How is online dissolved gas analysis of transformer oil conducted?

Online dissolved gas analysis (DGA) of transformer oil is a critical process for assessing the health and life expectancy of oil-filled transformers. This technique involves extracting a sample of the transformer oil, which is then analyzed for dissolved gases, such as hydrogen, methane, ethane, ethylene, acetylene, carbon monoxide, and carbon dioxide. The analysis is usually performed using gas chromatography, where the gases are separated and quantified, providing insights into the thermal and electrical stress conditions within the transformer. The results of the DGA help in detecting faults like overheating or arcing, aiding in predictive maintenance and extending the oil-filled transformer life expectancy by allowing timely interventions before severe damage occurs.