Research On Sensorless Vectorcontor System Of Inductionmotor Based On Reactive Poweradaptive Model

Induction motors are one of the most important electric equipment,which play an important role in people’s production and life.The AC drive technology of induction motor is becoming more and more mature.However,it is difficult to control the induction motor with high precision,fast response and high stability.This paper aims to improve the performance of induction motor in the whole control system,including the optimization of control loop,flux observer,speed identification,parameter identification and so on.Motor drive control is a comprehensive subject.This paper tries to optimize the control performance of Induction motor from each unit.In the design of motor control loop,the decoupling motor models is adopted,which includes the current controller,flux controller and speed controller.The voltage feedforward compensation is added to the current loop to increase the speed of the control loop.The regulators of each loop are designed by the typical aspect of control system,and the calculation methods of PI parameters from each regulator is given.The closed-loop flux observer is used to calculate the flux of stator,which could suppress the integral drift problem from the flux observer of voltage model.The rotor flux can be obtained by the method of rotor field-orientation after the stator flux is calculated.the calculation of rotor flux performs excellently through simulation analysis.The reactive power model based on model reference adaptive system(MRAS)is used for the estimation of speed.This mothed has excellent performance on the speed estimation,because the variation of stator resistance has little relation with the reactive model.Moreover,this model can be used to identify the rotor time constant by simple derivation of formulas.According to the principle of vector control system for the induction motor,the hardware and software of the digital control system are designed.The simulation and experiment result show the excellent performance of the control system with fast dynamic response and stability.Therefore,it is proved that it is feasible to achieve high performance digital control system of induction motor by global optimization.