| In recent years,with the new round of technological development and industrial transformation,the electric vehicle market has achieved leaps and bounds.With the gradual development of the new energy electric vehicle industry,the requirements for electric vehicles have also continued to increase,and quiet and comfortable electric vehicles have also become attractive.An important factor for consumers to buy.Since electric vehicles do not have components such as traditional car engines,although the overall noise will be reduced,at high frequencies,due to the lack of masking effect of engine noise,the high-frequency howling of electric motors in electric vehicles is more significant and unacceptable.At present,the problem of vibration noise of most motors is mainly due to excessive electromagnetic force excitation or the frequency of the electromagnetic force at a certain modal frequency causes the motor to resonate,resulting in greater motor noise,so the electromagnetic force on the motor,Modal and vibration and noise characteristics are of great significance.This article analyzes the characteristics of the 8-pole 48-slot permanent magnet synchronous motor from the perspective of the electromagnetic force,modal,vibration and noise of the motor.The main research content is divided into the following aspects:(1)To analyze the electromagnetic force characteristics,first of all,through theoretical analysis of the spectral characteristics and order of the radial electromagnetic force,the electromagnetic model of the motor is established,and then the radial electromagnetic force of the motor is simulated and analyzed.Two methods are used to study the space-time distribution law and frequency spectrum characteristics of electromagnetic force under no-load state and under load state.(2)Study and analyze the structural characteristics of the motor.Firstly,conduct a modal test to determine the modal properties of the motor structure,and then establish a finite element model of the motor.By studying the effects of material anisotropy and the equivalent of the winding model on the simulated modal frequency,the accurate simulation model is the vibration of the motor The foundation of noise simulation calculation.(3)To analyze the vibration and noise characteristics of the motor,first of all,the simulation analysis and acoustic response analysis of the vibration response of the permanent magnetsynchronous motor model.And the vibration and noise test of the permanent magnet synchronous motor was conducted in the semi-anechoic room to analyze the vibration and noise characteristics of the motor,and the accuracy of the vibration and noise simulation results of the motor was verified by comparing the two.Secondly,in view of the 1200 Hz peak problem during the test,it is presumed that there is eccentricity during the experiment,and it is verified by simulating the eccentric conditions.For the state of rotor eccentricity.First,through theoretical analysis,the characteristics of the spatial order and frequency of the electromagnetic force wave in this state are determined.Subsequently,electromagnetic force simulation and unbalanced magnetic tension simulation were carried out,and the simulated electromagnetic excitation was superimposed on the stator teeth of the motor for vibration and noise analysis to explore the characteristics of the motor vibration and noise in the eccentric state.(4)In view of the problem of vibration and noise caused by the excessive electromagnetic force amplitude of the motor,this article explores the influence of different factors on the electromagnetic force of the motor from the perspective of weakening the electromagnetic excitation source.Harmonic current,polar arc coefficient,slot width,rotor slotting and other factors are analyzed,with the minimum amplitude of electromagnetic force wave as the target,simulation research is conducted to explore the influence of various factors on the electromagnetic force of the motor and reduce the excitation of the motor source. |
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