Research On Speed Sensorless Speed Estimation Method Of Induction Motor

Energy is an important part of the development of modern industrial society,and electric energy is one of the most widely used and convenient energy.In recent years,with the development of modern power electronic technology and automation technology,people pay more attention to the development of asynchronous motor AC speed regulation system,and it’s becoming increasingly important in all walks of life.In the AC speed regulation system of asynchronous motor,the rotor speed of motor is the key factor of control system.In order to ensure the accuracy of motor speed measurement,designers usually install speed sensors on the motor rotating shaft.However,this scheme will not only increase the size of the motor system,but also increase the mechanical complexity of the motor system,and weakening the stability of the motor system.Moreover,the sensors are prone to failure in complex environment,which will become the accident source of the motor system.Therefore,the research direction of speed-sensorless three-phase asynchronous motor speed estimation system is developed.The system uses the stator voltage and current of the motor to obtain the motor speed indirectly through the speed estimation module,which simplifies the asynchronous motor system and improves the reliability of the system.At the same time,if applied the speed-sensorless speed estimation system of asynchronous motor to the practical project,it can effectively improve the project progress,ensure the construction safety and equipment stability.Therefore,the system has gradually become a research hotspot for the scholars.This paper combines with practical engineering experience,mainly studies the speed estimation method of induction motor based on model reference adaptive theory and the speed estimation of induction motor based on extended Kalman filter.Firstly,the mathematical model of induction motor is simplified according to it’s working principle and coordinate transformation theory.Then design the speed estimation method based on model reference adaptive system,and establish the model of speed-sensorless speed estimation.Next,design the sensorless-speed identification method based on extended Kalman filtering algorithm.Finally,compare the simulation results of the two speed estimation methods under different working conditions,different motor parameters and Gaussian white noise.It is concluded that the model reference adaptive method has good following performance,fast response speed and good dynamic performance,but it is slightly affected by the working environment.The speed estimation system based on extended Kalman filter has good stability,strong anti-interference ability and good static performance.However,due to the parameter correction,the accuracy of motor parameters has great influence on the algorithm.