Research On Protection Of Steay Current In Metro System

Metro system uses DC power supply leads to stray current leak, this issue received much attention. Stray current corrosion seriously affect the normal working state of equipment and the service life of pipelines, endangering people’s lives, it cannot be ignored. Therefore, the paper researches on stray current corrosion process, distribution, influencing factors and protective measures. Then the paper proposes a protection scheme of stray current for actual project, so as to provide a reference for the stray current protection of metro construction in the future.Study on the distribution of stray current can provide theoretical basis for stray current protection. Therefore, the paper set up the mathematical model of stray current distribution, and analyzing it with MATLAB software. By changing the parameters of the model to explore factors affecting the distribution of stray current, we can get the general rules of the stray current distribution. Stray current distribution is influenced by power supply mode, power distance, train current, rail resistance, insulation resistance, etc. By rational design of these factors in pre-construction, we can effectively reduce the stray current from the source.The paper introduces the stray current protection measures from three aspects, then explore the protective effect of source control method and current drainage net. Source control method can effectively reduce the leakage of stray current, current drainage net can effectively protect the buried metal structure, but also has some negative effects, it should be combined with monitoring system reasonably.Finally, the paper designs a scheme of stray current protection combined with the Qingdao Blue Silicon Valley Rail Express actual engineering, including measures to improve rail insulation, current drainage net setting and monitoring the components of the monitoring system. Finally, proposes requirements of stray current protection for construction and management, and provides a reference for the actual construction of metro.Stray current protection should be run through the design, construction, operation, maintenance and other links, involving a number of professional fields, all aspects should coordinate in order to reduce the corrosion of stray current as much as possible.