Simplified Design of RSFCL for Protecting HTS Cable in Distribution Network

It is benefit to connect different substations from the low voltage side by high temperature superconducting (HTS) cable to make full use of the remaining capacity of the transformer. Meanwhile, if necessary, the HTS cable can form an electromagnetic ring network with the original tie line to improve the power supply reliability. However, the short circuit fault at adjacent components of the HTS cable during closed loop operation may also cause the quench of the HTS cable, which brings difficulties to the protection of the HTS cable. Based on the actual project of HTS cable in Shenzhen Power Grid, this paper calculates the fault current flowing through the HTS cable in different operation modes. The parameter requirements of the resistance superconducting fault current limiter (RSFCL) are analyzed, and the design of the RSFCL is completed. The system with HTS cable and RSFCL was modeled in detail in Matlab software, and the effectiveness of the RSFCL design is verified.