Power transformers winding deformation diagnostic using a fast and affordable method for measuring leakage inductance

Due to the increasing number of transformers owned by different companies e.g. power plants, production facilities and tourist companies the main aim of this paper is to enable quick, reliable and cheap transformer winding diagnostics using the U-I method. Furthermore, the winding deformation test is described, based on the detailed description, recommended power transformer’s measuring connections and threshold values. Because power transformer unavailability could lead to large and hard-to-recover losses, undelivered energy and even blackouts, U-I method results are verified with a more complex and expensive frequency analysis (FRA) method.