Research on the Control Strategy of Three-Phase Four-Leg Inverter Based on 3D-SVPWM under Load Mutation of Permanent Magnet Synchronous Motor

Aiming at the problem of load mutation affecting the stable operation of permanent magnet synchronous motor, a control method of permanent magnet synchronous motor based on 3D-SVPWM three-phase four-leg inverter is proposed. Firstly, the operation principle of three-phase four-leg inverter before and after motor load mutation is analyzed. Then, the state of the 3D-SVPWM switching vector is explained, and the method for calculating the duty cycle is given to generate the 3D-SVPWM modulation wave; then, the double closed-loop control strategy of voltage and current is analyzed. Finally, the effectiveness and reliability of the method are verified by simulation. The simulation results show that the control method based on the 3D-SVPWM three-phase four-bridge inverter can effectively maintain the stable operation of the permanent magnet synchronous motor in the case of the sudden change of the load of the permanent magnet synchronous motor. It is of great significance to study the stable operation of permanent magnet synchronous motors in the case of sudden load changes.