Analysis of economical service period for power transformers

Making good balance between power demand growth-and power equipment installation is one of important issues of electric power companies. Appropriate strategies of managing existing power equipment and reinforcement are necessary for obtaining the maximum quality of electricity supply with the optimum energy cost. Strategies for the existing equipment include maintenance and replacement planning. In this article, a method to evaluate average annual cost for maintaining a transformer is introduced based on real failure data of transformers. Using the method, an economical service period of transformers can be eventually estimated. Cost analysis includes transformer´s initial cost, maintenance cost, and cost in the event of failure. Analysis is performed using statistical data from PT. PLN Indonesia.