Large Power – Shell type technology
Shell type technology is normally used for large power EHV transformers (above 220 kV and up to 800 kV), as well as for complex units such as phase shifters.
Commonly used in many countries, from USA to China and from Europe to Japan, its main assets are as follows:
- Natural withstand to short-circuit stresses
- High flexibility level towards impedances, allowing particularly low values
- Low weight and dimensions leading to reduced layout, transportation and civil works constraints
- Reduced needs in raw materials, in particular regarding oil, thus more environmentally friendly
With this technology, JST transformateurs succeeded as early as in 1968 in the world first short-circuit test on a 300 MVA 400/220 kV autotransformer.