Abstract: In order to study the problem of radiated noise of vehicle six-phase motor, this paper takes a certain electric drive assembly as the research object, tests and analyzes its noise, vibration and harshness (NVH) performance on end of line (EOL) bench. Test results show that the 48th order noise of the motor exceeds the target in the frequency band range of 988～1 325 Hz and 1 966～2 200 Hz, and the maximum excess scalar is about 7 dB. Then, using the method of combining theoretical analysis and simulation, it is concluded that the cause of the noise problem is that the radial electromagnetic force of the 12th order of the electrical frequency is too large, which provokes the structural mode of the 1 121 Hz and 2 023 Hz systems, and the stator vibration is caused by the noise radiated from the oil pan after the structure is amplified. In order to solve the problem of large radial electromagnetic force, this paper adopts an evolutionary algorithm to weaken the radial electromagnetic force of the 12th order harmonic of the 0th order time in space by using the rotor opening auxiliary slot and scheme. At the same time, the modal mode amplitude is reduced by optimizing the oil pan structure. Finally, the NVH performance of the motor is verified by simulation method, and the effectiveness of the scheme is verified.

Key words: Six-phase motor; Electromagnetic force; NVH; Mode

摘要： 为研究车载六相电机辐射噪声问题，文章以某款电驱动力总成为研究对象，测试分析 了其在整车下线流程（EOL）台架上的噪声、振动和声振粗糙度（NVH）性能表现。测试结 果分析发现电机 48 阶噪声在 988～1 325 Hz 和 1 966～2 200 Hz 频段范围内超过目标值，最大 超标量约为 7 dB。随后采用理论分析及仿真相结合的方法，得出噪声问题的原因为电频率 12 阶径向电磁力过大，激起 1 121 Hz 与 2 023 Hz 系统结构模态，定子振动经结构放大后由油底 壳辐射出噪声导致。针对径向电磁力较大的问题，文章采用进化算法，利用转子开辅助槽方 案削弱了空间 0 阶时间 12 阶次谐波径向电磁力。同时通过优化油底壳结构，降低了模态振型 幅值。最终通过仿真方法验证了电机的 NVH 表现，验证了方案的有效性。

关键词: 六相电机；电磁力；NVH；模态