The distributed power generation has increased due to the development of the electric power industry and the active generation of renewable energy. This causes a large increase in the fault current when fault occurs, which exceeds the capacity of the existing protective device. Thus it creates a risk of shutdown failure. The superconducting fault current limiter (SFCL) has been demonstrated by previous studies that one of the effective methods to limit the fault current. Installation of the SFCL is expensive, but it is more reasonable than replacement of existing protective equipment.
In addition, the superconducting fault current limiters studied in many cases are often designed as single phase, and when applied to three phases, three single phase superconducting fault current limiters are installed. In this case, at least three superconducting modules are required.
In this paper, the double quenching SFCL using E-I three-phase transformer core is proposed. The proposed superconducting fault current limiter is designed as three phases and has a similar fault current limiting effect to that of existing superconducting fault current limiters by using a small number of superconducting modules compared to existing ones. The primary side of the three-phase transformer is connected in series with the power system, and the secondary side is connected to the superconducting module. In the fault case, the single-quenching or double-quenching operation is performed depending on the magnitude of the fault current. In this paper, the operation characteristics of the proposed double quenching SFCL using E-I three-phase transformer core are analyzed through the experiments.