基于BUCK变换器调制的无刷直流电机转矩脉动分析

Torque Ripple Analysis of Brushless DC Motor Based on Buck Converter Modulation

为了抑制无刷直流电机换相转矩脉动,在三相桥式逆变电路前端引入BUCK变换器调制。通过换相的开关器件在断开前、导通后进行PWM调制来改变换相过程中绕组端电压,使得各换相电流下降和上升的速率相等,抑制换相转矩脉动。在Matlab/Simulink中搭建了相应的仿真模型,并通过波形分析与对比证明了加入BUCK变换器在换相时刻和非换相时刻都能抑制转矩脉动。

In order to suppress commutation torque ripple of brushless DC motor,BUCK converter was introduced in front of three-phase bridge inverters.PWM modulation was used to change the winding voltage before and after the commutation of the commutation switching device,which made the commutation current decrease and rise at the same rate and restrained the commutation torque ripple.The corresponding simulation model was built in Matlab/Simulink.Through waveform analysis and comparison,it was proved that the torque ripple can be suppressed by adding BUCK converter at commutation and non-commutation time.