Smart high voltage circuit breaker in overhead power lines for smart grid applications

Fault detection and protection is a major concern in electric transmission and distribution network. Faults having high impedance on an energized network are difficult to capture and pose great threat for safety and security. Smart circuit breaker is presented for detecting a fault during the real time operation of the power system. The proposed method monitors the high frequency impedance of the grid in a real time which can operate in both energized and de-energized conditions. In order to measure the impedance, circuit breaker injects high frequency signal into the line. Injected signal is blocked by a LC line trapper at the substation side and by an active blocker at the opposing end of the desired segment. Relative change in the measured impedance is a reference to detect the presence of the high impedance fault. The validity of the proposed method is verified with simulations.