Method On Vibration Suppression Of Switched Reluctance Motor Based On Current Loop

Due to the advantages such as simple structure,large starting torque and being independent of rare earth resources,the switched reluctance motor has drawn more and more attention from scholars and enterprises all over the world.However,the switched reluctance motor has obvious noise during operation,resulting in limited application in the field of noise sensitivity.Therefore,the study of the mechanism of vibration and the corresponding suppression strategies is of great significance for the further application of switched reluctance motors.In this thesis,the mechanism of the vibration of switched reluctance motor is analyzed in detail,and a current loop control vibration suppression method based on higher harmonic suppression is realized.First,the correlation between radial force and current is analyzed and derived from the frequency domain to verify the corelation among the current,radial force and vibration.Therefore,the method of harmonic suppression of phase currents is optimized.By optimizing the switch angle,the phase current waveform is pseudo sinusoidal.The higher harmonics of the current are suppressed,and the vibration can be suppressed when resonance is happened.Then,the finite element analysis is used to calculate the natural frequency of 4kW 12/8 three-phase switched reluctance motor,and the result is verified by hammering method.In addition,a simulation model of the switched reluctance motor drive system is built based on MATLAB/Simulink platform.Inclusively,the lookup table method is applied to build the magnetic characteristic module;the virtual displacement method and the radial force transfer function is employed to build the vibration module.The influences of different switch angle combinations on current,radial force and vibration of time domain and frequency domain are analyzed through simulation,and the feasibility of suppressing higher harmonics of current by optimizing the switching angle to reduce vibration is verified.Finally,a switched reluctance motor hardware test platform is set up.With the data of current and vibration acceleration at different speeds,the vibration mechanism is affirmed.With the data of the phase current and vibration acceleration under different switch angles,it is verified that the higher harmonics of current can be suppressed by optimizing the switch angle,and then the vibration of the motor is suppressed.Judging from the measured results,when the vibration suppression method demonstrated in this thesis is adopted,the peak value of vibration acceleration can be reduced by 35.5%,and the amplitude of 6th harmonic of vibration can be decreased by 43.3%.The error of vibration between simulated results and measured results is less than 12.5%.