地铁车辆辅助变流器噪声特性分析及改进

Noise characteristics analysis and improvement for auxiliary converter in metro vehicle

为实现某地铁车辆辅助变流器的降噪,先后对安装和去除铝箔吸声材料的原型机和裸机进行噪声测试及特性分析。对比分析可知进、出风口传播的气动噪声为最主要噪声源,电磁噪声和由柜体各壁板传播产生的振动噪声对整体噪声有不可忽略的贡献,原型机在噪声贡献最大的250~4 000 Hz频段范围内噪声峰值降低量较小。通过降噪量计算,提出了更换吸声材料、增加消声通道和吸声面积等改进方案,并通过测试确认,改进方案在不同工况下的平均降噪量可在原型机基础上提高4.8~5.1 d B(A)。

In order to reduce the noise of auxiliary converter in metro vehicle, noise test and characteristic analysis for prototype machine with sound absorbing material aluminum foil and bare machine are carried out successively. Based on the obtained result, it can be seen that the aerodynamic noise propagated at the inlet and the outlet is the main noise source, and the electromagnetic noise and the vibration noise generated by the propagation of the wallboard in the cabinet are of great contribution to the overall noise. Noise in frequency range of 250~4 000 Hz is the greatest, while during which the noise peak reduction of the prototype machine is small. According to the calculation of noise reduction quantity, improvement scheme of replacing the sound absorbing material, increasing the noise channel and the sound absorbing area is proposed. The average noise reduction quantity of the improved scheme under different working conditions can be improved by 4.8~5.1 d B（A）, compared with those of the prototype machine.