Research On Sensorless Control System Of Double-sided Linear Switched Reluctance Motor

The stator and mover of Double-sided Linear Switched Reluctance Motor(DLSRM)are salient pole type alveolar structure,composed of ordinary silicon steel laminations.The mover of DLSRM has no coils,so it has the advantages of simple structure,low cost,high temperature and adapt to the harsh environment.However,when motor runs,the position information of the mover in real time needs to be known all the time.If the position sensors added in the whole system,the system will be too complex to adapt the system in harsh environment.Therefore,the improved simplified flux-linkage which uses the information provided by the voltage and current estimating the position of mover is used in this paper to improve the reliability of the system.Firstly,this paper introduces the structure of DLSRM,the types of linear motors and several common sensorless control methods of linear motor.The advantages and disadvantages of various linear motors and sensorless control methods are compared.Secondly,the control mode of DLSRM is introduced,and the principle of initial excitation phase estimation,simplified flux-linkage estimation method and winding resistance correction are expounded.Based on the analysis of two common methods for obtaining the flux-linkage of switched reluctance motor,the measured two-dimensional and three-dimensional flux-linkage current position curves and the flux-linkage current curve at the alignment position are given.Then the nonlinear sensorless control system of DLSRM is modeled on the basis of the DLSRM sensorless electric and power generation control principle.Matlab/Simulink is used to build a controller module,a power converter module,a position estimation module,a winding resistance correction module,a speed calculation module and an electromagnetic thrust calculation module.And the simulation results of DLSRM simplified flux-linkage sensorless control are given.Then these lections of the controller,power converter,detection circuit,the principle of the drive circuit and various parts of the circuit device are introduced in detail.In the control program,the procedure of the sensorless control procedure is given respectively from two aspects of DLSRM electric operation and power generation operation,and the algorithms of initial conduction phase judgment,speed estimation and estimation speed display are introduced in detail.Finally,the hardware platform is used to study the influence of the coefficient on the demagnetization position under condition of electric and power generation.The accuracy of the position estimation of the improved simplified flux-linkage method is verified by changing the resistance of the pre-stored.Also,the closed loop control of the sensorless operation of electric operation and power generation operation under different working conditions is carried out in turn,and the position estimation error analysis of electric operation and power generation operation is given.The results of simulation and experiment show that the improved simplified flux-linkage position estimation method has high accuracy and good feasibility.