The Design Of Permanent Magnet Synchronous Motor And Research On Field Weakening Performance

Early at the seventies of last century, permanent magnet synchronous motorjust appear and has been widely used today.Because of its light weight, small size,high efficiency, field weakening expansion and fine characteristic etc, which isapplied in an aviation, aerospace, weaponsequipment, electric vehicles and otherimportant field. Due to the complexity of magnetic field structure of permanentmagnet synchronous motor, it is difficult to get accurate calculation, the pole shapeand size optimization, speed adjusting performance on permanent magnet motordesign.In resent years, design of permanent magnet synchronous motor（PMSM）andits control system becomes an important research focus.The main contents of this paper is to design the built-in permanent magnetsynchronous motor and research of field weakeding performance. Through theintroduction of permanent magnet synchronous motor and its control technologydevelopment trends, it is more and more important to develop high-performancepermanent magnet synchronous motor. Starting from electromagnetic structure ofpermanent magnet motor to optimize motor structure and parameters in order toreduce the torque ripple, at last this paper also research and analysis field weakeningcontrol performance of permanent magnet synchronous motor.This paper describes the design method of permanent magnet synchronousmotor, including winding design and structural design of rotor; then described indetail different rotor structures and their used place, and discuss their advantages anddisadvantages, and then using finite element principle, have comparative analysis ofbuilt-in structure and surface-mount structure permanent magnet motor on manyperformance, and obtained better performance of built-in permanent magnet motorstructure. This paper elaborates basic principle of built-in permanent magnet motorcogging torque, and discuss ways of weakening cogging torque, such as changes inpole arc coefficient and slot width, effects of slot、pole ratio, etc., by optimizingmotor parameters on cogging torque by finite element simulation, therefore built-inpermanent magnet motors torque ripple is smaller.According to mathematical model of built-in permanent magnet synchronousmotor, we can gain the impact parameters of field weaken and sped expansion,including permanent magnet flux and d axis inductance, and start to study the four angles，such as design of permanent magnets, air gap length, pole arc coefficient andstator slot width to optimize this motor, make permanent magnet synchronous motorhave good field weaken performance at high speed. And simulation and experimentalverify that built-in permanent magnet synchronous motor has a good dynamicresponse and field weaken performance, and this method has a strong engineeringpractical significance.