Switched Reluctance Motor Based On Sensorless Application Research Of Control System

Switched reluctance motors are widely used in electric vehicles and aerospace,household appliances and other fields by virtue of the advantages of small current,large torque,wide speed range during operation,simple and flexible control strategy during the startup phase.For a switched reluctance motor speed control system,accurate rotor position information acquisition is a prerequisite for precise control.Traditionally,the rotor position detection is realized by adding a position sensor and harsh environments such as high temperature and high dust greatly reduce the stability of the system.At the same time,frequent position sensor replacement increases the cost,which greatly limits the application fields of switched reluctance motors.Therefore,it has certain practical value to study the switch reluctance motor control system without position sensor.First introduced mathematical models such as linear models and quasi-linear models.Considering that the accuracy of the two models is insufficient,modeling with the help of finite element software.Obtain the motor flux-position-current characteristic curve,which provides the necessary parameters for building a more accurate non-linear model of the switched reluctance motor.Switched reluctance motor control schemes usually adopt the following control methods: current chopping control,angle position control,voltage chopping control and direct torque control.This article firstly establishes simulation models for the four control methods and summarizes their advantages and disadvantages.On this basis,a new position sensorless control scheme suitable for switched reluctance motors is designed,that is,a combined control scheme of chopping-PWM and chopping-commutation.Common switch reluctance motor position sensorless systems often use flux linkage method and simplified flux linkage method to detect rotor position,but in the process of theoretical analysis,it is found that there are problems in rotor position estimation discontinuity and more stored data.Therefore,a new improved simplified flux method is proposed in this paper.This method uses the current-flux characteristic data at the off position to replace a large amount of data in the traditional way,estimates the continuous speed and real-time rotor position by comparing the dynamic flux linkage with the actual flux linkage.In order to further optimize the system performance,relying on the combined control scheme of chopper-PWM and chopper-commutation to establish an on-off controllable model,the improved simplified flux linkage method position detection scheme can accurately obtain continuous speed and real-time rotor position information.This paper builds an overall simulation model of a switched reluctance motor without a position sensor,parameter optimization of improved simplified flux method position detection scheme under open loop,the position detection scheme of the improved simplified flux method under closed loop is compared with that of the traditional simplified flux method and then to the speed and torque mutation test test of the improved simplified flux linkage method position detection scheme,the precision control of position sensorless system of switched reluctance motor is realized.