Dissolved Gas Analysis (DGA) :
Dissolved Gas Analysis (DGA) is performed to detect the dissolved gases in transformer oil sample to assess healthiness of transformer. The faults in power transformers such as arcing, overheating, partial discharge, thermalaging of paper, oxidation vapourization, insulation decomposition, breakdown/ thermal degradation of oil and electrolyte action etc. May result in generation of gases such as CO, CH4, CO2, C2H4, C2H6, C2H2 and H2 etc. These gases remain in dissolved condition in the transformer oil. By carrying out DGA the dissolved gases are extracted, separated and identified accordingly. As per concentration of these gases analysis is done and fault is detected. Analysis is carried out on the basis of Roger's, Ratio Method & Key Gas Method. The concentration of gases is expressed in ppm.