Test Requirements and Performance Evaluation for Both Resistive and Inductive Superconducting Fault Current Limiters for 22.9 kV Electric Distribution Network in Korea

Abstract

Enlarging the electric power supply capacity of 22.9 kV distribution line by upgrading the main transformer from 60 MVA to 100 MVA has been under consideration in order to cope with increasing electric power demands of distriution line in Korea which aims to replace some 154 kV supply demands by 22.9 kV large-capacity distribution systems. In this case, the prospective fault current of 22.9 kV distribution line is much bigger than the rated withstand fault current level of conventional electric equipments. As a major feasible solution to reduce excessive fault current, superconducting fault current limiters (SFCLs) are considered to be installed at 154 kV/22.9 kV substation. But until now, certified specifications or test procedures were not available considering utilities' requirements. And the performances of various types of SFCLs were not deeply investigated regarding the reclosing scheme of conventional networks. In this paper, in order to determine the suitable type of SFCL for newly installed 22.9 kV large distribution line in Korea, requirements and specifications of SFCLs were proposed considering the installation spots of large-capacity distribution line. Four types of SFCLs were modeled and analyzed using EMTP and their performances focusing on the coordination with reclosers were investigated to verify the suitability into the large-capacity distribution line. Consequently, detailed specifications and expected installation sites were proposed and suitable types of SFCLs for 22.9 kV large-capacity distribution line were suggested.