Stray current protection in urban rail transit facilities

QIN Feng， ZHU Xiang-lian， XI Jie，YAO Jian
（Zhenjiang Daqo Secheron Traction Power Co.， Ltd.， Zhenjiang 212211， China）

Abstract： Aiming at the stray current which may lead to electrochemical corrosion on the subway（or light rail）facility，near utility lines and other buried metal structures，the generation，influencing factors and hazards of metro stray current were analyzed. The main measures and methods of detection and prevention of the metro stray current corrosion currently were summarized.From two aspects of reducing the metro stray current leakage and reducing the degree of stray current corrosion，pros and cons of these measures and methods were described. The protection of stray current corrosion and the principle and application of drainage cabinet were introduced. The results indicate that the principium of prevention of stray current on the subway（or light rail）facilities is "rely mainly on prevention while drainage subsidiary，combined with prevention and drainage，and strengthen detection." A system should be created to monitor and control the stray current. The system controls the drainage of the cabinet according to the monitoring situation to make the result perfect，then completely removes the stray current damage of urban railway transit system.
Key words： rail transit； stray current； protection； electrochemical corrosion； monitor voluntarily； automatic drainage