Analysis on Starting Current Limiting Characteristics of Induction Motor Using a Three-Phase Reactor Type Superconducting Fault Current Limiter

Starting current of induction motor is briefly high for a second and its starting current causes misoperation of protective devices such as over current relay, which can be lead to a large blackout. To prevent misoperation of protective devices, superconducting fault current limiter (SFCL) can be expected to be suitable method to limit starting current of induction motor because SFCL can perform the fault current limiting operation without additional detecting devices. Among the developed SFCLs, the transformer type SFCL has the merit easily to adjust the operational current by setting the turns ratio between the primary and the secondary windings. In this paper, the induction motor’s starting current limiting characteristics due to three-phase reactor type SFCL were analyzed together with its voltage drop suppressing operation. As its starting method, both wye and delta starting operations of the induction motor were selected and the operational characteristics of the SFCL were compared.