Analysis of Stray Current Corrosion on Buried Pipeline due to HVDC Grounding Current

The electrochemical corrosion of buried pipeline underground due to stray current has become a typical industrial problem. The stray current causes anodic electrochemical corrosion at defect area on the surface of buried pipeline. In this paper, the DC stray current, which was originally returning current from grounding electrodes of HVDC monopolar system, was analysed. A 3D model was built in COMSOL Multiphysics to demonstrate the distribution of stray current density along the path of buried pipeline nearby. The environmental parameters (soil conductivity, pipeline position with respect to grounding electrodes, angle between pipeline and HVDC cable) were analyzed to study their respective influence to the change of stray current distribution.