Overvoltage protection gap with corona stable trigger structure

Abstract

An overvoltage protection gap with a corona stable trigger mechanism comprises an upper insulation shell, a lower insulation shell, a cavity formed by an upper end flange and a lower end flange, a main discharge gap formed by an upper circular truncated cone electrode and a lower circular truncated cone electrode is arranged in the cavity, an annular third electrode is installed around the upper circular truncated cone electrode and the lower circular truncated cone electrode between the upper insulation shell and the lower insulation shell, and the annular third electrode is provided with an inclined Z-shaped end face. The annular third electrode is provided with two end faces corresponding to the side plane of the upper circular truncated cone electrode and the lower circular truncated cone electrode respectively. Under the action of lightning overvoltage, the pulse voltage between the annular third electrode and the lower electrode greatly exceeds the pulse voltage between the annular trigger electrode and the upper electrode, field breakdown occurs between the annular third electrode and the lower electrode, and conductive carriers are generated in the gap between the upper electrode and the lower electrode. The pulse breakdown voltage of the overvoltage protection gap can be reduced, and the voltage protection level of the overvoltage protection gap is improved.

Description

technical field [0001] The invention relates to a high-performance overvoltage protection gap in the fields of electric power, electronics and communication, high-speed information railway power transmission, etc., in particular to a trigger type overvoltage protection gap with a very simple structure. Background technique [0002] High-performance overvoltage protection gaps are key overvoltage protection devices in the fields of electric power, electronics and communications, high-speed information railways, etc. Most of the active overvoltage protection gaps used for overvoltage protection at home and abroad adopt field triggering or field distortion triggering , so that the voltage protection level of the active overvoltage protection gap is generally not too high, and the voltage ratio between the pulse breakdown voltage and the DC breakdown voltage is generally greater than 1, in the range of 1.1 to 1.5 or even greater. Invention patent ZL 2006 10104775.9 discloses an ...

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Problems solved by technology

Invention patent ZL 2006 10104775.9 discloses an overvoltage protection device with surface flashover in an air environment. A flashover rod is installed in the groove. When lightning overvoltage occurs, the main electrode of the overvoltage protection gap discharges the energy of the lightning current through the flashover rod along the surface, but at the same time it also causes surface pollution and consumption of the flashover rod along the surface, thus As a result, the service life of the overvoltage protection gap is affected. More importantly, the existence of flashover rods along the surface cannot reduce the voltage ratio of the overvoltage protection gap, and the pulse breakdown voltage of the overvoltage protection gap is reduced and the voltage protection level is improved. At the same time, the DC breakdown voltage of the overvoltage protection gap is also reduced, and the safety of normal operation is reduced. Therefore, the performance improvement of the overvoltage protection gap is limited

However, they have a common feature that they all need a coupling trigger circuit that couples lightning energy, and the circuit parameters of the coupling circuit need to be selected. For engineering applications, especially when the requirements for overvoltage protection are not very strict, this kind of The active protection gap of the structure will cause a certain degree of complexity, resulting in an increase in the difficulty of engineering applications and a waste of investment in some occasions without strict overvoltage protection requirements

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