Revista de Engenharia Elétrica e Tecnologia Eletrônica

Condition Assessment of Power Transformers using Dissolved Gas Analysis

Jennifer Ayain

Condition Assessment of Power Transformers using Dissolved Gas Analysis (DGA) is a widely used technique for detecting incipient faults in transformers. Power transformers are acute components of power systems and their failure can result in significant financial losses and even pose a threat to human life. DGA is a non-destructive, cost-effective and reliable method for assessing the condition of transformers. Dissolved gas analysis is based on the fact that when a transformer experiences a fault, gases are generated due to the breakdown of the insulating oil and solid insulation materials. These gases dissolve in the transformer oil and their presence can be used as an indicator of the type and severity of the fault. The most common gases generated in transformers during faults are Hydrogen (H2 ), Methane (CH4 ), Ethylene (C2H4 ), Acetylene (C2H2 ), Carbon Monoxide (CO), Carbon Dioxide (CO2 ), and Oxygen (O2 ). The concentrations of these gases can be measured in the oil sample and compared to the standard diagnostic ratios to identify the type of fault.