Research Of Direct Torque Control For PMSM Based On DSPACE

Permanent Magnet Synchronous Motor(PMSM)is being widely applied in industrial production because of its advantages of high efficiency and high power density.It is often chosen as drive Motor in rail and road traffic especially EV.As one of the most important two kinds of AC speed regulation technology,Direct Torque Control(DTC)has good dynamic performance,strong robustness and simple control structure.Developed from model design,V development model can greatly reduce the product development cycle.Based on dSPACE semiphysical simulation system,Direct Torque Control method for Permanent Magnet Synchronous Motor is researched in this paper.The structure and control strategy of permanent magnet synchronous motor are introduced in this paper.And it introduces the basic principle and realization method of the direct torque control technology of permanent magnet synchronous motor,then use the MATLAB/Simulink to set a PMSM-DTC simulation model and carry out a simulation research.Direct torque control don't need decoupling current,and the characteristic of direct to control torque make the dynamic response very quickly.In addition,DTC need no position of rotor,so its structure of system is simplified.This paper also introduces the concept of V development model and the dSPACE semi-physical simulation system.A PMSM control platform is set up for research of motor control,and PMSM-DTC experiment was completed on this platform.Both simulation and experiment show the excellent dynamic performance of the direct torque control.This paper analyzes the reasons of torque ripple and flux ripple under the traditional direct torque control for permanent magnet synchronous motor.Point out that the essence of hysteresis control is BANG-BANG control,and the ripple is inevitable.On this basis,explore the common used methods of suppressing the ripple,then analyzes the DTC based on duty cycle in detail.In order to simplify the calculation of the duty cycle and considering the torque ripple and flux ripple,this paper proposes an improved calculation method for cycle,gives a detailed calculation process.In the proposed method,the initial torque error and flux error of each control cycle are calculated,and it makes full use of the characteristic of the zero vector to reduce the torque.Simulation and experiment proves that this method can effectively suppress the torque ripple and the flux ripple.