Method for pulse heating power battery of electric vehicle and electric vehicle

An electric vehicle comprising:

• a power battery,
• two front wheels,
• two rear wheels,
• a first powertrain comprising a first motor controller and a first drive motor that is configured to be in transmission connection with the two front wheels of the electric vehicle;
• a second powertrain comprises a second motor controller and a second drive motor that is configured to be in transmission connection with the two rear wheels of the electric vehicle;
• and
• a vehicle controller, wherein the first motor controller comprises a first power circuit and a first bus capacitor, the second motor controller comprises a second power circuit and a second bus capacitor, the first power circuit comprises a first three-phase bridge arm, two ends of each bridge arm of the first three-phase bridge arm are respectively configured to connect two ends of the first bus capacitor, the second power circuit comprises a second three-phase bridge arm, two ends of each bridge arm of the second three-phase bridge arm are respectively configured to connect two ends of the second bus capacitor, the two ends of the first bus capacitor and the two ends of the second bus capacitor are separately configured to connect a positive electrode and a negative electrode of a power battery through a direct current bus;
• and the vehicle controller is configured to:
• after a temperature of the power battery is less than a first preset temperature, control one of the first power circuit and the second power circuit to output a three-phase current;
• and
• after the temperature of the power battery is less than a second preset temperature, control both the first power circuit and the second power circuit to output the three-phase current, wherein the second preset temperature is less than the first preset temperature;
• after a phase difference between a pulse alternating current generated by the first power circuit and a pulse alternating current generated by the second power circuit is greater than a preset value, adjust a switching frequency of a switching transistor of the first power circuit or a switching frequency of a switching transistor of the second power circuit to reduce the phase difference between the pulse alternating current output by the first power circuit and the pulse alternating current output by the second power circuit;
• and
• the three-phase current is used to generate a pulse alternating current on the direct current bus, and the pulse alternating current is used to heat the power battery.