de commande (3) pour émettre, selon le résultat de la comparaison, le signal de commande, soit en mesurant une première valeur d’une grandeur physique du signal de mesure alternatif dans son alternance, ou demi-période, positive et une deuxième valeur de ladite grandeur physique dans son alternance, ou demi-période, négative puis en effectuant leur différence et en la comparant à un seuil de référence pour émettre, selon le résultat de la comparaison, le signal de commande. Elle a également pour objet un tel appareil de protection convenant à la mise en œuvre dudit procédé. Figure à publier avec l’abrégé : Fig.1

Method for detecting leakage or fault currents in an electrical installation from a protection device providing at least differential protection and such a device suitable for the implementation of said process

Procédé de détection de courants de fuite ou de défaut dans une installation électrique à partir d’un appareil de protection assurant au moins une protection différentielle et un tel appareil convenant à la mise en œuvre dudit procédé. La présente invention a pour objet un procédé de détection de courants de fuite ou de défaut dans une installation électrique à partir d’un appareil de protection, ladite installation électrique étant alimentée par un courant circulant dans au moins deux conducteurs d'un réseau alternatif ou continu. Il consiste à détecter une dissymétrie du signal de mesure alternatif entre son alternance, ou demi-période, positive et son alternance, ou demi-période, négative générée par la présence d’harmoniques de rang pair dans ledit signal de mesure alternatif représentatives d’un courant continu relatif à un courant de défaut survenant dans le réseau : soit en déterminant, par analyse fréquentielle du signal de mesure alternatif, une valeur de mesure représentative de l’apparition d’harmoniques de rang pair dans ledit signal de mesure alternatif, puis en comparant ladite valeur de mesure avec un seuil de référence que comprend ladite unité de traitement et de commande (3) pour émettre, selon le résultat de la comparaison, le signal de commande, soit en mesurant une première valeur d’une grandeur physique du signal de mesure alternatif dans son alternance, ou demi-période, positive et une deuxième valeur de ladite grandeur physique dans son alternance, ou demi-période, négative puis en effectuant leur différence et en la comparant à un seuil de référence pour émettre, selon le résultat de la comparaison, le signal de commande. Elle a également pour objet un tel appareil de protection convenant à la mise en œuvre dudit procédé. Figure à publier avec l’abrégé : Fig.1 Method for detecting leakage or fault currents in an electrical installation using a protection device providing at least one differential protection and such a device suitable for ...

Zero-phase harmonic filter

본 발명은 영상고조파 필터에 관한 것으로서, 보다 상세하게는 3상4선식 배전 계통의 중성선에서 발생하는 과다한 영상고조파를 감쇄하는 영상고조파 필터에 있어서 상기 영상고조파 필터로 유입되는 영상고조파를 제어함으로써 과부하가 걸리는 것을 최대한 방지하여 안정성을 높임과 동시에 효율적으로 영상고조파 감쇄 기능을 수행할 수 있게 한 영상고조파 필터에 관한 것이다.

METHOD AND DEVICE FOR DETECTING ELECTRIC ARC

Procédé de détection d'arc électrique selon lequel : - on détermine des échantillons d'un premier, deuxième et troisième filtrages, en parallèle, d'un signal pour une fenêtre temporelle courante et pour une autre fenêtre temporelle, - on détermine une corrélation parmi : - une première corrélation entre lesdits échantillons issus du premier filtrage et déterminés pour la fenêtre courante et des échantillons issus du premier filtrage et déterminés pour l'autre fenêtre ; - une deuxième corrélation entre lesdits échantillons issus du deuxième filtrage et déterminés pour la fenêtre courante et des échantillons issus du deuxième filtrage et déterminés pour l'autre fenêtre; - une troisième corrélation entre lesdits échantillons issus du troisième filtrage et déterminés pour la fenêtre courante et des échantillons issus du troisième filtrage et déterminés pour l'autre fenêtre ; et - on détecte un arc électrique en fonction d'au moins d'au moins la corrélation déterminée. An electric arc detection method according to which: - samples of a first, second and third filtering, in parallel, of a signal for a current time window and for another time window are determined, - a correlation is determined among : a first correlation between said samples from the first filtering and determined for the current window and samples from the first filtering and determined for the other window; a second correlation between said samples from the second filtering and determined for the current window and samples from the second filtering and determined for the other window; a third correlation between said samples from the third filtering and determined for the current window and samples from the third filtering and determined for the other window; and an arc is detected according to at least at least the determined correlation.

Method and apparatus for protecting a power transformer from large electromagnetic fluctuations

Zero-phase harmonic reduction device

The present invention relates to a zero-phase harmonic reduction device to cope with open phase in a three-phase line, which comprises: a zero-phase harmonic filter adopting zigzag wire connection; N-phase current detector measuring a current flowing from the zero-phase harmonic filter to a neutral line; an N-phase switch provided to open/close the neutral line; and a control unit controlling whether to disconnect the N-phase switch according to frequency changes of the current on the neutral line acquired by the current detector. According to the present invention, the zero-phase harmonic reduction device can correctly and easily determine whether a phase is open and/or reversed with a simple circuit.

Device for differentially protecting a power transformer

A preprocessing circuit (12) receives signals representative of a current (I1) circulating in a primary winding (1) and of a current (I2) circulating in a secondary winding of a transformer (T). The signals representative of currents are used to calculate the values of a through current (Ir) and a differential current (Id). The preprocessing circuit performs a spectral analysis and provides a neural network (13) with signals representative of the fundamental component of the through current (HIR), of the fundamental component of the differential current (H1D), of the second harmonic (H2D) and of the fifth harmonic (H5D) of the differential current. The neural network identifies fault conditions and normal operation states, and supplies a triggering and/or alarm signal to an output when a fault condition is detected.

Method for discriminating abnormal current including arc current in ac load circuit and apparatus for executing the same

An abnormal current discriminating method including an arc current detecting method and the apparatus for performing the same in which the arc current method includes the steps of: extracting a predetermined transition pattern specified by the combination of fluctuation patterns of peak values of three continuous half waves from the peak value for each half wave detected from an alternating current flowing to the AC load circuit which is sampled in a predetermined cycle and converted into a digital value, counting the number of appearances of the predetermined transition pattern, and comparing the count value with a predetermined threshold. According to which, a series arc which may be caused in a relative small current range by an apparatus cord or the like which has not been detected by an instantaneous breaker and an arc short-circuit phenomenon generated together with an arc through the contact between the cores in a cord and an interior wiring can be detected by executing simple algorithm without error detecting.

Harmonics Filter Which Detecting The Reverse Phase and The Absent Phase

본 발명은 3상4선식 전력 시스템에 장착되는 고조파필터에 있어서, 상기 전력 시스템의 3상의 위상선과 중성선에 연결되는 지그재그 결선 변압기; 상기 지그재그 결선 변압기의 온도 상태를 검출하는 온도검출부; 상기 전력 시스템의 부하단에 전력 공급을 개폐하는 제1스위치부; 상기 전력 시스템과 지그재그 결선 변압기의 각 연결단을 개폐하는 제2스위치부; 상기 전력 시스템의 3상의 위상선과 중성선의 전압을 검출하는 전압검출부; 상기 전력 시스템의 3상의 위상선과 중성선의 전류를 검출하는 전류검출부; 2개 이상의 포토커플러를 포함하여 상기 전력 시스템의 3상의 위상선의 위상 상태를 감지하는 위상검출부; 상기 위상검출부에서 감지된 3상의 위상선의 위상상태를 분석하여 역상 여부를 판단하는 역상판단모듈과, 상기 전압검출부에서 3상의 위상선 중 하나 이상의 상 전압이 검출되지 않으면 결상으로 판단하는 결상판단모듈과, 상기 결상판단모듈에서 결상 신호를 수신하여 상기 제1스위치부를 작동시키는 제1스위치작동모듈과, 상기 온도검출부에서 검출된 온도 상태를 분석하여 상기 제2스위치부의 작동을 제어하는 제2스위치작동모듈을 포함하는 제어부; 상기 전력 시스템의 중성선의 고조파 전압과 고조파 전류를 분석하여 상기 전력 시스템의 부하단이 고조파 발생원인지 흡수원인지 결정하는 고조파추적부; 및 상기 온도검출부, 전압검출부, 전류검출부, 결상판단모듈, 역상판단모듈, 고조파추적부에서 감지된 각각의 정보를 외부로 현출하는 상태표시부를 포함하여 구성되는 것을 특징으로 한다. The present invention provides a harmonic filter mounted on a three-phase four-wire power system, comprising: a zigzag connection transformer connected to a three-phase phase line and a neutral line of the power system; A temperature detector detecting a temperature state of the zigzag connection transformer; A first switch unit configured to open and close a power supply to a load end of the power system; A second switch unit for opening and closing each connection end of the power system and the zigzag connection transformer; A voltage detector detecting voltages of three phase lines and a neutral line of the power system; A current detector for detecting currents of the phase line and the neutral line of the three phases of the power system; A phase detector including two or more photocouplers to detect a phase state of three phase lines of the power system; An inverted phase determination module for determining whether a phase is reversed by analyzing a phase state of the phase lines of the three phases sensed by the phase detection unit, and an phase determination module for determining phase if one or more phase voltages of the phase lines are detected in the voltage detector; A first switch operation module for ...

Dc power generation system and protection method for dc power generation system

System and method for high resistance ground fault detection and protection in power distribution systems

Protection relay arrangement

Arc-detection

在用于检测在用于将DC输入功率转换成输出功率的转换器装置（2）的电流路径中的电弧的方法中，电弧通过下述步骤来检测：借助于电流变压器（11）感测电流路径中的电流（4），用模拟带通滤波器（14）对电流信号（4'）进行滤波，将模拟滤波的电流信号（4''）转换成数字信号（4'''），确定数字电流信号（4'''）的谐波含量（19）并且然后如果谐波含量（19）超过阈值则判定电弧是否存在，其中阈值在开始被确定为在电流信号的特定时间段期间的平均谐波含量的倍数。

Continuous uninterruptable AC grounding system for power system protection

A continuous grounding system for use in an alternating current system including a transformer is disclosed. The system includes a switch assembly connected between a transformer neutral of a transformer and a ground, the switch assembly having an open position and a closed position, the open position disrupting the path through the switch assembly between the electrical connection and the transformer neutral, and the closed position establishing a path connecting the electrical connection to the transformer neutral through the switch assembly, wherein in normal operation of the alternating current electrical device the switch assembly remains in a closed position. The system also includes a DC blocking component positioned in parallel with the switch assembly and connected between the transformer neutral and the ground. The system further includes a control circuit configured to control the switch assembly, the control circuit including a sensor configured to actuate the switch assembly to an open position upon detection of a predetermined harmonic signal threshold at one of the transformer phases or a predetermined threshold of DC current between the transformer neutral and ground.

METHOD FOR THE SELECTIVE DETECTION OF A RESISTANT FAULT IN AN ELECTRICAL POWER DISTRIBUTION NETWORK AND DEVICE FOR ITS IMPLEMENTATION.

Arc detection based on variance of current flow

Arc fault detection devices and methods are described current between a source and a load is periodically measured. A variance of the periodically measured current values is derived and an arc fault can be detected abased on the derived variance. A variance interval signal can be incremented based on the derived variance increasing above a threshold level and a low pass filter arranged to detect an arc based on the incremented variance interval signal.

Arc fault detector with circuit interrupter

There is here disclosed a method and apparatus for detecting the occurrence of arcing of a conductor by monitoring the current on an AC power line. The signal detected is split and directed along four separate paths to generate four signals having separate characteristics which represent the current in the line. A first path is for a signal representative of the current flowing in the line. A second path is for a signal having a pulse for each occurrence of a positive step change in current that is significant and has a di/dt value above a predetermined value. A third path is for a signal having a pulse for each occurrence of a negative step change in current that is significant and has a di/dt value above a predetermined value. A fourth path is for a signal having a voltage level representative of the broadband noise signal on the line. Using at least one of five different methods in combination with one of three input signals, a reference signal designated as “SINE” is generated. The SINE signal generated in combination with a CURRENT input is used to produce a control waveform “DELTA”. DELTA can be represented as a relative value or as an absolute difference between the SINE and the CURRENT. Each occurring half cycle of the DELTA signal is analyzed by, for example, a micro-controller for specific identifiable characteristics found to indicate the presence of arcing. Upon the detection of arcing, an output signal can be generated to activate a circuit interrupting mechanism, sound an audio alarm and/or alert a central monitoring station.

continuous uninterruptible ac grounding system for power system protection

sistema de aterramento ca ininterrompível contínuo para proteção de sistema de energia. a presente invenção refere-se a um sistema de aterramento contínuo para utilização em um sistema de corrente alternada que inclui um transformador. o sistema inclui um conjunto de comutador conectado entre um neutro de transformador de um transformador e um terra, o conjunto de comutador tendo uma posição aberta e uma posição fechada, a posição aberta interrompendo o percurso através do conjunto de comutador entre a conexão elétrica e o neutro de transformador, e a posição fechada estabelecendo um percurso que conecta a conexão elétrica no neutro de transformador através do conjunto de comutador, em que em operação normal do dispositivo elétrico de corrente alternada o conjunto de comutador permanece em uma posição fechada. o sistema também inclui um componente de bloqueio de cc posicionado em paralelo com o cojunto de comutador e conectado entre o neutro de transformador e o terra. o sistema ainda inclui um circuito de controle configuarado para controlar o conjunto de comutador, o circuito de controle incluindo um sensor configurado para atuar o conjunto de comutador para uma posição aberta quando da detecção de um limite de sinal harmônico predeterminado em uma das fases de transformador ou um limite predeterminado de corrente cc entre o neutro de transformador e o terra. continuous uninterruptible ac grounding system for power system protection. The present invention relates to a continuous grounding system for use in an alternating current system including a transformer. The system includes a switch assembly connected between a transformer neutral of a transformer and a ground, the switch assembly having an open position and a closed position, the open position interrupting travel through the switch assembly between the electrical connection and the transformer neutral, and the closed position establishing a path that connects the electrical connection to the transformer ...

Method for avoiding overcurrents in reactive power compensation capacitors of a reactive power compensation system having at least one capacitor stage on a single-phase or multi-phase AC network by means of a discrete Fourier transformation of the temporal voltage curve

Continuous uninterruptable AC grounding system for power system protection

A continuous grounding system for use in an alternating current system including a transformer is disclosed. The system includes a switch assembly connected between a transformer neutral of a transformer and a ground, the switch assembly having an open position and a closed position, the open position disrupting the path through the switch assembly between the electrical connection and the transformer neutral, and the closed position establishing a path connecting the electrical connection to the transformer neutral through the switch assembly, wherein in normal operation of the alternating current electrical device the switch assembly remains in a closed position. The system also includes a DC blocking component positioned in parallel with the switch assembly and connected between the transformer neutral and the ground. The system further includes a control circuit configured to control the switch assembly, the control circuit including a sensor configured to actuate the switch assembly to an open position upon detection of a predetermined harmonic signal threshold at one of the transformer phases or a predetermined threshold of DC current between the transformer neutral and ground.

Device for differentially protecting a power transformer

一预处理电路(12)接收代表流通于变压器(T)的初级绕组(1)之中的电流((I1)和次级绕组(2)之中的电流(I2)的信号。代表这些电流的信号用以计算直通电流(Ir)和差电流(Id)的数值。预处理电路进行频谱分析并向神经元式网络(13)提供代表直通电流的基波分量(H1R)、差电流的基波分量(H1D)、差电流的二次谐波分量(H2D)和差电流的五次谐波分量(H5D)的信号，该神经元式网络识别各种故障状态和各种正常操作状态，并在检测到一故障状态向输出端提供一断路和/或报警信号。

Arc detection based on current variance

描述了电弧故障检测装置和方法。周期性地测量源与负载之间的电流。推导出该周期性测量的电流值的方差，并且可基于该推导出的方差来检测电弧故障。可基于增加至高于阈值水平的该推导出的方差来使方差间隔信号递增，并且低通滤波器被布置成基于该递增的方差间隔信号来检测电弧。

Earth leakage-current protection system

Arcing fault detection system

A system for testing an arcing fault detection System in an electrical distribution network having a line conductor carrying an electrical signal between a power source and a load, the arcing fault detection system including a sensor coupled to the line conductor for monitoring the electrical signal and generating a sensor signal representing the electrical signal, the arcing fault detection system generating an arc-indicative signal in response to the sensor signal having characteristics indicative of an arcing fault. The testing system couples the sensor to a test line simultaneously with the line conductor and periodically produces a test signal on the test line. The sensor simultaneously monitors the test signal and the electrical signal and produces a sensor signal representing both the test signal and the electrical signal when the test signal is present on the test line. The arcing fault detection system generates an arc-indicative signal in response to the sensor signal associated with either the test line or line conductor having characteristics indicative of an arcing fault. A diagnostic test integrator evaluates the status conditions of the test signal and the arc-indicative signal and generates a trip signal to trigger the interruption of the electrical signal in response to certain status conditions of the test signal and the arc-indicative signal.

Apparatus and method to detect a series arc fault of an electrical circuit

An apparatus is for a power circuit providing an alternating current to a load. The apparatus includes a high frequency current sensor structured to cooperate with the power circuit to provide a high frequency current signal. A voltage zero crossing detector is structured to cooperate with the power circuit to provide a voltage zero crossing signal. A high pass filter is structured to provide a filtered current signal from the high frequency current signal. A threshold comparator is structured to provide an output when the filtered current signal exceeds a predetermined value. A processor is structured to receive the voltage zero crossing signal and the output of the threshold comparator and output a trip signal in response to undesired series arcing by detecting an unsymmetrical high frequency signal for a predetermined number of cycles.

Testing device for detecting and locating arc faults in an electrical system

A testing device for detecting and locating an arcing fault in an electrical system includes a detector circuit for detecting one or more characteristics of the arcing fault proximate the arcing fault and outputting a responsive signal. An annunciator speaker or display annunciates the responsive signal when the detector circuit is proximate the arcing fault, in order to locate the arcing fault in the electrical system.

Methods of detecting arc faults characterized by consecutive periods of arcing

An apparatus and method for detecting electrical arc faults that has reduced susceptibility to nuisance tripping. The apparatus includes a current sensor, an input sense circuit, an arcing sense circuit, a power supply, a tripping circuit, a processing unit, and an electromechanical interface. The processing unit measures multiple voltage levels provided by the arcing sense circuit during a specified number of consecutive time periods. Next, the processing unit determines the number of consecutive time periods during which the voltage levels exceeded a specified minimum value, take on successively lower or higher values, or fall outside a predetermined normal range of values. Based upon the results of this determination, the processing unit either trips the electromechanical interface to interrupt power to a load, or inhibits tripping of the electromechanical interface, thereby reducing the occurrence of nuisance tripping.

Method for identifying arcing faults and circuit breaker

본 발명은 계통 주파수, 전류 및 전압을 갖는 회로 내의 아크형 결함들을 식별하기 위한 방법(60, 76, 88, 112)에 관한 것으로, 상기 방법에 있어서 LF1 주파수 미만의 주파수 및 LF1 한계 임계치를 초과하는 전류 세기를 갖고 야기되는 간섭 신호(28)가 LF1 신호(34)를 규정하고, 야기되는 다수의 간섭 신호들(28)의 수가 HF2 수(50)보다 크거나 그와 같은 경우 및 두 개의 연속적 간섭 신호들(28) 간의 시간 간격이 HF2 시간(46)보다 적은 경우, HF2 주파수(42) 미만의 주파수를 갖는 다수의 간섭 신호들(28)이 HF2 신호(48)를 형성하기 위해 결합되고, 시간 기간들(52)의 수가 누적 수(58) 보다 많거나 같은 경우 누적 길이(54)로 되는 각각의 길이를 갖고 시간적으로 서로 직접 이어지고 각각의 경우에 그 안에 적어도 하나의 HF2 신호(48)가 존재하는 다수의 시간 기간들(52)이 누적(56)을 규정한다. The present invention relates to a method (60, 76, 88, 112) for identifying arc-type defects in a circuit having a system frequency, current and voltage, characterized in that in the method the frequency below the LF1 frequency and above the LF1 threshold threshold When the interference signal 28 caused by the current intensity defines the LF1 signal 34 and the number of the plurality of interfering signals 28 caused is greater than or equal to the HF2 number 50 and two consecutive interference When the time interval between signals 28 is less than HF2 time 46 a number of interfering signals 28 having a frequency less than HF2 frequency 42 are combined to form HF2 signal 48, If the number of periods 52 is greater than or equal to the cumulative number 58, the cumulative length 54 has a length of each and has a length that is directly proportional to each other and in each case at least one HF2 signal 48 is present A plurality of time periods 52, And regulations.

Arc detection based on changes in current flow

アーク不良検出デバイス及び方法が説明され、ソースと負荷との間の電流が、周期的に測定される。周期的に測定される電流値の変化が導出され、導出された変化に基づいてアーク不良を検出することができる。変化間隔信号は、閾値レベルを超えて増加する導出された変化と、増分した変化間隔信号に基づいてアークを検出するように配置されたローパスフィルタと、に基づいて増分させることができる。

Method for identifying arcing faults and corresponding circuit breaker

The method involves defining a low frequency signal comprising frequency below a high frequency level (42). Interference signals (28) which occur at the low frequency signal are combined together to form a high frequency signal (48), if the number of the interference signals is greater than or equal to a high frequency number (50) and the time interval between two successive interference signals is less than a high frequency time (46), where the interference signal has frequency below a low frequency level and current intensity above a low frequency limit threshold. An independent claim is also included for a circuit breaker that is utilized for implementing the method for identifying arcing faults within the power circuit.

Earth fault identification process for power distribution network

A process for identifying earth faults in power supply networks with multiple outlets (A1...An) and earth fault compensation consists of measuring the total current and filtering out at least one harmonic, preferably the fifth harmonic. The amplitude of the harmonic at each outlet is measured continuously and the outlets with the greatest harmonic amplitude are determined and shown as subject to earth faults. The issued voltage of the network is also measured. When this exceeds a predetermined limit the outlets subject to earth faults are displayed. Earth faults can be detected in this way by simple preparation of existing equipment and irrespective of the type of network. Very accurate and therefore expensive total current instruments are not necessary.

Arcing fault detection module

An arcing fault detection module (4) for detecting arcing faults in an electrical current distribution circuit (8) comprises a filter circuit (9) and an autocorrelation circuit (10). The filter circuit (9) is electrically connected to the distribution circuit (8) and samples current with the distribution circuit. The filter circuit (9) includes a band pass filter (12) to filter out fundamental and high frequency components from the sampled current, and a comparator (13) to convert the sampled current to a digital signal. The autocorrelation circuit (10) receives the digital signal from the filter circuit (9). The autocorrelation circuit (10) includes a plurality of shift registers (15-18) for storing the digital signal for a predetermined sample period, and a plurality of EXCLUSIVE-OR gates (35-37,41, 43, 44) and OR gates (38, 39) to detect odd and even harmonic signals. An integrator-counter (47) electrically connects to certain EXCLUSIVE-OR and OR gates, and provides an arc indicative signal when the absolute value of the even and odd harmonic signals is equal to a predetermined number.

Arc fault detector and method

The present invention discloses an arc fault detector including a shunt resistor deployed in a circuit being protected, an arc discriminator sensing voltages across the shunt resistor and outputting an arc detection signal when it detects current variations caused by parallel and series arc faults, a signal transformer buffering the arc detection signal and outputting a pulse, a switch transient detector detecting a voltage differential across load switches and outputting a pulsed switch transient detection signal when the voltage differential across load switches exceeds a reference value, a line interrupter such as a static relay, a switch controller including logic gates generating a trip signal based on predetermined criteria, and a manual switch for resetting the line interrupter. A second embodiment of the present invention senses voltage induced in a coil wrapped around a toroidal core to detect current variations in conductors which pass through the center of the toroidal core.

Self-testing features of sensing and control electronics for a power grid protection system

Systems and method for detecting potentially harmful harmonic and direct current signals at a transformer are disclosed. One system includes a protection circuit electrically connected to a transformer neutral, the transformer electrically connected to a power grid, the protection circuit including a DC blocking component positioned between the transformer neutral and ground and one or more switches selectively actuated to form a path between the transformer neutral and ground in the event of unwanted DC current at the transformer neutral. The system also includes a control circuit electrically connected to the protection circuit and positioned to selectively actuate the switches based on observed conditions within the protection circuit. The system further includes a plurality of test connections disposed within the protection circuit and useable to test electrical properties of the protection circuit.

Continuous uninterruptable AC grounding system for power system protection

A continuous grounding system for use in an alternating current system including a transformer is disclosed. The system includes a switch assembly connected between a transformer neutral of a transformer and a ground, the switch assembly having an open position and a closed position, the open position disrupting the path through the switch assembly between the electrical connection and the transformer neutral, and the closed position establishing a path connecting the electrical connection to the transformer neutral through the switch assembly, wherein in normal operation of the alternating current electrical device the switch assembly remains in a closed position. The system also includes a DC blocking component positioned in parallel with the switch assembly and connected between the transformer neutral and the ground. The system further includes a control circuit configured to control the switch assembly, the control circuit including a sensor configured to actuate the switch assembly to an open position upon detection of a predetermined harmonic signal threshold at one of the transformer phases or a predetermined threshold of DC current between the transformer neutral and ground.

Arc detection

In a method for detection of an arc in a current path of a converter arrangement ( 2 ) for converting a DC input power to an output power, an arc is detected by sensing the current ( 4 ) in the current path by means of a current transformer ( 11 ), filtering the current signal ( 4 ′) with an analog band pass filter ( 14 ), converting the analog filtered current signal ( 4 ″) into a digital current signal ( 4 ′″), determining the harmonic content ( 19 ) of the digital current signal ( 4 ′″) and then deciding whether an arc exists if the harmonic content ( 19 ) exceeds a threshold, where the threshold is determined at the beginning as a multiple of the average harmonic content during a certain period of time of the current signal.

Device for recognising insulation deterioration

The main object of the invention is to obtain a device (1) for recognising an insulation deterioration, which is capable of recognising without fail a short-duration in-phase current oscillating at high frequency, such as flows at the initial stage in the occurrence of an insulation deterioration, and to determine the corresponding circuit line in which such a deterioration is occurring. The tertiary in-phase voltage (V0) from an earthed transformer and in-phase currents (Ig1-Ign) from in-phase follow-current convertors are input into the device in corresponding circuit lines. There they pass through a corresponding half-wave filter (4) into a peak-value holding stage (5) for a corresponding circuit line. The corresponding peak values are summed for each circuit line by an arithmetic stage (6) and the positive or negative polarity of each total value is compared in a polarity-comparator stage (7) with the positive or negative polarity of the in-phase voltage. If matching of the polarities is recognised for one circuit line, this is determined as being the circuit line having insulation deterioration. <IMAGE>

Multi-pole arcing fault circuit breaker including a neutral current sensor

A fault detection system is provided for a power distribution system having at least first and second line conductors carrying AC currents that are out of phase with each other from a source to a load, and a common neutral conductor. The system includes an arcing fault current sensor comprising a coil wound on a hollow core and coupled to both of the line conductors in a manner that the electrical currents in the line conductors flow in opposite directions inside the hollow core, thus inducing in the coil an output signal that is a function of the difference of the electrical currents in the line conductors. A neutral current sensor produces an output signal representing the magnitude and phase direction of current in the neutral conductor. An arcing fault detection circuit includes a processor programmed to (1) respond to a change in the first output signal to analyze the second output signal to determine whether the change in the first output signal is attributable at least in part to current in a line-to-line circuit, (2) if the answer is affirmative, determine a scaling factor to be used to adjust the value of the first output signal, and (3) analyze the adjusted first output signal to determine whether an arcing fault has occurred and produce a trip signal in response to the detection of an arcing fault.

medium voltage mains disconnecting sectioning method showing disturbance, medium voltage mains disconnecting line applied to it and electronic circuit for detecting faulty current comprised in said mating

Método de seccionamento com seccionador de linha de distribuição de energia elétrica de média tensão que exibe distúrbio, seccionador de linhas de distribuição de energia elétrica de média tensão a ele aplicado e circuito eletrónico para detectar corrente defeituosa compreendido no mencionado seccionador. Método de seccionamento de linha de média tensão que apresenta distúrbio, que compreende: (a) avaliação de corrente com bobina de detecção; (b) conversão da intensidade em diferença de potencial, transferindo as informações para microprocessador; (c) análise do perfil da onda gerada pela corrente por meio algoritmo para análise de harmónicos por meio de Séries de Fourier; e (d) determinação do comportamento do seccionador a partir do resultado obtido em (c). A etapa (d) compreende: não efetuar contagem para desconexão se (i) a corrente não exceder valor previamente determinado como corrente defeituosa; (ii) o perfil de onda corresponder a corrente "in-rush"; ou (iii) efetuar contagem para desconexão se o perfil de onda corresponder a curto-circuito que excede o valor previamente determinado como corrente defeituosa. Dado o caso de (d) (ii), o método compreende (e>: (i> não acionar o mecanismo de desconexão no caso de falha transitória; ou (ii) efetuar a desconexão ao atingir-se número de contagens previamente determinado. O método pode ainda, simultaneamente com (e) (ii), compreender (f) envio de sinal de RF a outro(s) seccionador(es) conectado(s) em paralelo em um ponto da linha de distribuição, para que sejam desconectados em conjunto. Seccionador de linhas de distribuição de energia elétrica para ramais auxiliares, em que a linha principal é protegida por disjuntor de reposição automática, que compreende circuito eletrónico com microprocessador capaz de identificar corrente defeituosa permanente de transitória, imunizando o seccionador contra as correntes "in-rush"; e o mencionado circuito eletrónico. Disruption method with medium voltage ...

Electric arc identification equipment, corresponding method and electronic unit

本发明涉及一种识别设备（100），用于识别在第一载电流的元件（103a；903a）与至少一个能导电的元件（103b，108；903b，907）之间出现的电弧（104a‑i；909）；所述识别设备（100）具有至少一个测量装置（101；901，902）和分析装置（102）；所述至少一个测量装置（101；901，902）被构造为，测量流经所述第一载电流的元件（103a；903a）的电流（I）；所述分析装置（102）被构造为：确定所测量到的电流（I）的频谱，并且基于所确定的频谱的高频范围，识别出在所述第一载电流的元件（103a；903a）与所述至少一个能导电的元件（103b，108；903b，907）之间出现的电弧（104a‑i；909）。

Electric short circuit monitoring device for speed-controlled three phase current motors, including their leads

Method and apparatus for protecting power transformers from large electro-magnetic disturbances

A protective system for a power transformer having a neutral line connected to ground where large currents can flow in the neutral line due to electro-magnetic disturbances. The system includes circuitry for; (a) sensing the current level in the neutral line and whether it exceeds a predetermined threshold for a predetermined period; and (b) sensing and processing the harmonic content of the load current and determining the existence of certain relationships of the "even" and "odd" harmonics. Signals, including alarms, indicative of excessive conditions are produced. The system may also include circuitry for sensing the load current level and generating a signal alarm if the load level is above a given value when the harmonics and the DC current have values in excess of certain predetermined values.

A protection relay for preventing over-current caused by harmonic wave

A protection relay for preventing an over-current caused by a harmonic wave is provided to protect a system according to a characteristic of the harmonic wave by calculating currents of R, S, T, and N phases. Current detection units(20) are connected to the R, S, T, and N phases passing through a circuit breaker(10) and detect currents of R, S, T, and N phases respectively. A harmonic wave analyzing unit(40) receives the currents of the R, S, T, and N phases and detects fundamental wave currents of the phases and harmonic wave currents by orders. An A/D conversion unit(50) converts signals of the fundamental wave currents of the phases and the harmonic wave currents by each of the orders into digital signals. A microprocessor(60) outputs a control signal to generate a trip signal or an alarm signal to trip the circuit breaker when an operated value exceeds a predetermined value. The operated value is obtained by giving weights in proportion to frequencies of corresponding fundamental waves and harmonic waves by each of the orders to the fundamental wave currents and the harmonic wave currents by each of the orders. An input and output unit(70) transmits the predetermined value to the microprocessor and outputs the control signal from the microprocessor. A trip output unit(80) outputs the trip signal to trip the circuit breaker according to the control signal of the microprocessor.

Dry-type hollow series reactor turn-to-turn fault monitoring and protection identification method

本发明公开了一种用于并联电容器组的干式空心串联电抗器匝间故障监测及保护识别方法，涉及电力系统电气设备故障保护领域。目前，缺乏对电容器组并联串联电抗器匝间短路故障发展过程中引发、激发复杂电磁场能量转化的认识，没有关注到匝间短路故障会伴随次生接地故障发生。本方法通过采集母线PT电压，采集角形接线变压器角内套管CT三相电流(I a 、I b 、I c )或电容器支路CT电流I′ a 、I′ b 、I′ c ，实时计算HR(I ab )、HR(I bc )、HR(I ca )值或HR(I′ a )、HR(I′ b )、HR(I′ c )值及相互关系识别；在谐波电流的主导频次与电抗率的一致性识别和母线接地辅助信号识别后实现故障识别和保护，该方法能在设备发生匝间故障初期进行准确识别与故障相位确定，及时进行告警及切断电源。

People protecting ground fault circuit breaker utilizing waveform characteristics

46,196 PEOPLE PROTECTING GROUND FAULT CIRCUIT BREAKER UTILIZING WAVEFORM CHARACTERISTICS ABSTRACT OF THE DISCLOSURE A ground fault circuit breaker is provided which includes means for sensing ground fault current and for analyzing the waveform of the ground fault current. An operating mechanism automatically separates the contacts of the circuit breaker upon detection of ground fault current waveforms corresponding to the waveform of current passing through human skin. In a preferred embodiment, means are provided to synchronously detect the third harmonic com-ponent of ground fault current using phase and amplitude information to determine the presence of a ground fault path through human skin. Alternatively, means are provided to sense peak and average values of ground fault current and to trip the breaker whenever the ratio of peak to average ground fault current exceeds a predetermined level. In another alternative, the slope of the ground fault current at zero crossing is detected and compared to the ground fault current peaks. Whenever the ratio of peak current to zero crossing slope exceeds a predetermined level, the mechanism of the breaker is tripped.

Panel board built-in zero harmonic filter equipped function of saving power

본 발명은 절전 기능이 내장된 영상 고조파 필터가 내장된 분전반에 관한 것이다. 본 발명의 바람직한 일 실시예에 따른 영상 고조파 필터가 내장된 분전반은 절전 기능이 내장된 영상 고조파 필터가 내장된 분전반에 있어서, R 상 부스바, S 상 부스바, T 상 부스바 및 N 상 부스바와 전기적으로 연결되며, 영상 고조파를 내부에서 순환시키는 것에 의해 영상 고조파를 제거하는 지그재그결선 변압기; 상기 지그재그결선 변압기와 상기 R 상 부스바, S 상 부스바 및 T 상 부스바를 각각 연결하는 라인 상에 위치하는 스위칭부: 및 상기 스위칭부를 온 또는 오프시키는 것에 의해, 상기 지그재그결선 변압기를 상기 R 상 부스바, S 상 부스바 및 T 상 부스바와 전기적으로 연결 또는 분리시키는 제어부를 포함한다. The present invention relates to a distribution board having a built-in image harmonic filter with a built-in power saving function. A distribution board having a video harmonic filter according to a preferred embodiment of the present invention includes an image harmonic filter having a built-in power saving function. The distribution board includes an R phase busbar, an S phase busbar, a T phase busbar, A zigzag wiring transformer electrically connected to the bar to eliminate image harmonics by circulating image harmonics internally; A switching unit located on a line connecting the zigzag wiring transformer and the R phase booth bar, the S phase booth bar and the T phase booth bar, respectively; and switching the zigzag wiring transformer on the R phase And a control section for electrically connecting or disconnecting the busbar, the S phase busbar, and the T phase busbar.

Method and apparatus for detecting faults in an electric power distribution system

Open conductors in an electric power distribution system are detected by sensing the abrupt change in balance of transformer magnetizing current among phases, particularly the third harmonic of the power system frequency. The current is sensed in each phase and the absolute magnitude of the third harmonic current is compared among the phases. When imbalance exceeds a predetermined value, a signal is produced.

Protection apparatus for inverter of solar power generation

The present invention relates to a device for protecting an inverter for photovoltaic power generation, the device which performs operation for protecting an inverter, when not only an N line is disconnected but also external force is generated, and can automatically re-operate the inverter when the external force is removed. The device for protecting an inverter for photovoltaic power generation comprises: a voltage sensing unit which is connected to a three-phase and four-wire type power line and senses and notifies each three-phase voltage; a failure cause determination unit which identifies and notifies disconnection of the N line, when three-phase voltages are different from each other but the sum of all three-phase voltages is a predetermined value, and identifies and notifies the generation of external force when the three-phase voltages are different and the sum of all three-phase voltages is different from the predetermined value; an N line replacement unit which performs an operation for replacing the N line when disconnection of the N line is identified; and an inverter operation control unit which stops operation of the inverter when generation of the external force is identified.

Arc fault detector with circuit interrupter

A method and apparatus are provided for detecting the occurrence of arcing of a conductor by monitoring the current on an AC power line.

Arc protection device and method of operating the same

本发明涉及用于检测电网络和电设施中的电弧作用并且保护电网络和电设施免受电弧作用的方法和装置。用于保护受保护电路免受电弧作用的装置的操作方法包括：在每个电压半周期中测量处于高频带的电流信号、处于中频带的电流信号、处于低频带的电压信号以及处于中频带的电压信号。基于所测量的信号，确定每个电压半周期中被分离电弧的存在；收集设定的时间段内关于被分离电弧的信息，并且以电弧参数的形式存储所述信息。当电弧参数达到设定值时，记录电弧，并生成用以将受保护电路与网络断开连接的信号。用于保护电路免受电弧作用的装置(1)包括电压读取单元(2)、电流传感器(3)、高频电流信号检测单元(4)、中频电流信号检测单元(5)、微控制器(6)、电源单元(7)和断开连接构件(8)。本发明的技术结果在于增加确定电弧事件的准确性，减少电弧保护装置的误启用的数量，以及增加工作范围、所连接的电器设备的数量、受保护电路的长度及其包含的分支的数量。

Method for identifying arcing faults and circuit breaker

The invention relates to a method (60, 76, 88, 112) for identifying arcing faults within a circuit having a system frequency, an electrical current and an electrical voltage, in which method an interference signal (28) occurring, which has a frequency below an LF1 frequency and a current intensity above an LF1 limit threshold, defines an LF1 signal, in which a number of interference signals (28) occurring, which have a frequency below an HF2 frequency (42), are combined to form an HF2 signal (48) if the number of interference signals (28) occurring is greater than or equal to an HF2 number (50) and the time interval between two successive interference signals (28) is less than an HF2 time (46), in which the number of time periods (52) with a respective length which amounts to an accumulation length (54) and which follow one another directly in time and in which in each case at least one HF2 signal (48) is present define an accumulation (56) when the number of time periods (52) is greater than or equal to an accumulation number (58).

Digital protective relay

The present disclosure relates to provide an active erroneous sample elimination device or erroneous sample elimination method for a relay capable of correctly implementing erroneous sample elimination processing even during a plurality of electrical disturbances mixed with an electrical quantity detection signal, and a digital protective relay according to the present disclosure may include a converter that samples an analog signal and converts the sampled signal to a digital signal; and a processor that searches an inflection point at which an electrical variation quantity varies from an increase to a decrease or from a decrease to an increase based on the digital signal, and compares an electrical variation quantity prior to and subsequent to the inflection point with a preset electrical quantity.

Transformer protection circuit and method

Systems and methods for protecting an electrical component in an alternating current system that includes a transformer are disclosed. In one aspect, a circuit includes a switch assembly connected between a transformer neutral of a transformer and a ground and having an open position and a closed position. In normal operation, the switch remains in a closed position. The circuit further includes a DC blocking component positioned in parallel with the switch assembly and connected between the transformer neutral and the ground, a voltage probe connected between the transformer neutral and ground and configured to monitor an instantaneous voltage level at the transformer neutral, and a control circuit configured to control the switch assembly, the control circuit including a sensor configured to actuate the switch assembly to an open position at least upon detection of a harmonic signal in at least one phase of the transformer or a predetermined threshold of DC or quasi DC current between the transformer neutral and the ground.

Sensing and control electronics for a power grid protection system

Systems and method for detecting potentially harmful harmonic and direct current signals at a transformer are disclosed. One such system includes a plurality of detection components electrically connected to electrical signal lines leading from one or more connection points on a power grid, and a plurality of threshold detectors, each threshold detector configured to compare an incoming signal from a detection component to a predetermined signal having a threshold. The system also includes a controller receiving an output from each of the plurality of threshold detectors and configured to drive at least one external component in response to receiving an indication from at least one of the plurality of threshold detectors of a detected signal above a threshold.

Fault detection and circuit interrupter devices and systems

Arc fault current interrupter electrical devices and systems. An example is an electrical device comprising: a contact configured for electrical connection to a power line; at least one sensor to detect at least voltage signals indicative of the power line; and a processor configured to determine from the detected voltage signals that a series arc fault has occurred.

Relay protection method of LC parallel circuit detuning faults and device thereof

本发明公开LC并联回路失谐故障的继电保护方法，步骤是：继电保护装置对并联LC(电抗器和电容器)的电流进行采样，对流过整个LC的总电流进行采样；将电抗器电流转换为等效电容器电流；采用全周波傅立叶等数值算法，计算得到等效电容器电流和实际电容器电流的幅值，计算得到流过LC的总电流幅值；进一步计算等效电容器与实际电容器的电流幅值比率；当流过LC的总电流幅值足够大时，如果电流比率超出预先整定上限、下限范围，则经延时发出报警信号或跳闸信号及输出跳闸继电器空接点。另外本发明还提供了相应的装置。此发明保留了原有接线简单、方法可靠的特点，同时改善了电流比率计算结果的稳定性，提高了保护的灵敏度与快速性。

Coordinated high-impedance fault detection systems and methods

Systems and methods are presented for detecting high-impedance faults (HIFs) in an electric power delivery system using a plurality of coordinated high-impedance fault detection systems. In certain embodiments, a method for HIFs may include receiving first and second current representations associated with first and second locations of the electric power delivery system respectively. Based on at least one of the first and second current representations, the occurrence of an HIF may be determined. A relative location of the HIF may be determined based on a relative amount of interharmonic content associated with an HIF included in the first and second current representations, and a protective action may be taken based on the determined relative location.

Sensing and Control Electronics for a Power Grid Protection System

변압기에서 잠재적인 유해 고조파 및 직류 신호를 검출하기 위한 시스템 및 방법이 개시된다. 이와 같은 시스템은 전력망 상의 하나 이상의 연결지점으로부터 이어지는 전기 신호선에 전기적으로 연결된 복수의 검출 컴포넌트, 및 복수의 임계값 검출기를 포함하며, 각 임계값 검출기는 검출 컴포넌트로부터 들어오는 신호와 임계값을 가지는 소정의 신호를 비교한다. 이 시스템은 복수의 검출기 각각으로부터 출력을 수신하고, 임계값 이상으로 검출된 신호에 대한 복수의 임계값 검출기 중 적어도 하나로부터 수신되는 지시에 대응하여 외부 컴포넌트를 구동하도록 구성된 컨트롤러를 또한 포함한다. Systems and methods are disclosed for detecting potentially harmful harmonics and direct current signals in a transformer. Such a system includes a plurality of detection components electrically connected to electrical signal lines running from one or more connection points on the power grid, and a plurality of threshold detectors, each threshold detector having a predetermined value with a signal coming from the detection component and a threshold value. Compare the signals. The system also includes a controller configured to receive an output from each of the plurality of detectors and to drive an external component in response to an indication received from at least one of the plurality of threshold detectors for the signal detected above the threshold.

Afci self-test

Um einen Fehler (F) in einer Anordnung, umfassend einen Transformator (2), welcher eine in Serie zu einer Gleichspannungsleitung (DC+, DC-) geschaltete Primärwicklung (L1) und eine mit der Primärwicklung (L1) magnetisch gekoppelte Sekundärwicklung (L2) aufweist, und umfassend eine Auswerteeinheit (5), welche ein Sekundärsignal (i2) auf der Sekundärwicklung (L2) verarbeitet, zu erkennen wird erfindungsgemäß aus dem Sekundärsignal (i2) ein Signalanteil (n(fn)) bei zumindest einer Frequenz (fn) ermittelt und ein Signalpegel (P(fn)) des Signalanteils (n(fn)) mit einer Signalschwelle (P_min(fn)) verglichen. Der der Fehler (F) wird detektiert, wenn der Signalpegel (P(fn)) die Signalschwelle (P_min(fn)) unterschreitet. An error (F) in an arrangement, comprising a transformer (2) which has a primary winding (L1) connected in series with a DC voltage line (DC +, DC-) and a secondary winding (L2) magnetically coupled to the primary winding (L1) , and comprising an evaluation unit (5) which processes a secondary signal (i2) on the secondary winding (L2). According to the invention, a signal component (n (fn)) is determined from the secondary signal (i2) at at least one frequency (fn) and a signal level (P (fn)) of the signal component (n (fn)) is compared with a signal threshold (P_min (fn)). The fault (F) is detected when the signal level (P (fn)) falls below the signal threshold (P_min (fn)).

Apparatus and method to detect a series arc fault of an electrical circuit

本发明涉及用于检测电路的串联电弧故障的装置和方法。装置(50)用于向负载(66)提供交流电流的电力电路(68)。该装置包括高频电流传感器(52)，其构成为与电力电路配合以提供高频电流信号。电压过零检测器(62)构成为与电力电路配合以提供电压过零信号(74)。高通滤波器(54)构成为由高频电流信号提供滤波后的电流信号。阈值比较器(58)构成为当滤波后的电流信号超过预定值时提供输出(59)。处理器(60)构成为接收电压过零信号和阈值比较器的输出，通过对于预定周期数检测不对称高频信号，响应于不希望的串联电弧(70)地输出脱扣信号(76)。

HIGH RESISTANCE IN AN ENERGY DISTRIBUTION NETWORK BY MEASURING ELECTRICITY

Method for the selective detection of resistance defects in power distribution networks

Earth protection device sensitive to arc currents, trip device and circuit breaker comprising such a device

An earth protection device having an input for receiving a first signal representative of an earth fault current, a first signal processing module, and a module for processing protection functions connected to the first signal processing module. The device includes a second signal processing module connected between the input and the first signal processing module for processing the first signal representative of the earth fault current and for supplying to the first signal processing module a second signal representative of the earth fault current. In order to increase the value of the second signal over an RMS value when the fault current comprises pulses of short duration, the second signal has, at decreasing second signal values, a gradient lower than a preset gradient limiting value.