No abstract

Transformers are critical equipment of the electrical power supply system and the most expensive asset in the electric power transmission network. Therefore, power transformer condition assessment method is needed to determine the actual condition of power transformer on operating. Indeed, they are several methods of condition assessment for power transformers have been implemented. The transformer data is divided into different levels and parts, so multi-parameter analysis is carried on both by direct condition data and by indirect computing history data. Some method use only one-step process, while others through many stages. This paper proposes a power transformer condition assessment with three stages. First step are Health Index and Susceptibility. Second step is Probability of Failure, that is combination between Health Index and Susceptibility. The last stage is Risk Based Priority as a result of combining Probability of Failure and Criticality Level. The outputs of condition assessment are analysis lifetime prediction, abnormality, recommendations for next action and determine maintenance or replacement priorities. This study has investigated 303 units of power transformers in Western Java Transmission unit. The result of study is useful for the utility company to improve their transformers asset quality.