车用交流发电机电磁噪声特性的实验研究

Experimental Research on Electromagnetic Noise Characteristics of Automotive Alternators

针对车用交流发电机在低转速下噪声值偏高并伴有啸叫声的现象,基于实验研究车用交流发电机的噪声特性。首先在发电机上布置转速仪、加速度传感器和传声器,采集发电机在空载及负载状态下振动和噪声的时域信号;其次利用频谱、阶次分析等方法,找出了发电机在负载工况下低转速时噪声峰值的主要阶次成分;最后提出改进措施,对改进后的发电机进行测试,并对比分析改进前后发电机噪声的变化情况。分析结果表明,在低转速下发电机的主要噪声是电磁噪声,该电磁噪声的阶次成分与定子铁芯槽的个数相关,并且提出的改进措施能有效的降低发电机的电磁噪声。

For the noise of automotive alternators at low speed is high and accompanied by whistle, the noisecharacteristics of a vehicle’s alternator were studied experimentally. Firstly, tachometer, acceleration sensors andmicrophones were laid out in the generator and the signal of the generator in time domain under load- free and loadingcondition was collected. Secondly, the main order components of the noise peak value of the generator were found throughthe methods of frequency spectrum and order analysis in the loading condition and at low speed. Finally the improvementmeasures are put forward and the improved generator was tested. The noise of the improved generator is compared with thatof the original generator. Analysis results show that the main noise of the generator at low speed is electromagnetic noise; theorder components of the electromagnetic noise is associated with the slot number of stator core; and the improvementmeasures can effectively reduce the electromagnetic noise of the generator.