Evaluation of DC-Subway Stray Current Corrosion With Integrated Multi-Physical Modeling and Electrochemical Analysis

Zhichao Cai,Xianwei Zhang,Hao Cheng

doi:10.1109/access.2019.2953960

Abstract

Leakage of stray current can cause serious problems by accelerating the corrosion process of a buried pipeline in the subway. A multi-physical finite element model of the DC-subway traction system was established in this study, and the dynamic process of the stray current corrosion on buried pipeline was calculated according to the real time traction conditions. In this study, the corrosion rate variation of stray current is evaluated, and the corrosion trend of stray current is quantitatively calculated. The model simulation shows that the stray current corrosion is significantly higher than other processes during the acceleration process of the subway locomotive. And the potential of the buried pipeline reaches a maximum value when an up-rush of traction current occurs. The corrosion is mainly concentrated in the anode region of the buried pipeline, and the closer the buried pipeline is to the rail the more serious the corrosion is. A corrosion experiment of N20 carbon steel was carried out and verified by finite element model. The results further show that the finite element model can quantitatively calculate and predict the mass loss of buried metal caused by stray current corrosion.

Highlights

With the advancement of urbanization, traffic congestion is widespread in large and medium-sized cities
The consistency on the results of carbon steel corrosion test and FEM simulation demonstrates that the integrated multi-physical model is feasible for analyzing the stray current corrosion quantitatively
2) The leakage of the stray current reaches a larger value at the positions of the locomotive and substation

Summary

INTRODUCTION

With the advancement of urbanization, traffic congestion is widespread in large and medium-sized cities. By comparison with the traditional models, the simulation models can reduce oversimplification, which provide effective tools for analyzing the distribution of stray current under complex environmental conditions. The above models provide effective tools for analyzing the leakage and distribution of stray current. The study of the distribution of stray current is only the beginning of stray current corrosion analysis It will be more instructive for preventing and controlling stray currents, if a model for directly calculating stray current corrosion of buried metals can be established. The proposed multi-physical FEM Model can simulate the dynamic distribution of the stray current in the subway. The dynamic FEM modeling process and simulation results based on the moving conditions of the subway locomotive are introduced in Sections III and IV, respectively.

SYSTEM AND LOAD CONDITION DESCRIPTION

PHYSICAL MODEL

RESULTS AND DISCUSSION

CONCLUSION