Research On Multiple Physical Fields Analysis And Speed Control System Of Switched Reluctance Motor

Switched reluctance motor(SRM)is widely used in petroleum excavating machinery,home appliances and so on because of its advantages such as large starting torque,wide speed range and flexible control.However,the high torque ripple and vibration noise limit the application of the motor in other industries and fields.This paper aims to solve the key theoretical issues and the bottleneck techniques that involved in the suppression of vibration.Research in field of the vibration mechanism and simulation methods,is going to reveal the principle of vibration caused by multiple physical fields and their coupling effect,and the switched reluctance motor speed control strategy.Firstly,a finite element modal simulation method for SRM based on statics pre-simulation is proposed.The modes of the motor are calculated by this method.Moreover,the simulation results are verified by the motor modal experiment,which proves that the method can improve the accuracy of the existing methods for low-frequency modal calculation.Secondly,the multiple physics field and its coupling effect of SRM are deeply studied.The effect mechanism of electromagnetic characteristic and thermodynamic characteristic on vibration is investigated.The influence of temperature change on electromagnetic field distribution and structure field deformation is revealed.The analysis result prove that the electromagnetic force is the main excitation source of the switched reluctance motor vibration,but the change of temperature will have a great influence on the performance of the motor.The validity of the simulation results is also proved through the verification experiments.Then,the joint simulation model of the SRM speed control system is designed.The simulation model is used to simulate the speed control and torque control strategies,and the influence of different control strategies on motor torque ripple and vibration noise is explored.The results show that:PID speed control strategy will cause motor torque ripple,and current hysteresis control can effectively suppress the generation of the torque pulsation.Finally,the experiment platform of SRM is built.The modal measurement experiments and flux characteristic measurement experiments are carried out respectively.The mode results and flux characteristic curves of the switched reluctance motor are obtained.In addition,the validity of the simulation analysis is proved,so the simulation results can be used as theoretical basis for further researches.