This presentation will cover various techniques used to decide about the end of life for power transformers. The emphasis will be on the insulation system in power transformers although other components will also be briefly discussed.

Various methods used to ensure proper operation and to detect premature aging of insulation on transformers will be discussed, including both on-line and off-line methods. These methods have been used widely in industry with varying degrees of success. The emphasis will be on practical usefulness and limitations of various methods. Criteria used to determine the end of life (and hence the need for replacement) of the equipment in service will be discussed wherever possible.

Bal Gupta is a principal scientist/engineer with AOK Technologies Inc. involved with condition assessment and failure analysis of electrical equipment. Up to July 2000, he was a principal research engineer/physicist with Ontario Power Technologies (formerly Ontario Hydro Research Division), where he was involved in application and development of measurement techniques to assess the condition of electrical equipment. He was project leader/principal investigator in many projects on transformers, rotating machines, cables and capacitors.

He earned a Ph.D. in Physics from University of Toronto, and is a registered professional engineer in the Province of Ontario. He has authored/co-authored over 70 technical papers and three patents. He is a fellow of IEEE and is/has been involved in IEEE activities as member and/or chair of various working groups, subcommittees and committees in Power Engineering Society and Dielectrics and Electrical Insulation Society. Dr. Gupta was an Associate Editor of IEEE Transactions on Dielectrics and Electrical Insulation from 1988 to 1996.