New method for protective coordination for power distribution system with superconducting fault current limiter

摘要

PURPOSE: A protection coordinating method used in applying a superconductive current limiter to a distribution system is provided to solve a protection coordinating problem due to reduction of a fault current in applying a superconductive current limiter to a protection coordinating system of an existing distribution system by operating a corresponding protection device after determining a fault position. CONSTITUTION: A superconductive current limiter includes a current transformer, a digital relay, a communication device, and a circuit breaker. The current transformer detects a current of an individual protection device(1~8). The digital relay calculates a current detected in the current transformer as an effective value corresponding to a system power frequency with a fixed sampling interval. The communication device delivers a signal generated by the calculating method to high link digital relays adjacent to a power side of the digital relay. The circuit breaker is tripped by delivering the signal generated by the calculating method from low link digital relays adjacent to a load side of the digital relay to the digital relay through the communication device.