Strategy of efficiency optimization of PMSM-DTC system used for EVs

A loss minimization strategy for PMSMs used for EVs is proposed in this paper which is based on PMSM-DTC loss model. Through the analysis of the relationship between kinds of losses and exciting current, the optimal given values are obtained. The control principles of stator flux, torque angle and torque of PMSM-DTC system are analyzed to propose a voltage vector selection strategy of twelve sectors substituting the traditional switching table. The results verify that the loss minimization strategy can improve the efficiency of the system, decrease current and torque ripples, and improve the dynamic and static performance of the system.