Development of an Expert System for Detecting Incipient Fault in Transformer by Dissolved Gas Analysis

Power transformer is a vital component of power system, which has no substitute for its major role. They are quite expensive also. It is therefore, very important to closely monitor it’s in – service behavior to avoid costly outages and loss of production. Many devices have evolved to monitor the serviceability of power transformers. These devices such as Buchholz relay or differential relay respond only to a severe power failure requiring immediate removal of transformer from service, in which case, outages are inevitable. Thus, preventive techniques for early detection of faults to avoid outages would be valuable. A prototype of an expert system based on Dissolved Gas Analysis (DGA) technique for diagnosis of suspected transformers faults and their maintenance action are developed. The synthetic method is proposed to assist the popular gas ratio methods. This expert system is implemented into PC by using “Turbo Prolog” with rule based knowledge representations. The designed expert system has been tested for N.T.P.C., Talcher (India) transformer’s gas ratio records to show its effectiveness in transformer diagnosis.