Sensorless Control Technology Of Switched Reluctance Motor

The switched reluctance motor（SR motor）has a special structure.In the case of using permanent magnet materials,it has high operability,large starting torque and many controllable parameters,which are also favored by researchers.The key point of the control of the switched reluctance motor is to determine the rotor position information and give the corresponding control angle according to the rotor position information.In the traditional switch reluctance motor speed control system,the key problem is how to know the current rotor position.The first one is speed control with position sensor,but the existence of position sensor increases the cost and design difficulty of the entire motor system.And the position sensor itself is easily damaged by external influences.This restricts the speed control system of the switched reluctance motor,so the research on the positionless control of the switched reluctance motor has been paid more and more attention and in-depth research by more and more researchers.This paper first expounds the special structure of the switched reluctance motor without rotor winding,and then gives the basic setting of its operation according to the magnetic minimum.On the basis of these,switch reluctance motors based on different precision flux linkage models are studied,and their schematic diagrams are given.Based on this,the current images of different control strategies of the switched reluctance motor are introduced,and the basic control scheme is built.Finally,the simulation results of positional control based on MATLAB/Simulink simulation software are given,and the simulation analysis of the current and flux linkage of the SR motor under different conditions verifies the rationality of the simulation parameters.The second is the research on the positionless control strategy in the control scheme.There are two main methods,namely the high frequency pulse injection method and the positionless control based on the improved sliding mode observer.The high-frequency pulse injection method is different from the traditional method of injecting high-frequency signals only in the non-conducting phase to obtain the current guide value and commutate.The traditional method generally performs commutation at the maximum inductance,which results in the injection of current for too long and large torque ripple.Compared with the traditional method,the injection time of high-frequency pulses in this paper is shortened,the switching loss is reduced,and the original performance of the method is also improved.For the position sensorless control technology of sliding mode observer,the position sensorless model of sliding mode observer on switched reluctance motor is given first.Secondly,considering to reduce the impact of chattering,an increased low-pass filter and an improved continuous sliding mode shear function are used,and the performance differences between the sign function and the improved function are compared.Finally,the control results of the two observers are compared by simulation,and the effectiveness of the improved sliding mode observer without position control is verified.Compared with the traditional method,the speed jitter of the improved sliding mode observer without position control method is reduced,and the overall performance of the motor is improved.In this paper,the research on the position sensorless control technology of switched reluctance motor is detailed and complete from theory to simulation,which provides a certain reference value for the practical application of switched reluctance motor in industry.