车用交流发电机电磁振动噪声预测研究

Research on Electromagnetic Vibration and Noise Prediction for Vehicle Alternators

为了从发电机设计之初就能精确预测其振动和噪声,进而进行优化设计,需要建立一个电磁振动噪声预测分析模型。以一台36槽6极对的爪极发电机为研究对象,利用有限元法计算作用在定子铁芯上的电磁力,再耦合到电机结构模型中计算瞬态电磁振动,最后将电机振动响应作为声学边界条件,利用时域边界元法计算出电机的辐射噪声。计算表明该发电机的电磁振动噪声频率以36谐次为主,与实验测试的噪声频谱分布相同,两者最大声压级相差2.9 d B,实现了较高精度的电磁振动噪声预测分析,对发电机NVH研究具有指导意义。

In order to accurately predict electromagnetic vibration and noise at the beginning of alternator design for optimization,it is necessary to build a model for prediction of electromagnetic vibration and noise.In this paper,a36s6p claw-pole alternator is researched.Finite element method is used to calculate the electromagnetic force acting on the stator.And the transient electromagnetic vibration is calculated by loading the electromagnetic force to the structural model.Finally,with the electromagnetic vibration results as the boundary condition,the boundary element method in the timedomain is used to calculate the electromagnetic radiation noise of the alternator.Results of calculations suggest that the36-th order noise dominates the electromagnetic noise,which is well consistent with the experiment results.The error of the maximum SPL is only2.9dB.Thus,the results achieve high precision of noise prediction.This work gives the guidance to the NVH research of alternators.