Analysis of Different Operating Modes of PMSM during Regeneration with Uncontrolled Rectifier

In this paper, the exact analytical solution for braking torque in the motor and dc current going into the battery during regeneration is obtained for different operating regions. The variation of braking torque and dc current with rotor speed is analysed. The boundary for different regions of operation along with its variation with battery voltage, rotor speed, and winding impedance is provided. The analytical expressions for currents and torque in each operating region and the boundaries between operation modes are presented. The analysis is done for operation during fault mode, i.e. all the switches are turned off and the inverter acts as a diode rectifier.