Detecting and locating turn to turn Fault on layer winding of distribution transformer

Power transformer is the most important and most expensive part of electric power transmission and distribution networks. Among different faults identifying in transformers, identifying winding fault is not easily recognizable because of lower domain effect in terminal voltages and currents. In this article, frequency response analysis (FRA) method is used as an efficient method to recognize turn to turn fault. By comparing frequency response in fault and intact conditions, fault detecting in winding becomes possible. In order to determine frequency response, the detailed model is used. Analyzing the model is done by MATLAB software. The accuracy of this model is very dependent on determining its parameters. In order to get more accuracy, parameters of equivalent circuit were estimated by FEM based on design geometrical and material information. Considering frequency dependency of elements has culminated to more accurate results. Finally, the effect of Turn to Turn fault and its location on layer winding of a distribution transformer is evaluated.