Model-based loss minimization of direct torque controlled permanent magnet synchronous motors

The purpose of this paper is to improve the efficiency of permanent magnet synchronous motors under a direct torque control system. The nature of the system necessitates that the stator flux linkage amplitude is employed as the loss minimization control variable. Thus, the optimal stator flux linkage is determined in a way that the total electrical loss is minimized. Then the optimal flux is considered as the reference flux. The extensive simulation results confirm the effectiveness of the proposed loss minimization control system under varying motor operating conditions.