磁场干涉对永磁电机电磁力特性影响研究

摘要

Aiming at the underwater acoustical directivity of permanent magnet(PM)motor, theoretical and numerical simulation methods are used to study radial force characteristics of fractional slot motor, when ideal sine wave power and containing harmonic current power supplied.It is found that radial force of the fractional slot PM motor with ideal sinusoidal phase current periodically appears after some teeth. When phase current contains noninterfering harmonic current, the radial force is aperiodic in time do-main,but it is still periodic in frequency domain.When harmonic current in phase current is interferen-tial,the radial force is aperiodic in both time domain and frequency domain.The aperiodic law is verified by an experiment in which phase current containing interfering harmonic current caused by pulse width modulation(PWM).The radial force is the driving source of electromagnetic vibration and noise.Differ-ent forces leads to different vibrations on tooth.The aperiodic law of radial force can explain the acoustic directivity.%针对亲水永磁电机水下噪声声学指向性问题,用理论和数值仿真的方法研究了分数槽电机,在理想正弦波供电、含有谐波电流供电时,磁势干涉后齿上径向力的特点.发现理想正弦波供电时,齿上径向力间隔特定个齿后周期性出现.相电流中存在谐波电流,耦合磁势的频率不相互干涉时,齿上径向力时域无周期性,频域幅值依然存在周期性;若耦合磁势干涉时,则时域、频率都不存在周期性.实验的相电流存在大量可耦合出干涉磁势的谐波电流,振动测试的结果验证了干涉后,电磁力频域幅值非周期性的规律.不同的径向力会导致齿上不同的振动.该理论可以从电磁力激励源上解释亲水永磁电机水下噪声声学指向性的现象.