Dissolved Gas Analysis (DGA)
A diagnostic technique analyzing gases dissolved in transformer oil to detect internal faults before they become critical.
DGA is the primary diagnostic for oil-immersed transformer condition. When faults develop—overheating, PD, arcing—oil and insulation decompose producing characteristic gases.
Analyzing H2, CH4, C2H6, C2H4, C2H2, CO, CO2 identifies fault type. Methods: Duval Triangle, Rogers Ratios, IEC 60599.
Signatures: thermal <300C (CH4, C2H6); 300-700C (C2H4); arcs (C2H2); PD (H2); cellulose (CO, CO2). Regular monitoring enables predictive maintenance.
QDTB recommends regular DGA for all power transformers and provides factory baseline analysis. Our smart O&M includes advanced diagnostics.
Related Products
Related Terms
Buchholz Relay
A gas-actuated protective relay between transformer tank and conservator detecting internal faults by sensing gas accumulation.
Partial Discharge (PD)
Localized electrical discharges in small insulation regions not bridging electrodes, indicating defects or aging.
Oil-Immersed Transformer
A transformer using mineral oil as insulation and cooling medium, most common for outdoor power and distribution.
Moisture Content
The amount of water in transformer oil and solid insulation, critical for dielectric strength and insulation life.
More Terms Starting with “D”
Distribution Transformer
A transformer stepping down voltage from the distribution network (11-33 kV) to utilization voltage (400/230V) for end consumers.
Dry-Type Transformer
A transformer using air or solid insulation instead of liquid, ideal for indoor applications with fire safety priority.
Dielectric Strength
The maximum electric field an insulating material can withstand before breakdown, measured in kV/mm.
More in “Diagnostics & Maintenance”
Furan Analysis
A diagnostic measuring furan compounds in transformer oil to assess cellulose insulation degradation.
Moisture Content
The amount of water in transformer oil and solid insulation, critical for dielectric strength and insulation life.
Partial Discharge (PD)
Localized electrical discharges in small insulation regions not bridging electrodes, indicating defects or aging.
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