An electric transformer bushing is a component used to insulate and connect conductors passing through the transformer tank to the external high-voltage (HV) and low-voltage (LV) electrical systems.
Transformers have active parts and auxiliary parts, One of the most important auxiliary parts is Bushings. The primary purpose of transformer bushings is to provide electrical insulation and support for the conductors, preventing electrical breakdown and ensuring the safe and reliable operation of the transformer.
Here are the main reasons why transformers have bushings:
Insulation: Transformer bushings are designed to insulate the internal conductors from the grounded tank and from each other. This is crucial to prevent electrical arcing and short circuits, which could damage the transformer and interrupt the flow of electrical power.
Support: Bushings provide mechanical support for the conductors that pass through the transformer tank. They help secure the conductors in place and prevent them from vibrating or moving, which could lead to mechanical failure.
Sealing: Bushings also serve as a means to seal the transformer tank, preventing the ingress of moisture, contaminants, and other environmental factors. This is essential for maintaining the dielectric properties of the insulating oil and ensuring the long-term reliability of the transformer.
Voltage Tapping: In some transformers, bushings are used to provide access points for tapping into different voltage levels. This allows for flexibility in the transformer’s output voltage, catering to various requirements in the electrical grid.
There are different types of transformer bushings, including oil-filled bushings and dry-type bushings.
Oil-filled bushings are immersed in the insulating oil of the transformer, providing additional cooling. Dry-type bushings, on the other hand, use solid insulation materials and do not rely on oil for cooling.
Overall, transformer bushings play a critical role in maintaining the electrical integrity and reliability of transformers, which are essential components in electrical power systems for voltage transformation and distribution.
