弓网系统滑动电接触电磁噪声形成机理与抑制方法研究

To reduce the harm of electromagnetic noise caused by pantograph-catenary system of electric locomotive, the formation mechanism and suppressing method of electromagnetic noise are researched in the view of sliding electrical contact. Aiming at different friction pair materials and different working conditions, the experimental group is designed by orthogonal experiments and lots of electromagnetic noise experiments are carried out with self-developed sliding electrical contact electromagnetic noise experimental platform. Based on the statistical analysis of experimental data, the probability statistical distribution for characteristic parameters of electromagnetic noise parameters are analyzed and the time domain and frequency domain characteristics of electromagnetic noise are researched. The relationship between arc characteristics and working condition parameters are analyzed by adopting various analysis methods such as time-frequency analysis method, clustering analysis, multiple regression analysis and so on, and then the arc's influencing factors are explored. The movement pattern and typical feature of pantograph-catenary arc are researched by analyzing the arc image sampled with high-speed camera. Based on the analysis of material surface of friction pair and application of gas discharge theory, arc and electrical contact theory, the physical process of pantograph-catenary arc discharge phenomenon is researched, and then the formation mechanism of electromagnetic noise is investigated. The effective suppressing methods of electromagnetic noise are proposed. The research results can provide theoretical support and technical reference for weakening pantograph-catenary arc and suppressing electromagnetic noise.

为减轻电力机车弓网系统电磁噪声带来的危害，从滑动电接触的角度研究弓网系统电磁噪声的形成机理及其抑制方法。针对不同的摩擦副材料配对，采用正交实验法设计实验组别，利用研制的滑动电接触电磁噪声实验平台，开展不同工况条件下的弓网系统滑动电接触电磁噪声实验；通过分析实验数据，得出电磁噪声特征参数的概率统计分布规律，研究电磁噪声的时域、频域特性；采用时频分析法、聚类分析法、多元回归分析法，寻找弓网电弧特性与工况条件参数之间的作用关系，进而揭示弓网电弧的影响因素；分析高速摄像机拍摄的弓网电弧图像，研究弓网电弧的运动形态并归纳其典型特征；分析实验后的摩擦副表面，利用气体放电理论、电弧与电接触理论等来研究弓网电弧放电的物理过程及其作用机理；寻求工程上有效的弓网系统滑动电接触电磁噪声的抑制方法。本项目的研究成果为减弱弓网电弧、抑制电磁噪声提供理论支持和技术参考。

为了减轻弓网电弧电磁噪声带来的危害，利用成功研制的弓网电弧电磁噪声实验系统，开展了大量的弓网电弧电磁噪声特性实验，采用实验、仿真和理论分析相结合的方法，较为系统地研究了弓网电弧电磁噪声特性、形成机理、影响因素及抑制方法等科学问题。弓网电弧使接触电流产生直流分量和奇次谐波、间谐波分量。其中，直流分量、3次谐波、5次谐波、7次谐波分量分别占9.94%、19.95%、15.29%和6.78%，间谐波主要分布在0－100Hz。弓网电弧的传导噪声为低频噪声，其幅值随接触压力、回路电流、噪声频率的增加而减小，随滑动速度的增加而增大；传导噪声的频率随接触压力的增加而增大，随滑动速度、回路电流的增加而减小。因此，有效调节接触压力可以减弱传导噪声。弓网系统的接触压力是驼峰状周期性波动变化的动态接触压力，其波动范围随滑动速度的提高而变大。弓网电弧的辐射噪声为电场噪声，主要分布在30－500MHz之间，会影响无线列调系统的正常工作。弓网电弧的电场噪声分布随回路电流的增加、功率因数的减小而变得更加密集，随滑动速度或接触压力的增加，先变得稀疏然后变得密集。弓网电弧电场噪声的干扰水平随回路电流、供电电源电压的升高而增加，随着功率因数的增加，电场噪声的干扰水平与滑动速度无关。因此，提高回路功率因数有利于抑制弓网电弧的电场噪声。弓网电弧在车厢尾端方向的辐射强度最大、辐射噪声随辐射距离的增加不断衰减，特别是在辐射源25m范围内衰减较快。此外，还获得了高速强电流条件下弓网系统滑动电接触接触区域的温度场分布规律。本项目已全面完成计划任务书所规定的研究内容，共发表或录用学术论文15篇、授权国家发明专利2项、培养研究生15名。