Research On The Driving System Design And Control Strategy Of Switched Reluctance Motor

Switched reluctance motors are characterized by sturdy structure,low manufacturing cost,simple control,fault tolerance and strong environmental adaptability.In recent years,with the development of power electronics technology,computer technology and control technology,switched reluctance motors have been widely used in various fields.At present,more and more scholars are devoted to the research of switched reluctance motors,including the optimization of motor bodies,the design of power converters,the research of position sensorless control algorithms,and the optimization of torque ripple suppression control strategies.Based on the research of the predecessors,this paper designs a new switched reluctance motor power converter topology,and optimizes the direct torque control strategy based on the converter.First,the operation mode and advantages of the asymmetric half-bridge converter are analyzed,and based on this,a dual-bus drive topology for switched reluctance motors for electric vehicles is designed.This kind of work mode switching includes generator power supply mode,battery power supply mode,dual power supply mode,brake feedback mode and static charging mode.At the same time,the phase current and phase voltage of the switched reluctance motor in the excitation,circulation and freewheeling states are analyzed under various operating modes.Compared with asymmetric half-bridge converters,dual bus converters have more operating modes,higher excitation and freewheeling voltages,wider speed range and higher output power.Then,the problems of the dual bus converter are analyzed,and a multilevel variable power converter is designed.This topology adds the battery energy management function on the basis of retaining the various operating modes of the dual bus converter.The battery energy management circuit is a modular design,which can add or reduce the number of battery modules according to the power requirements of the system.Each battery module can be individually controlled according to the working status and requirements of the system to achieve the SOC balance of the battery,thereby extending the battery life.Multi-level power converter greatly improves the fault tolerance and reliability of the systemFinally,on the basis of the multilevel power converter,the direct instantaneous torque control strategy based on the torque distribution function is optimized.According to the characteristics of the new converter,a new hysteresis controller is designed.Level power converter simulation platform to carry out experiments,and finally verify that the new torque control strategy has a better suppression effect on the torque ripple during the commutation phase of the motor.There are 69 figures,3 tables and 84 references in this thesis.