Insulation detection method and system for automobile fuel cell system

Abstract

The invention discloses an insulation detection method and system for an automobile fuel cell system. The method comprises the following steps: S1, electrifying a vehicle in a pure electric mode; and S2, closing a fuel cell relay; judging whether the insulation value of the vehicle is greater than a set value; if yes, executing the step S3, and starting the fuel cell system; and if no, executing the step S4, disconnecting a fuel cell relay, starting the fuel cell cooling system when the vehicle is in a pure electric mode so as to conduct ion filtering on a cooling medium of the fuel cell, and executing the step S2 after the vehicle runs for a set time. According to the method, the insulation value of the fuel cell system is increased through control and adjustment of the fuel cell cooling system, the situation that the fuel cell system cannot be started due to too high conductivity of a cooling medium is avoided, and normal use of a vehicle is ensured.

Description

technical field [0001] The invention relates to the technical field of vehicle fuel cells, in particular to an insulation detection method and system for a vehicle fuel cell system. Background technique [0002] At present, fuel cell vehicles mainly use electric-electric hybrids, that is, fuel cell systems and power battery systems for energy storage are used as power sources. Fuel cell vehicles use a high-voltage platform (such as 350V / 550V). In order to prevent personnel from accidentally touching the high-voltage system and causing potential safety hazards, there are requirements for insulation values. [0003] Currently, when a fuel cell vehicle is started, the vehicle performs insulation testing, and if it is judged that the insulation value of the vehicle is lower than the set value, the output power is cut off. The cooling medium of the fuel cell system is in contact with the internal bipolar plate of the stack, resulting in the conductivity of the cooling medium. It...

AI Technical Summary

Problems solved by technology

After the fuel cell vehicle is parked for a long time, the ion release of the cooling system is high, which leads to an increase in the conductivity of the cooling medium, a decrease in the insulation value, and the vehicle cannot be powered on and started.

The cooling medium of the fuel cell can be circulated to the deionizer by running the pump for ion filtration to reduce the conductivity, but because the insulation value cannot meet the requirements, the vehicle cannot be powered on, so it cannot be filtered, and if it cannot be filtered, the insulation value cannot be improved, and it cannot be connected Electricity, thus causing an endless loop, affecting the use of vehicles

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