Study And Optimization Of Harmonic Of Permanent Magnet Synchronous Motor For Pure Electric Vehicles

The motor is a major component of electric vehicle drive system, and the merits and demerits of its performance decide safety and comfort of electric vehicle. Due to the distortion of air-gap magnetic field genetates the current waveform through the nonlinear characteristics of the inverter, resulting in motor electromagnetic torque ripple, reducing performance of the motor and damaging intuitive feelings for driving the electric vehicles. Analysis and suppression permanent magnet synchronous motor, It has become the researching focus at home and abroad to analyze and restrain harmonic of PMSM.Firstly, this paper finds the factors effecting air-gap flux density through analyzing air-gap magnetic field of radial PMSM. Tooth width, tooth height, pole arc coefficient, gap length and the length of the magnetization direction of the permanent magnet impact on flux density harmonic.Secondly, it is simulation analysis and comparison to factors effecting air-gap flux density through enumeration and orthogonal test. According cogging torque, back-EMF and torque ripple it is to comprehensively evaluate factors effecting air-gap flux density.Thirdly, according to the above factors combined with considerations of process and cost, the optimization will be made in the motor, and compares with the prototype through the simulation results. The performance after optimization is better than before in consideration of the harmonic content of air-gap flux density, cogging torque, back-EMF, the teeth yoke flux density, torque ripple.Finally, the phototype’s performance is tested with experiment, and compares with the phototype’s simulation results to indirectly verify the material properties, boundary conditions, excitation conditions, etc.. And it is proved to the reliability and correctness of the optimization results with electromagnetism simulation in paper.