Research Of Three-phase Asynchronous Motor Variable Frequency Speed Regulation System Based On DsPIC

Later in the20thcentury, the development of power electronic device andmicroprocessor provides technical support for AC speed regulation system to replace theDC speed control system. Asynchronous motor are widely used in the field of motioncontrol, however, due to its structure and operational characteristics, it has many uniqueadvantages. This paper mainly research three aspects from the mathematical model ofasynchronous motor, system established and controller design.Hysteresis current SPWM control technology is used in AC speed regulation system.According to the equation of the two-phase stationary coordinate system of asynchronousmotor, the motor dynamic mathematical model is established. Control system structure isdesigned based on the dsPIC and the master chip using dsPIC5015, which make the systemmore simple and efficient control.In the field of motion control mechanism, mechanism simple, flexible structurechanged conventional PID is widely used; however, motor parameter tuning depends onaccurate mathematical model, the more accurate mathematical model, the more effectcontrol. Since the motor will run in a variety of operation conditions it is unable to avoidthe influence by the external operating environment, which leads to the motor parameterschanged with the external environment and its own temperature rise and the skin effect; ifthe original parameters are used to calculate the rotor flux, the excitation and the torquecomponent of stator current will emerge error which affect the dynamic performance of thespeed regulation system. According to the actual characteristics of asynchronous motor,this paper presents novel rotor resistance identification methods, which derives rotorresistance parameter adaptive law using lyapunov stability theory and greatly improve thesystem control accuracy.The speed regulation system of rotor resistance parameter identification is simulatedin the MATLAB simulation environment to verify the influence of rotor resistance tovector control system and the validity of parameter identification and the robust of speed regulation system in this control strategy.