A bushing current transformer is a window-type current transformer. It is mounted around the bushing’s flange. It may be either inside the main tank or mounted externally. A bushing type current transformer contains only a steroidal-shaped core with a secondary winding. The role of the bushing’s center is to form a single turn primary of the BCT.
- More than one ratio can be provided by tapping the secondary winding at multiple increments the winding.
- The secondary winding terminals of the transformer can be accessed in the control cabinet of the transformer.
- Bushing Current Transformers are used for protective relaying purposes.
A current transformer is made for saturating at very high current levels. The reason behind this is to allow the bushing current transformer to perform its required function of accurately capturing (high) fault current information. Nevertheless, if the current transformer has excessive residual magnetism, it can saturate sooner than expected.
Use of bushing current transformer
The bushing current transformer is designed to be used to relay and meter on existing power transformers or circuit breakers. Bushing is an important component when it comes to using transformers to withstand mechanical, voltage and environmental stresses while making external input and output connections of transformers.
It is always advisable to keep the sensing equipment (CT) as close as possible to the transformer that needs to be protected. It allows preventing the reactance or losses that would generally come in the picture if CT’s were connected to the transformer by an overhead conductor or tubular bush bars.
11 KV Double Bushing Current Transformer
Bushing transformers are made of insulators depending on the amount of voltage being transmitted. A disc of bushing can provide insulation of about 11KV. They are also used for preventing direct contact between the tank of the transformer and the bud. Direct contact between these two makes the corrugated tank of the transformer changed which leads to causing electrocution or damaging the transformer itself since heat will be generated. This generated heat can also degrade the transformer oil insulation property. In addition, bushings have the quality to provide a conduction path for current from the transformer windings to the transmission lines.
Below are some of the benefits of 11 KV Double Bushing Current Transformer
- It reduces the risk of fire
- The oil leakage is stopped
- Mechanically rigid design
- They do not need oil supervision
- Reduces the downtime in case of major failures
- Lightweight and compact
- Easy transport and stored
- Option to install at any angle
- Can be energized soon after the installation
To know more about 11 KV Double Bushing Current Transformer, talk to our experts at +91-9958904598.
