Lightning protection system of ultra-high voltage alternating-current double-loop circuit

Abstract

The invention discloses a lightning protection system of an ultra-high voltage alternating-current double-loop circuit. The system comprises an ultra-high voltage alternating-current double-loop tension-resistant tower (10) and an ultra-high voltage alternating-current linear tower (1). The best ultra-high voltage alternating-current double-loop circuit lightning protection model is determined through different arrangement and combination of an OPGW (optical fiber composite overhead ground wire) optical cable or earth wire (6), a V-shaped suspension string (7), a suspension string (8) of the OPGW optical cable or a lightning wire, and a tension-resistant string (9) of the OPGW optical cable and the lightning wire, wherein an upper layer of cross arm (2) and a middle layer of cross arm (3) of the ultra-high voltage alternating-current linear tower (1) are laterally hung to the OPGW optical cable or the earth wire (6); and the upper layer of cross arm (2), the middle layer of cross arm (3) and a lower layer of cross arm (4) are downwards hung to the V-shaped suspension string (7) and a multi-splitting lead (5). The system can effectively prevent shielding lightning and is high in lightning protection effect.

Description

Technical field: [0001] The invention relates to a lightning protection system for ultra-high voltage AC double-circuit lines, which belongs to the field of design, operation and maintenance of overhead transmission lines in power systems. Background technique: [0002] At present, it has been recorded in public literature that shielding is the main reason for lightning tripping of UHV lines. It is believed that special attention should be paid to the shielding problem of mountainous lines with large ground inclination angles. It is suggested to reduce the protection angle of the ground wire to reduce the shielding trip rate. It is proposed that the ground protrusions within 38m on both sides of the line will cause lightning strikes. The published literature puts forward the shielding analysis model for pilot development, and the calculation results are basically consistent with the actual operation of the 1000kV double-circuit line in Japan; while the results obtained by us...

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Problems solved by technology

[0004] Patent Document 2 (a method for improving the lightning protection capability of ultra-high voltage and ultra-high voltage transmission lines, patent number ZL200910061120.1) The upper and middle cross arms are hung with OPGW optical cables or lightning conductors, and the upper, middle and lower cross arms The poles are all hung with I-type suspension strings. Although the OPGW optical cable or lightning conductor of the middle cross-arm has strengthened the anti-circling lightning of the upper and middle phase conductors; The safety distance, but the central safety distance in the gear cannot meet the requirements of the design specifications, and there is no obvious change to the protection angle of the lower phase conductor

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