Traction battery heating circuit, system, and control method, and electric device

A traction battery heating control method, applied by a traction battery heating circuit, wherein the traction battery heating circuit comprises a power supply module, an inverter module, a driving module, and a control module,

• wherein the power supply comprises at least one battery group,
• the inverter module is connected to the power supply module and comprises an M-phase leg circuit, wherein the M-phased leg circuit is connected in parallel to the battery group, and M is an even multiple of three,
• the driving module comprises a motor having M windings, wherein the M windings are respectively connected to M phase legs of the leg circuit in one-to-one correspondence,
• the control module is connected to the leg circuit,
• wherein the traction battery heating control method comprises:
• sending, by the control module, an enabling signal to the inverter module, the enabling signal comprising a first enabling signal and a second enabling signal at a preset frequency, wherein
• the first enabling signal controls upper legs of at least three phase legs in the M-phase leg circuit and lower legs of the same number of phase legs in remaining legs of the M-phase leg circuit to be turned on and controls the lower legs of the at least three phase legs and upper legs of the remaining phase legs to be turned off, so that the power supply module, the inverter module, and the driving module of the battery heating circuit form a charge loop,
• the second enabling signal controls the lower legs of the at least three phase legs and the upper legs of the remaining phase legs to be turned on and controls the upper legs of the at least three phase legs and the lower legs of the remaining phase legs to be turned off to form a discharge loop, whereby the charge loop and the discharge loop are alternately switched.