A Review of Dissolved Gas Analysis in Power Transformers

Dissolved gas analysis (DGA) of transformers can provide insights into thermal and electrical stresses sustained by oil-immersed power transformers. Because it detects incipient transformer faults, DGA can help prevent further damage. Moreover, DGA is a sensitive and reliable technique for detecting incipient fault conditions in oil-immersed transformers. The many approaches developed for analyzing these gases and interpreting their significance include Key Gas, Dornenburg Ratio, Rogers Ratio, Nomograph, IEC Ratio, Duval Triangle, and CIGRE. This study compares the effectiveness of these methods for interpreting transformer conditions.