船舶永磁推进电机电流测量误差抑制技术

Current Measurement Error Suppression Technology of Marine Permanent Magnet Propulsion Motor

电流测量误差会造成永磁同步电机矢量控制系统的稳态转速、转矩脉动,同时会增大电机相电流的低次谐波含量。文章从坐标变换角度出发,分析出其根源在于dq轴稳态电流出现与电机定子角频率相关的1次、2次交流分量,并提出一种旋转坐标系下截止频率动态变化的低通滤波方法,用于抑制电流测量误差的影响。根据电机固有机电时间常数与滤波器截止频率的关系,结合船舶永磁同步推进电机的应用场合,推导出内环调节器零点与滤波器非零极点相消方法的PID控制器参数整定方法,进行仿真和实验验证。结果表明该方法能显著提高电机的稳态性能、降低谐波含量。

Current measurement error can cause steady-state speed and torque ripple of PMSM vector control system, and it increases the low harmonic content of the motor phase current. From the perspective of coordinate transformation, the root cause is that the steady-state current of dq axis has primary and secondary AC components related to the stator angular frequency of the motor. A low pass filter with dynamic cut-off frequency in rotating coordinate system is proposed to suppress the influence of current measurement error. Based on the relationship of the inherent electromechanical time constant of the motor and the cut-off frequency of the filter,and combining the application of marine permanent magnet synchronous propulsion motor, one of the tuning method is chosen, which can make the zero point of inner loop regulator equals to the non zero pole of the filter.The simulation and experiment results show that the method can significantly improve the steady state performance of the motor and reduce the harmonic content of the motor.