Dissolved Gas Analysis (DGA) to Diagnose the Internal Faults of Power Transformer by using Fuzzy Logic Method

Abstract

Power transformer is very important part of power system and its proper working results in to reliability of power supply. Hence its frequent monitoring is required to avoid failure and it is related to internal fault. It impacts on economics of electricity distribution franchisee. There are numbers of techniques developed and all are dependent on the expert’s opinion, which may lead error in the interpretation of various tests. It contents the fuzzy logic tool developed to show the correct stage of internal fault. The electrical, mechanical and thermal faults are considered existing in the transformer. It uses the test data of Dissolved Gas Analysis (DGA), SFRA (Sweep frequency response analysis) and Total Dissolved Gas Analysis (TDCG) to reduce the misinterpretation. It also indicates the existing conditions of partial discharge, oil thermal, electrical arc, Break down Voltage (BDV), mechanical deformation of core and winding. This system has eleven fuzzy logic controllers and are arranged to connect as per technical conditions. It results in highly precise to identify the situation of transformer and identify the existing condition.