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US 11,688,867 B2Granted
Fuel cell system
AssigneeToyota Jidosha Kabushiki Kaisha
InventorTokio Kato
Life of this patent
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Abstract
To provide a fuel cell system capable of evaluating degradation of an electrolyte membrane by quantifying metal ions involved in degradation of an electrolyte membrane instead of evaluating degradation of an electrolyte membrane itself. A fuel cell system comprising a fuel cell, a fuel gas system for supplying fuel gas to an anode of the fuel cell, an oxidant gas system for supplying oxidant gas to a cathode of the fuel cell, a voltage detector for detecting a voltage of the fuel cell, and a controller.
Claims6
A fuel cell system comprising:
- a fuel cell,
- a fuel gas system for supplying fuel gas to an anode of the fuel cell,
- an oxidant gas system for supplying oxidant gas to a cathode of the fuel cell,
- a voltage detector for detecting a voltage of the fuel cell, and
- a controller,
- wherein the controller preliminarily stores an initial time constant τ0 derived from a first transient response waveform of the voltage of the fuel cell, which is obtained by increasing an output current value of the fuel cell in a predetermined output current value increasing condition at the time of initial operation of the fuel cell;
- wherein the controller preliminarily stores a data group indicating a relationship between a second transient response waveform of the voltage of the fuel cell, which is obtained by increasing the output current value of the fuel cell in the predetermined output current value increasing condition, and an amount of metal ions contained in an electrolyte membrane of the fuel cell;
- wherein the controller diagnoses degradation of the electrolyte membrane of the fuel cell at a predetermined time;
- wherein, in the electrolyte membrane degradation diagnosis, the controller acquires a time constant τ derived from the second transient response waveform;
- wherein the controller determines whether or not the time constant τ is smaller than the initial time constant τ0;
- wherein, when the controller determines that the time constant τ is smaller than the initial time constant τ0, the controller estimates the amount of the metal ions by comparing the second transient response waveform with the data group;
- wherein the controller determines whether or not the estimated amount of the metal ions is within a predetermined threshold range;
- and
- wherein, when the controller determines that the estimated amount of the metal ions is outside the predetermined threshold range, the controller diagnoses the electrolyte membrane as being degraded.
11 more elements
Dependencies are inferred from the claim text.