Lightning protection device in multilevel clearance series connection

Abstract

The invention discloses a lightning protection device in multilevel clearance series connection. The lightning protection device in multilevel clearance series connection includes a high-voltage wireinlet end, a grounding end, a metal oxide arrester (MOA), N voltage partition capacitors, N voltage partition inductors in series connection, N-1 loop voltage partition inductors and N discharging gaps at equal intervals. Since a multilevel clearance series connection structure is adopted, the lightning protection device can be resistant to high working-frequency voltage, and a breakdown voltage value of the lightning protection device under the working-frequency voltage is extremely higher than a breakdown voltage value under lightning impulse voltage. After clearances in multilevel series connection are broken down, the metal oxide arrester starts to work, wherein the metal oxide arrester (MOA) has the characteristics of generating no continuous current under work frequency. The lightning protection device has the advantages that not only is the breakdown voltage value of the lightning protection device under the working-frequency voltage extremely higher than the breakdown voltage value under the lightning impulse voltage, but also the lightning protection device is high in work reliability, free of continuous current under the working frequency and long in service life.

Description

technical field [0001] The invention relates to the technical field of electric power equipment, in particular to a lightning protection device connected in series with multi-level gaps. Background technique [0002] In the AC power system, lightning protection mainly uses lightning arresters for lightning protection. With the increase of transmission lines, the line trip accidents caused by lightning strikes are increasing day by day. Therefore, in order to reduce the line trip rate, under the premise of ensuring the protection performance, higher requirements are put forward for the long-term operation reliability of the arrester itself. [0003] At present, the arresters mainly used for line lightning protection have two structures: non-gap metal oxide arresters and single air gap series metal oxide arresters. For the gapless metal oxide arrester, it works under high power frequency overvoltage for a long time, and it is easy to be damaged or exploded due to the limited ...

AI Technical Summary

Problems solved by technology

For gapless metal oxide surge arresters, which work under high power frequency overvoltage for a long time, they are prone to damage or explosion due to limited flow capacity; for single air gap series metal oxide surge arresters, although there is a single gap isolation , the arrester body only works when lightning strikes, prolonging the service life of the arrester, but the discharge dispersion of a single air gap is large, and the reliability of the arrester cannot be guaranteed

And for the above two current lightning protection methods, their breakdown voltage values ​​under the lightning impulse voltage are greater than their breakdown voltage values ​​under the power frequency voltage, that is, before the lightning protection device operates, the AC system needs to withstand Higher lightning impulse voltage peak value is detrimental to the normal operation of the AC system. In order to better protect the normal operation of the AC system, the lightning protection device should be able to operate and protect the AC system at a lower lightning voltage

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