BATTERY PACK HEATING SYSTEM AND CONTROL METHOD THEREOF

The present disclosure provides a battery pack heating system and a control method thereof, which is related to field of battery. The battery pack heating system includes: a main positive switch (Kl), a main negative switch (K2), an inverter (P2), an external port (Gl, G2), a motor (P3), a control module for auxiliary charging branch (P8), a vehicle control unit (P5), a motor control unit (P7), and a battery management module (P6). The battery management module (P6) is to acquire a state parameter of the battery pack (P1), and send, when the state parameter of the battery pack (P1) meets a preset low-temperature-low-power condition, a low-temperature-low-power heating request instruction to the vehicle control unit (P5) and the control module for auxiliary charging branch (P8) respectively. The control module for auxiliary charging branch (P8) is to send a first control signal to control the auxiliary charging branch (P4) to be connected. The vehicle control unit (P5) is to send a second control signal to enable the motor control unit (P7) to control on-off of the switch modules (P21, P22, P23, P24, P25, P26) in the inverter (P2), and a third control signal to enable the battery management module (P6) to control on-off of the main positive switch (Kl), to enable transmission of energy between the battery pack (P1) and the motor (P3), so as to heat the battery pack (P1). The heating efficiency of the battery pack (P1) can be improved with the technical solutions of the present disclosure.