Flux weakening control for torque and efficiency optimization of a vector controlled four switch three phase inverter fed induction motor drive

This paper proposes a novel flux weakening control scheme for Four Switch Three Phase Inverter (FSTPI) drive to improve the speed-torque characteristics and motor efficiency in the high-speed region. In the proposed scheme, a method to calculate the optimal flux reference and slip frequency command for the high-speed region is explained in detail. The proposed method is verified by experiment and results show an improvement in the maximum attainable torque and motor efficiency of the drive.