Vibration Analysis And Structure Optimization Of Permanent Magnet Synchronous Motor

PMSM(Permanent magnetic synchronous motor)has a simple structure with high power density and efficiency.Due to these advantages,PMSM has been applied to AUV,which has limited space and energy supply.However,its inherent characteristic would introduce radial electromagnetic force and cogging torque.The vibration caused by these stimulations becomes the origin of noise,which will do harm to the stability of the motor and AUV's stealth performance.This dissertation studies onthe vibration and optimization of a PMSM equipped on an AUV.Focusing on vibration and optimization of the PMSM,multiphysics fields are built,including electromagnetic field,structure field andcoupled transient-structure field,from the perspective of analysis,simulation and experiment.The main content of the paper is shown as follows:Firstly,the electromagnetic stimulation which causes vibration of the PMSM is analyzed.Orders and frequencies of theelectromagnetic force are calculated using analytical method.FEAmodel is established to obtain further information about the magnetic field's distribution spanning in time and space.FFT is performed to acquire the magnetic field's distribution in frequency domain.The cogging torque is also analyzed and simulated.Then,the dissertation focuses on the modal analysis of the stator from the mechanism perspective.Electromechanical analogy is utilized to acquire the analysis formula for the natural frequencies of the stator system.Simulation is then conducted to obtain the accurate value of the natural frequencies and modal shapes.OMA is performed to identify modal parameters experimentally.Thirdly,vibration response is studied.The coupledmodel between the electromagnetic field and the structure field is established.The electromagnetic stimulation is loaded onto the stator system to get time-domain response of a point.The result is then transferred by FFT to frequency domain.Vibration amplitudes under different working conditionsare measured by experiment to validate the previous methodology.At last,a method intended to reduce vibration is performed.In order to reduce the stimulation amplitudes and adjust the natural frequency,effects of several structural parametersare studied.Based on the previous analysis,the simulation result shows that the motor after optimization has lower vibration level.