Research Of Automobile Claw Pole Alternator Noise

As the car ownership in China continue to increase,car has entered thousand of households and in our daily life.As a mature and professional consumer,we are no longer pursuit of outstanding controls and its better fuel economy blindly,auto harshness performance are also becoming more and more attention by people.As one of the automobile power system,generator undertakes the important responsibility to supply power for the electrical equipment in car.A good harshness performance is self-evident in car.So in order to improve the ride comfort of vehicle,auto generator requires good vibration noise characteristics.This article makes the research of noise characteristic based on a type generator.The electromagnetic noise and aerodynamic noise as the search subject,Main contents such as the noise level,the structure characteristics and the magnetic field distribution are as follows:(1)Completed the motor A levels noise test in the no-load and load conditions.Based on the order analysis method to study the experimental data and found that the electromagnetic noise of generator makes the largest contribution to the total sound pressure level in low and middle speed,and the noise is 36 order,Summarizing the speed and frequency which corresponds to the peak noise in this rotate speed section based on the experimental data.Provide the basis for subsequent noise analysis.At the high speed fan noise is the main noise source.(2)Completed the modal tapping experiment for generator parts based on the modal experiment,summarizing the resonant frequency of components,compared with the electromagnetic excitation frequency and find out the source of resonance,provide the basis for structure optimization.(3)The shape of claw determines the air-gap magnetic field waveform,Analysis the electromagnetic field of the claw,without reducing the performance of generator,implement the claw pole optimization scheme.(4)Completed the optimization design of the fan blade angle based on the synthetic vector,in this way reducing the single frequency noise.