Diagnostic system, fuel cell system having a diagnostic system, and method for determining cathode gas contamination

Patent metadata

Field	Value
Publication number	US-2019157693-A1
Application number	US-201816193149-A
Country	US
Kind code	A1
Filing date	Nov 16, 2018
Priority date	Nov 17, 2017
Publication date	May 23, 2019
Grant date	—

Abstract

A diagnostic system for determining the cathode gas quality of a fuel cell system has a fuel cell stack, with a diagnostic fuel cell which can be connected at the cathode side to a cathode supply line and at the anode side to an anode supply line of the fuel cell system. The diagnostic system furthermore comprises a detection unit which is configured to detect a measured value or the measured value time curve of the diagnostic fuel cell operating with the cathode gas provided via the cathode supply line and with the anode gas provided via the anode supply line. The present disclosure moreover relates to a fuel cell system having a diagnostic system, and to a corresponding method.

First claim

1 . A diagnostic system for determining a quality of a cathode gas in a fuel cell system having a fuel cell stack, the diagnostic system comprising:
a diagnostic fuel cell having a cathode side and an anode side, the diagnostic fuel cell connectable on the cathode side with a cathode supply line of the fuel cell system that supplies the cathode gas and on the anode side with an anode supply line of the fuel cell system that supplies an anode gas; and a detection unit which is configured to detect a measured value or a measured value time curve of the diagnostic fuel cell when in operation with the cathode gas provided via the cathode supply line and with the anode gas provided via the anode supply line.

2 . The diagnostic system according to claim 1 , further comprising a comparator unit configured to detect a deviation between the measured value detected by the detection unit or the measured value time curve detected by the detection unit and a nominal value stored in a memory or a nominal value time curve stored in the memory.

3 . The diagnostic system according to claim 1 , wherein the detection unit comprises a voltmeter and/or a current meter, and the detected measured value or the detected measured value time curve is a voltage or a voltage curve generated in the diagnostic fuel cell and/or a current or a current curve generated in the diagnostic fuel cell.

4 . The diagnostic system according to claim 1 , further comprising a voltage source for impressing a periodically increasing and decreasing voltage on an electrode of the diagnostic fuel cell.

5 . The diagnostic system according to claim 4 , wherein the voltage source is designed to impress a delta voltage on the electrode.

6 . A fuel cell system comprising:
a fuel cell stack; and a diagnostic system connected to a cathode supply line that supplies a cathode gas and an anode supply line that supplies an anode gas; wherein the diagnostic system includes a diagnostic fuel cell having a cathode side and an anode side, the diagnostic fuel cell connectable on the cathode side with the cathode supply line and on the anode side with the anode supply line and a detection unit which is configured to detect a measured value or a measured value time curve of the diagnostic fuel cell when in operation with the cathode gas and the anode gas.

7 . The fuel cell system according to claim 6 , further comprising a comparator unit configured to detect a deviation between the measured value detected by the detection unit or the measured value time curve detected by the detection unit and a nominal value stored in a memory or a nominal value time curve stored in the memory.

8 . The fuel cell system according to claim 6 , wherein the detection unit comprises a voltmeter and/or a current meter, and the detected measured value or the detected measured value time curve is a voltage or a voltage curve generated in the diagnostic fuel cell and/or a current or a current curve generated in the diagnostic fuel cell.

9 . The fuel cell system according to claim 6 , further comprising a voltage source for impressing a periodically increasing and decreasing voltage on an electrode of the diagnostic fuel cell.

10 . The fuel cell system according to claim 9 , wherein the voltage source is designed to impress a delta voltage on the electrode.

11 . A method for determining a cathode gas contamination in a fuel cell system, comprising:
connecting a diagnostic system having a diagnostic fuel cell to a cathode supply line and an anode supply line of the fuel cell system; operating the diagnostic fuel cell of the diagnostic system with cathode gas provided by the cathode supply line and with anode gas provided by the anode supply line; detecting a measured value or a measured value time curve of the diagnostic fuel cell; comparing the detected measured value or the detected measured value time curve with a predefined nominal value or a predefined nominal value time curve; and outputting a deviation value or a deviation signal as a function of a deviation determined between the detected measured value or the detected measured value time curve and the nominal value or the nominal value time curve.

12 . The method according to claim 11 , further comprising:
impressing a voltage on an electrode of the diagnostic fuel cell; and detecting a response current as a function of the impressed voltage.

13 . The method according to claim 11 , wherein a delta voltage is impressed on the electrode of the diagnostic fuel cell.

14 . The method according to claim 11 , wherein a temperature is increased in a fuel cell stack of the fuel cell system based on the deviation value or the deviation signal.

15 . The method according to claim 11 , wherein a humidity of the cathode gas in the fuel cell system is increased based on the deviation value or the deviation signal.

Assignees

• Audi Ag
• Volkswagen Ag

Inventors

• Schmidt Lasse
• Kirsch Sebastian
• Hübner Gerold

Classifications

• H01M8/04701

  Temperature · CPC title

• H01M8/04828

  Humidity; Water content · CPC title

• H01M8/04671

  of the individual fuel cell · CPC title

• H01M8/04455 Primary

  of cathode reactants at the inlet or inside the fuel cell · CPC title

• H01M8/04544

  Voltage · CPC title