三电平SVM-DTC的无轴承异步电机研究

Research on three level SVM-DTC bearingless induction motor

针对无轴承异步电机多变量、非线性、强耦合的特性,直接转矩控制(DTC)优秀的控制的特点已经成为一种突出的无轴承异步电机控制性能方案。常规的两电平逆变器具有高的转矩脉动和大谐波的问题,三电平中点钳位逆变器(NPC)广泛应用于变频调速系统,其特点是逆变器开关器件分压使得器件端电压幅值降低,输出纹波脉动,控制性能优良,因此文中通过使用三电平逆变器的空间矢量调制用于直接转矩控制(SVM-DTC)来抑制电机定子转矩脉动。仿真结果表明,三电平逆变器的SVM-DTC能够有效地使无轴承异步电动机稳定悬浮,并且SVM-DTC能有效的抑制转矩脉动和转子的径向位移,提高了系统的精准度并保持了DTC系统的快速转速动态响应。

In view of the characteristics of multi-variable,nonlinear and strong coupling of bearingless induction motor,direct torque control（DTC） has become an outstanding performance control scheme for bearingless induction motors.Two level inverter with conventional high torque ripple and harmonic problems,three level neutral point clamped inverter（NPC） is widely used in frequency control system,has low requirements on breakdown voltage,low harmonic outputcontrol,as well as good performance,so this paper uses the space vector modulation based on three level inverter used to control control of torque ripple reduction.The simulation results show that this method of asynchronous motor bearing on the effective implementation of the DTC system in the three level inverter,and the SVM-DTC method greatly reduces the torque ripple,maintains a rapid speed of the dynamic response of DTC system.