Active discharging system and method for electric vehicle

The invention belongs to the technical field of new energy automobiles, and discloses an electric vehicle active discharging system and method.The system comprises a low-voltage MCU, an isolation unit, a high-voltage detection unit, an emergency power supply unit, a delay power supply unit, a logic management unit, a driving unit and a load unit, and all the units form a system circuit. By designing the isolation unit, effective active discharge logic is executed during normal low-voltage power supply, the low-voltage side abnormal state can be accurately diagnosed during abnormal low-voltage power failure, high-voltage side discharge logic is triggered, and the structure implementation form is simple and reliable; through the design of the delay circuit unit, 200 ms discharge logic delay time can be generated after low-voltage power failure, and enough time is reserved for complete disconnection of a high-voltage contactor of a whole vehicle. And unexpected consequences of the discharge resistor and the disc