Dynamic equivalent magnetic network model and drive system of permanent magnet synchronous motor with double V-shaped magnet structure

Abstract

In order to improve the driving performance of electric vehicles (EV), a permanent magnet synchronous motor with double V-shaped magnet structure (DVMPMSM) and its driving system are studied in this paper. A 150kW DVMPMSM for EV is designed firstly, and the design parameters of the motor are determined. In order to overcome the drawbacks of the finite element analysis (FEA), especially the issue on calculating time, a dynamic equivalent magnetic network (EMN) model of the DVMPMSM is constructed, by which the air gap flux density, back electromotive force, electromagnetic torque and winding inductance parameters of the motor can be solved. Compared with the FEA, the dynamic EMN model constructed in this paper greatly increases the calculation speed while the calculation accuracy is maintained well. This paper also introduces the stator winding switching method to replace the field-weakening control method. Then, a vector control method of DVMPMSM based on dynamic EMN model and stator winding switching is proposed. The demands brought forward by EV for high torque output under low speed and high upper limit of speed can be well satisfied. Finally, the accuracy of the dynamic EMN model and the effectiveness of the proposed control method is validated through prototype experiments.