Analysis of Winding Deformation Diagnosing of Power Transformer

Abstract: It is significant to use frequency response approach (FRA) to determine whether the windings of power transformers have serious deformation after short circuit impacts. Based on the basic principle of FRA and a great deal of field experience, a horizontal comparison method is presented, that is, to analyze the windings’ deformation in terms of comparing the consistency of the windings’ frequency response feature graph of one phase with those of other two phases as well as in comparison with other same type transformers’ curves produced by the same factory. Furthermore, a relevant coefficient is presented to quantify the consistency of two graphs. And the relation between value and the graphs’ consistency is obtained. In particular, the test wiring method and main precautions are also descried in this paper.  

Key words: power transformer, winding deformation, fault diagnosis, comparison method