Condition assessment of 230 kV cables at a power plant. Study of remaining life and life extension

The reliability of the electricity network and the necessity to reduce to a minimum the economic losses due to unexpected outages at the power plants, have led utilities to introduce extensive programs for diagnostics and predictive maintenance, with the purpose of evaluating the condition of the high voltage cables and their remaining life under normal service condition. The paper presents the experience gained in the condition assessment of 230 kV cables installed at a hydropower plant in Colombia, using the most updated techniques for offline and online testing, a full inspection of the installation and a thorough analysis of the events recorded during its service lifetime. Technical findings were matched with economic and strategic criteria. The result of the activities was the development of a novel methodology to assess the remaining life of the cables at its present condition and draw a life extension program for the short and long term. The project was tendered by one of the main utilities in Colombia. The main contractor was TECNALIA, one of the leading Research and Testing institutes in Europe, with a large experience in the condition assessment of HV cables.