Transmission Structure Corrosion Due to Stray Currents and the Inspection and Mitigation Techniques: A Review

Transmission structures cost about 50% of the project budget on material for transmission grids. Corrosion of transmission structures is a primary cause of in-service equipment degradation and is an increasing engineering and economic problem, with electric utilities spending more of their maintenance budget on inspection and refurbishment of corroded structures each year. The increasing congestion from the shared Right-of-Ways (ROWs) with other infrastructures also negatively impacts transmission structures due to their stray currents interactions. In this paper, the impact of below-grade corrosion on electric power transmission structures is reviewed with a focus on electrolytic corrosion due to the stray current interference reported in the literature. Corrosion inspection and mitigation techniques are also reviewed. The future research direction is recommended in this important but rarely studied area.