How is dissolved gas analysis performed and what faults can it detect?

Dissolved gas analysis (DGA) is performed by extracting oil samples from power transformers and analyzing them for dissolved gases using gas chromatography. This technique detects gases such as hydrogen, methane, ethylene, and acetylene, which indicate various faults. For instance, high levels of acetylene suggest arcing, while increased hydrogen may indicate overheating. DGA helps identify issues like insulation breakdown, overheating, and electrical discharges, enabling proactive maintenance and fault prevention.