三电平逆变器系统直接转矩复式控制

Research on Direct Torque's Compound Control Technique for Three-Level Inverter System

针对异步电动机在三电平逆变器供电下 ,其恒转矩区域运行时的特点 ,提出一种直接转矩复式控制技术 .根据不同的运行速度 ,选用不同的电压空间矢量进行线性组合 ,控制电机的定子磁链和电磁转矩 .通过仿真研究 ,该方法既能优化功率器件的开关频率 ,同时又有效抑制了三电平逆变器中点电压的偏离 ,提高了传动系统的整体性能 .

The paper presents a direct torque's compound control technique,which means to select different voltage vector varying from speed,working on constant torque area when the induction motor is fed by three-level inverter.Simulation results of the method for a three-level inverter feeding induction motor are presented.The simulation results confirm that the control method is very effective in optimizing the frequency of switching devices,balancing the neural point voltage of three-level inverter,and improving drive system performance.