Maximum torque per ampere control of brushless doubly fed induction machine using variable structure approach

In this paper, a variable structure controller is proposed to control the torque of brushless doubly fed induction machine with considering maximum torque per Ampere (MTPA) strategy. Based on this control approach, a sliding mode controller with a linear PI is designed to control the torque considering applying the MTPA scheme. The proposed controller is able to reduce the torque pulsations during steady-state behavior while the fast response and robustness merits of the classic DTC are preserved. Also, this method decreases the copper losses with minimizing the magnitude of power and control winding currents while increasing the overall efficiency of the BDFIM without deteriorating the dynamic performance. The validity and effectiveness of the method is verified by simulation results.