Study On Automotive Alternator Noise Testing And Noise Reduction Method

At present, automotive alternator manufacturers have a serious problem which is itsalternator noise level can not meet customers’ requirements. Their products can not be fitted tohigh-end cars because of big noise. Noise problem has become the bottleneck in thedevelopment of automotive alternator manufactures. It is very important to research on thecurrent problems about automotive alternator electromagnetic noise and ventilation noise.Study on automotive alternator noise testing and noise reduction method is necessary.This paper is supported by "192F automotive alternator vibration and noise research "(Jinzhou Halla Electrical Equipment Co. Ltd project, project number:2012050). Questionsabout electromagnetic noise and ventilation noise of the automotive alternator are researched.The mechanism of noise generation is analyzed. Experimental study based on the structure ofthe automotive alternator. With the aid of advanced noise laboratory, noise test scheme wasdesigned according to the test requirements of relevant enterprise. The automotive alternatornoise data are tested and analyzed. The effectiveness of the test noise data is analyzed. Thestudy provides a reference for automotive alternator noise test and automotive alternator noisesource identification. Automotive alternator electromagnetic noise problems at low speed andelectromagnetic abnormal noise at high speed are analyzed. The electromagnetic noise datawere studied according to order tracking method. The main contribution order ofelectromagnetic noise and noise value changes with speed were found out. Firstly, theproposed solutions to the electromagnetic noise at low speed were provided. Secondly, theelectromagnetic abnormal noise at high speed caused by the stator structure was verified byfinite element simulation. Noise reduction methods are reasonable. Automotive alternatorventilation noise problems at overall speed are analyzed. Ventilation noise data were studiedby order tracking method. The main contribution order of ventilation noise and noise valuechanges with speed were found out. The study provides a basis for optimal design to the fanof automotive alternator. It also has a very important meaning to noise identification and noisecontrol. Then, the distribution of the fan angels were optimized in order to solve the problemof the single-frequency noise is too prominent.