传统异步电机直接转矩控制改进及仿真

Improvement and Simulation of Traditional Induction Motor Direct Torque Control

为了克服传统电压-电流型磁链观测方法所存在的积分初始值与直流误差问题和减小传统直接转矩控制磁链脉动,启动过程电流过大,采用了双低通滤波器定子磁链观测器法代替传统磁链观测器,将6扇区变为12扇区,并将定子电流和磁链幅值进行限制,采用Matlab进行了仿真。仿真结果表明,磁链轨迹、转速及转矩脉动明显变小,异步电机三相定子电流波形更加圆滑,更加接近于正弦波形。结论是转矩、转速响应速度较快而且平稳,采用双低通滤波器法外加扇区细分和磁链、电流幅值控制确实可改善控制系统动静态性能。

For the optimization of the integral initial value and the DC error problems which exist in the traditional voltage-current flux observation method,meanwhile,to minish the traditional direct torque control magnetic chain pulsation as well as the starting current of the motor,the stator flux observer of dual low pass filter was used to replace the traditional flux observer,and the six sectors were changed into twelve sectors.The stator current and flux amplitude were limited.Then,the method was verified by Matlab.The results show the significant decrease in the flux linkage locus,the speed and torque ripple.At the same time,the stator current waveform was closer to the sine wave.Finally,it comes to a conclusion that the decrease of the three-phase asynchronous motor torque ripple and its smooth running can be realized by utilizing the double low pass filter plus sector segmentation method and the magnetic chain,current amplitude control.Consequently,the dynamic and static performance of the control system are ameliorated.