Arrester deterioration protection device

Abstract

A lightning arrester degradation protection device, which relates to the technical field of lightning arresters. The upper end of the lightning arrester degradation protection device is connected to the lightning arrester, and the lower end is connected to the grounding copper bar. It includes a compensation impedance element, an increasing resistance switch and a control unit. The compensation impedance element One end is connected to the low-voltage end of the arrester, the compensation impedance element is connected in parallel with the resistance increasing switch and then grounded, the circuit after the compensation impedance element and the resistance increasing switch is connected in parallel is connected in series with the control unit through the magnetic flux sensor, and the described The control unit controls the connection of the increasing resistance switch. During normal operation, the increasing resistance switch is closed and the compensation impedance element is short-circuited, which is equivalent to directly grounding the ground terminal of the arrester. When the control unit detects that the leakage current of the arrester exceeds the limit value, it sends an opening command to drive the The resistance switch is disconnected, and the compensation impedance element is connected in series to the arrester circuit to achieve the purpose of reducing the leakage current.

Description

technical field [0001] The invention relates to the technical field of lightning arresters, in particular to a degradation protection device for lightning arresters. Background technique [0002] Surge arrester is a system overvoltage protection device commonly used in power grid operation. It is responsible for limiting various overvoltages in the system caused by lightning strikes, harmonics and operations, etc., and plays a vital role. However, the operation safety of the zinc oxide arrester itself is often ignored. With the accumulation of overvoltage impact energy, its performance will gradually deteriorate, mainly manifested in the increase of leakage current. The process is relatively slow and has a certain degree of concealment. If it is not discovered in time, breakdown failure is very likely to occur. Although the value of the lightning arrester body is not high, once an explosion accident occurs, it will generally cause a power outage in the system, and the produ...

AI Technical Summary

Problems solved by technology

However, the operation safety of the zinc oxide arrester itself is often ignored. With the accumulation of overvoltage impact energy, its performance will gradually deteriorate, mainly manifested in the increase of leakage current. The process is relatively slow and has a certain degree of concealment. If it is not discovered in time, breakdown failure is very likely to occur

Although the value of the lightning arrester body is not high, once an explosion accident occurs, it will generally cause a power outage in the system, and production will be forced to stop, causing indirect losses that are often immeasurable

[0003] At present, the methods to solve the problem of arrester degradation and explosion generally use wired monitors, thermal fusion or thermal explosion releases, but they all have certain limitations in operation practice: first, thermal fusion releases It is difficult to control the inverse time curve of the thermal-explosive tripping device, and sometimes the action of thermal-melt tripping and the explosion of the arrester occur at the same time; second, the thermal-explosive tripping device is not suitable for use in the switch cabinet, and requires a relatively large site space; third, the online detector It is only to provide monitoring results. If the phenomenon exceeds the standard, it will face the contradiction between "timely power outage replacement" and "continuous production", especially when the arrester is located in a remote area with inconvenient maintenance such as an unattended substation, and the replacement is not timely, making the system In the state of running with faults and defects, the meaning of online detection has been lost to a certain extent

Furthermore, even if the thermal fuse or thermal explosion release can safely disengage the deteriorated arrester from the system, it loses the function of protecting the system.

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