Earthing mode of optical fiber compound overhead ground wire and earthing pilot arc clearance

Abstract

The invention relates to a grounding method and grounded arc gap of Optical fiber composite overhead ground wire (OPGW), which is characterized in that: a grounded arc gap is arranged between OPGW and each pole tower; while in normal operation, OPGW is insulated from the whole line, and when a transient high voltage arises on the OPGW due to lightening strike or failures of the line, the OPGW can be electrically switched into conduction and grounded. Each grounded arc gap comprises a composite insulating bar, and a plurality of electrodes arranged at both ends of a plurality of hardware fittings; wherein, the gap between the electrodes can be adjusted according to voltage level of the power transmission line. The discharging guided by the electrodes at both ends of the hardware fittings are conducted between the arc gaps, the arc root of the electric arc is restricted at the ends of the electrodes, so as to prevent the high temperature at the arc root from burning out a single wire of the OPGW. The invention has the advantages of preventing reflows among the ground wire, pole towers and the earth during normal operations, greatly reducing the electric energy loss on transmission lines, lessening the probability of lightening strikes on the OPGW, and guarding against strand breakage of the OPGW due to electric arcs and communication interruption.

Description

technical field [0001] The invention belongs to the field of high-voltage transmission lines, and relates to a grounding method for an optical fiber composite overhead ground wire and a grounding arc gap device. Wire. Background technique [0002] At present, the OPGW grounding method is adopted in high-voltage power transmission line projects at home and abroad. Related technologies and specific design methods can be found in the "Design Manual for Power Engineering High-Voltage Power Transmission Lines" edited by Zhang Diansheng, published by China Electric Power Publishing House, but this grounding method is likely to cause large circulation losses. (5~10)×10 4 kWh / 100km·year, the ground wire loss of 500kV line is about 500×10 4 kilowatt-hour / 100 km / year. Since the higher the voltage level, the greater the power loss will be. For the AC UHV 1000kV line under construction and the 750kV line of the Northwest Power Grid, the power loss caused by base-by-base grounding of...

AI Technical Summary

Problems solved by technology

If the full insulation method is used, although the problem of circulating energy consumption is solved, when a lightning strike to the OPGW or a line fault causes a transient high voltage on the OPGW, a discharge arc may be formed between the OPGW and the grounding piece, and the arc root may cause OPGW stock cut and communication cut off

In addition, sometimes under normal working conditions, if the electrostatic induction voltage is high and the air gap between the OPGW and the grounding piece is too small, intermittent discharge sparks will also be formed, which will cause the OPGW to break after a long time

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