Research On SRM Sensorless Control System Based On Pulse Injection Method

Switched Reluctance Motor(SRM)has the characteristics of low cost in producing,simple mechanical structure,strong fault-tolerant ability when running,high reliability and so on.However,due to the double salient pole structure,the magnetic edge effect and the magnetic saturation effect,the flux and torque of each phase in the motor are strong coupling nonlinear functions between the rotor positions and the stator currents.And then,resulting in serious nonlinearity of the motor model.Therefore,the reliable operation of the SRM depends on the accurate determination of the rotor position,the traditional position sensor could reduce the reliability of the entire switched reluctance motor system,meanwhile increase the cost and complexity of the control system.The sensorless control of SRM has become a hotspot in the field of the SRM control technology.The work of this paper mainly includes the following aspects:(1)The basic operation principle of switched reluctance motor is described,and the mathematical model is analyzed,which provides a theoretical basis for the subsequent position sensorless control methods.(2)This paper introduces the methods of position sensorless control of SRM,analyzes the advantages and disadvantages of these methods,and focuses on the research of the high frequency pulse injection method.Aiming at the different states,the front-phase and post-phase detection control strategy are proposed to realize the non-reverse start-up and subsequent high-speed operation.(3)Based on the theory,a sensorless control system of SRM is designed,which includes the drive circuit based on MOSFET and the control circuit based on STM32 with related control program.(4)The test platform of SRM control system is built to verify the effectiveness of the high frequency pulse injection control strategy and the reliability of the whole control system.