Power-down detection circuit and control method

A power-down detection circuit, comprising:

• a low-voltage side power supply, a voltage conversion unit, a power-down detection sub-circuit, a controller, a memory and a high-voltage side current sensor;
• the low-voltage side power source is connected to the power-down detection sub-circuit and the voltage conversion unit, configured to provide an output voltage of the low-voltage side power supply to the power-down detection sub-circuit and supply power for the power-down detection sub-circuit, the controller and the memory via the voltage conversion unit;
• the voltage conversion unit is connected to the power-down detection sub-circuit, the controller and the memory, configured to convert a voltage of the low-voltage side power source into a standard power supply voltage to supply power for the power-down detection sub-circuit, the controller and the memory;
• the power-down detection sub-circuit is connected to the controller, configured to acquire the output voltage of the low-voltage side power source, determine, according to the output voltage of the low-voltage side power source, whether a power-down event occurs in the low-voltage side power source, and send, in the case where it is determined that a power-down event occurs, a power-down signal to the controller;
• the controller is connected to the memory and the high-voltage side current sensor, configured to receive the power-down signal and control the memory to record fault information including current information sensed by the high-voltage side current sensor;
• and
• the high-voltage side current sensor is configured to sense the current information on a high-voltage bus.