基于线电压差积分的无刷直流电机无位置传感器控制方法

Sensorless Control Method of Brushless DC Motor Based on Integral of Line Voltage Difference

针对无刷直流电机换相误差在转速变化时难以准确测量的问题,分析了电机线电压差积分和电机转角之间的关系,证明了电机准确换相点处的线电压差积分值在不同工况下均为定值,基于此提出了无刷直流电机无位置传感器精确换相控制方法。此外,为减小滤波后的波形畸变,保证积分值的准确性,设计了具有群时延特性的有限冲击响应(FIR)数字滤波器。仿真和实验结果表明,线电压差积分大小能准确反映电机的换相误差情况,所提方法使电机在转速变换时也具有良好的换相精度。

In view of the problem that the commutation error of brushless DC motor is difficult to accurately measure during variable speed operation,the relationship between the integral of line voltage difference and the motor rotation angle was analyzed,and it was proved that the integral value of the line voltage difference is a fixed value at the accurate commutation point of the motor under different working conditions.Based on this,a precise sensorless commutation control strategy for brushless DC motor was proposed.In addition,in order to reduce the waveform distortion and ensure the accuracy of the integral value,a finite impulse response(FIR)filter with group delay characteristics was designed.The simulation and experimental results show that the line voltage difference integral can accurately reflect the commutation error of the motor,and the proposed strategy has good commutation accuracy during variable speed operation.