基于电机本体的新能源客车电磁噪声分析

Analysis of Electromagnetic Noise of New Energy Busfor the Motor Structure Optimization

为了研究新能源整车在行驶过程中的高频电磁噪声,采用试验与仿真相结合的方法,对某款新能源客车进行噪声、振动与声振粗糙度(NVH)测试,对新能源客车电机进行电磁仿真分析。对求解的电磁力密度进行时空的二维傅里叶变换,结合试验数据确定了电磁噪声主要来自于0阶72倍频;从电机本体出发,以电机转子的磁钢夹角、磁钢长宽等结构参数为设计变量,优化电机电磁力密度与转矩脉动;同时对优化后的模型利用有限元方法进行电磁、结构与声学的多物理场联合仿真,进一步求解电机的电磁噪声,并进行整车的NVH试验验证。试验结果表明:优化后的整车总体噪声减小了8.53 dB(A),电机72倍频噪声最大值减小了18.59 dB(A),减速机7阶噪声最大值减小了5.02 dB(A),仿真结果与试验测试结果吻合。

To study the high frequency electromagnetic noise of the new energy electric vehicle during running,the noise,vibration and harshness(NVH)test and electromagnetic simulation analysis of some kind of new energy bus are carried out.Two-dimensional Fourier transform is made in the time domain and space domain on the solved electromagnetic force density,and it is determined that the electromagnetic noise is mainly caused by the 0 order 72nd harmonics according to the experimental data.The motor structural parameters of the motor rotor such as the angle between the magnetic steels,the length and width of the magnetic steel and so on,are taken as design variables to optimize the electromagnetic force density and torque ripple of the motor.Meanwhile,the multi-physics fields simulation of the electromagnetic field,structure and acoustics is made to solve the electromagnetic noise with the finite element method based on the optimized model,and the NVH tests of the vehicle are carried out to validate the simulation results.Test results show that the overall noise of the vehicle is reduced by 8.53 dB(A),the maximum noise of the 72nd harmonics of the motor is reduced by 18.59 dB(A),and the maximum 7th order noise of the gearbox is reduced by 5.02 dB(A).Simulation results are consistent with experimental test results.