Practical Anatomy: The Influence of Cooling System on Carbon Dioxide Concentration and Dissipated Heat of the Oil Immersed Power Transformers.

Dissolved gas analysis (DGA) is the most effective method to evaluate, diagnose, and predict the oil-immersed power transformers’ internal parts condition. Internal faults can be identified with the values of the generated gases or with the estimated ratios of dissolved gases. It was observed that the carbon monoxide (CO) concentration value was higher than the standard values in the healthy power transformers. However, carbon dioxide is the most important indicator of solid paper insulation degradation. It is critical to identify the primary source of these gases. Oil oxidation, with the help of continuous bulk oil temperature increase through various load operations, is one of the sources that produces plenty of carbon monoxide. This paper represents a practical solution for optimize the concentration of carbon dioxide and the thermal stability of the power transformers’ internal parts through the set-point modification of the cooling system.