Maintenance strategies of transmission towers on the peruvian coast affected by salt pollution

Summary

In transmission systems, many losses are related with corrosive processes especially in areas with high salt pollution level. This situation is often a big concern in coastal areas where the wind blows seawater particles to the land and the salt deposition can start the corrosion into elementary components from electric network, such as, cable and transmission towers. In most of the cases, transmission towers are constructed using galvanized steel, which is corrosion resistant. However, galvanization will not last a lifetime and the power companies have to deal with this problem as part of their maintenance program. Currently around 60% of transmission lines from Red de Energía del Perú (REP) are located in the Peruvian coastline, which is remarkably known for its climate conditions, that is, high humidity due to sea salt breeze with scarce rainy seasons. Under these circumstances, the deterioration of metallic structures due to corrosion may cause additional disturbance related for example to energy supply interruption. In order to mitigate this natural process, REP has implemented in its maintenance methodology applying anti-corrosive coating with a refresh rate of 10 years. This technical report aims to present in detail the methodology adopted for identifying the corrosion rate of towers in the Peruvian coastline through the deposition of soluble contaminants and the procedures used to minimize its impact in the energy systems, both to power utility and costumers. Although, the cost and the logistic involved in the development and implementation of this analysis in field can be a concerning factor, the results have proved it is necessary. From 3707 transmission towers situated under REP system, more than 38% presented corrosion problems in a period of 16 years (from 1999 to 2015) and less than 9% had to be repainted, demonstrating the efficiency of the predictive maintenance.

Additional informations

Authors

S.A. ASTO SOTO

Keywords

Transmission tower corrosion, anti-corrosive coating