DEMO200 – Concept and Design of a Superconducting 200 kA DC Busbar Demonstrator for Application in an Aluminum Smelter

A number of technical applications such as aluminum smelters, electrolysis plants or large data centers require DC feeding currents of several hundred kA. Within the project DEMO200 we want to show the feasibility of a superconducting single-pole 200 kA DC busbar. To this end, a technology demonstrator of 2 m length will be developed and tested. It is based on REBCO superconducting tapes and will consist of ten identical modules with a current capacity of 20 kA each. These modules are joined in a compact structure fitting in a cryostat with an inner diameter of 30 cm. In contrast to the target application, the ten modules of this demonstrator will be electrically connected in series, thus a 20 kA DC source is sufficient for demonstration. Two different module designs are investigated, either with HTS Cross Conductors (CroCo) or wave-shaped stacks. Except for the additional electrical insulation between the modules, the mechanical structure of the demonstrator, local self-fields and the Lorentz forces will be the same as in the application case. Solutions for key technical challenges, such as current leads, Lorentz forces, low-ohmic soldered joints, and the compensation of the thermal contraction are proposed.