Comparison between flux weakening and PWM inverter with voltage booster for permanent magnet synchronous motor drive

The operation by the PWM inverter with voltage booster is compared with the flux weakening operation for 1.5 kW interior permanent magnet synchronous motor drives. Equations are derived and performances are analyzed for both operations. Current trajectories in the i/sub d/-i/sub q/ plane are shown. In addition, torque, voltage, current and efficiency versus speed characteristics, which are obtained from analysis for both operations, are compared. The results show some advantages of the operation by the PWM inverter with voltage booster.