动态杂散电流的时频特征及腐蚀行为研究  

Time-frequency Characteristics and Corrosion Behavior of Dynamic Stray Current

作　　者：夏雪 杨晓峰[1] 陈茂鲁 郑琼林[1] XIA Xue;YANG Xiaofeng;CHEN Maolu;ZHENG Trillion Q(School of Electrical Engineering,Beijing Jiaotong University,Beijing 100044)

机构地区：[1]北京交通大学电气工程学院,北京100044

出　　处：《都市快轨交通》2023年第5期117-124,共8页Urban Rapid Rail Transit

基　　金：北京市自然科学基金项目(3222054),国家自然科学基金重点项目(51737001)。

摘　　要：城市轨道交通直流牵引供电系统中,部分走行轨回流电流泄漏至大地形成杂散电流,易导致埋地金属的电化学腐蚀问题。实际系统中多列车频繁启停使得杂散电流表现为典型的动态信号,时频特征的提取有助于研究其腐蚀行为。在建立杂散电流数学模型的基础上,通过S变换提取杂散电流的典型时频分布特征,并基于失重测试及电化学测试研究典型频率下杂散电流的腐蚀行为。实验结果表明,动态杂散电流的直流及低频交流分量均会影响金属的电化学腐蚀过程,且腐蚀速率随电流密度的增大及交流频率的降低而增加。In the DC traction power supply system of an urban rail transit system,the partial return current from running rails may leak to the earth and form a stray current,which can easily cause the electrochemical corrosion of buried metals.A stray current would appear as a nonstationary signal owing to the frequent start and stop of multiple trains in an actual system.Its time–frequency characteristic is conducive to the study of its corrosion behavior.Based on the mathematical model of the traction power system,a time–frequency analysis of the stray current signal was conducted using the S-transform.Furthermore,the corrosion behavior of stray currents at typical frequencies was studied based on weight-loss and electrochemical tests.The experimental results show that both the DC and low-frequency AC components of the dynamic stray current affect the electrochemical corrosion process of metals and that the corrosion rate increases with increasing current density and decreasing AC current frequency.

关 键 词：城市轨道交通 杂散电流 电化学腐蚀 S变换 电化学测试 

分 类 号：TM922[电气工程—电力电子与电力传动] TM46