Study On Stray Current Monitoring And Protection Scheme Of Subway Lines

Since the reform and opening up,the domestic rail transit industry has made great progress.And the research of rail transit has made great progress.For the entire subway return system,the loop current cannot return 100% to the system due to insulation,and part of the current flows into the ground.This part of the current is called the stray current because it has a greater corrosion effect on the buried metal.Electric current will continue to threaten the urban rail transit system,so it is of great significance to strengthen its monitoring and protection.This thesis first establishes the stray current distribution model of the subway under different working conditions,and numerically derives each model.The two-layer and three-layer resistance network structure model mainly solves the problem of differential equations.In the four-layer network model,it mainly passes Matlab software solves higher order differential equations.At the same time,the model generated after joining the drainage cabinet was calculated.Finally,mathematical expressions of rail voltage,rail current,drain network voltage,and stray current of each model are obtained.Then,using Matlab software to simulate the derived numerical models,observe the simulation curves of different parameter variables,and finally get the main factors that affect the distribution of stray current.By simulating and summarizing the main subway stray current monitoring methods in the current project,and finally comparing the advantages and disadvantages of the distributed monitoring system and the centralized monitoring system applied in the current project,a DZJ series stray current monitoring and protection system is proposed.To summarize the protection methods commonly used in engineering now,and then to solve the problem that the control strategy of the drainage cabinet in the current project is not intelligent,the fifth chapter of This thesis proposes a fuzzy strategy control of automatic drainage cabinet drainage based on BP neural network algorithm.This strategy greatly improves the intelligent level of drainage.Finally,according to the actual field test results of the stray current of Ningbo Line 1 in the actual urban rail transit system,suggestions for the stray current monitoring and protection scheme for the Ningbo Line 1 project are proposed.Among them,the improvement measures mainly include: the single guide device is opened after the operation of the random car,the daily operation and maintenance of the stray current protection system,and the metal protection near the line.