Design And Research Of The Motor Variable-frequency Speed Regulating System Based On DSP And SVPWM

In this paper, a motor variable-frequency speed regulating system is designed and used in electric actuator. This system can improve the effect of motor control, fits well with the needs of automatic centralized control in modern industry system.Because the operation of electric actuator is done by motor, so the control of motor directly influence the performance of electric actuator. Use direct torque control(DTC) strategy for triple-phase asynchronous motors, the conventional DTC method is illustrated through theoretical analysis and simulation, and designs DTC-SVM control strategy which space vector modulation (SVPWM) technique is applied in the DTC method to decrease the torque ripple.The DTC-SVM control strategy includes the saturation feedback integrators based on coordinate transform to improve the observation model of stator flux, and the observation error of stator flux is reduced. At the same time, a speed estimation method is used in the strategy to form speed loop, the model reference adaptive speed estimation method is introduced, and this paper mainly study the full-order flux observer to estimate the rotor speed. This paper build the simulation model, through analyze the simulation results, the validity of motor mathematical model and the feasibility of the control strategy is testified.At last, the hardware circuit and software program of the variable-frequency speed regulating system is preliminarily designed in this paper. The hardware part includes DSP peripheral circuit, local control, remote control, main circuit, driving circuit, sampling circuit design and so on. The software includes main control board program and subordinate control board program, according to the requirement, finished the design of main program, communication program, A/D sampling program, SVPWM modulation program and DTC-SVM modulation program, etc. Based on hardware and software design, the electric actuator experimental system has been built and test, the reasonability and reliability of the system is verified by the experimental waveforms.