定子电流矢量定向下PMSM转矩脉动抑制方法

Torque Ripple Suppression of PMSM Based on Stator Current Vector Orientation

齿槽转矩和谐波转矩均会引起永磁同步电机输出转矩脉动,导致电流波形畸变。基于永磁同步电机电磁转矩的磁共能模型,提出一种基于定子电流矢量定向闭环I/f控制的永磁同步电机转矩脉动抑制方法。综合考虑气隙磁场畸变、齿槽转矩和电流畸变等多种因素,推导电机转矩脉动最小化条件下的最优定子谐波电流约束条件,利用反推控制原理构建了谐波抑制控制器。此外,还设计了一种带遗传因子最小二乘算法的永磁同步电机转速辨识方法。仿真和实验表明,设计的转速辨识算法能在较宽范围内实现电机速度辨识,所提控制方法提升了系统的控制精度,改善了电流波形,有效抑制了电机运行时的转矩脉动。

Cogging torque and harmonic torque in permanent magnet synchronous motor(PMSM)will cause its torque ripple and distort current waveform.Based on the magnetic common energy model of electromagnetic torque in PMSM,a torque ripple suppression method for PMSM based on stator current vector oriented closed loop I/f control was proposed.Considering a variety of factors such as magnetic field distortion in air gap,cogging torque and current distortion,the constraints of optimal stator harmonic current under the condition of torque ripple minimization were derived,and the harmonic suppression controller was constructed by backstepping control principle.In addition,a speed identification algorithm of PMSM through the least square algorithm with a forgetting factor was also designed.Simulations and hardware experiments both show that the identification algorithm can estimate the speed of the motor in a wide range.The proposed control method enhances the control precision of the system,improves the current waveform,and inhibits torque ripple of the motor effectively.