DIFFERENCES BETWEEN CORE TYPE AND SHELL-TYPE TRANSFORMERS
Transformer plays an essential role in operating the electrical grid. Depending on the shape of the magnetic core, there are two main types of transformers: core type transformers, and shell-type transformers (and less commonly, air-core transformers).
In this title, we will learn about the differences between core-type transformers, and shell-type transformers.
Table of contents
Difference between core type and shell-type transformers
Core type transformer
The core of Core type transformers is a rectangular frame made of laminated ferromagnetic steel. The windings are wrapped around the limbs of the core. The low voltage winding is made closer to the core the high voltage winding surrounds it. The HV and LV winding are insulated from each other and the core itself.
Shell type transformer
The windings are wrapped around the middle limb and the core surrounds the winding. The HV and the LV winding are divided into a number of coils and are arranged alternatively.
Difference between core type and shell-type transformers
The difference between the core type and shell-type transformers is illustrated in the above figures.
|
Items |
Core Type Transformer |
Shell Type Transformers |
Construction
|
- The winding surrounds the core => Easier to dismantle and repair |
- The winding surrounds the middle limb of the core and the side limbs surround the windings |
Short circuit withstand ability |
=> the windings are susceptible to damage under short circuit conditions |
- a greater capacity to withstand the short circuit conditions. |
Leakage reactance
|
|
|
Ease of maintenance
|
- The windings in a core type transformer can be accessed easily. => easy to dismantle for maintenance |
- The coil is surrounded by the core, => difficult to inspect and repair. |
Cooling |
=> cooling is better in the winding than in the core.
|
=> cooling is better in the core than in the winding.
|
