Modular Design of 3 MJ/2 MW Toroidal Magnet and Analysis of Dynamic Temperature Rise

The power industry is changing rapidly. One approach to accommodate a part of the change is the use of energy storage, in particular superconducting magnetic storage systems (SMES). Both solenoidal and toroidal magnets storing a few megajoules have been designed and valuated for this application. Solenoidal magnets have extensive stray fields, which are one of the serious limitations. Toroidal magnets require more conductor and are more complicated in terms of construction and insulation. The existing power systems require 100 s of megawatts of power from energy storage systems, whereas the power capacity of a single SMES installation will be quite limited. Modular SMES may provide a solution to this limitation. This article describes a 3 MJ/2 MW modular toroidal SMES using YBCO tape. The design approach is aimed at the reduction of the insulation requirement; and a slit structure of the cooling plate is designed to reduce the eddy current loss. The cooling process and losses of the magnet are analyzed.