由于受逆变器固有的非线性特性和气隙磁通谐波等因素的影响,永磁同步电机定子电流中含有大量的高次谐波分量,这些谐波电流分量与转子永磁体磁场作用,使电机产生谐波转矩脉动,特别是在直接驱动系统中,转矩脉动更为严重.针对这一问题,从转矩脉动产生的机理出发,提出一种基于比例积分-准谐振控制器的转矩脉动抑制方法.该方法根据理想谐振控制器在谐振频率点处的增益为无穷大,可以对谐振频率点处的正弦信号实现零稳态误差跟踪控制,将谐振控制器与电流环PI控制器并联,对定子电流中的谐波分量进行补偿,改善定子电流波形,实现抑制转矩脉动的目的.仿真与实验结果证明了所提方法的正确性和有效性.%Influenced by the nonlinear characteristics of inverter,the air gap flux harmonics and other factors,the stator current of permanent magnet synchronous motor contains a lot of high order harmonic currents,which results in the motor generating harmonic torque ripple.The torque ripple is more serious for direct-drive system.Focused on the problem,a new control method of suppressing the torque ripple based on proportional-integral and quasi-resonant controller is proposed.Because the gain of the ideal resonant controller is infinity great at the resonant frequency,zero steady state error control can be achieved for sinusoidal signal of the resonant frequency.By connecting the resonant controller in parallel with the current loop proportional-integral controller and compensating the harmonic currents,the current waveform can be improved and the torque ripple can also be suppressed with it.The validity and effectiveness of the proposed method are demonstrated by simulation and experimental results.
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