非对称中点钳位型逆变电路的开关磁阻电机模型预测直接转矩控制方法

Model Predictive Direct Torque Control Method of Switched Reluctance Motors of Asymmetric Neutral Point Clamped Converter

针对开关磁阻电机(SRM)转矩脉动过大的问题,提出一种非对称中点钳位型逆变电路的模型预测直接转矩控制方法,该控制方法基于开关磁阻电机的电感特性及转矩产生原理对扇区进行重新划分,对非对称中点钳位型逆变电路的基本工作模式进行分析并选取基本电压状态,根据直接转矩控制原理及扇区实际意义制定新型矢量选择方案,减少每个控制周期中的预测状态数;在每个采样时刻求解基于离散时间非线性预测模型的最优控制问题来抑制转矩脉动。在Matlab/Simulink环境下搭建电机仿真模型,与直接转矩控制对比仿真结果表明,该控制方法对开关磁阻电机具有更好的调节效果.能有效抑制转矩脉动。

In order to suppress the torque ripple of switched reluctance motor,a model predictive direct torque control method is proposed based on asymmetric neutral point clamped converter.The discrete prediction model of SRM is established based on the electromagnetic characteristics of SRM.The inductance characteristics and principle of torque of switched reluctance motor are used to divide new sectors.The basic voltage state is selected based on the analysis of the working mode of the asymmetric neutral point clamped converter.According to the principle of direct torque control and the practical meaning of sectors,a new vector selection scheme is developed to reduce the number of predicted states in each control cycle.At each sampling moment,an optimal control problem based on the discrete time nonlinear prediction model is solved to suppress the torque ripple.Finally,by setting up the motor simulation model in the Matlab/Simulink environment and comparing the simulation with direct torque control,it is shown that the control method has better adjustment effect on switched reluctance motor and can effectively suppress torque ripple.