External force factor diagnostic method causing single phase ground connection breakdown of electric transmission line

Abstract

The invention discloses an external force factor diagnostic method causing single phase ground connection breakdown of an electric transmission line. The method firstly starts from the moment when the single phase ground connection breakdown of the electric transmission line occurs. The method ends with the moment until a breakdown line disconnector trips with the breakdown sampling interval time increasing. An electric transmission line breakdown phase current waveform is searched and judged in sequence, thus a discontinuous area is judged by the fact that if the discontinuous area exists in the vicinity of a zero point of the electric transmission line breakdown phase current wave form. The number of wave crests and the number of wave troughs of the electric transmission line breakdown phase current wave form are recorded. The external force factor causing the single phase ground connection breakdown is diagnosed according to the number of the wave crests, the number of the wave troughs, the fact that whether the discontinuous area exists in the vicinity of the zero point of the electric transmission line breakdown phase current wave form and the condition of distance I section protection movement. The external force factor causing the single phase ground connection breakdown of an electric transmission line is diagnosed precisely, a strong reference frame is provided for the fact that a breakdown is rapidly searched, a line breakdown is checked and line power supply is restored after the electric transmission line single phase ground connection breakdown occurs.

Description

technical field [0001] The invention relates to the technical field of intelligent diagnosis of power system faults, in particular to a method for diagnosing external force factors that cause single-phase grounding faults in power transmission lines. Background technique [0002] Single-phase ground faults account for more than 80% of line fault types, and the external force factors that cause single-phase ground faults in lines usually include floating objects that cause line-to-ground short circuits, muddy water flowing down after the bird's nest is damp, causing short circuits to relative ground lines, and smoke from burning mountains causing line-to-ground short circuits. Short circuit to ground and smoke caused by villagers burning land, short circuit to ground caused by lightning strikes, single-phase ground short circuit caused by insufficient safe distance between the boom of the crane and the live wire, etc. More than 90% of transmission line faults are caused by ex...

AI Technical Summary

Problems solved by technology

More than 90% of transmission line faults are caused by external force damage to the power grid. Every time a single-phase ground fault occurs on a transmission line, according to the fault point reference area provided by the protection distance measurement results, the aimless patrol of the line is often the discharge point. The characteristic area is small and difficult to detect, so it is often three or four times to inspect the line to find out the cause of the fault, which will increase the workload of the line inspection

Due to the lack of a diagnostic method for external force factors that cause single-phase ground faults on transmission lines, fault line inspection has always been a difficult problem for power workers.

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