Three-level electric driving system and control method thereof

The invention provides a three-level electric driving system and a control method thereof, and the three-level electric driving system divides a power battery into two parts which are connected in series on the basis of a midpoint clamping type three-phase inverter, and connects the connection point of the series connection of the batteries with the midpoint of a three-level inverter capacitor. Based on the three-level electric driving system, when the three-level inverter drives the motor to operate, the stability of the three-level midpoint voltage can be enhanced by using the stability of the battery voltage, so that the capacity requirements on the first direct-current bus capacitor and the second direct-current bus capacitor are reduced, the cost and the size of the inverter are effectively reduced, and the power consumption is reduced. Meanwhile, the control quality of the motor is improved, internal resistance heating of the batteries can be achieved by adjusting three-phase zero-sequence voltage and i