Vacuum lightning protection gap device based on hollow cathode effect

Abstract

The invention discloses a vacuum lightning protection gap device based on a hollow cathode effect, comprising a vacuum gap unit and a voltage division loop unit. The vacuum gap unit is of a three-electrode structure, wherein the anode and the cathode of a main gap are of a cavity structure with a hole in the center, a pre-ionization electrode is of a needle structure, and the pre-ionization electrode is arranged inside the cathode and forms a pre-ionization gap with the cathode. The voltage division loop unit is composed of a resistor and a capacitor which are connected in parallel between the main gap and the pre-ionization electrode. Compared with the existing air jet arcing lightning protection gap technology, the advantages of the device are that power-frequency follow current can be cut off in a timely and reliable manner, the device can be reused and has a long service life, and the device is convenient to produce and low in cost of maintenance. Moreover, the device is externally provided with external insulation protection, and can work safely and reliably.

Description

technical field [0001] The invention relates to the technical field of lightning protection devices for power systems, in particular to a novel vacuum lightning protection gap device based on the hollow cathode effect. Background technique [0002] At present, lightning protection of transmission lines is one of the important guarantees for the stable operation of power systems. The overvoltage generated during lightning strikes may cause flashover of power equipment, and then generate power frequency freewheeling, seriously endangering the safety of power equipment and the stable operation of the power grid. Therefore, the power sector generally adopts parallel lightning protection gaps on transmission lines or power equipment to achieve protection effects. The existing lightning arresters adopt a variety of different technical routes. Although the commonly used lightning protection gaps and line arresters with airflow injection are widely used, there are still many obviou...

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Problems solved by technology

[0003] 1. Most of the existing lightning protection gap devices with air jets are complex in structure, large in size, high in use and maintenance costs, and prone to damage and failure

Moreover, the service life is short, limited by the number of gas pills used for arc extinguishing, it can only work several times or even once, and needs to be replaced frequently

[0004] 2. Although the existing line arrester is cheap and has a strong ability to suppress overvoltage, it may not be able to disengage automatically when a fault occurs, endangering the safety of the power system. Disposable

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