Speed Sensorless Control System Of Synchronous Reluctance Motor

Synchronous reluctance motor,because of its simple and firm structure,low manufacturing cost,and no risk of demagnetization at high temperatures,can work in harsh working conditions.At the same time,compared to traditional induction motors,the efficiency of synchronous reluctance motors is 5 to 10 percentage higher,so there are good application prospects for this machine.In order to achieve good control performance of synchronous reluctance motors,vector control methods can be used to establish motor control systems.For purpose of vector control,accurate motor position data needs to be obtained to achieve speed estimation and coordinate transformation,which can be gotteen by position sensors.However,the installation of mechanical position sensors will undoubtedly increase the system cost and reduce the reliability of the control system,which runs counter to the original intention of applying synchronous reluctance motors.Therefore,it is of obvious significance to study a reliable synchronous reluctance motor sensorless control method.This article first gives a brief overview of the development history of the synchronous reluctance motor and its speed sensorless control system,and then briefly introduces its operating principle,mathematical model and vector control.On this basis,the initial position identification method of synchronous reluctance motor with pulsating sine wave injection method is introduced,and on this basis,an offline parameter identification scheme of synchronous reluctance motor is designed.In order to avoid the problems caused by the filter,the filterless square wave signal injection method is used to realize the effective control of the synchronous reluctance motor under the conditions of zero and low speed.In the medium and high-speed ranges,the full-order sliding mode observer based on extended back EMF observation and the active flux observer based on flux observation are introduced respectively.Then these two methods are analyzed,and the effective flux observer is selected as the final experimental method.In order to achieve stable control in the full-speed range,a weighted function method is used to switch between different methods.In order to verify the effectiveness of the above method,a DSP-based synchronous reluctance motor speed sensorless vector control program was written using CCS software.On the motor control experiment platform built,the effectiveness of the method was proved by experimental results.