Adaptive approach for fault detection in power transformer based on oil testing

Transformers are an integral part of power systems and their reliable operation directly impacts on the whole network. Statistics about failures of power transformers constitute an important basis for asset management of a fleet of transformers. Periodic review of these statistics becomes necessary where they can be used to influence transformer design and technology. Recent utility survey shows that a large proportion of transformers has attained their designed life and is operating close to their nameplate rating or beyond. The load growth is compounding this problem on the existing transformers due to fewer extension projects. To enhance utility reliability, it is pertinent to identify problems that normally encountered in the past on a particular class of transformers, Identify Manufacturer, type of fault, frequency of occurrence, failure analysis, failure origin and causes of probable physical damage leading to catastrophic failure & hence interruption in supply of electric energy in a given locality. This paper describes case studies of failure of power transformers and failure reports, effect of aging and loading conditions on the life of Power Transformer and test reports of various categories of power transformers belonging to several electric utilities.