Research And Simulation On Direct Torque Control Method Of PMSM

Comparing with traditional AC motor, advantages with PMSM are more efficacious, reliable, fast corresponding and so on. The development of permanent magnetic material during recent decades has provided a wide field of application for the permanent magnet synchronous motor. In traditional method of PMSM control, constant voltage frequency ratio control and vector control did not pay attention to the control of torque, but the direct torque control method regard flux and torque as a control object, which giving DTC more innate kinematics advantage. The traditional DTC is working in the bang-bang control,this simple motor control method has rapid response and strong robustness, meanwhile contain some problems as torque ripple. Because the traditional motor flux data estimation method is integral method, this will lead to error accumulation.So the researching of direct torque control is necessary.Based on the traditional PMSM-DTC, this paper carries out some optimization. First,using the kalman filter to estimate for flux calculating by voltage current signal, then established the S function of the EKF flux estimate in the simulation and obtained better effect compared with the traditional flux integral method.Secend, set up PMSM-DTC simulation platform in the MATLAB/Simulink software.Thirdly,do some study in the field of torque ripple which is seemed as a hot reasearch spot. The insert zero vector method as a improved swith table has taken apart in the DTC control, and the available performance given by the simulation make it sure that torque ripple is somehow retrained. Finally,given the related circuit diagram and software flow chart in the DTC experimental control-working-platform based on ARM7.