A method for fast identification of transmission line faults

Abstract

The invention discloses a rapid judgment method for faults of transmission lines. The rapid judgment method comprises the following steps: carrying out same low-pass filtering on a three-phase measuring voltage and current and a memory voltage at a protective mounting site; calculating a set-point voltage by combining with the measuring voltage and current at the protective mounting site after low-pass filtering based on a line model; detecting whether the measuring voltage at the faulted protective mounting site is lower than a threshold value, if not, carrying out comparison on the polarityof the set-point voltage in a short time window after the fault and the polarity of the measuring voltage at the protective mounting site, if the polarities are the same, determining the fault as an external fault, and if the polarities are opposite, determining the fault as internal fault; and if the measuring voltage at the faulted protective mounting site is lower than the threshold value, carrying out comparison on the polarity of the memory voltage at the protective mounting site and the polarity of the set-point voltage, if the polarities are the same, determining the fault as a reversefault and omitting the operation, and if the polarities are opposite, determining the fault as a positive direction fault. According to the rapid judgment method, the faults of the transmission linescan be rapidly judged, and the problems in the judgment of three-phase fault direction judgment of an outlet can be effectively solved.

Description

technical field [0001] The invention relates to the field of relay protection of electric power systems, in particular to a method for quickly distinguishing transmission line faults. Background technique [0002] The action speed of transmission line relay protection is of great significance to ensure the safe and stable operation of the power grid. As the voltage level of transmission lines increases and the transmission capacity further increases, high-speed fault discrimination methods are of great significance for further improving the safe and stable operation of the power grid. [0003] Traditional relay protection generally relies on power frequency phasors, and its action speed generally requires several power frequency cycles, which can no longer meet the needs of modern power grid development. Therefore, how to further improve the transmission line fault discrimination speed is a problem that those skilled in the art need to solve at present. Contents of the inv...

AI Technical Summary

Problems solved by technology

[0003] Traditional relay protection generally relies on power frequency phasors, and its action speed generally requires several power frequency cycles, which can no longer meet the needs of modern power grid development

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