Nonfault detection for three-phase reclosure in reactor-compensated transmission lines based on fault location

Abstract

A novel nonfault detection method using fault location to calculate the differential currents at fault point is proposed for three-phase reclosure in transmission lines with shunt reactors. In the case of a transient fault with the extinction arc namely nonfault, the differential currents of three-phase at fault point are all zeros. But in the case of an arcing transient fault or a permanent fault, the differential currents in the fault phases are non-zero because of the fault branch, and the differential currents of the healthy phases are close to zero as that of an arc extinction transient fault. Meanwhile, the fault phase can be confirmed as well based on the differential currents in the fault phases. It is noted that the presented non-fault detection is independent on fault phase selection and is able to detect non-fault reliably before three-phase reclosing, which is helpful to avoid blind reclosing and identify the fault phase for the arcing faults especially serious permanent faults. Moreover, simulations verify the correctness and effectiveness of this non-fault detection method, which is helpful to improve successful reclosing rate for three-phase reclosure.