DGA diagnostics save transformers - case studies

Abstract

Dissolved gas analysis (DGA) is proving to be the most promising and simplest tool for condition monitoring of transformer. The experimental results of the level and the change in concentration of different combustible gases dissolved in the insulating oil is a trustworthy diagnostic tool which can be used as indicator of undesirable events developing inside the transformer, such as hot spots, electrical arcing or partial discharges. Several DGA diagnostics methods (expert systems) are available to interpret different incipient faults in transformers. The paper showcases the implementation & diagnosis of all expert system in 1single MATLAB program to reduce the analytical time and human errors. Paper also discusses 4 different cases to interpret the transformer condition and incipient faults using MATLAB program. Also, it compares interpreted data using different expert system with actual fault found in transformer. The objective of this paper is mainly to analyze available data from DGA to arrive at conclusion of type of fault to further investigate or to save the transformer and correlate the fault found with DGA data.