基于电压补偿的低速永磁电机谐波抑制控制策略研究

扭矩扳子自动化检定装置用低速永磁同步电机通常工作于300 r/min以下,由于电机本体气隙磁场畸变、逆变器死区时间、开关管压降等非线性因素,电机在运行过程中会产生高次谐波,引起转矩脉动,导致加载过程中输出扭矩波动,影响检定过程。针对上述问题,提出了一种针对低速永磁电机的谐波抑制控制策略,建立了低速永磁电机的谐波数学模型,采用电压补偿的方法,根据谐波数学模型计算谐波电压补偿量,并采用PI控制,对电机运行过程中的相电流谐波进行抑制,从而减小扭矩扳子自动化检定装置的转矩脉动。通过仿真表明,该方法可以显著降低谐波,从而减小电机输出转矩脉动。

Control strategy of low-speed permanent magnet synchronous motor current harmonics suppression based on voltage compensation

Low-speed permanent magnet synchronous motor (Low-speed PMSM) which used in torque wrench calibrating device usually works below 300 revolutions per minute. There was a lot of high order harmonic in the motor phase current due to the distortion of air-gap magnetic field, the dead-time and tube voltage drop of the inverter, which caused the torque ripple and the output torque fluctuates during loading, the measurement process was influenced. A novel harmonic suppression method for low-speed PMSM based on voltage compensation was proposed in view of this problem. The model of low-speed PMSM was established considering the existence of current harmonics. The method of voltage compensation was adopted, and harmonic compensation was calculated based on the model of low-speed PMSM. The current harmonics were compensated by PI control strategy. Simulation results show that the method based on voltage compensation can suppress the harmonic currents and reduce torque ripple effectively.