Robust Flux-Weakening Control Approach for Three-Phase Induction Motor Drives

A robust flux-weakening control strategy for induction motor drives is presented in this article. The voltage feedback part, which is the difference in amplitude between the command voltage and the voltage limit, is utilized to enhance the tracking accuracy of the weakening current rather than using only the feedforward control as the conventional method. The limitation of the maximum q-axis current is adapted in any flux-weakening region. The maximum torque per ampere (MTPA) trajectory is implemented in the constant torque region in order to achieve the maximum torque. Likewise, the maximum slip speed can be obtained based on the optimal current condition in the flux-weakening region II, in which cannot accessible by the conventional method. Indeed, the proposed method provides a reduction of the rotor flux appropriately to the increased speed in the flux-weakening regions under the controllable operation, resulting in a robust control strategy. The effectiveness of the proposed method is confirmed by simulation results.