Design of a Module for a 10 MJ Toroidal YBCO Superconducting Magnetic Energy Storage

In this work, we presented the design of a module of a 10 MW toroidal SMES, tailored for a charge/discharge time of 1 s aimed at compensating the intermittency of a solar photovoltaic system. The design is performed through an approach based on the functional analysis: first, the functions that must be satisfied by the SMES are identified, together with constraints such as the performance of commercial YBCO tapes. Then, the pre-conceptual design of, among the different components, the winding pack and the cryostat is performed, to cope with the constraints and comply with the assigned functions. Finally, the design is verified through a detailed numerical analysis, checking that the requested function is in fact satisfied. The design leads to a multi-layer coil with radius ∼ 0.45 m, wound using a stack of 7 commercial 12 mm-width tapes with 52 layers in parallel, each with 26 turns. The total inductance is ∼2 H and a maximum self-field below 4 T. Nine modules are needed for the entire SMES, which is designed to operate at 50 K.