无刷直流电机直接转矩控制下的转矩脉动抑制

Torque Ripple Inhibition of Brushless DC Motor by DTC

为了减少无刷直流电机的转矩脉动,提高系统动态性能,将直接转矩控制(DTC)应用于无刷直流电机控制系统中。在分析传统脉冲宽度调制(PWM)电流控制的基础上,研究了DTC对无刷直流电机非理想反电动势和换相引起的转矩脉动的抑制作用。根据无刷直流电机两相导通的特点,建立了有磁链观测和无磁链观测的无刷直流电机DTC系统模型,仿真与试验结果均表明,系统实现了对电流和转矩的有效控制,比传统PWM电流控制对转矩脉动具有更好的抑制性能,提高了无刷直流电机的动态性能。

To minimize torque ripple and improve dynamic performance of brushless DC motor（BLDCM）, the direct torque control（DTC） is applied to the BLDCM drive system. Based on the analysis of the pulse width modulation（PWM） current control, this paper researches into the torque ripple inhibition with DTC method, where the torque ripple is produced by both non-ideal back electromotive force （back-EMF） and current commutation. According to the characteristics of the BLDCM in two-phase conducting mode, a BLDCM-DTC drive system with and without stator flux control is established. Simulation and experimental results prove that the system makes effective control on torque and current, and gains better inhibition of torque ripple and faster dynamic response of the BLDCM, compared with conventional PWM current control.