Research And Implementation Of Direct Torque Control For Permanent Magnet Linear Synchronous Motor

Permanent magnet linear synchronous motor not only has the advantages of high efficiency and energy saving, but has the advantages of simple structure, high reliability, low manufacturing cost, small mechanical loss, fast response, easy control and so on. Direct torque control technology is a typical method to realize the direct torque control of permanent magnet linear synchronous motor. It is also a hot spot of current research. This paper discusses the realization of the direct torque control system of permanent magnet linear synchronous motor, which is based on the PID control and sliding mode control for permanent magnet linear synchronous motor direct torque control system.Firstly, the mathematical model of permanent magnet linear synchronous motor is presented after doing coordinate change. According to the mathematical model,the simulation model is built. Then considering the characteristics of the direct torque control system, this paper build the voltage space vector module, thrust and flux linkage calculation module and the switch table module and then do the simulink experience.Secondly, the paper introduces the sliding mode control to the control system of permanent magnet linear synchronous motor. Based on the sliding mode control theory, the paper designs a kind of sliding mode controller. The simulation model of the permanent magnet linear synchronous motor direct torque control system is proposed. This model reduces the effect of the sliding mode controller because of buffeting so the stability and robustness of the system are improved.In the end, the importance of the primary flux linkage to the permanent magnet linear synchronous motor direct torque control system is analyzed, and the primary winding resistance of the permanent magnet linear synchronous motor is designed. The paper designs the simulation model of the permanent magnet linear synchronous motor based on flux linkage. Through simulation analysis, this kind of compensator can effectively reduce the error caused by the change of primary resistance, and increase the accuracy of the primary flux linkage, which elevates the stability of the permanent magnet linear synchronous motor direct torque control system.