DIAGNOSIS OF FAULT IN THE TRANSFORMER WINDINGS BY SWEEP FREQUENCY RESPONSE ANALYSIS (SFRA)

Abstract

Power transformers, one of the vital elements of the power system network, are exposed to different types of winding faults, radial and axial deformation continuously. Monitoring at regular interval should be done in a way that will minimize(i.e take less time) its affect due to power outage on consumers. Sweep frequency response analysis is one such method. But it requires expert supervision in differentiating visual data records at normal and faulty condition. This work presents interpretation of data records by calculating statistical parameters which help in analyzing the location of fault in the winding and to differentiate between different faults. Faulty conditions were created arti cially in the winding at differnt locations by shorting the tappings. Simulation data can be obtained with the help of MATLAB and Ltspice programming. For this parameters of the winding should be known which can be calculated if dimensions of the winding are known. Different type of faults show changes in different frequency bands and hence value of parameters changes.