Novel adaptive distance relay algorithm considering the operation of 154 kV SFCL in Korean power transmission system

•This paper presents an outline of the new project of the 154 kV SFCL in Korea.•And then we review some protection problems for the application of 154 kV SFCLs.•This paper proposes a new adaptive protection algorithm for 154 kV SFCLs.•The developed algorithm is tested in a simple distance relay system.

In general, SFCLs can have a negative impact on the protective coordination in power transmission system because of the variable impedance of SFCLs. It is very important to solve the protection problems of the power system for the successful application of SFCLs to real power transmission system. This paper reviews some protection problems which can be caused by the application of 154 kV SFCLs to power transmission systems in South Korea. And then we propose an adaptive protection algorithm to solve the problems. The adaptive protection algorithm uses the real time information of the SFCL system operation.