Method for obtaining OPGW total current generated when overhead transmission line is in unbalanced short circuit

Abstract

The invention relates to a method for obtaining OPGW total current generated when an overhead transmission line is in unbalanced short circuit. The method includes the steps of calculating mutual impedance between a phase line and an OPGW through the distance between the transmission phase line and the OPGW, forming an equivalent circuit by determining the spans between towers of the overhead transmission line, selecting different equivalent calculation models by determining the types of unsymmetrical faults of the overhead transmission line, obtaining the total current of the short-circuit current after the faults according to the different equivalent calculation models, determining total current components on the OPGW and obtaining distribution of the short-circuit total current on the OPGW according to the shunt characteristic of the total current of the short-circuit current after the faults, and obtaining the waveform of the short-circuit total current on the OPGW through drawing. By the method, analysis and summarization of the distribution characteristics and waveform of the components of the total current of the short-circuit current on the OPGW are facilitated.

Description

technical field [0001] The invention relates to the technical field of power system analysis and control, in particular to a method for obtaining the full current of an OPGW line when an overhead transmission line is asymmetrically short-circuited. Background technique [0002] At present, the composite optical ground wire (OPGW) has both lightning protection function and communication function. Transmission lines with a voltage level of 220kV and above basically choose OPGW as the communication carrier. When a short-circuit fault occurs on a transmission line, the short-circuit current will directly affect the safety of the transmission system and the reliability of power communication. Among various types of faults, asymmetrical short-circuit faults include single-phase-to-ground faults, two-phase phase-to-phase short-circuits and two-phase-to-ground faults, among which single-phase short-circuits have the highest frequency of occurrence. The distribution of short-circui...

AI Technical Summary

Problems solved by technology

At the same time, the calculation and analysis of the short-circuit current on the OPGW line in the past were all based on the steady-state short-circuit current after the short-circuit, ignoring the transient process after the short-circuit

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