What Are the Advantages of Shell-Form Transformers?
Shell-form transformers have several advantages, especially when used in high voltage and large capacity and higher medium voltage applications, such as better short-circuit strength, higher mechanical and dielectric strength and better control of leakage magnetic flux. In addition, shell-form transformers have an efficient cooling system, a flexible design and a compact size.
The vertically arranged coils of the shell-form transformer are enclosed in an iron core . This core has a form-fitting tank that provides added stability and reinforces the coils against any movement. The short-circuit strength of the transformer is increased through the use of alternating high and low voltage windings, but the size of the coils does not increase with the transformer's capacity increase. This gives shell-form an advantage over core-form transformers which have coils that would become significantly large in a winding arrangement.
Shell-form transformers also have greater seismic-withstand capabilities, and they are able to withstand difficult transportation demands. The transformers can be shipped through different means, such as land, sea and air, and they can be transported on their sides in case of dimensional limitations.
Shell-form transformers are also protected against leakage magnetic flux in case of local heating. Their iron core absorbs the leakage flux from the coils. Compared to core-form transformers, there is flexibility in the selection of the wire size, which further helps prevent local heating.