**1. Introduction**

Transmission System Operators (TSOs) are responsible for the security of power grids and maintaining the balance between power generation and demand. However, new trends have emerged in power systems, pushing for a change in the way that networks are controlled, giving the TSOs plenty of new challenges to face in order to maintain the reliability and the security of power exchanges. The traditional power grids are gradually evolving towards power networks with high penetration of large-scale Renewable Energy Sources (RES) in both distribution and transmission level. In addition, more of the networks' equipment are reaching their capacity limits, while at the same time the utilities face several converging challenges caused by demand growth. All these factors bring about

new challenges for future power systems, requiring the development of bulk power corridors as interconnections between different countries, and the upgrading of existing networks. Consequently, in order to avoid technologically, economically, and socially challenging solutions, such as building of new substations [1], there is a need for the investigation of new technologies which can overcome these restrictions and increase the electrical capacity and flexibility of the network.

In addition, the penetration of RES changes significantly the fault levels and the resulting fault current signatures. Such changes imply the need for upgrading the existing switchgear and protection systems. As a result, the utilization of Resistive Superconducting Fault Current Limiters (RSFCLs) has been proposed by [2–5] as a viable solution towards addressing the challenge of managing short circuit currents in power-dense systems. However, the RSFCLs are very expensive. Therefore, many researchers have been focused on the integration of fault current limiting features into other power system devices, in an attempt to take advantage of the unique features of the superconducting materials while fulfilling the cost requirements [6]. The studies presented in this paper promote that the utilization of SCs with a copper stabilizer layer connected in parallel. The main scope of this research is to study the fault current and voltage signatures resulted by the utilization of the SCs. Emphasis is given to the fault current limitation feature (as an extension to the cable's primary function as a lossless transmission media during steady state operation), in conjunction with the assessment of the potential benefits of the copper stabilizer layer during transient phenomena. The obtained results provide useful information regarding the fault analysis of future power grids integrating SCs and high amounts of RES, which can be considered as a prerequisite step for designing effective protection schemes.
