Power transformer loading studies considering overexcitation

The paper addresses the problem of transformer loading calculations considering overexcited transformer operation. General aspects of the current loading guides are presented and discussed on the light of the transformer design characteristics. Overexcitation and its impact on the loading conditions are discussed. A loading calculation method is proposed, and a database consisting of around 50 power transformers real test data is used to analyze the overexcitation problem and its impact on the insulation transformer life expectancy.