Implementation of Risk Assessment in Determining the Optimal Decision Making with Risk Cost Benefit Output in Transformer Replacement

Power transformers have an important role in transferring energy from power plants to consumers. There are 325 banks of power transformer had been installed in PLN UITJBB which various ages and manufacturers. To manage the assets, PLN UITJBB implemented an asset management system based on ISO 55001. One of asset management objectives is to fulfill transmission service quality level. However, transformer failures will not fulfill the objective. PLN UITJBB had developed a model to determine the risk of transformer failure. When determining the appropriate mitigation decisions for transformer assets, it is not only based on health index but also on the probability of failure of the asset, which serves as an input in conducting a risk assessment for the transformer. Of course, there is not just one mitigation option due to budget considerations and limited execution time, also known as workability. Therefore, several mitigation options are considered, considering their risks, costs, and benefits before deciding to replace the transformer asset. This paper discusses the implementation of risk assessment in supporting optimal and targeted mitigation decisions for transformer assets at Angke and Teluk Naga substations.