Fast Fault Detection And Location System For Distribution Network Lines Based On Power Electronic Disturbance Signals

The traditional reclosing device cannot distinguish the fault nature of blind reclosing, which will cause secondary damage to the faulty power system. In addition, the existence of fault resistance makes fault location complicated. This paper proposes an automatic reclosing device which enters the fault line through the single-phase AC voltage signal of the power electronic converter. The device responds to the comprehensive utilization of the system harmonic impedance and locates the fault current through the comprehensive utilization of the system harmonic impedance judgment. So, the device can eliminate the influence of fault resistance for positioning the result. Because the measurement is performed only at the head-end circuit, no communication line is required. If a permanent fault is found in the system, the fault information and the latching circuit breaker should be indicated. If there is no fault notification, the circuit breaker should be switched. The equipment has been proved to have accurate identification to detect the results of various fault types, so it can avoid the secondary damage of the power system caused by blind reclosing.