电动汽车充电桩的气动噪声分析和优化

Aerodynamic noise analysis and optimization for charging pile of electric vehicle

分析180 kW大功率直流充电桩在不同工况下的气动噪声特性,进行整桩的降噪优化设计.采用计算流体力学(CFD)与计算气动声学(CAA)分步耦合仿真的方法,分析整桩的噪声频谱和声场分布规律;开展整桩试验测试,验证仿真的精确性;对比、分析不同降噪方案的降噪性能,并进行方案的试验验证.结果显示,整桩噪声主频为830 Hz,整桩噪声次频为650 Hz,分别与电源模块风扇以及系统风扇的叶片通过频率重合;在电源模块进风口布置吸音棉能够有效消除整桩噪声第三、第四峰值频率幅值;在系统风扇出风口布置吸音棉能够使整桩A计权声压级总值降低约1.2 dB;相同布置位置,在保证散热的同时增加吸音棉厚度的降噪效果不显著,整桩A计权声压级总值降低不足1.0 dB.

The aerodynamic noise characteristics of the 180 kW high-power DC charging pile under different working conditions were analyzed,and the optimization design was applied for noise reduction of the charging pile.The noise spectrum and sound field distribution of the charging pile were simulated by the multi-step coupling method of computational fluid dynamics(CFD)and computational aeroacoustics(CAA).The test of the charging pile was carried out to verify the accuracy of the simulation.The effectiveness of different noise reduction schemes was compared and analyzed,and the test validation of the schemes was carried out.Results showed that the basic frequency of the charging pile noise was 830 Hz,which coincided with the blade passing frequency of the fan in the power module,and the second peak frequency of the charging pile noise was 650 Hz,which coincided with the blade passing frequency of the system fan.The third and fourth peak frequency amplitudes of the charging pile noise were effectively eliminated by arranging sound-absorbing cotton in the power module air inlet.The overall A-weighted sound pressure level of the charging pile was reduced by about 1.2 dB by arranging sound-absorbing cotton in the system fan outlet.At the same arrangement position,the noise reduction effect of increasing the sound-absorbing cotton thickness was not remarkable while ensuring heat dissipation,and the reduction of the overall A-weighted sound pressure level of the charging pile was less than 1.0 dB.