Power Transformer and Reactors Operational Experiences

Power Transformers are most vital equipment in power system connecting generating station to customer premises through transmission network. One important objective of every utility is to extend the life of transformers and if possible increase the utilization of transformer capacity. Power utilities have large populations of power transformers in operation and same needs to be kept in healthy condition due to requirement of continued service and cost required to replace the same. The periodic maintenance becomes a most important issue to understand the healthiness of the equipment and to avoid unexpected total failure. With the spread of network of system across the country, every utility also needs to procure new power transformer and during the procurement, they need to ensure that proper specification has been placed before manufacturing industry with special emphasis on less maintenance required during the operating period. This paper covers all the aspects from utility perspective such as precaution during the procurement and commissioning process and maintenance practices during the operation stage. The paper also includes case studies with proper analysis of the events which have avoided failure of transformers and reactors.