基于特定换相调制占空比的永磁无刷直流电机换相转矩脉动研究

摘要

永磁无刷电机转矩波动是影响其运行稳定性的重要问题之一,为了研究其中的换相转矩波动问题,采用基于电流环的PWM_ON调制方式,分析了换相期间PWM调制对换流过程的影响,推导出在低转速情况下能够完全补偿换向电流脉动的特定占空比公式,并提出了在高转速情况下抑制电流脉动的方法.仿真和实验结果表明在换相期间采用特定占空比调制能够较好地抑制电流脉动,进而抑制转矩脉动.%Torque ripple is one of the main factors affecting the stable operation of BLDC motors. Based on PWM_ON modulation with current loop, this paper analyzed the motor phase current during commutation and presented a particular PWM duty cycle with which the non-commutation phase current ripple was eliminated at a low speed. Moreover, this paper put fordward a method to reduce the phase current ripple at a high speed. Finally, the results of simulation and experiments prove that the phase current can keep constant with the help of particular PWM duty cycle during commutation, and so does the torque.