Electrothermal design of DC busbars for fusion facilities

The power supplies of nuclear fusion facilities are normally placed far (hundreds of meters) from the load coils and are connected to them through proper DC busbars. The design of such busbars is not trivial, as it must identify a tradeoff among different specifications. In this paper, the busbar electrothermal design is approached by specific tools and optimization criteria, taking into account the expected operating scenarios. The developed practical formulae, after being validated and extended by a finite-element method (FEM), were used to size the busbars according to the adopted criteria. It interesting that different criteria are predominant in case of steady-state or pulsed busbars, leading to selection of different materials and configurations. The described algorithms were applied for the design of the busbar system of the DTT facility, but they can also be exploited in many applications and fields.