An electrical schematic solution for superconducting fault current limiter access to the power system

High-temperature superconducting current limiters (SFCL) can suppress the short-circuit current of the power grid effectively. The 220kV and 35kV SFCL have been applied and connected to the power system in China. The 500kV SFCL equipment has been developed through the prototype and has the conditions to access the power grid. In this paper, the possible fault conditions of SFCL and the electrical scheme for connecting to the power grid are studied. The low-temperature system of SFCL is the weak point of the equipment that is prone to failure. An electrical schematic solution is proposed according to the characteristics of the SFCL equipment. This solution has the advantages of high reliability, flexibility, and convenient operation and maintenance, and it can be applied to various voltage levels of the power system.