Method and device for suppressing overvoltage of iron tower head when lightning strike of transmission line

Abstract

The invention relates to the technical field of high voltage lightning protection for power engineering transmission line, especially to a method and device for suppressing overvoltage of an iron tower head when lightning strike of a transmission line. The method comprises the following steps of: setting a coaxial overhead cable according to a magnitude of a wave impedance value of an overhead lightning protection line; designing a low-impedance coaxial cable down conductor; and connecting and installing the coaxial overhead cable, the coaxial cable down conductor and a ground lightning arrester to the iron tower, and connecting the ground lightning arrester to a grounding grid. The occurrence of tripping accidents and counterattacks during lightning strikes can be reduced.

Description

technical field [0001] The invention relates to the technical field of high-voltage lightning protection for electric power transmission lines, in particular to a method and a device for suppressing overvoltage at the head of an iron tower when a transmission line is struck by lightning. Background technique [0002] In recent years, due to the increasing lightning activity, the accidents caused by lightning strikes on the line are increasing, which poses a serious threat to the safe operation of the line and seriously affects the power supply reliability of the transmission line. At present, the lightning protection measures of the transmission line itself mainly rely on the overhead ground wire erected on the top of the iron tower. The operation and maintenance work is mainly to detect and modify the grounding resistance of the iron tower. Due to the singleness of its lightning protection measures, it cannot meet the lightning protection requirements. Due to the high light...

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Problems solved by technology

[0017] Therefore, when the lightning strikes the line and strikes back, as the potential of the tower top increases, the voltage borne by the insulator also gradually increases. When the voltage exceeds the insulation flashover voltage of the iron tower, the insulator is likely to undergo surface flashover or even breakdown, that is, when Lightning strikes on the top of the iron tower often cause extremely high voltage counterattack accidents. To solve the counterattack problem, it is necessary to reduce the potential Utop of the top of the tower pole. Large ground network area), line installation coupling ground wire and other schemes, but the effect is very poor

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