What is the process of transformer oil filter and when is it required?

The process of transformer oil filtration involves removing impurities, moisture, and gases from the insulating oil to enhance the transformer’s performance and longevity. This is typically achieved through methods such as vacuum dehydration, adsorption, or centrifugal separation. Transformer oil filtration is required when the oil shows signs of contamination, such as increased moisture content or reduced dielectric strength, or during routine maintenance to ensure optimal operation and prevent failures.