Fuel cell reliability improvement by using stack end plate temperature sensors

A fuel cell system comprising:

• a fuel cell stack including end cells;
• an end cell temperature sensor in each end cell of the stack, each end cell temperature sensor providing an end cell temperature signal;
• a cooling fluid temperature sensor positioned within a cooling fluid loop outside of the fuel cell stack and providing a cooling fluid temperature signal indicative of the temperature of the cooling fluid;
• and
• a controller responsive to the end cell temperature signals from the end cell temperature sensors and the cooling fluid temperature signal from the cooling fluid temperature sensor, said controller calculating an average end cell temperature from the end cell temperature signals, determining if any of the end cell temperature signals are outlying by comparing each end cell temperature signal to the average end cell temperature, recalculating the average end cell temperature without the outlying temperature measurement signals, comparing the cooling fluid outlet temperature signal to the average end cell temperature, determining that the cooling fluid outlet temperature sensor has possibly failed if the measured cooling fluid outlet temperature is greater than the average end cell temperature and the measured cooling fluid outlet temperature minus the average end cell temperature is greater than a first predetermined temperature value, and determining that the fuel cell stack may be overheating if the average end cell temperature is greater than the measured cooling fluid outlet temperature and the average end cell temperature minus the measured cooling fluid outlet temperature is greater than a second predetermined temperature value.

A fuel cell system comprising:

• a fuel cell stack including end cells;
• an end cell temperature sensor in each end cell of the stack, each end cell temperature sensor providing an end cell temperature signal;
• a cooling fluid temperature sensor positioned within a cooling fluid loop outside of the fuel cell stack and providing a cooling fluid temperature signal indicative of the temperature of the cooling fluid;
• and
• a controller responsive to the end cell temperature signals from the end cell temperature sensors and the cooling fluid temperature signal from the cooling fluid temperature sensor, said controller determining if the fuel cell stack may be overheating based on the temperature signals.