Systeme und Verfahren zum Vorhersagen von Polarisationskurven in einem Brennstoffzellensystem

Die vorliegende Offenbarung betrifft Systeme und Verfahren, die verwendet werden können, um eine Leistungsmetrik einer Brennstoffzelle vorherzusagen. Ein System in Übereinstimmung mit der vorliegenden Offenbarung kann Sensoren in Kommunikation mit dem Brennstoffzellenstapel, ein Leistungsmetrik-Vorhersagesystem und ein Steuerungssystem umfassen. Das Leistungsmetrik-Vorhersagesystem kann eine Stromdichte auf der Basis von Eingängen, die von den Sensoren bereitgestellt werden, bei einer Vielzahl von Zeitspannen bestimmen, einen ersten Parameter berechnen, während die Stromdichte unter einer unteren Schwelle liegt, und einen zweiten Parameter berechnen, während die Stromdichte über einer oberen Schwelle liegt. Der erste Parameter und der zweite Parameter können verwendet werden, um selektiv eine Brennstoffzellen-Polarisationskurve mit der Zeit anzupassen. Auf der Basis der Polarisationskurve kann eine Leistungsmetrik des Brennstoffzellenstapels vorhergesagt werden. Das Steuerungssystem kann eine Steuerungsaktion auf der Basis der Leistungsmetrik umsetzen.

Method to perform adaptive voltage suppression of a fuel cell stack based on stack parameters

Feedback control of H2 injection during park based on gas concentration model

A method for determining when to inject hydrogen gas into the anode side of a fuel cell stack associated with a fuel cell vehicle when the vehicle is off. The method includes estimating the concentration of hydrogen gas in the anode side of the fuel cell stack using a gas concentration model and determining if the estimated concentration of hydrogen gas is below a first predetermined threshold. If the estimated hydrogen gas is less than the threshold, then hydrogen gas is injected into the anode side from a hydrogen source. While the hydrogen gas is being injected, the method compares the estimated concentration of the hydrogen gas in the anode side to a desired concentration, and generates an error signal there between. If the error signal is greater than a second predetermined threshold, the algorithm continues to inject the hydrogen into the anode side of the fuel cell stack.

Verfahren zum Verbessern der Zuverlässigkeit eines Brennstoffzellensystems mit Hilfe von Detektion einer leistungsschwachen Zelle bei Betrieb mit niedriger Leistung

Ein System und Verfahren zum Detektieren einer leistungsschwachen Zelle in einem Brennstoffzellenstapel mit Hilfe von gemessenen elektrischen Zellenspannungen. Das Verfahren umfasst das Ermitteln, dass der Brennstoffzellenstapel in Betrieb ist, die Kühlmitteltemperatur des Stapels über einer bestimmten Temperatur liegt und die elektrische Stromdichte des Stapels innerhalb eines relativ niedrigen Leistungsbereichs liegt. Das Verfahren umfasst weiterhin das Berechnen der durchschnittlichen elektrischen Zellenspannung und das Ermitteln, ob die Differenz zwischen der durchschnittlichen elektrischen Zellenspannung und der elektrischen Zellenmindestspannung größer als ein vorbestimmter Schwellenwert ist. Wenn die Differenz zwischen der durchschnittlichen elektrischen Zellenspannung und der elektrischen Zellenmindestspannung größer als der vorbestimmte Schwellenwert ist und die elektrische Zellenmindestspannung kleiner als ein anderer vorbestimmter Schwellenwert ist, dann inkrementiert das Verfahren ein Zeitglied einer leistungsschwachen Zelle. Ein Verhältnis des Zeitglieds der leistungsschwachen Zelle und eines Systembetriebszeitglieds wird berechnet, um eine leistungsschwache Zelle festzustellen.

Verfahren zur automatischen Aktivierung/Deaktivierung einer Stapel-Wiederaufbereitungsprozedur auf der Basis einer Brennstoffzellenstapelparameterabschätzung

System und Verfahren zum Bestimmen, wann eine Wiederaufbereitung eines Brennstoffzellenstapels ausgelöst werden soll und wann die Wiederaufbereitung des Brennstoffzellenstapels deaktiviert werden sollufbereitung ausgelöst, wenn eine Maximalstapelleistungsabschätzung unter eine erste vorbestimmte Leistungsschwelle fällt. Die Wiederaufbereitung des Stapels kann deaktiviert werden, sodass sie nicht ausgeführt wird, wenn die Auslösung stattfindet, falls der Wiederaufbereitungsprozess die Maximalleistungsabschätzung nicht über eine zweite vorbestimmte Leistungsschwelle erhöht oder die Zeit von einer Wiederaufbereitungsauslösung zu einer nächsten Wiederaufbereitungsauslösung kürzer ist als eine vorbestimmte Zeitschwelle, oder beides der Fall ist.

Verfahren und System zum Ermitteln, wann Wasserstoffgas in eine Anode eines Brennstoffzellensystems zu injizieren ist

Verfahren zum Ermitteln, wann Wasserstoffgas in eine Anode eines Brennstoffzellensystems zu injizieren ist, wenn das System abgeschaltet ist, wobei das Verfahren gekennzeichnet ist durch:Schätzen der Wasserstoffgaskonzentration in der Anode;Ermitteln, ob die geschätzte Wasserstoffgaskonzentration in der Anode unter einem vorbestimmten Schwellenwert liegt; undEinspritzenlassen von Wasserstoffgas von einer Wasserstoffquelle in die Anode, während das Brennstoffzellensystem abgeschaltet ist, wenn die geschätzte Wasserstoffgaskonzentration in der Anode kleiner als der Schwellenwert ist.

Method to perform adaptive voltage suppression of a fuel cell stack based on stack parameters

The present invention relates to a method to perform adaptive voltage suppression of a fuel cell stack based on stack parameters. A system and method for maintaining the voltage of fuel cells in the fuel cell stack below a predetermined maximum voltage. The method determines a desired voltage set-point value that defines a predetermined maximum fuel cell voltage value and uses the voltage set-point value and an average fuel cell voltage to generate an error value there-between. The method generates a minimum gross power prediction value using the modified voltage set-point value to prevent the fuel cell voltages from going above the predetermined maximum fuel cell voltage value and generating a supplemental power value based on the minimum gross power prediction value and the error value to determine how much power needs to be drawn from the stack to maintain the fuel cell voltage below the predetermined maximum voltage value. The method uses the supplemental power value to charge the battery ...

Online Low Performing Cell (LPC) Prediction and Detection of Fuel Cell System

A system and method for detecting and predicting low performing cells in a fuel cell stack. When the fuel cell stack is running and certain data validity criteria have been met, an algorithm collects the data, such as stack current density, average cell voltage and minimum cell voltage. This information is used to estimate predetermined parameters that define the stack polarization curve. The system defines a predetermined minimum current density that is used to identify a low performing cell. The system then calculates an average cell voltage and a minimum cell voltage at the minimum current density set-point, and calculates a cell voltage difference between the two. If the cell voltage difference is greater than a predetermined low voltage threshold and the minimum cell voltage is less than a predetermined high voltage threshold, the algorithm sets a flag identifying a potential for a low performing cell.

Verfahren zur Detektion einer leistungsschwachen Zelle in einem Brennstoffzellenstapel

Verfahren zur Detektion einer leistungsschwachen Zelle in einem Brennstoffzellenstapel, wobei das Verfahren umfasst, dass: eine Polarisierungskurve des Brennstoffzellenstapels unter Verwendung von Systemparametern für sowohl eine durchschnittliche Zellenspannung als auch eine minimale Zellenspannung errechnet wird; ein Stromdichte-Sollwert für eine leistungsschwache Zelle bestimmt wird; aus der Polarisierungskurve eine durchschnittliche Zellenspannung bei dem Stromdichte-Sollwert berechnet wird; aus der Polarisierungskurve eine minimale Zellenspannung bei dem Stromdichte-Sollwert berechnet wird; eine Differenzspannung zwischen der durchschnittlichen Zellenspannung und der minimalen Zellenspannung bestimmt wird; und bestimmt wird, ob die Differenzspannung größer als eine erste vorbestimmte Spannungsschwelle ist und/oder die minimale Zellenspannung kleiner als eine zweite vorbestimmte Spannungsschwelle ist, um zu bestimmen, ob der Brennstoffzellenstapel eine leistungsschwache Zelle aufweist.

Adaptive method for conversion of external power request to current setpoint to a fuel cell system based on stack performance

Ein System und Verfahren zum Umwandeln eines Brennstoffzellenstapel- Leistungsforderungssignals in einen Stapelstrom-Sollwert, der Stapelleistungsparameter berücksichtigt. Das Verfahren umfasst das Erhalten einer Kurve der Beziehung von Leistung/elektrischem Strom des Brennstoffzellenstapels, um Stapelparameter, einschließlich Austauschstromdichte und Stoffübergangskoeffizient, vorzusehen. Dann berechnet das Verfahren eine Steigung für den Stapel unter Verwenden der Parameter aus der Schätzung der Kurve der Beziehung von Leistung/elektrischem Strom, was das Berechnen einer Zellenspannung bei zwei vorbestimmten Stapel-Stromdichten umfasst. Dann berechnet das Verfahren als Reaktion auf das Leistungsforderungssignal, die elektrische Spannung des Stapels, den elektrischen Strom des Stapels und die berechnete Steigung eine Änderung des elektrischen Stroms und nutzt die Änderung des elektrischen Stroms, um den Stromsollwert für den Stapel zu aktualisieren.

Verfahren zur Vorhersage der minimalen Zellenspannung aus dem diskreten minimalen Zellenspannungsausgang einer Stapelfunktionszustandsüberwachungseinrichtung und ein System zum Schätzen von Parametern eines Brennstoffzellenstapels

Verfahren zur Vorhersage des Trends einer minimalen Zellenspannung von Brennstoffzellen in einem Brennstoffzellenstapel (20), wobei das Verfahren umfasst, dass:eine Brennstoffzellenstapelspannung und -stromdichte des Brennstoffzellenstapels (20) überwacht werden;eine durchschnittliche Zellenspannung aus der gemessenen Stapelspannung auf der Basis der Anzahl von Brennstoffzellen in dem Stapel (20) bestimmt wird;eine minimale Zellenspannung der Zellen in dem Stapel (20) überwacht wird;bestimmt wird, ob die minimale Zellenspannung unter einen ersten vorbestimmten Schwellenwert fällt;ein erster Satz von künstlichen Datenpunkten für eine Zellenspannung nahe dem ersten Schwellenwert erzeugt wird, wenn die minimale Zellenspannung unter den ersten Schwellenwert fällt;bestimmt wird, ob die minimale Zellenspannung unter einen zweiten vorbestimmten Schwellenwert fällt, wobei der zweite vorbestimmte Schwellenwert kleiner ist als der erste vorbestimmte Schwellenwert;ein zweiter Satz von künstlichen ...

SYSTEMS AND METHODS FOR PREDICTING POLARIZATION CURVES IN A FUEL CELL SYSTEM

The present disclosure relates to systems and methods that may be used to predict a performance metric of a fuel cell. A system consistent with the present disclosure may include sensors in communication with the fuel cell stack, a performance metric prediction system, and a control system. The performance metric prediction system may determine a current density based on inputs provided by the sensors at a plurality of time periods, calculate a first parameter while the current density is below a lower threshold, and calculate a second parameter while the current density is above an upper threshold. The first parameter and the second parameter may be used to selectively adjust a fuel cell polarization curve over time. Based upon the polarization curve, a performance metric of the fuel cell stack may be predicted. The control system may implement a control action based upon the performance metric.

Algorithmus zur adaptiven Online-Schätzung einer Polarisationskurve eines Brennstoffzellenstapels

Ein Algorithmus zur Ermittlung einer Polarisationskurve eines Brennstoffzellenstapels. Wenn der Brennstoffzellenstapel läuft und gewisse Datenvaliditätskriterien erfüllt sind, tritt der Algorithmus in eine Datensammelbetriebsart ein, in der er Stapeldaten sammelt, beispielsweise eine Stapelstromdichte, eine mittlere Zellenspannung und eine minimale Zellenspannung. Wenn der Stapel ausgeschaltet wird, verwendet der Algorithmus ein Zellenspannungsmodell, um ein Problem kleinster Quadrate zur Schätzung vorbestimmter Parameter zu lösen, welche die Polarisationskurve definieren. Wenn die geschätzten Parameter gewisse Endkriterien erfüllen, dann werden die geschätzten Parameter gespeichert, um von einem Systemcontroller zur Berechnung der Polarisationskurve des Stapels verwendet zu werden.

Adaptive gain scheduled control for current limitation based on voltage performance of a fuel cell system

A system and method for limiting the output current of a fuel cell stack as the stack degrades overtime. A look-up table identifies a predetermined voltage set-point for stack current density. A first comparator provides a voltage difference signal between the set-point and the stack voltage. The voltage difference signal is provided to a controller, such as a proportional-integral controller, that provides a current limiting signal. The current limiting signal and a current request signal are provided to a second comparator that selects which signal will be used to limit the maximum output current of the stack. A polarization curve estimator estimates parameters of the stack that will change over the life of the stack. The parameters are provided to a gain scheduler that provides gains to the controller that are based on where in the life of the stack it is currently operating.

SYSTEMS AND METHODS FOR PREDICTING POLARIZATION CURVES IN A FUEL CELL SYSTEM

The invention relates to systems and methods for predicting polarization curves in a fuel cell system. The present disclosure relates to systems and methods that may be used to predict a performance metric of a fuel cell. A system consistent with the present disclosure may include sensors in communication with the fuel cell stack, a performance metric prediction system, and a control system. The performance metric prediction system may determine a current density based on inputs provided by the sensors at a plurality of time periods, calculate a first parameter while the current density is below a lower threshold, and calculate a second parameter while the current density is above an upper threshold. The first parameter and the second parameter may be used to selectively adjust a fuel cell polarization curve over time. Based upon the polarization curve, a performance metric of the fuel cell stack may be predicted. The control system may implement a control action based upon the performance ...

Power management method using feedback current bias for simultaneously controlling low cells and overall stack voltage

A method for controlling the current output from a fuel cell stack to prevent the stack voltage or the minimum fuel cell voltage from dropping below predetermined voltage set-points. The method for the stack voltage control includes determining whether the stack voltage has dropped to the predetermined voltage set-point, and if so, capturing and holding the actual stack current at that point as the maximum allowed stack current. If the stack voltage continues to fall below the voltage set-point, then the voltage set-point is subtracted from the actual voltage to get a positive error signal. Controller gains are then multiplied by the error signal to reduce the current allowed from the stack to drive the error signal to zero, and increase the stack voltage. The method for the minimum fuel cell voltage operates in the same manner, but with different values.

Verfahren zur Berechnung der maximalen Nettoleistung für ein Brennstoffzellensystem auf der Basis eine Online-Polarisationskurvenabschätzung

Es ist ein Algorithmus zum Ermitteln der maximalen Nettoleistung, die von einem Brennstoffzellenstapel verfügbar ist, während der Stapel mit der Zeit degradiert (abgenutzt wird), unter Verwendung einer adaptiven Online-Abschätzung einer Polarisationskurve des Stapels vorgesehen. Der Algorithmus trennt den Stromdichtebereich des Stapels in Abtastbereiche auf und wählt einen ersten Abtastbereich von ganz links von der abgeschätzten Polarisationskurve. Dann berechnet der Algorithmus die Zellenspannung für diesen Stromdichteabtastbereich und ermittelt, ob die berechnete Zellenspannung kleiner oder gleich einer vorbestimmten Zellenspannungsgrenze ist. Wenn die berechnete Zellenspannung nicht kleiner ist als die Zellenspannungsgrenze, dann wählt der Algorithmus den nächsten Abtastbereich entlang der Polarisationskurve. Wenn die berechnete Zellenspannung diese Zellenspannungsgrenze erreicht, dann verwendet der Algorithmus die Stromdichte für den analysierten Abtastbereich, um die maximale Leistung ...

Verfahren zum Verringern und Steuern der Stromabgabe eines Brennstoffzellenstapels

Verfahren zum Verringern und Steuern der Stromabgabe von einem Brennstoffzellenstapel (12) als Antwort darauf, dass eine Ausgangsspannung des Brennstoffzellenstapels auf einen vorgegebenen Stapelspannungs-Sollwert fällt, wobei das Verfahren umfasst: Bestimmen, ob die Stapelspannung auf den vorgegebenen Spannungssollwert gefallen ist (34, 36, 42); Halten der Stromabgabe, die dem Brennstoffzellenstapel (12) entnommen wird, wenn die Spannung auf den Spannungssollwert fällt, als eine maximale Stapelstromabgabe, die von dem Brennstoffzellenstapel (12) zulässig ist (62); Bestimmen, ob die Stapelspannung unter den Stapelspannungs-Sollwert gefallen ist (52); Subtrahieren des Stapelspannungs-Sollwerts von der tatsächlichen Stapelspannung, um ein erstes positives Fehlersignal zu erhalten, falls die Stapelspannung unter den Spannungssollwert gefallen ist (38, 54); und Multiplizieren des Fehlersignals mit wenigstens einem Verstärkungssignal, um die maximale Stapelstromabgabe zu verringern, die von ...

Method to improve reliability of a fuel cell system using low performance cell detection at low power operation

A system and method for detecting a low performing cell in a fuel cell stack using measured cell voltages. The method includes determining that the fuel cell stack is running, the stack coolant temperature is above a certain temperature and the stack current density is within a relatively low power range. The method further includes calculating the average cell voltage, and determining whether the difference between the average cell voltage and the minimum cell voltage is greater than a predetermined threshold. If the difference between the average cell voltage and the minimum cell voltage isgreater than the predetermined threshold and the minimum cell voltage is less than another predetermined threshold, then the method increments a low performing cell timer. A ratio of the low performing cell timer and a system run timer is calculated to identify a low performing cell.

Regelung von H2-Injektion beim Parken beruhend auf Gaskonzentrationsmodell

Ein Verfahren zum Ermitteln, wann Wasserstoffgas in die Anodenseite eines einem Brennstoffzellenfahrzeug zugeordneten Brennstoffzellensystems zu injizieren ist, wenn das Fahrzeug abgeschaltet ist. Das Verfahren umfasst das Schätzen der Wasserstoffgaskonzentration in der Anodenseite des Brennstoffzellenstapels unter Verwenden eines Gaskonzentrationsmodells und das Ermitteln, ob die geschätzte Wasserstoffgaskonzentration unter einem ersten vorbestimmten Schwellenwert liegt. Wenn das geschätzte Wasserstoffgas weniger als der Schwellenwert ist, dann wird Wasserstoffgas von einer Wasserstoffquelle in die Anodenseite injiziert. Während das Wasserstoffgas injiziert wird, vergleicht das Verfahren die geschätzte Wasserstoffgaskonzentration in der Anodenseite mit einer Sollkonzentration und erzeugt ein Fehlersignal dazwischen. Wenn das Fehlersignal größer als ein zweiter vorbestimmter Schwellenwert ist, spritzt der Algorithmus weiter den Wasserstoff in die Anodenseite des Brennstoffzellenstapels ...

Regelung mit Terminierung adaptiver Verstärkung für Strombegrenzung beruhend auf Spannungsleistung eines Brennstoffzellensystems

Ein System und Verfahren zum Begrenzen des Ausgangsstroms eines Brennstoffzellenstapels bei Degradieren des Stapels im Laufe der Zeit. Eine Lookup-Tabelle ermittelt einen vorbestimmten Spannungssollwert für Stapelstromdichte. Ein erster Komparator sieht ein Spannungsdifferenzsignal zwischen dem Sollwert und der Stapelspannung vor. Das Spannungsdifferenzsignal wird einem Regler, beispielsweise einem Proportional-Integral-Regler, geliefert, der ein Strombegrenzungssignal vorsieht. Das Strombegrenzungssignal und ein Stromanforderungssignal werden einem zweiten Komparator geliefert, der wählt, welches Signal zum Begrenzen des maximalen Ausgangsstroms des Stapels verwendet wird. Ein Polarisationskurven-Schätzer schätzt Parameter des Stapels, die sich über die Lebensdauer des Stapels ändern. Die Parameter werden einer Verstärkungsablaufsteuerung geliefert, die dem Regler darauf beruhende Verstärkungen liefert, wo in der Lebensdauer des Stapels er gerade arbeitet.

Verfahren zum Halten einer Ausgangsspannung von Brennstoffzellen in einem Brennstoffzellenstapel bei oder unter einer maximalen Spannung

Verfahren zum Halten einer Ausgangsspannung von Brennstoffzellen in einem Brennstoffzellenstapel bei oder unter einer maximalen Spannung, wobei das Verfahren umfasst, dass: ein gewünschter Spannungssollwert modifiziert wird, der einen vorbestimmten maximalen Brennstoffzellenspannungswert definiert; ein Fehlerwert zwischen dem modifizierten Spannungssollwert und einer durchschnittlichen Brennstoffzellenspannung von den Brennstoffzellen in dem Brennstoffzellenstapel bestimmt wird; ein Minimalbruttoleistungsvorhersagewert mithilfe des modifizierten Spannungssollwerts bestimmt wird, der verwendet wird, um zu verhindern, dass die Brennstoffzellenspannung das vorbestimmte Maximum überschreitet; ein Zusatzleistungswert auf der Basis des Minimalbruttoleistungsvorhersagewerts und des Fehlerwerts bestimmt wird, um zu bestimmen, wie viel Leistung von dem Stapel bezogen werden muss, um die Brennstoffzellenspannung unter dem vorbestimmten maximalen Spannungswert zu halten; eine Batterie mithilfe von ...

Leistungsmanagementverfahren unter Verwendung eines Rückkopplungsvorstroms zum gleichzeitigen Steuern niedriger Zellen- und Gesamtstapelspannung

Ein Verfahren zum Steuern der Stromabgabe von einem Brennstoffzellenstapel, um zu verhindern, dass die Stapelspannung oder die minimale Brennstoffzellenspannung unter vorgegebener Spannungssollwerte fällt. Das Verfahren für die Stapelspannungssteuerung enthält das Bestimmen, ob die Stapelspannung auf den vorgegebenen Spannungssollwert gefallen ist, und wenn das der Fall ist, das Erfassen und das Halten des tatsächlichen Stapelstroms an diesem Punkt als den maximal zulässigen Stapelstrom. Falls die Stapelspannung weiter unter den Spannungssollwert fällt, wird der Spannungssollwert von der tatsächlichen Spannung subtrahiert, um ein positives Fehlersignal zu erhalten. Daraufhin werden die Controllerverstärkungen mit dem Fehlersignal multipliziert, um den von dem Stapel zulässigen Strom zu verringern, um das Fehlersignal auf null anzusteuern und um die Stapelspannung zu erhöhen. Das Verfahren für die minimale Brennstoffzellenspannung arbeitet auf dieselbe Weise, aber mit anderen Werten.

Method to automatically enable/disable stack reconditioning procedure based on fuel cell stack parameter estimation

A system and method for determining when to trigger reconditioning of a fuel cell stack and when to disable the reconditioning of the fuel cell stack. In one embodiment, the stack reconditioning is triggered when a maximum stack power estimation falls below a first predetermined power threshold. The reconditioning of the stack can be disabled so it is not performed when the trigger occurs if the reconditioning process does not raise the maximum power estimation above a second predetermined power threshold or the time from one reconditioning trigger to a next reconditioning trigger is less than a predetermined time threshold, or both.

Selektives Reagieren auf die minimale Zellspannungsabfallrate in einem Brennstoffzellensystem

Ein System und ein Verfahren, welches die Rate eines Spannungsabfalls von Brennstoffzellen in einem Brennstoffzellenstapel überwacht, um zu bestimmen, ob der Spannungsabfall ein Ergebnis einer Verarmung an Kathodenreaktanten oder einer Verarmung an Anodenreaktanten ist. Das Verfahren untersucht eine abfallende Spannung einer Brennstoffzelle, um zu bestimmen, ob die Rate des Abfalls in der Spannung anzeigt, dass eine Verarmung an Wasserstoff an der Anode der Brennstoffzelle auftritt. Das Verfahren zieht dabei die tatsächliche Spannung der Brennstoffzelle in Betracht, welche abfällt, um zu bestimmen, ob diese unter einem vorbestimmten minimalen Spannungsschwellwert ist, welcher ferner anzeigt, dass eine Verarmung an Wasserstoff an der Anode der Brennstoffzelle auftritt. Wenn eine Verarmung an Wasserstoff auftritt, führt das Verfahren eine Beschränkung der Leistungsabgabe des Brennstoffzellenstapels entweder basierend auf der Rate oder der Spannungshöhe aus.

Verfahren zur Vorhersage der minimalen Zellenspannung aus dem diskreten minimalen Zellenspannungsausgang einer Stapelfunktionszustandsüberwachungseinrichtung

System zum Schätzen von Parametern eines Brennstoffzellenstapels. Das System umfasst eine Stapelfunktionszustandsüberwachungseinrichtung zur Überwachung einer minimalen Zellenspannung, der Stapelspannung und der Stromdichte des Brennstoffzellenstapels. Die Stapelfunktionszustandsüberwachungseinrichtung zeigt auch an, wann ein vorbestimmtes minimales Zellenspannungsschwellenniveau erreicht wurde. Das System umfasst ferner einen Controller, der ausgebildet ist, um den Brennstoffzellenstapel zu steuern, wobei der Controller die durchschnittliche Brennstoffzellenspannung bestimmt und speichert. Der Controller erzeugt und speichert künstliche Datenpunkte nahe dem einen oder der mehreren vorbestimmten minimalen Zellenspannungsschwellenniveaus jedes Mal, wenn die minimale Zellenspannung unter das eine oder die mehreren vorbestimmten minimalen Zellenspannungsschwellenniveaus fällt, um so eine Schätzung der Brennstoffzellenstapelparameter einschließlich des Trends einer minimalen Zellenspannung ...

Online-Vorhersage und -Detektion leistungsschwacher Zellen (LPC) von Brennstoffzellensystemen

System und Verfahren zur Detektion und Vorhersage leistungsschwacher Zellen in einem Brennstoffzellenstapel. Wenn der Brennstoffzellenstapel läuft und bestimmte Datenvaliditätskriterien erfüllt worden sind, sammelt ein Algorithmus die Daten, wie Stapelstromdichte, durchschnittliche Zellenspannung und minimale Zellenspannung. Diese Information wird dazu verwendet, vorbestimmte Parameter zu schätzen, die die Stapelpolarisierungskurve definieren. Das System definiert eine vorbestimmte minimale Stromdichte, die dazu verwendet wird, eine leistungsschwache Zelle zu ermitteln. Das System berechnet dann eine durchschnittliche Zellenspannung und eine minimale Zellenspannung bei dem minimalen Stromdichte-Sollwert und berechnet eine Zellenspannungsdifferenz zwischen den beiden. Wenn die Zellenspannungsdifferenz größer als eine vorbestimmte Niedrigspannungsschwelle ist und die minimale Zellenspannung kleiner als eine vorbestimmte Hochspannungsschwelle ist, setzt der Algorithmus einen Flag, der ein ...

Verfahren zur Verbesserung der Leistungsfähigkeit eines Brennstoffzellensystems unter Verwendung einer Zellenspannungsvorhersage eines Brennstoffzellenstapels

System und Verfahren zur Bestimmung der maximal zulässigen Stapelstrombegrenzungsrate für einen Brennstoffzellenstapel, das die Zellenspannung berücksichtigt. Das Verfahren umfasst, dass eine Brennstoffzellenstapelspannung auf Grundlage eines Brennstoffzellenwiderstandswertes, von Stapelvariablen und eines Stromanforderungssignals geschätzt wird. Der Brennstoffzellenwiderstandswert kann auf Grundlage von Stapeltemperatur und relativer Feuchte des Stapels modelliert werden. Die Stapelvariablen können Austauschstromdichte und Massenübertragungskoeffizient aufweisen. Das Verfahren verwendet dann die geschätzte Brennstoffzellenspannung und eine Nachschlagetabelle auf Grundlage von geschätzter Spannung, um einen Stromratenbegrenzungswert zur Änderung des Stromes des Stapels zu bestimmen. Das Verfahren addiert dann den Stromratenbegrenzungswert und das Stromanforderungssignal, um den Stromeinstellpunkt zu erhalten.

Estimation method of hydrogen and nitrogen concentration for use in fuel cell system, involves estimating amount of hydrogen in anode flow-field and plumbing volume, and cathode flow-field volume

The estimation method involves defining fuel cell system (10) as discrete volume including anode flow-field and anode plumbing volume, and estimating amount of hydrogen and nitrogen in anode flow-field and anode plumbing volume, cathode flow-field volume, and cathode header and plumbing volume when fuel cell system is shutdown. The amount of hydrogen in anode flow-field and plumbing volume, and cathode flow-field volume is estimated based on estimation of hydrogen and nitrogen in the anode flow-field and plumbing volume, cathode flow-field volume, and cathode header and plumbing volume. An independent claim is also included for a hydrogen and nitrogen concentration estimation system in fuel cell system.

SYSTEME UND VERFAHREN ZUM VERBESSERN EINER INBETRIEBNAHME EINES BRENNSTOFFZELLENFAHRZEUGS

Verfahren und Systeme zum Verbessern der Leistungsfähigkeit von Brennstoffzellen in Brennstoffzellenfahrzeugen. Einige Ausführungsformen umfassen ein Stromsteuermodul zum Steuern des Anlegens einer Last an die Brennstoffzelle sowie ein Spannungsüberwachungsmodul zum Überwachen einer oder mehrerer Spannungen in der Brennstoffzelle. Das Stromsteuermodul kann derart konfiguriert sein, eine Verzögerungsperiode anzulegen, bevor eine Last an die Brennstoffzelle angelegt wird, nachdem die Brennstoffzelle eine Leerlaufspannung erreicht hat. Bei anderen Ausführungsformen kann eine fixierte Verzögerungsperiode angelegt werden, bevor eine Last an die Brennstoffzelle angelegt wird, nachdem die Brennstoffzelle eine Leerlaufspannung erreicht hat, oder beispielsweise ein inkrementeller Satz von Verzögerungsperioden angelegt werden, die zunehmen, wenn die gemessene Temperatur abnimmt.

SPECTRAL NOISE SHAPING IN AUDIO CODING BASED ON SPECTRAL DYNAMICS IN FREQUENCY SUB-BANDS

A technique of spectral noise shaping in an audio coding system is disclosed. Frequency decomposition of an input audio signal is performed to obtain multiple frequency sub-bands that closely follow critical bands of human auditory system decomposition. The tonality of each sub-band is determined. If a sub-band is tonal, time domain linear prediction (TDLP) processing is applied to the sub-band, yielding a residual signal and linear predictive coding (LPC) coefficients of an all-pole model representing the sub-band signal. The residual signal is further processed using a frequency domain linear prediction (FDLP) method. The FDLP parameters and LPC coefficients are transferred to a decoder. At the decoder, an inverse-FDLP process is applied to the encoded residual signal followed by an inverse TDLP process, which shapes the quantization noise according to the power spectral density of the original sub-band signal. Non-tonal sub-band signals bypass the TDLP process.

Brennstoffzellensysteme und Verfahren zum Begrenzen des Ausgangsstroms eines Brennstoffzellenstapels

Brennstoffzellensystem umfassend: einen Brennstoffzellenstapel, der ein Ausgangsspannungssignal und ein Ausgangsstromsignal liefert; eine Umwandlungstabelle zum Umwandeln des Ausgangsstromsignals des Brennstoffzellenstapels in ein Spannungssollwertsignal; einen ersten Komparator, der das Spannungssollwertsignal und das Spannungsausgangssignal des Brennstoffzellenstapels miteinander vergleicht und daraus ein Spannungsdifferenzsignal bildet; einen Strombegrenzungsregler, der auf das Spannungsdifferenzsignal und ein von der sich über die Lebensdauer des Brennstoffzellenstapels ändernden maximal aufbringbaren Stapelleistung abhängiges Regelungssignal anspricht, und ein Strombegrenzungssignal liefert; und einen zweiten Komparator, der das Strombegrenzungssignal und ein Stromanforderungssignal miteinander vergleicht und das kleinere dieser beiden Signale auswählt, wobei er dieses kleinere Signal an den Brennstoffzellenstapel liefert, um den von dem Brennstoffzellenstapel maximal abrufbaren Strom ...

Method for maintaining output voltage of fuel cells in fuel cell stack at/below maximum voltage for vehicle, involves coupling auxiliary load to fuel cell stack to reduce fuel cell voltage if maximum battery charge limit is reached

The method involves modifying a desired voltage set-point value and determining a supplemental power value based on a minimum gross power prediction value and an error value to determine power needed to be drawn from the stack to maintain a fuel cell voltage below a predetermined maximum voltage value. A high voltage battery (46) is charged using stack power based on the supplemental power value to reduce the fuel cell voltage. An auxiliary load is coupled to a fuel cell stack (12) to reduce the fuel cell voltage if a maximum battery charge limit is reached. An independent claim is included for system for maintaining output voltage of fuel cells in fuel cell stack.

Algorithm for online adaptive polarization curve estimation of a fuel cell stack

Method to improve reliability of a fuel cell system using low performance cell detection at low power operation

A system and method for detecting a low performing cell in a fuel cell stack using measured cell voltages. The method includes determining that the fuel cell stack is running, the stack coolant temperature is above a certain temperature and the stack current density is within a relatively low power range. The method further includes calculating the average cell voltage, and determining whether the difference between the average cell voltage and the minimum cell voltage is greater than a predetermined threshold. If the difference between the average cell voltage and the minimum cell voltage is greater than the predetermined threshold and the minimum cell voltage is less than another predetermined threshold, then the method increments a low performing cell timer. A ratio of the low performing cell timer and a system run timer is calculated to identify a low performing cell.

Spectral noise shaping in audio coding based on spectral dynamics in frequency sub-bands

A technique of spectral noise shaping in an audio coding system is disclosed. Frequency decomposition of an input audio signal is performed to obtain multiple frequency sub-bands that closely follow critical bands of human auditory system decomposition. The tonality of each sub-band is determined. If a sub-band is tonal, time domain linear prediction (TDLP) processing is applied to the sub-band, yielding a residual signal and linear predictive coding (LPC) coefficients of an all-pole model representing the sub-band signal. The residual signal is further processed using a frequency domain linear prediction (FDLP) method. The FDLP parameters and LPC coefficients are transferred to a decoder. At the decoder, an inverse-FDLP process is applied to the encoded residual signal followed by an inverse TDLP process, which shapes the quantization noise according to the power spectral density of the original sub-band signal. Non-tonal sub-band signals bypass the TDLP process.

Online low performing cell (LPC) prediction and detection of fuel cell system

A system and method for detecting and predicting low performing cells in a fuel cell stack. When the fuel cell stack is running and certain data validity criteria have been met, an algorithm collects the data, such as stack current density, average cell voltage and minimum cell voltage. This information is used to estimate predetermined parameters that define the stack polarization curve. The system defines a predetermined minimum current density that is used to identify a low performing cell. The system then calculates an average cell voltage and a minimum cell voltage at the minimum current density set-point, and calculates a cell voltage difference between the two. If the cell voltage difference is greater than a predetermined low voltage threshold and the minimum cell voltage is less than a predetermined high voltage threshold, the algorithm sets a flag identifying a potential for a low performing cell.

Verfahren zum Abschätzen der maximalen Stapelleistung von einem Brennstoffzellenstapel während des Betriebs des Brennstoffzellenstapels

Verfahren zum Abschätzen der maximalen Stapelleistung von einem Brennstoffzellenstapel während eines Betriebes des Brennstoffzellenstapels, wobei das Verfahren umfasst, dass: eine durchschnittliche Zellenspannungsgrenze für eine Brennstoffzelle, die mit durchschnittlicher Leistung arbeitet, in dem Brennstoffzellenstapel gewählt wird; eine minimale Zellenspannungsgrenze für eine mit minimaler Leistung arbeitende Brennstoffzelle in dem Brennstoffzellenstapel gewählt wird; eine separate Polarisationskurve des Brennstoffzellenstapels für sowohl eine durchschnittliche Zellenspannung als auch eine minimale Zellenspannung abgeschätzt wird; ein Stromdichtebereich des Brennstoffzellenstapels in eine vorbestimmte Anzahl von Abtastbereichen in aufsteigender Reihenfolge aufgetrennt wird; ein erster Abtastbereich gewählt wird; eine durchschnittliche Zellenspannung und eine minimale Zellenspannung bei der Stromdichte für den gewählten Abtastbereich ermittelt werden; ermittelt wird, ob die Zellenspannung ...

Method to automatically enable/disable stack reconditioning procedure based on fuel cell stack parameter estimation

The invention relates to a method to automatically enable/disable stack reconditioning procedure based on fuel cell stack parameter estimation. A system and method for determining when to trigger reconditioning of a fuel cell stack and when to disable the reconditioning of the fuel cell stack. In one embodiment, the stack reconditioning is triggered when a maximum stack power estimation falls below a first predetermined power threshold. The reconditioning of the stack can be disabled so it is not performed when the trigger occurs if the reconditioning process does not raise the maximum power estimation above a second predetermined power threshold or the time from one reconditioning trigger to a next reconditioning trigger is less than a predetermined time threshold, or both.

Adaptive gain scheduled control for current limitation based on voltage performance of a fuel cell system

A system and method for limiting the output current of a fuel cell stack as the stack degrades overtime. A look-up table identifies a predetermined voltage set-point for stack current density. A first comparator provides a voltage difference signal between the set-point and the stack voltage. The voltage difference signal is provided to a controller, such as a proportional-integral controller, that provides a current limiting signal. The current limiting signal and a current request signal are provided to a second comparator that selects which signal will be used to limit the maximum output current of the stack. A polarization curve estimator estimates parameters of the stack that will change over the life of the stack. The parameters are provided to a gain scheduler that provides gains to the controller that are based on where in the life of the stack it is currently operating.

SELECTIVELY REACTING TO THE MINIMUM CELL VOLTAGE DROP RATE IN A FUEL CELL SYSTEM

A system and method that monitor the rate of a voltage drop of fuel cells in a fuel cell stack to determine whether the voltage drop is a result of cathode reactant starvation or anode reactant starvation. The method looks at a falling voltage of a fuel cell to determine whether the rate of the fall in voltage indicates that hydrogen starvation of the anode of the fuel cell is occurring. The method also looks at the actual voltage of the fuel cell that is falling to determine whether it is a below a predetermined minimum voltage threshold also indicating that hydrogen starvation of the anode of the fuel cell is occurring. If hydrogen starvation is occurring, the method performs power limiting of the fuel cell stack either based on the rate or the voltage level. 1. A method for operating a fuel cell system , said fuel cell system including a fuel cell stack having a plurality of fuel cells electrically coupled in series , said method comprising:monitoring a voltage of the fuel cells in the fuel cell stack;determining that the voltage of a minimum voltage fuel cell is falling over time;determining that the fall in voltage of the minimum voltage fuel cell is a result of hydrogen starvation of an anode of the fuel cell if a rate of the fall in voltage is greater than a predetermined threshold rate;determining that the fall in voltage of the minimum voltage fuel cell is a result of hydrogen starvation of the anode of the minimum voltage fuel cell if the voltage of the minimum voltage fuel cell is below a predetermined voltage threshold; andpower limiting an output of the fuel cell stack if it is determined that the fall in voltage of the minimum voltage fuel cell is a result of hydrogen starvation of the anode of the minimum voltage fuel cell.2. The method according to wherein power limiting the fuel cell stack includes power limiting the stack as a function of a magnitude of the rate of the fall in voltage.3. The method according to wherein power limiting the fuel cell ...

Online method to estimate hydrogen concentration estimation in fuel cell systems at shutdown and startup

A system and method for estimating the amount of hydrogen and/or nitrogen in a fuel cell stack and stack volumes at system start-up and shut-down. The method defines the fuel cell stack and stack volumes as discrete volumes including an anode flow-field and anode plumbing volume, a cathode flow-field volume and a cathode header and plumbing volume. The method estimates the amount of hydrogen and/or nitrogen in the anode flow-field and anode plumbing volume, the cathode flow-field volume and the cathode header and plumbing volume when the fuel cell system is shut down, during a first stage when the hydrogen partial pressure between the anode and cathode is not in equilibrium and during a second stage when the hydrogen partial pressure between the anode and cathode is in equilibrium by considering various flows into and out of the volumes.

VERFAHREN ZUM STEUERN EINER INBETRIEBNAHME EINES BRENNSTOFFZELLENSYSTEMS SOWIE ENTSPRECHEND EINGERICHTETES BRENNSTOFFZELLENSYSTEM

Verfahren zum Steuern einer Inbetriebnahme eines Brennstoffzellensystems, wobei das Verfahren die Schritte umfasst: Auslösen einer Inbetriebnahmevorgehensweise für ein Brennstoffzellensystem ohne Anlegen einer Last an einen Brennstoffzellenstapel mit mehreren Brennstoffzellen; Zulassen, dass der Brennstoffzellenstapel eine Leerlaufspannung erreicht; Messen einer Temperatur in dem Brennstoffzellensystem; Anlegen einer Verzögerungsperiode mit einem Stromsteuermodul, nachdem der Brennstoffzellenstapel die Leerlaufspannung erreicht hat; und Anlegen einer Last an den Brennstoffzellenstapel mit dem Stromsteuermodul; dadurch gekennzeichnet, dass der Schritt zum Anlegen einer Verzögerungsperiode die Verwendung der gemessenen Temperatur umfasst, um eine minimale Verzögerungsperiode zu schätzen, nachdem der Brennstoffzellenstapel die Leerlaufspannung erreicht hat, um Verzögerungen der Brennstoffzelleninbetriebnahme aufgrund kalter Temperaturen zu vermeiden; und dass die Last an den Brennstoffzellenstapel ...

Selektives Reagieren auf die Zellspannungsabfallrate in einem Brennstoffzellensystem

Ein Verfahren zum Betreiben eines Brennstoffzellensystems, wobei das Brennstoffzellensystem eine Vielzahl von elektrisch in Reihe gekoppelten Brennstoffzellen aufweist, wobei das Verfahren umfasst:- Überwachen einer Spannung der Brennstoffzellen in dem Brennstoffzellenstapel;- Bestimmen, dass die Spannung einer Brennstoffzelle mit einer minimalen Spannung über die Zeit abfällt;- Bestimmen, dass der Abfall in der Spannung der Brennstoffzelle mit der minimalen Spannung ein Ergebnis einer Verarmung an Wasserstoff an einer Anode der Brennstoffzelle ist, wenn eine Rate des Abfalls in der Spannung größer als eine vorbestimmte Schwellenwertrate ist oder wenn die Spannung der Brennstoffzelle mit der minimalen Spannung unterhalb eines vorbestimmten Spannungsschwellenwertes ist; und- Beschränken einer Leistungsabgabe am Ausgang des Brennstoffzellenstapels, wenn bestimmt wird, dass der Abfall in der Spannung der Brennstoffzelle mit der minimalen Spannung ein Ergebnis einer Verarmung an Wasserstoff ...

Verfahren zum Auslösen und Deaktivieren eines Brennstoffzellenstapel-Wiederaufbereitungsprozesses

Verfahren zum Auslösen und Deaktivieren eines Brennstoffzellenstapel-Wiederaufbereitungsprozesses, wobei das Verfahren umfasst, dass: die Spannung und der Strom von Brennstoffzellen in dem Brennstoffzellenstapel bestimmt werden; eine Polarisationskurve für den Brennstoffzellenstapel auf der Basis der/des bestimmten Spannung und Stromes erzeugt wird; Polarisationskurvenparameter auf der Basis der Polarisationskurve abgeschätzt werden; eine Maximalstapelleistungsabschätzung des Brennstoffzellenstapels auf der Basis der Polarisationskurvenparameter bestimmt wird; der Stapel-Wiederaufbereitungsprozess ausgelöst wird, wenn die Maximalstapelleistungsabschätzung für eine vorbestimmte Zeitspanne unter eine erste vorbestimmte Maximalleistungsschwelle fällt; und der Wiederaufbereitungsprozess jedes Mal ausgelöst wird, wenn die Maximalstapelleistungsabschätzung unter die erste vorbestimmte Maximalleistungsschwelle fällt, nachdem die Maximalstapelleistungsabschätzung von einem vorhergehenden Stapel-Wiederaufbereitungsprozess ...

VERFAHREN ZUR BERECHNUNG EINER POLARISATIONSKURVE EINES BRENNSTOFFZELLENSTAPELS SOWIE BRENNSTOFFZELLENSYSTEM

Verfahren zur Berechnung einer Polarisationskurve für einen Brennstoffzellenstapel, wobei das Verfahren umfasst: Sammeln von Daten von dem Brennstoffzellenstapel; Bereitstellen eines Zellenspannungsmodells; gekennzeichnet durch Lösen eines nichtlineares Problem kleinster Quadrate unter Verwendung des Zellenspannungsmodells und der gesammelten Daten zur Schätzung vorbestimmter Parameter; und Verwenden der geschätzten Parameter, um die Polarisationskurve zu berechnen.

Method for Maximum Net Power Calculation for Fuel Cell System Based on Online Polarization Curve Estimation

An algorithm for determining the maximum net power available from a fuel cell stack as the stack degrades over time using an online adaptive estimation of a polarization curve of the stack. The algorithm separates the current density range of the stack into sample regions, and selects a first sample region from the far left of the estimated polarization curve. The algorithm then calculates the cell voltage for that current density sample region, and determines whether the calculated cell voltage is less than or equal to a predetermined cell voltage limit. If the calculated cell voltage is not less than the cell voltage limit, then the algorithm selects the next sample region along the polarization curve. When the calculated cell voltage does reach the cell voltage limit, then the algorithm uses that current density for the sample region being analyzed to calculate the maximum power of the fuel cell stack.

Method for maximum net power calculation for fuel cell system based on polarization curve estimation

The invention realtes to a method for maximum net power calculation for fuel cell system based on polarization curve estimation. An algorithm for determining the maximum net power available from a fuel cell stack as the stack degrades over time using an online adaptive estimation of a polarization curve of the stack. The algorithm separates the current density range of the stack into sample regions, and selects a first sample region from the far left of the estimated polarization curve. The algorithm then calculates the cell voltage for that current density sample region, and determines whether the calculated cell voltage is less than or equal to a predetermined cell voltage limit. If the calculated cell voltage is not less than the cell voltage limit, then the algorithm selects the next sample region along the polarization curve. When the calculated cell voltage does reach the cell voltage limit, then the algorithm uses that current density for the sample region being analyzed to calculate ...

TEMPORAL MASKING IN AUDIO CODING BASED ON SPECTRAL DYNAMICS IN FREQUENCY SUB-BANDS

An audio coding technique based on modeling spectral dynamics is disclosed. Frequency decomposition of an input audio signal is performed to obtain multiple frequency sub-bands that closely follow critical bands of human auditory system decomposition. Each sub-band is then frequency transformed and linear prediction is applied. This results in a Hilbert envelope and a Hilbert Carrier for each of the sub-bands. Because of application of linear prediction to frequency components, the technique is called Frequency Domain Linear Prediction (FDLP). The Hilbert envelope and the Hilbert Carrier are analogous to spectral envelope and excitation signals in the Time Domain Linear Prediction (TDLP) techniques. Temporal masking is applied to the FDLP sub-bands to improve the compression efficiency. Specifically, forward masking of the sub-band FDLP carrier signal can be employed to improve compression efficiency of an encoded signal.

POWER MANAGEMENT METHOD USING FEEDBACK CURRENT BIAS FOR SIMULTANEOUSLY CONTROLLING LOW CELLS AND OVERALL STACK VOLTAGE

A method for controlling the current output from a fuel cell stack to prevent the stack voltage or the minimum fuel cell voltage from dropping below predetermined voltage set-points. The method for the stack voltage control includes determining whether the stack voltage has dropped to the predetermined voltage set-point, and if so, capturing and holding the actual stack current at that point as the maximum allowed stack current. If the stack voltage continues to fall below the voltage set-point, then the voltage set-point is subtracted from the actual voltage to get a positive error signal. Controller gains are then multiplied by the error signal to reduce the current allowed from the stack to drive the error signal to zero, and increase the stack voltage. The method for the minimum fuel cell voltage operates in the same manner, but with different values.

Feedback control of H2 injection during park based on gas concentration model

A method for determining when to inject hydrogen gas into the anode side of a fuel cell stack associated with a fuel cell vehicle when the vehicle is off. The method includes estimating the concentration of hydrogen gas in the anode side of the fuel cell stack using a gas concentration model and determining if the estimated concentration of hydrogen gas is below a first predetermined threshold. If the estimated hydrogen gas is less than the threshold, then hydrogen gas is injected into the anode side from a hydrogen source. While the hydrogen gas is being injected, the method compares the estimated concentration of the hydrogen gas in the anode side to a desired concentration, and generates an error signal there between. If the error signal is greater than a second predetermined threshold, the algorithm continues to inject the hydrogen into the anode side of the fuel cell stack.

Method to improve fuel cell system performance using cell voltage prediction of fuel cell stack

A system and method for determining the maximum allowed stack current limit rate for a fuel cell stack that considers cell voltage. The method includes estimating a fuel cell stack voltage based on a fuel cell resistance value, stack variables and a current request signal. The fuel cell resistance value can be modeled based on stack temperature and stack relative humidity. The stack variables can include exchange current density and mass transfer coefficient. The method then uses the estimated fuel cell voltage and a look-up table based on estimated voltage to determine a current rate limit value for changing the current of the stack. The method then adds the current rate limit value and the current request signal to obtain the current set-point.

Temporal masking in audio coding based on spectral dynamics in frequency sub-bands

An audio coding technique based on modeling spectral dynamics is disclosed. Frequency decomposition of an input audio signal is performed to obtain multiple frequency sub-bands that closely follow critical bands of human auditory system decomposition. Each sub-band is then frequency transformed and linear prediction is applied. This results in a Hilbert envelope and a Hilbert Carrier for each of the sub-bands. Because of application of linear prediction to frequency components, the technique is called Frequency Domain Linear Prediction (FDLP). The Hilbert envelope and the Hilbert Carrier are analogous to spectral envelope and excitation signals in the Time Domain Linear Prediction (TDLP) techniques. Temporal masking is applied to the FDLP sub-bands to improve the compression efficiency. Specifically, forward masking of the sub-band FDLP carrier signal can be employed to improve compression efficiency of an encoded signal.

SYSTEMS AND METHODS FOR ENHANCING FUEL CELL VEHICLE STARTUP

Methods and systems for enhancing the performance of fuel cells in fuel cell vehicles. Some embodiments comprise a current control module for controlling the application of a load to the fuel cell and a voltage monitoring module for monitoring one or more voltages within the fuel cell. The current control module may be configured to apply a delay period before applying a load to the fuel cell after the fuel cell has reached an open circuit voltage. In other embodiments, a fixed delay period may be applied before applying a load to the fuel cell after the fuel cell has reached an open circuit voltage or, for example, an incremental set of delay periods that increase as measured temperature decreases. 1. A method for controlling a fuel cell system startup , the method comprising the steps of:initiating a startup procedure for a fuel cell system without applying a load to the fuel cell;allowing the fuel cell to reach an open circuit voltage;applying a delay period with a current control module after the fuel cell has reached the open circuit voltage; andapplying a load to the fuel cell with the current control module after the delay period has expired.2. The method of claim 1 , further comprising measuring a temperature within the fuel cell system.3. The method of claim 2 , wherein the step of applying a delay period comprises using the measured temperature to estimate a minimum delay period after the fuel cell has reached the open circuit voltage for avoiding fuel cell startup delays due to cold temperatures.4. The method of claim 3 , wherein the step of applying a delay period further comprises comparing an operating circuit voltage time comprising a time period during which the fuel cell has been measured at the open circuit voltage with the minimum delay period.5. The method of claim 4 , wherein the step of applying a load to the fuel cell comprises claim 4 , in response to a determination that the operating circuit voltage time is greater than the minimum delay ...

METHOD TO PREDICT MIN CELL VOLTAGE FROM DISCRETE MIN CELL VOLTAGE OUTPUT OF STACK HEALTH MONITOR

A system for estimating parameters of a fuel cell stack. The system includes a stack health monitor for monitoring minimum cell voltage, stack voltage and current density of the fuel cell stack. The stack health monitor also indicates when a predetermined minimum cell voltage threshold level has been achieved. The system further includes a controller configured to control the fuel cell stack, where the controller determines and records the average fuel cell voltage. The controller generates and stores artificial data points proximate to the one or more predetermined minimum cell voltage threshold levels each time the minimum cell voltage drops below the one or more predetermined minimum cell voltage threshold levels so as to provide an estimation of the fuel cell stack parameters including a minimum cell voltage trend and a minimum cell voltage polarization curve.

Power management method using feedback current bias for simultaneously controlling low cells and overall stack

The invention discloses a power management method using a feedback current bias for simultaneously controlling low cells and overall stack. A method for controlling the current output from a fuel cellstack to prevent the stack voltage or the minimum fuel cell voltage from dropping below predetermined voltage set-points. The method for the stack voltage control includes determining whether the stack voltage has dropped to the predetermined voltage set-point, and if so, capturing and holding the actual stack current at that point as the maximum allowed stack current. If the stack voltage continues to fall below the voltage set-point, then the voltage set-point is subtracted from the actual voltage to get a positive error signal. Controller gains are then multiplied by the error signal to reduce the current allowed from the stack to drive the error signal to zero, and increase the stack voltage. The method for the minimum fuel cell voltage operates in the same manner, but with differentvalues ...

Power management method using feedback current bias for simultaneously controlling low cells and overall stack

The invention discloses a power management method using a feedback current bias for simultaneously controlling low cells and overall stack. A method for controlling the current output from a fuel cell stack to prevent the stack voltage or the minimum fuel cell voltage from dropping below predetermined voltage set-points. The method for the stack voltage control includes determining whether the stack voltage has dropped to the predetermined voltage set-point, and if so, capturing and holding the actual stack current at that point as the maximum allowed stack current. If the stack voltage continues to fall below the voltage set-point, then the voltage set-point is subtracted from the actual voltage to get a positive error signal. Controller gains are then multiplied by the error signal to reduce the current allowed from the stack to drive the error signal to zero, and increase the stack voltage. The method for the minimum fuel cell voltage operates in the same manner, but with different values ...

Algorithm for stack current controller based on polarization curve estimation of a fuel cell stack

A method for providing a current density set-point for a fuel cell stack in response to a power request from the stack where the set-point is determined based on system parameters that identify the life and degradation of the stack. The method includes dividing a current density range of the fuel cell stack into a predetermined number of sample regions, and selecting the sample regions in order from low to high during the current set-point analysis. The method calculates an average cell voltage for the current density of the selected sample region, and stack power from the average cell voltage. The method then determines whether a power request signal is less than the stack power for the selected sample region and greater than the calculated power for the previous sample region, and if so, calculates the current density set-point at the requested power based on these values.

Algorithm for Stack Current Controller Based on Polarization Curve Estimation of a Fuel Cell Stack

A method for providing a current density set-point for a fuel cell stack in response to a power request from the stack where the set-point is determined based on system parameters that identify the life and degradation of the stack. The method includes dividing a current density range of the fuel cell stack into a predetermined number of sample regions, and selecting the sample regions in order from low to high during the current set-point analysis. The method calculates an average cell voltage for the current density of the selected sample region, and stack power from the average cell voltage. The method then determines whether a power request signal is less than the stack power for the selected sample region and greater than the calculated power for the previous sample region, and if so, calculates the current density set-point at the requested power based on these values.

Online low performing cell prediction and detection of fuel cell system

A system and method for detecting and predicting low performing cells in a fuel cell stack. When the fuel cell stack is running and certain data validity criteria have been met, an algorithm collects the data, such as stack current density, average cell voltage and minimum cell voltage. This information is used to estimate predetermined parameters that define the stack polarization curve. The system defines a predetermined minimum current density that is used to identify a low performing cell. The system then calculates an average cell voltage and a minimum cell voltage at the minimum current density set-point, and calculates a cell voltage difference between the two. If the cell voltage difference is greater than a predetermined low voltage threshold and the minimum cell voltage is less than a predetermined high voltage threshold, the algorithm sets a flag identifying a potential for a low performing cell.

Spectral noise shaping in audio coding based on spectral dynamics in frequency sub-bands

A technique of spectral noise shaping in an audio coding system is disclosed. Frequency decomposition of an input audio signal is performed to obtain multiple frequency sub-bands that closely follow critical bands of human auditory system decomposition. The tonality of each sub-band is determined. If a sub-band is tonal, time domain linear prediction (TDLP) processing is applied to the sub-band, yielding a residual signal and linear predictive coding (LPC) coefficients of an all-pole model representing the sub-band signal. The residual signal is further processed using a frequency domain linear prediction (FDLP) method. The FDLP parameters and LPC coefficients are transferred to a decoder. At the decoder, an inverse-FDLP process is applied to the encoded residual signal followed by an inverse TDLP process, which shapes the quantization noise according to the power spectral density of the original sub-band signal. Non-tonal sub-band signals bypass the TDLP process.

FEEDBACK CONTROL OF H2 INJECTION DURING PARK BASED ON GAS CONCENTRATION MODEL

A method for determining when to inject hydrogen gas into the anode side of a fuel cell stack associated with a fuel cell vehicle when the vehicle is off. The method includes estimating the concentration of hydrogen gas in the anode side of the fuel cell stack using a gas concentration model and determining if the estimated concentration of hydrogen gas is below a first predetermined threshold. If the estimated hydrogen gas is less than the threshold, then hydrogen gas is injected into the anode side from a hydrogen source. While the hydrogen gas is being injected, the method compares the estimated concentration of the hydrogen gas in the anode side to a desired concentration, and generates an error signal there between. If the error signal is greater than a second predetermined threshold, the algorithm continues to inject the hydrogen into the anode side of the fuel cell stack.

Online method to estimate hydrogen concentration estimation in fuel cell systems at shutdown and startup

A system and method for estimating the amount of hydrogen and/or nitrogen in a fuel cell stack and stack volumes at system start-up and shut-down. The method defines the fuel cell stack and stack volumes as discrete volumes including an anode flow-field and anode plumbing volume, a cathode flow-field volume and a cathode header and plumbing volume. The method estimates the amount of hydrogen and/or nitrogen in the anode flow-field and anode plumbing volume, the cathode flow-field volume and the cathode header and plumbing volume when the fuel cell system is shut down, during a first stage when the hydrogen partial pressure between the anode and cathode is not in equilibrium and during a second stage when the hydrogen partial pressure between the anode and cathode is in equilibrium by considering various flows into and out of the volumes.

Systems and methods for predicting polarization curves in a fuel cell system

The present disclosure relates to systems and methods that may be used to predict a performance metric of a fuel cell. A system consistent with the present disclosure may include sensors in communication with the fuel cell stack, a performance metric prediction system, and a control system. The performance metric prediction system may determine a current density based on inputs provided by the sensors at a plurality of time periods, calculate a first parameter while the current density is below a lower threshold, and calculate a second parameter while the current density is above an upper threshold. The first parameter and the second parameter may be used to selectively adjust a fuel cell polarization curve over time. Based upon the polarization curve, a performance metric of the fuel cell stack may be predicted. The control system may implement a control action based upon the performance metric.

Algorithm for online adaptive polarization curve estimation of a fuel cell stack

An algorithm for determining a polarization curve of a fuel cell stack. When the fuel cell stack is running and certain data validity criteria have been met, the algorithm goes into a data collection mode where it collects stack data, such as stack current density, average cell voltage and minimum cell voltage. When the stack is shut down, the algorithm uses a cell voltage model to solve a least squares problem to estimate predetermined parameters that define the polarization curve. If the estimated parameters satisfy certain termination criteria, then the estimated parameters are stored to be used by a system controller to calculate the polarization curve of the stack.

Method to improve fuel cell system performance using cell voltage prediction of fuel cell stack

Online low performing cell prediction and detection of fuel cell system

A system and method for detecting and predicting low performing cells in a fuel cell stack. When the fuel cell stack is running and certain data validity criteria have been met, an algorithm collects the data, such as stack current density, average cell voltage and minimum cell voltage. This information is used to estimate predetermined parameters that define the stack polarization curve. The system defines a predetermined minimum current density that is used to identify a low performing cell. The system then calculates an average cell voltage and a minimum cell voltage at the minimum currentdensity set-point, and calculates a cell voltage difference between the two. If the cell voltage difference is greater than a predetermined low voltage threshold and the minimum cell voltage is less than a predetermined high voltage threshold, the algorithm sets a flag identifying a potential for a low performing cell.

Method for system combination in an audio analytics application

Exemplary embodiments of the present invention provide a method of system combination in an audio analytics application including providing a plurality of language identification systems in which each of the language identification systems includes a plurality of probabilities. Each probability is associated with the system's ability to detect a particular language. The method of system combination in the audio analytics application includes receiving data at the language identification systems. The received data is different from data used to train the language identification systems. A confidence measure is determined for each of the language identification systems. The confidence measure identifies which language its system predicts for the received data and combining the language identification systems according to the confidence measures.

ALGORITHM FOR ESTIMATING POLARIZATION CURVE ADAPTED FOR FUEL CELL STACK ONLINE

PROBLEM TO BE SOLVED: To provide an algorithm for a judgement of a polarization curve of a fuel cell stack. SOLUTION: When the fuel cell stack is in operation and a predetermined data adequacy standard is satisfied, the algorithm enters into a data collection mode and stack data such as a current density, an average cell voltage and a minimum cell voltage are collected. When the stack is shut down, the algorithm solves an exercise of at least a square by using a cell voltage model and estimates a predetermined parameter to define a polarization curve. If the estimated parameter satisfies the predetermined completion standard, the estimated parameter is stored and is used by a system controlling device for calculating the stack polarization curve. COPYRIGHT: (C)2008,JPO&INPIT ...

Systems and methods for enhancing fuel cell vehicle startup

Methods and systems for enhancing the performance of fuel cells in fuel cell vehicles. Some embodiments comprise a current control module for controlling the application of a load to the fuel cell and a voltage monitoring module for monitoring one or more voltages within the fuel cell. The current control module may be configured to apply a delay period before applying a load to the fuel cell after the fuel cell has reached an open circuit voltage. In other embodiments, a fixed delay period may be applied before applying a load to the fuel cell after the fuel cell has reached an open circuit voltage or, for example, an incremental set of delay periods that increase as measured temperature decreases.

ADAPTIVE METHOD FOR CONVERSION OF EXTERNAL POWER REQUEST TO CURRENT SETPOINT TO A FUEL CELL SYSTEM BASED ON STACK PERFORMANCE

A system and method for converting a fuel cell stack power request signal to a stack current set-point that considers stack performance parameters. The method includes obtaining a power-current relationship curve of the fuel cell stack to provide stack parameters including exchange current density and mass transfer coefficient. The method then calculates a slope for the stack using the parameters from the power-current relationship curve estimation that includes calculating a cell voltage at two predetermined stack current densities. The method then calculates a change in current in response to the power request signal, the stack voltage, the stack current and the calculated slope, and uses the change in current to update the current set-point for the stack.

METHOD FOR SYSTEM COMBINATION IN AN AUDIO ANALYTICS APPLICATION

Exemplary embodiments of the present invention provide a method of system combination in an audio analytics application including providing a plurality of language identification systems in which each of the language identification systems includes a plurality of probabilities. Each probability is associated with the system's ability to detect a particular language. The method of system combination in the audio analytics application includes receiving data at the language identification systems. The received data is different from data used to train the language identification systems. A confidence measure is determined for each of the language identification systems. The confidence measure identifies which language its system predicts for the received data and combining the language identification systems according to the confidence measures. 1. A method of system combination in an audio analytics application , comprising:providing a plurality of language identification systems, wherein each of the language identification systems includes a plurality of probabilities, wherein each probability is associated with the system's ability to detect a particular language;receiving data at the language identification systems, wherein the received data is different from data used to train the language identification systems;determining a confidence measure for each of the language identification systems, wherein the confidence measure identifies which language its system predicts for the received data; andcombining the language identification systems according to the confidence measures.2. The method of claim 1 , wherein the language identification systems have different feature extraction methods from each other.3. The method of claim 1 , wherein the language identification systems have different modeling schemes from each other.4. The method of claim 1 , wherein the language identification systems have different noise removal schemes from each other.5. The method of claim ...

Adaptive method for conversion of external power request to current setpoint to a fuel cell system based on stack performance

The invention relates to an adaptive method for conversion of external power request to current setpoint to a fuel cell system based on stack performance. A system and method for converting a fuel cell stack power request signal to a stack current set-point that considers stack performance parameters. The method includes obtaining a power-current relationship curve of the fuel cell stack to provide stack parameters including exchange current density and mass transfer coefficient. The method then calculates a slope for the stack using the parameters from the power-current relationship curve estimation that includes calculating a cell voltage at two predetermined stack current densities. The method then calculates a change in current in response to the power request signal, the stack voltage, the stack current and the calculated slope, and uses the change in current to update the current set-point for the stack.

Algorithm for online adaptive polarization curve estimation of a fuel cell stack

An algorithm for determining a polarization curve of a fuel cell stack. When the fuel cell stack is running and certain data validity criteria have been met, the algorithm goes into a data collection mode where it collects stack data, such as stack current density, average cell voltage and minimum cell voltage. When the stack is shut down, the algorithm uses a cell voltage model to solve a least squares problem to estimate predetermined parameters that define the polarization curve. If the estimated parameters satisfy certain termination criteria, then the estimated parameters are stored to be used by a system controller to calculate the polarization curve of the stack.

Adaptive method for conversion of external power request to current setpoint to a fuel cell system based on stack performance

A system and method for converting a fuel cell stack power request signal to a stack current set-point that considers stack performance parameters. The method includes obtaining a power-current relationship curve of the fuel cell stack to provide stack parameters including exchange current density and mass transfer coefficient. The method then calculates a slope for the stack using the parameters from the power-current relationship curve estimation that includes calculating a cell voltage at two predetermined stack current densities. The method then calculates a change in current in response to the power request signal, the stack voltage, the stack current and the calculated slope, and uses the change in current to update the current set-point for the stack.

Adaptive Gain Scheduled Control for Current Limitation Based on Voltage Performance of a Fuel Cell System

A system and method for limiting the output current of a fuel cell stack as the stack degrades overtime. A look-up table identifies a predetermined voltage set-point for stack current density. A first comparator provides a voltage difference signal between the set-point and the stack voltage. The voltage difference signal is provided to a controller, such as a proportional-integral controller, that provides a current limiting signal. The current limiting signal and a current request signal are provided to a second comparator that selects which signal will be used to limit the maximum output current of the stack. A polarization curve estimator estimates parameters of the stack that will change over the life of the stack. The parameters are provided to a gain scheduler that provides gains to the controller that are based on where in the life of the stack it is currently operating.

METHOD TO AUTOMATICALLY ENABLE/DISABLE STACK RECONDITIONING PROCEDURE BASED ON FUEL CELL STACK PARAMETER ESTIMATION

A system and method for determining when to trigger reconditioning of a fuel cell stack and when to disable the reconditioning of the fuel cell stack. In one embodiment, the stack reconditioning is triggered when a maximum stack power estimation falls below a first predetermined power threshold. The reconditioning of the stack can be disabled so it is not performed when the trigger occurs if the reconditioning process does not raise the maximum power estimation above a second predetermined power threshold or the time from one reconditioning trigger to a next reconditioning trigger is less than a predetermined time threshold, or both.

Method for maximum net power calculation for fuel cell system based on online polarization curve estimation

An algorithm for determining the maximum net power available from a fuel cell stack as the stack degrades over time using an online adaptive estimation of a polarization curve of the stack. The algorithm separates the current density range of the stack into sample regions, and selects a first sample region from the far left of the estimated polarization curve. The algorithm then calculates the cell voltage for that current density sample region, and determines whether the calculated cell voltage is less than or equal to a predetermined cell voltage limit. If the calculated cell voltage is not less than the cell voltage limit, then the algorithm selects the next sample region along the polarization curve. When the calculated cell voltage does reach the cell voltage limit, then the algorithm uses that current density for the sample region being analyzed to calculate the maximum power of the fuel cell stack.

Algorithm for Online Adaptive Polarization Curve Estimation of a Fuel Cell Stack

An algorithm for determining a polarization curve of a fuel cell stack. When the fuel cell stack is running and certain data validity criteria have been met, the algorithm goes into a data collection mode where it collects stack data, such as stack current density, average cell voltage and minimum cell voltage. When the stack is shut down, the algorithm uses a cell voltage model to solve a least squares problem to estimate predetermined parameters that define the polarization curve. If the estimated parameters satisfy certain termination criteria, then the estimated parameters are stored to be used by a system controller to calculate the polarization curve of the stack.

Adaptive gain scheduled control for current limitation based on voltage performance of a fuel cell system

A system and method for limiting the output current of a fuel cell stack as the stack degrades overtime. A look-up table identifies a predetermined voltage set-point for stack current density. A firstA system and method for limiting the output current of a fuel cell stack as the stack degrades overtime. A look-up table identifies a predetermined voltage set-point for stack current density. A firstcomparator provides a voltage difference signal between the set-point and the stack voltage. The voltage difference signal is provided to a controller, such as a proportional-integral controller, tha comparator provides a voltage difference signal between the set-point and the stack voltage. The voltage difference signal is provided to a controller, such as a proportional-integral controller, that provides a current limiting signal. The current limiting signal and a current request signal are provided to a second comparator that selects which signal will be used to limit the maximum output cut ...

Method and apparatus for increasing a reliability of a fuel cell system

A technique that is usable with a fuel cell stack includes detecting a negative cell voltage condition of the fuel cell stack and operating the fuel cell stack for an amount of time during which the negative cell voltage condition is present until the amount of time exceeds a first time threshold. The technique further includes determining the first time threshold based on the magnitude of the negative cell voltage.

Selectively reacting to the minimum cell voltage drop rate in a fuel cell system

A system and method that monitor the rate of a voltage drop of fuel cells in a fuel cell stack to determine whether the voltage drop is a result of cathode reactant starvation or anode reactant starvation. The method looks at a falling voltage of a fuel cell to determine whether the rate of the fall in voltage indicates that hydrogen starvation of the anode of the fuel cell is occurring. The method also looks at the actual voltage of the fuel cell that is falling to determine whether it is a below a predetermined minimum voltage threshold also indicating that hydrogen starvation of the anode of the fuel cell is occurring. If hydrogen starvation is occurring, the method performs power limiting of the fuel cell stack either based on the rate or the voltage level.

Method to predict min cell voltage from discrete min cell voltage output of stack health monitor

A system for estimating parameters of a fuel cell stack. The system includes a stack health monitor for monitoring minimum cell voltage, stack voltage and current density of the fuel cell stack. The stack health monitor also indicates when a predetermined minimum cell voltage threshold level has been achieved. The system further includes a controller configured to control the fuel cell stack, where the controller determines and records the average fuel cell voltage. The controller generates and stores artificial data points proximate to the one or more predetermined minimum cell voltage threshold levels each time the minimum cell voltage drops below the one or more predetermined minimum cell voltage threshold levels so as to provide an estimation of the fuel cell stack parameters including a minimum cell voltage trend and a minimum cell voltage polarization curve.

Method and system for maximum net power calculation for fuel cell system based on polarization curve estimation

The invention realtes to a method for maximum net power calculation for fuel cell system based on polarization curve estimation. An algorithm for determining the maximum net power available from a fuel cell stack as the stack degrades over time using an online adaptive estimation of a polarization curve of the stack. The algorithm separates the current density range of the stack into sample regions, and selects a first sample region from the far left of the estimated polarization curve. The algorithm then calculates the cell voltage for that current density sample region, and determines whether the calculated cell voltage is less than or equal to a predetermined cell voltage limit. If the calculated cell voltage is not less than the cell voltage limit, then the algorithm selects the next sample region along the polarization curve. When the calculated cell voltage does reach the cell voltage limit, then the algorithm uses that current density for the sample region being analyzed to calculate ...

Method to improve fuel cell system performance using cell voltage prediction of fuel cell stack

The invention relates to a system and a method for improving fuel cell system performance using cell voltage prediction of a fuel cell stack. A system and a method determine the maximum allowed stack current limit rate for a fuel cell stack that considers cell voltage. The method includes estimating a fuel cell stack voltage based on a fuel cell resistance value, stack variables and a current request signal. The fuel cell resistance value can be modeled based on stack temperature and stack relative humidity. The stack variables can include exchange current density and mass transfer coefficient. The method then uses the estimated fuel cell voltage and a look-up table based on estimated voltage to determine a current rate limit value for changing the current of the stack. The method then adds the current rate limit value and the current request signal to obtain the current set-point.

CELL-BASED CANCER VACCINES AND CANCER THERAPIES

Described are cell-based cancer vaccines and anti-cancer immunotherapies. The vaccines include isolated tumor cells activated with one or more genotoxic drugs, and, optionally, treated with one or more MK2 inhibitors. The activated cells are highly immunogenic non-proliferative cells, and may be tested for immunogenicity ex vivo for priming T cells by co-incubating the isolated activated cells with dendritic cells and T cells. The vaccines are typically administered into patient's tumor to provide an intratumoral immune activation. Immune checkpoint inhibitor(s) (ICI) may be administered before, during, or after vaccine administration. ICI may be a component of the vaccine. The vaccines confer heightened cytotoxic immune response against the cancer cells, induce tumor regression, and enhance survival from cancer. The vaccines prevent tumor recurrence and induce a long-lasting anti-tumor immunological memory. 1. A composition for treating a patient with cancer , and/or preventing recurrence of the cancer , the composition comprising isolated , activated , primary tumor cells.2. The composition of claim 1 , wherein the cells are live claim 1 , injured cells.3. The composition of claim 2 , wherein the isolated activated cells are activated with one or more genotoxic drugs selected from the group consisting of alkylating agents claim 2 , antimetabolites claim 2 , antimitotics claim 2 , anthracyclines claim 2 , cytotoxic antibiotics claim 2 , and topoisomerase inhibitors claim 2 , and claim 2 , optionally claim 2 , with one or more MAPK-activated protein kinase-2 (MK2) inhibitors.4. The composition of claim 3 , wherein the concentration of drug is sufficient to injure the cells and induce stress signaling claim 3 , but not sufficient to induce maximal cell death of the cells.5. The composition of claim 4 , wherein the genotoxic drug is selected from the group consisting of doxorubucin claim 4 , etoposide claim 4 , mitoxantrone claim 4 , cisplatin claim 4 , oxaliplatin ...

Systems and methods for predicting polarization curves in a fuel cell system

The present disclosure relates to systems and methods that may be used to predict a performance metric of a fuel cell. A system consistent with the present disclosure may include sensors in communication with the fuel cell stack, a performance metric prediction system, and a control system. The performance metric prediction system may determine a current density based on inputs provided by the sensors at a plurality of time periods, calculate a first parameter while the current density is below a lower threshold, and calculate a second parameter while the current density is above an upper threshold. The first parameter and the second parameter may be used to selectively adjust a fuel cell polarization curve over time. Based upon the polarization curve, a performance metric of the fuel cell stack may be predicted. The control system may implement a control action based upon the performance metric.

SYSTEM AND METHOD FOR MULTI-TYPE MEAN FIELD REINFORCEMENT MACHINE LEARNING

A system for a machine reinforcement learning architecture for an environment with a plurality of agents includes: at least one memory and at least one processor configured to provide a multi-agent reinforcement learning architecture, the multi-agent reinforcement learning model based on a mean field Q function including multiple types of agents, wherein each type of agent has a corresponding mean field. 1. A computer-implemented method for multi-agent reinforcement learning , the method comprising:for an agent of multiple agents in an environment, identifying other agents in a neighbourhood of the environment of the agent;classifying each of the other agents into a type of multiple types;determining a mean action for each of the multiple types;inputting a state of the agent, an action of the agent, and the mean action for each of the types to a Q function to predict a policy that maps states and actions to probable rewards; andrecursively updating the Q function to obtain an optimal policy that maximizes expected cumulative rewards among possible policies.6. The computer-implemented method of claim 1 , wherein the type of each of the other agents is defined.7. The computer-implemented method of claim 1 , wherein the type of each of the other agents is initially unknown.8. The computer-implemented method of claim 7 , further comprising performing k-means clustering to approximate a type for the initially unknown types.9. The computer-implemented method of claim 1 , wherein the recursively updating is performed to converge to a fixed point within a bounded distance of a Nash equilibrium.10. A non-transitory computer readable medium comprising a computer readable memory storing computer executable instructions thereon that when executed by a computer cause the computer to perform the method of .11. A system for a machine reinforcement learning architecture for an environment with a plurality of agents claim 1 , the system comprising:at least one memory and at least ...

Cell-based cancer vaccines and cancer therapies

Described are cell-based cancer vaccines and anti-cancer immunotherapies. The vaccines include isolated tumor cells activated with one or more genotoxic drugs, and, optionally, treated with one or more MK2 inhibitors. The activated cells are highly immunogenic non-proliferative cells, and may be tested for immunogenicity ex vivo for priming T cells by co-incubating the isolated activated cells with dendritic cells and T cells. The vaccines are typically administered into patient's tumor to provide an intratumoral immune activation. Immune checkpoint inhibitor(s) (ICI) may be administered before, during, or after vaccine administration. ICI may be a component of the vaccine. The vaccines confer heightened cytotoxic immune response against the cancer cells, induce tumor regression, and enhance survival from cancer. The vaccines prevent tumor recurrence and induce a long-lasting anti-tumor immunological memory.

Method to perform adaptive voltage suppression of a fuel cell stack based on stack parameters

A system and method for maintaining the voltage of fuel cells in the fuel cell stack below a predetermined maximum voltage. The method determines a desired voltage set-point value that defines a predetermined maximum fuel cell voltage value and uses the voltage set-point value and an average fuel cell voltage to generate an error value there-between. The method generates a minimum gross power prediction value using the modified voltage set-point value to prevent the fuel cell voltages from going above the predetermined maximum fuel cell voltage value and generating a supplemental power value based on the minimum gross power prediction value and the error value to determine how much power needs to be drawn from the stack to maintain the fuel cell voltage below the predetermined maximum voltage value. The method uses the supplemental power value to charge the battery or operate an auxiliary load coupled to the stack.

Temporal masking in audio coding based on spectral dynamics in frequency sub-bands

An audio coding technique based on modeling spectral dynamics is disclosed. Frequency decomposition of an input audio signal is performed to obtain multiple frequency sub-bands that closely follow critical bands of human auditory system decomposition. Each sub-band is then frequency transformed and linear prediction is applied. This results in a Hilbert envelope and a Hilbert Carrier for each of the sub-bands. Because of application of linear prediction to frequency components, the technique is called Frequency Domain Linear Prediction (FDLP). The Hilbert envelope and the Hilbert Carrier are analogous to spectral envelope and excitation signals in the Time Domain Linear Prediction (TDLP) techniques. Temporal masking is applied to the FDLP sub-bands to improve the compression efficiency. Specifically, forward masking of the sub-band FDLP carrier signal can be employed to improve compression efficiency of an encoded signal.