What are furan compounds in transformer oil?

Furan compounds in transformer oil are degradation products formed from the thermal and oxidative breakdown of cellulose insulation materials within the transformer. These compounds, such as 2-furaldehyde, are significant indicators of insulation condition and aging. Monitoring the concentration of furan compounds in transformer oil helps assess the health of the insulation system, allowing for predictive maintenance and timely interventions to prevent transformer failures.