A phase current modulation method that suppresses commutating torque pulsation of brushless direct current motor under non-ideal back EMF was proposed to solve commutating toque ripple problem. This method calculates the duty cycle and commutation time by acquiring the line voltage in real time, and controls the modulation of different duty cycles of the power device to ensure that the on-phase and off-phase current changes at the same rate during commutation, and finally suppresses non-commutation phase current pulsates. It assures the consistent change rate of conducting-phase and shut-off phase currents at commutation, and thereby suppresses non-commutation torque ripple. Moreover, the proposed method realized indirect observation of non-ideal back EMF through real-time acquisition of line voltage, which prevents the difficulty and poor accuracy of observation of back EMF. Comparing with phase current modulation method considering armature resistance, the proposed method can control non-commutation current control at the commutation moment more accurately. The experimental results show that the phase current ripple coefficient is only 11.1% at 1000r/min and 13.9% at 2000 r/min, while the phase current ripple coefficient under contrast method control is 15.3% at 1000r/min and 19.4% at 2000r/min. The ripple of non-commutation current and commutation torque is smaller at the commutation moment.

提出了一种抑制非理想反电动势下无刷直流电动机换向转矩脉动的相电流调制方法，以解决换向转矩脉动问题。该方法通过实时获取线路电压来计算占空比和换相时间，并控制功率器件不同占空比的调制，以确保在换相期间同相和异相电流以相同的速率变化，最终抑制了非换相相电流脉动。它确保了换相时导电相和关断相电流的一致变化率，从而抑制了非换相转矩脉动。此外，通过实时采集线电压，该方法实现了对非理想反电动势的间接观测，这避免了反电动势观测的困难和准确性差。与考虑电枢电阻的相电流调制方法相比，该方法可以更精确地控制换相时刻的非换相电流控制。实验结果表明，相电流纹波系数在1000r / min时仅为11.1％，在2000r / min时为13.9％，而对比法控制的相电流纹波系数在1000r / min时为15.3％，在2000r / min时为19.4％。分钟 在换向时刻，非换向电流和换向转矩的波动较小。实验结果表明，相电流纹波系数在1000r / min时仅为11.1％，在2000r / min时为13.9％，而对比法控制的相电流纹波系数在1000r / min时为15.3％，在2000r / min时为19.4％。分钟 在换向时刻，非换向电流和换向转矩的波动较小。实验结果表明，相电流纹波系数在1000r / min时仅为11.1％，在2000r / min时为13.9％，而对比法控制的相电流纹波系数在1000r / min时为15.3％，在2000r / min时为19.4％。分钟 在换向时刻，非换向电流和换向转矩的波动较小。