一种基于辅助升压前端的无刷直流电机换相转矩脉动抑制方法研究

Research on Suppressing Commutation Torque Ripple of Brushless DC Motor Based on an Auxiliary Step-up Front End

无刷直流电机在换相过程中存在转矩脉动,严重制约了其在高性能领域的应用。该文提出一种基于辅助升压前端的无刷直流电机换相转矩脉动抑制方法,升压前端主要由反激变压器、电容和转换电路组成。在电机非换相期间,电源通过变压器将电容充电至期望电压值。电机换相开始时,转换电路将充电电容串联入直流母线提高母线电压,通过斩波调制逆变器使电机输入电压与反电动势满足4倍幅值的关系,从而抑制换相转矩脉动。在每个开关周期,变压器将存储的能量回馈至电源,提高了能量的利用率。除此之外,该方法还可以减少换相时间。最后,通过实验验证了所提方法的正确性与有效性。

There exists torque ripple in the commutation process of brushless DC motor(BLDCM),which seriously restricts its application in high performance field.This paper proposed a commutation torque ripple suppression method for BLDCM based on an auxiliary step-up front end,which consists of a flyback transformer,a capacitor and a switch selection circuit.During the non-commutation period of the motor,the power supply charges the capacitor to the desired voltage through the transformer.At the beginning of commutation,the charging capacitor was connected in series to the DC-bus by the switch selection circuit to increase the DC-bus voltage,so that the input voltage of the motor was equal to four times back-EMF amplitude for restraining commutation torque ripple.The energy stored in the transformer was returned to the power source in each switching cycle,which improved the energy utilization rate.In addition,this method can also reduce commutation time.Finally,the validity and effectiveness of this method was verified by experiments.