A transformer bushing is a critical component of a transformer, used to guide the current from inside the transformer to the external circuit while ensuring electrical insulation and mechanical support. The main components of a transformer bushing include:
Conductive Rod (Conductor): This is the primary part through which the current flows, typically made of copper or aluminum to ensure good conductivity.
Insulation Materials: Used to isolate the conductive rod from the external environment, preventing current leakage and short circuits. Common insulation materials include:
- Solid Insulation Materials: Such as epoxy resin, fiberglass, and oil-impregnated paper.
- Liquid Insulation Materials: Such as transformer oil, which provides both insulation and cooling.
Housing (Bushing Body): Usually made of ceramic or composite materials, providing mechanical protection and insulation support.
Flange and Grounding Device: The flange is used to secure the bushing to the transformer, and the grounding device ensures the safe grounding of the bushing.
Sealing System: Includes various seals and gaskets to ensure that the internal insulation oil or gas does not leak and that moisture and impurities do not enter from outside.
Pressure Relief Device: Some bushings come with a pressure relief device to release internal pressure if it becomes too high, preventing the bushing from breaking.
Test Tap: Some advanced transformer bushings have a test tap for online monitoring and testing of the insulation condition.
The design and manufacture of transformer bushings must consider voltage levels, operating environment, mechanical strength, thermal management, and other factors to ensure their reliability and safety in practical applications.