基于阶次分析的爪极发电机电磁噪声源分析

摘要

Vehicle alternators noise seriously affects the vehicle’s NVH performance. Based on a certain type of vehicle claw-pole alternator, noise tests are done in load-free state and hot loading state in a specifically designed lab. It is found in the data processing that the electromagnetic noise is the major noise source of the alternators at low speed. And the main noise component of the 36 th order electromagnetic noise is shown in the order analysis. Then, the Maxwell electromagnetic model of a sample alternator is built to complete electromagnetic simulation. The results show that there are high peaks at 12, 24 and 36 th order electromagnetic force frequencies in the frequency spectrum. Stator model is established by means of the equivalent volume method according to the structure of the coils and the stator core. Then, the model of the global alternator is built and the modal simulation and the modal test are completed. The results show that the electromagnetic noise in low speed range is induced by structural resonance under electromagnetic excitation force. This work may provide references for analysis and control of the electromagnetic noise.%爪极发电机噪声严重影响汽车的NVH性能。基于某型爪极发电机，在标准噪声实验室进行冷态空载和热态为负载工况下的台架噪声试验。处理数据发现，在低转速段，电机的电磁噪声偏大且出现了峰值，阶次分析显示36阶次主要噪声成分。建立样机的电磁学模型，对峰值噪声转速进行电磁仿真求取电磁力，其频谱显示12、24和36阶次为电磁力主要阶次。采用等效体积法建立定子模型，并装配整机模型，完成了模态仿真和模态试验。结合仿真和试验结果，发现低速电磁噪声源是电磁激振力作用下的结构共振产生，对电磁噪声的分析和控制具有一定参考价值。