How Is The Transformer Oil Filled in A Large Power Transformer?

How Is The Transformer oil filled in a large power transformer?

Transformer oil is filled into large power transformers by first generating a deep vacuum inside the transformer tank and then introducing pre-heated, degassed oil into the tank under vacuum to ensure the solid insulation is fully impregnated and no air or moisture remains. This vacuum filling process is crucial for preventing future problems like corona discharge, which occurs when air is left trapped in the insulation. 

 

 

Preparation

1. Pre-checks and Setup:

The procedure begins with checks of the transformer's technical condition, ensuring all valves are in the correct position and equipment for vacuum generation and oil filling is properly connected.

2. Oil Preparation:

The insulating oil itself must be prepared by being degassed to remove gases like oxygen and moisture, and preheated to ensure it will be absorbed effectively by the transformer's insulation materials.

 

Monitoring and Completion

1. Oil Level Monitoring:

After filling, the oil level is monitored using oil level indicators to ensure the oil is at the correct level.

2. Oil Quality Analysis:

Samples of the oil are analyzed after filling to confirm its quality and to check for any contamination from the filling process.

3. System Connections:

Once filling is complete, connections are made, and the transformer is ready for operation.