抑制BLDCM换相转矩脉动的超前换相控制策略

An advance commutation control method is presented to suppress commutation torque ripple of brushless direct control motors(BLDCM). This method is based on current lag which is the main reason of commutation torque ripple. This method impelled the motor to commutate for a period of time in advance to improve the current lag. Meanwhile, it modulated three-phase cooperatively to eliminate difference between slew rates of switching-in phase and switching-out phase. The directions of the current in different internals during commutation were analysed in detail and the analytic expression of the time in advance was derived with the method. The current waveform was given under different load torque and speeds in the experiments. The current fluctuation was analysed by comparing the waveforms of the proposed method and the conventional method. The results show that the current fluctuation of the conventional method is far higher than that of the proposed method. The results prove the validity of the proposed method in suppressing commutation torque ripple.