An OPGW-based identification method for transmission line induction lightning and direct lightning strike

Abstract

The invention discloses an identification method of an indirect lightning strike and a direct lightning flash for a power transmission line based on an OPGW. The method includes: step 1, acquiring lightning stroke signals induced in an OPGW fiber; step 2, determining whether the peak value of the lightning stroke signals is greater than a threshold v1; step 3, determining whether the oscillation frequency of the lightning stroke signals in a wave head nearby period threshold t1 is greater than a threshold A and whether the average oscillation peak value amplitude is greater than a threshold B; step 4, determining whether the energy ratio C of a signal spectrum distribution map of the lightning stroke signals after a frequency threshold f1 is greater than 90%; step 5, determining whether the lightning stroke signals present slow (small damping) oscillation attenuation; step 6, determining whether the duration of the lightning stroke signals is greater than a time threshold t2; and step 7, indicating the direct lightning flash if determination results of steps 2-6 are all yes, and otherwise, indicating the indirect lightning strike. According to the method, technical problems of high cost, complicated installation, and difficult discrimination of the direct lightning flash and the indirect lightning strike are solved.

Description

technical field [0001] The invention belongs to the technical field of on-line monitoring and identification of lightning strikes in electric power systems, and in particular relates to an identification method for induction lightning and direct lightning strikes of transmission lines based on OPGW. Background technique [0002] The high-voltage transmission system has a long line, the geographical environment it passes through is very complex, and the climate difference along the way makes the transmission line vulnerable to lightning strikes. As the voltage level becomes higher and higher, the height of the transmission line tower is also increasing. The lightning strike failure of the transmission line More and more frequently, operating experience shows that the tripping of transmission lines caused by lightning strikes accounts for a large proportion of the total number of line faults, and is one of the main reasons for line insulation accidents. Significance. Identify...

AI Technical Summary

Problems solved by technology

[0004] The technical problem to be solved by the present invention is to provide an OPGW-based identification method for induction lightning and direct lightning strikes on transmission lines, so as to solve the problem of identifying lightning shielding strikes and counterattacks by using insulator potential difference and tower ground current to identify lightning strikes in the prior art. The existence cost is high and the installation is complicated; the three-phase transient current characteristics of the transmission line are used for identification, but this method can only identify lightning faults and non-lightning faults, and it is difficult to distinguish between induced lightning and direct lightning; lightning strikes based on the traveling wave method The transmission line will introduce high-frequency components, the overvoltage signal has time-varying non-stationarity, and the waveform is easy to attenuate and distort, and the simple time-domain feature quantity is greatly affected by the fault condition and the line operating state and other technical problems

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