Estimation and Methods of Equalizing Leakage Reactance for Multi-Winding Transformers

Abstract

Prediction of leakage reactance in multi-winding transformer is not simple due to unconventional reluctance model. Need of predicting actual leakage reactance beforehand, accurately, arises due to its effect on transformer's performance, output and characteristic behaviour. Incorrect methodology of leakage reactance estimation gives large error in value of windings which are adjacent. Moreover, leakage reactance between winding is also not equal, causing flow of leakage current. This produces loss beyond committed value. Incapability to provide committed leakage reactance value to customer, burdens company in form of penalty. Apart from loss, controlled or semi-controlled switches may misfire. Thus, this paper deals with accurate prediction of leakage reactance between individual winding of multi-winding transformers along with a model which is industrially feasible and possessing equal leakage reactance between individual winding using finite element analysis.