Mechanism Modeling Of Pipe Ground Potential Caused By Metro Stray And Their Pertinence Analysis

Nowadays, high speed rail and urban rail transport development quickly, it’s inevitable to generate some rail traffic current, corroding pipelines. As the length of pipeline increases year by year, the safety of the pipeline becomes more and more important. And the stray current is an important factor affecting the safety of the pipeline. However, at present, the research about mechanism of underground pipeline is still not enough. Connection between operation condition of rail transit and ground potential is not clear. In the pipeline maintenance work, although pipeline operators can detect stray current, the subway operators refuse to acknowledge. Therefore, it’s necessary to search the connection between stray current and rail transport.Through literature research, discuss three kinds of mathematical model, namely are BP neural network model, based on the stray current model of electric field and circuit element model.Construct a single machine single point model with the condition that the rail transit has a locomotive and buried pipeline near the rail has a leak point, establish the control equations and boundary conditions, and eventually solve the problem. Compare the simulation results with the actual measurement, it’s found that the model is good to use. Then this thesis analyze some factors such as the unit length of the track resistance, the locomotive load current, the distance between the adjacent traction substation and so on to find the connection between rail transit and ground potential.Analysis found that some factors are positive to change range of ground potential, such as the unit length rail line resistance, locomotive load current, and the distance between adjacent traction powers; some factors are negative such as resistance between rail line transition and mental pipe; some factors are irrelevant such as resistance between rail line transition and ground.Consider the condition that there may exist two locomotives or two leak points based on the model of a single locomotive with a single point. We built a single locomotive with two points model and double locomotive with a single point model. Analyze some factors such as number of locomotives and locomotive leaks. We found that the number of locomotives and locomotive leaks influence the tube ground potential directly.Combined with the established model, discuss the general trend of the change of the potential of the tube with three different sources of electric welding, high voltage transmission line and rail transit. Discuss the correlation between the three kinds of interference sources and the change of the potential of the ground potentialin four cases of the different seasons, hours, minutes and random, providing some suggestions to find the location of the interference source.