The Study Of SVM-DTC Control Strategy For Permanent Magnet Synchronous Motor

Permanent magnet synchronous motors have the advantages of high efficiency,highpower factor,simple structure,and are widely used in the field of industrial motor speed regulation.Direct torque control technology has simple control strategy and fast dynamic response.Combined with the advantages of permanent magnet synchronous motor,the direct torque control technology of permanent magnet synchronous motor developed has been gradually applied in various high performance motor control applications.This article takes a sine-wave permanent magnet synchronous motor as the controlled object and studies its direct torque control strategy.This paper first introduces the basic characteristics of permanent magnet synchronous motor,and systematically introduces the basic principle of permanent magnet synchronous motor direct torque control.The traditional direct torque control system has problems such as large output torque ripple,unstable switching frequency of the power converter and low utilization of space voltage vector.For the shortage of the traditional DTC system,the SVPWM method was used to improve,and the basic principle of the SVM-DTC control strategy was introduced in detail.In the SVM-DTC system,the shortage of the traditional stator flux observer under the condition of non-constant flux amplitude given is studied,and an improved method is proposed to improve the accuracy of the flux observation.Secondly,this paper gives the block diagram of the permanent magnet synchronous motor SVM-DTC system.The simulation model of the entire system is established in Matlab/Simulink.The simulation results show that the new flux linkage observer has accurate observation of the flux linkage under non-constant conditions,and can greatly reduce the torque ripple caused by the traditional direct torque control strategy.The feasibility of the normal operation of permanent magnet synchronous motor SVM-DTC system under the condition of non-constant magnetic flux amplitude given by the simulation was verified.In order to realize the permanent magnet synchronous motor SVM-DTC control strategy,a motor control platform based on TMS320F28335 was built.Taking the IPM intelligent power module as the main switching device,the hardware circuit for driving and the hardware circuit for current and speed acquisition were designed.Finally,the hardware circuit debugging,experimental results show that the SVM-DTC method used in this paper has good output performance,which verifies the feasibility of the SVM-DTC scheme and lays a theoretical foundation for practical engineering applications.