12. Super conducting transformers
12.5 Transformer specification items and design
Rated voltage for each winding, rated capacity, rated insulation level, short-circuit impedance, short-circuit withstandability, etc. are to be considered. Moreover, the maximum permissible (without quenching) over current of each winding is of great importance which is a main factor to decide the cross section of the winding conductor and also the total amount of the super conductive material. Thus the total loss in the material which is proportional to the total material amount is decided. Short circuit current with DC component and inrush magnetizing current have to be considered. As for the former, 10 ---20 times of the rated current crest value is probable.
Insulation in ultra low temperature environment is also great important. As the insulation media, most probably, liquid helium will be provided. But for the insulation property of the media, much more investigations are required. Permission of the vaporization or not would affect much to the insulation design.
Finally and as the most important items, the cost, dimensions, transportations, necessary area for the installation are to be considered.
This page is based on Prof. E.Haginomori's lectures
in Tokyo Institute of Technology, and edited by Japanese ATP User Group.
Copyright (C) Eiichi Haginomori and Japanese ATP User Group.