Research Of Speed Sensorless Direct Torque Control For PMSM Based On DSPACE

Permanent magnet synchronous motor(PMSM)is widely used in various fields of the society,especially in the new energy automobile industry,because of its high efficiency and large power density.With the development of AC motor speed control technology,direct torque control technology has attracted widespread attention due to its fast dynamic response,simple control structure,strong robustness and so on.However,the speed sensor in the control system is vulnerable to the impact of the environment and reduces the system reliability,and increases the cost of the system.Therefore,speed sensorless has become a hot research topic in recent years.The V process development model based on model design is widely used in automobile industry because of its short development cycle and high efficiency.In this paper,the direct torque control technology of the face mounted permanent magnet synchronous motor(PMSM)is studied by using the dSPACE semi physical platform which can develop the whole V process.Firstly,this paper introduces the basic structure and the mathematical model of permanent magnet synchronous motor and principle of direct torque control,then use Matlab/Simulink to build the system simulation model,the results show that DTC has the advantage of fast dynamic response,but its torque and flux ripple are large.In order to solve the problems of torque ripple and flux ripple in traditional DTC,a sliding mode controller based on sliding mode control is designed,which combines the space vector modulation technology with direct torque control(DTC),and the SVM-DTC system based on sliding mode control is established.Matlab/Simulink simulation analysis shows that the proposed strategy can reduce the torque and flux ripple effectively and maintain the fast response ability.Secondly,the sliding mode observer is used to estimate the speed of the motor instead of the speed sensor,and the speed sensorless control system is established.The model is simulated and analyzed in Matlab/Simulink environment.The results show that the system runs well and has strong robustness and has theoretical feasibility.Finally,this paper introduces the dSPACE hardware system,and builds the permanent magnet synchronous motor control platform based on dSPACE.The traditional direct torque control experiment of permanent magnet synchronous motor(PMSM)is carried out by using the platform.The SVM-DTC experiment based on sliding mode control and the speed sensorless control system experiment are carried out.The experimental results show that the traditional DTC has good dynamic response capability,but the torque and flux ripple are large.It is proved that the proposed strategy can reduce the torque and flux ripple effectively,and verify the feasibility of speed sensorless control system.