Position Tracking Control Of Switched Reluctance Motor Based On Current-Sharing Method

The terms "si fu" comes from the English word "Servo",which means that the system automatically accomplishes the desired movement with the external input commands.Therefore,servo system also can be called as Follow-Up system.Servo system developed from the hydraulic system,pneumatic system to the electrical system,and the electrical servo system mainly contains the controller,servo motor and feedback device.DC motor was used as servo motor at the earliest time.Since the 1970 s,with the cost performance ratio of AC motor continuing to increase,it has replaced the DC motor and become the mainstream of the servo motor.In recent years,the switch reluctance motor(SRM)has been gradually revealed its good prospects for development,because of its advantages such as simple structure,strong and durable performance,withstanding high temperatures and easily cooling nature,good fault tolerance,low starting current and large starting torque,etc.Therefore,it is of great significance to carry out the research on the position servo control system of SRM.Firstly,the basic structure and the operation principle of SRM are introduced in this paper.Then the paper gives the mathematical models which include linear model,quasi linear model and nonlinear model.Based on the above analysis,the traditional control methods of SRM is also demonstrated.In the meantime,this part analyses theoretically the sources of the advantages of SRM and its research value.Secondly,the current status of the research on the position control of SRM is introduced.At present,almost of the existing control strategies need the model of SRM to achieve accurate position tracking control of SRM,furthermore,the model plays an important role in the control design.The modeling of SRM mainly includes the relationship between the torque or flux linkage and the rotor position and the phase current.The offline modeling needs measurement equipment,undoubtedly which will increase the cost of design,and the parameters of the model are not constant.The online real-time modeling will increase the complexity of the control design.Therefore,this paper introduces a novel position tracking control method for SRM,which is based on the current-sharing method.In addition to the number of motor phases,this control method needs no information of the model.Furthermore,it only needs the position loop and current loop.Finally,in the environment of Matlab/Simulink,simulation study was carried out with a four phase 8/6 pole SRM as the research object.And the results show the control method is effective.A hardware experimental platform was built to further test the position tracking control strategy in the practical application.The platform includes core controller TMS320F2812,power drive circuittraditional asymmetric half bridge circuit and data observer LabVIEW.The experimental study was completed based on this hardware platform and the final results show that the method can achieve position tracking control.