A Conceptual Design Optimization for a MgB2 DC Transmission Line

This work presents a tool to define an optimized architecture of DC superconducting cables realized with magnesium diboride (MgB2), aimed at minimizing the cable system costs by determining the optimal values of the geometric, physical, and operating parameters. The methodological approach is implemented in the numerical tool OSCaR, previously developed for HTS AC coaxial cables, and adapted here to the analysis of MgB2 conductors. The major updates to the original code are listed in a dedicated section of this manuscript. As an upgrade of the previous version of the model, the fluid-dynamic constraints are evaluated with an accurate modeling of the thermodynamic and thermophysical properties of the cryogenic fluid. Helium gas is selected as the cable cryogen, but the tool allows the user to select also other cryogenic fluids (e.g., liquid hydrogen). As an example of the flexibility of the proposed tool, the results of a parametric analysis are provided. The optimized costs of the cable system, distinguishing between several cost indexes, and some optimized individual design parameters of the MgB2 line are presented as a function of the delivered power.