Fuel cell system with high-potential protection function

Abstract

The invention discloses a fuel cell system with a high-potential protection function. An anti-freezing heating resistor of the fuel cell system is connected with high voltage output of a fuel cell stack through a stack protection contactor, in the processes of starting, stopping, standing by and low-load operation of the fuel cell stack, when the output voltage of the stack is higher than the setstack protection voltage, the stack protection contactor is controlled to be closed, the anti-freezing heating resistor is used for consuming some fuel cell electric energy, and catalyst deteriorationcaused by stack high-voltage operation is avoided; when the stack output voltage is lower than the stack protection cancel voltage for a certain period of time, the stack protection contactor is controlled to be switched off, and the fuel cell stack performs normal output; the resistance of the anti-freezing heating resistor is matched, it can be ensured that the output voltage of the stack is lower than the stack protection voltage under the non-load condition; according to the method, the anti-freezing heating resistor can be used for effectively restraining catalyst deterioration caused byexcessively high output voltage of the fuel cell.

Description

technical field [0001] The invention relates to the field of fuel cells, in particular to a fuel cell system with high potential protection. Background technique [0002] In recent years, the application of fuel cells as a zero-emission vehicle power system has received extensive attention. For vehicle fuel cell systems, when idling, low-speed driving, and regenerative braking, the power demand of the vehicle is low, and the fuel cell system is in extremely low power output or does not output externally, or even temporarily enters a shutdown state. At this time, the fuel cell The stack is in a high potential state. When the fuel cell stack is in a high potential state, it will accelerate the degradation of the catalyst, thereby shortening the working life of the stack. Therefore, in the case of low power output or shutdown of the fuel cell stack, measures need to be taken to avoid the high potential state of the stack. [0003] Prior art approaches perform fuel cell stack...

AI Technical Summary

Problems solved by technology

This kind of high potential avoidance strategy will easily cause the fuel cell system to enter the process of frequent start and stop, and it will also damage the life of the fuel cell

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