Multifunctional combined secondary cable lightening protection and equipotential protection method and device

Abstract

The invention discloses a multifunctional combined secondary cable lightening protection and equipotential protection method and a multifunctional combined secondary cable lightening protection and equipotential protection device. The device consists of an enclosed pipeline consisting of an upper metal shielding material and a lower metal shielding material, flanges, horizontal connecting bolts and nuts, vertical connecting bolts and nuts, equipotential connection grounding and a ratproof fireproof blocking layer, and has functions of preventing lightning current spark from passing through a secondary cable, preventing inductive thunder overvoltage, preventing rats and fire, equipotential connection and the like. The protection device can be vertically disassembled in sections, and is convenient to expand and maintain. The invention has the advantages of good lightening shielding effect, simple structure, wide application range, safety and reliability.

Description

Technical field [0001] The present invention mainly relates to the field of secondary cable protection, and particularly refers to a method and device that can protect secondary cables from spark discharge caused by thunder and lightning, induced overvoltage, equipotential connection, and rodent and fire prevention protection. Background technique [0002] When the lightning current enters the ground through the ground lead of lightning protection equipment such as lightning rods, lightning conductors or lightning arresters, spark breakdown will occur at the entry point. If there are secondary cables for control, protection or communication nearby, the lightning current will enter the ground The spark discharge generated at the time will burn through the secondary cable, or cause lightning interference to the secondary cable; when there is lightning activity above the secondary cable such as control, protection or communication, it will produce an induced lightning overvoltage on ...

AI Technical Summary

Problems solved by technology

[0002] When the lightning current enters the ground through the grounding down conductor of the lightning protection equipment such as lightning rod, lightning conductor or lightning arrester, spark breakdown will occur at the entry point. If there are secondary cables such as control, protection or communication nearby, the lightning current will enter the ground. The spark discharge generated during the operation will pass through and burn the secondary cable, or cause lightning interference to the secondary cable; when there is lightning activity above the secondary cable such as control, protection or communication, an induced lightning overvoltage will be generated on the secondary cable, resulting in The induced lightning overvoltage invades the control, protection or communication unit along the cable line, which will cause these system dysfunction or equipment damage. Although the secondary cables such as control, protection or communication have a mesh metal shielding layer, this metal shielding layer There are still loopholes in the shielding effect of lightning, and induced overvoltage will still be generated, especially the lightning current and spark passing through the cable cannot be effectively protected; when power frequency short-circuit current or lightning current enters the ground in power plants and substations, it will cause grounding network When the local potential rises, the potential difference of the ground network will be coupled into the secondary circuit through differential mode interference or common mode interference, forming ground potential interference

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