Simplified Design of R-SFCL With Shunt Reactor for Protecting HTS Cable in Distribution Network

The high temperature superconducting (HTS) cable can be used as a low-voltage tie line between substations for its characteristic of high currentdensity. In this way, the remaining capacity on the low-voltage side of the transformer can be fully utilized. Moreover, The HTS cable can run in parallel with the original tie line, forming an electromagnetic ring network, to ensure the power supply of important loads. However, the short circuit current of the distribution network is large, and the electromagnetic ring network operation results in the quench of HTS cable when the short circuit fault is outside the HTS cable. It is important to ensure the safety of HTS cable under various short circuit faults. To ensure the safe operation of HTS cable in Shenzhen Power Grid, this paper built a distribution network model with HTS cable in Matlab/Simulink. The fault current and thermal process in different fault situation were analyzed. The design of fault current limiter (FCL) which is composed of the resistive superconducting fault current limiter (R-SFCL) and a shunt reactor was completed. The model of R-SFCL using R - Q method is build, and the effectiveness of the R-SFCL design is verified.