Research On Performance Of Multi Winding Stator Permanent Magnet Synchronous Motor

The permanent magnet synchronous motor(PMSM),which plays a major role in driving a new energy vehicle,have higher power density and better regulation performance compared to induction motor.These advantages make(PMSM)a popular research area of electric vehicle.But limited by the operating rules,a PMSM with high torque usually could not reach high speed.This paper mainly focus on how to improve high-speed performance of PMSM in constant power area.Through the study of flux-weakening control,it finds that this control theory exists a series of problems,such as High dependence on vector control;Too sensitive to parameter changes;Involvement of high precision sensor and high performance DSP that make the system more costly.To solve the above problem,the paper proposes a solution called multi—winding stator permanent magnet synchronous motor solution which has a remarkable results in increasing the peak speed.Through two sets of winding embedded in the stator slots,the motor can switch to the winding in series when the vehicle is climbing at low speed or starts with full power and switch to the winding in parallel when the vehicle need to achieve high-speed operation.Due to significant variations of flux linkage and inductance.Two different type of motors integrated into one motor,and high-speed performance were highly upgraded.In the basis of analyzing the theories and experimental results,the following conclusions are obtained:(1)At the same speed,the Back EMF of motor with parallel coil can be reduced to half compared to the motor with series coil;(2)Experiments on prototype motor shows that by switching to the parallel coil winding,the maximum speed of motor under the same torque would raise by 15% compared to series coil winding.(3)The efficiency-torque curve of the PMSM in two different type of winding has an intersection point which means the winding-switching strategy exits optimal solution.