Research On Structural Torque Ripple Suppression Method Of Switched Reluctance Motor

With the increasing of environmental pollution and energy crisis,new energy vehicles with environmental protection and energy saving have attracted widespread attention.Motor drive system is one of the core components of new energy vehicles,and the research on its key technologies is of great significance.Switched reluctance motor(SRM)is widely used in aviation,mining and other fields because of its simple structure,high efficiency,flexible control,large starting torque and no cooling requirement of rotor.However,the application of switched reluctance motor in the field of new energy vehicles is limited due to its high torque ripple and other shortcomings.In this paper,the structure of torque ripple suppression of switched reluctance motor is studied.Firstly,the working principle and basic equation of switched reluctance motor are introduced.Based on the linear model of SRM,the electromagnetic torque is analyzed.On this basis,the causes of the torque ripple of switched reluctance motor are analyzed from the aspects of motor structure and motor control strategy.A 1.5kW,12/8 pole switched reluctance motor is selected as the prototype.The prototype model is established and the performance of the motor is simulated by finite element method.The prototype experiment platform is built and the prototype operation experiment is carried out.The validity of the motor model is verified by comparing the measured data with the finite element simulation data.Based on the prototype model,the effects of basic structural parameters such as stator,rotor outer diameter,winding turns,stator and rotor pole arc coefficient on the torque waveform,torque ripple and average output torque are analyzed,and the influences of each structural parameter on motor torque output are obtained.Based on the method of software integration,an optimization platform for motor structural parameters is built.The platform integrates the performance requirements of motor such as torque ripple and average out-of-torque through data interaction between software,and achieves the optimal design of motor structural parameters.In order to minimize the torque ripple and maximize the average output torque,a multi-objective optimization solution of the basic structure parameters is carried out by using NSGA-II algorithm.The optimization results show that the motor torque ripple decreases under several different speed conditions.Starting from the relationship between the electromagnetic force and the torque ripple phenomenon during the operation of SRM,the analytical formula of the electromagnetic force is deduced by using Maxwell stress method.On this basis,a torque ripple suppression structure based on the rotor of SRM with rectangular holes is proposed.The principle of the torque ripple suppression structure is analyzed and its effect is verified by finite element method.The multi-objective optimization of the parameters of the torque ripple suppression structure is carried out,the optimization results show that compared with the pre-optimization and initial prototype,the torque ripple decreases at different speeds under the condition of ensuring the average output torque of the motor.Finally,the implementation scheme of the structural torque ripple suppression method proposed in this paper is described,which provides an idea for designing a low torque ripple switched reluctance motor.