What is the process of transformer oil treatment?

Transformer oil treatment is a process used to purify, dehydrate, and restore the insulating oil in transformers to extend its lifespan and improve its performance. Over time, transformer oil can accumulate contaminants, water, and gases that reduce its insulating properties, potentially leading to transformer failure. The treatment process typically involves several key steps:

1. Degassing:

   - The oil is passed through a vacuum chamber to remove dissolved gases, such as oxygen, nitrogen, and carbon dioxide, which can form due to oxidation or other chemical reactions inside the transformer.

   - The vacuum also helps to remove other volatile impurities that could interfere with the oil’s dielectric strength.

2. Dehydration:

   - Moisture in the oil can drastically lower its dielectric strength, so it’s essential to remove both dissolved and free water.

   - Under vacuum conditions, any water present in the oil is vaporized and then removed by condensation, resulting in dry oil.

3. Filtration:

   - Solid particles, such as metal, dust, or other impurities, are removed through multi-stage filtration.

   - Different filters, including primary and fine filters, trap contaminants and particulates, which improves the oil’s quality and prevents abrasion of transformer components.

4. Acid Neutralization and Sludge Removal:

   - Acids and oxidation byproducts can build up in the oil, causing it to form sludge that can clog parts of the transformer and impact efficiency.

   - Absorbents or special filters may be used to neutralize acids and remove oxidation products to restore the oil’s chemical stability.

5. De-aeration (if needed):

   - Further de-aeration may be conducted to ensure all entrapped air is removed. This step can help prevent air bubbles from impacting the dielectric strength.

6. Vacuum Refilling:

   - After purification, the treated oil is carefully returned to the transformer under vacuum conditions to prevent contamination with air, moisture, or particles.

   - Vacuum filling ensures the oil is stable and free of contaminants when it’s reintroduced to the transformer.

7. Optional Regeneration (for heavily aged oil):

   - Regeneration goes beyond purification to restore the oil’s chemical properties. It involves passing the oil through activated clay or other adsorbents to remove acids, sludge, and color impurities.

   - Regenerated oil can closely resemble new oil in properties, extending its functional life further.

8. Testing and Quality Control:

   - The treated oil undergoes dielectric strength, moisture content, acidity, and gas content testing to ensure it meets operational standards.

   - These tests verify that the oil can maintain its insulating and cooling properties within the transformer.

 Benefits of Transformer Oil Treatment

- Extended Transformer Life: Regular oil treatment helps maintain oil quality, reducing the wear and tear on transformer components.

- Improved Reliability: Treated oil improves the dielectric properties, reducing the risk of breakdowns.

- Reduced Maintenance Costs: Preventing contamination and degradation can reduce the frequency and cost of repairs.

Transformer oil treatment is typically done on-site with mobile oil purification units, allowing transformers to be serviced without needing full disassembly or transport. Regular oil analysis and treatment help maintain transformer efficiency and prevent costly failures.