A Method to Quantify Technical-Economic Aspects of HTS Electric Power Cables

Abstract

In prevision of an expansion in the installed power and the progressive increase in electrification toward energy transition, high-efficiency electric grids are required. In this process, superconducting power cables could play an important role as they can be installed either to realize new lines or to replace existing infrastructures, potentially reducing the costs and the environmental impact compared to conventional solutions. The technical-economic convenience of the superconducting choice depends on the design parameters of the line, such as the voltage and power levels and the line length. For each condition, the configuration of the cable and its cooling system must be optimized while complying with a number of electrical and geometrical constraints. Identifying a priori the optimal cable configuration is not trivial, as the numerous variables involved are mutually dependent. This article describes a novel tool developed to quantify technical-economic aspects of superconducting cables, allowing the user to freely select the operating conditions for a generic electric line. The tool adopts a genetic algorithm to solve a constrained minimization problem for a multivariable function, returning the cable configuration characterized by the lowest costs. For this study, ac concentric cables realized with high temperature superconductors are selected, but the approach described can easily be adapted to other types of cable. By means of suitable simplifying hypotheses, the equations used to size the cable components and their corresponding costs, estimate the thermal inputs and describe the cryogen flows are introduced as parametric equations. Finally, the results of a detailed study on the impact of the relevant parameters on the cable design and costs is provided.