抑制无刷直流电动机转矩脉动的改进型Z源变换器

Torque Ripple Minimization of Brushless DC Motor with Modified Z-Source Converter

无刷直流电动机换相时存在转矩脉动的问题,影响了其在高精度领域中的应用。分析了转矩脉动产生的原因,提出了通过改进型的Z源变换器来调整母线电压进而抑制转矩脉动的方法。Z源变换器近年来常用于无刷直流电动机的控制,但其存在增益不够高的问题。针对该问题,提出了改进型的Z源变换器,通过增加一级电容电感网络,获得了比传统Z源变换器更高的增益,并用数学方程分析了所提出电路结构的特性。仿真结果表明:将所提出的Z源变换器用于无刷直流电动机控制中,能有效地改变直流母线电压,抑制了转矩脉动,并且在低速和高速不需改变电路结构,具有较好的普适性。

The problem of the torque ripple exists in the commutation of the brushless DC motor,affecting its application in the field of high precision. The cause of the torque ripple was analyzed in the paper and the method of changing the bus voltage with the suppression of the torque ripple was proposed by the improved Z- source converter. In recent years,the Z- source converter has often been used in the control of brushless DC motor,but there is a problem of low gain of the Z- source converter. Therefore,the proposed improved Z- source converter well solves the problem by increasing the capacitance network. As a result,higher gain than that in traditional Z- source converter was acquired,and the characteristics of proposed circuit structure was analyzed by using a mathematical equation. The simulation results show that the proposed Z- source converter used in brushless DC motor control can effectively change the DC bus voltage,reducing the torque ripple without changing the circuit structure at low speed or at high speed,so it has a good applicability.