Metal oxide arrester overvoltage detection method and system based on three-stage voltage division

Abstract

The invention discloses a metal oxide arrester overvoltage detection method and system based on three-stage voltage division. A three-stage voltage division module, a signal processing module, a triggering and collecting module and a data comparison module are used for detecting an arrester overvoltage signal and evaluating the state of the arrester overvoltage signal. The method comprises the following steps: carrying out primary voltage division with a small voltage division ratio by utilizing a valve plate of the metal oxide arrester to obtain a high-voltage signal U1; inputting U1 obtainedthrough primary voltage division is input into a capacitive voltage divider through a built-in lead to be subjected to secondary voltage division, and obtaining a low-voltage signal U2; after voltagedivision, inputting the U2 to a trigger and signal processing circuit through a coaxial cable for three times of voltage division, impedance matching and signal filtering, and finally obtaining a transient overvoltage signal U3 of the lightning arrester; and matching the acquired U3 with residual voltage characteristic parameters of the lightning arresters in different states, and evaluating anddetermining the insulation state of the tested metal oxide lightning arrester. The detection and evaluation result of the invention has high accuracy and reliability, and is easy to popularize and apply.

Description

technical field [0001] The invention relates to the technical field of surge arrester overvoltage detection and state evaluation, in particular to a method and system for detecting overvoltage of a metal oxide arrester based on three-stage voltage division. Background technique [0002] The safe operation of the power grid is the basis for ensuring a stable and reliable power supply. The collapse of the power grid and large-scale power outages will not only cause huge economic losses and affect people's normal life, but also endanger public safety and cause serious social losses. According to the national grid operation analysis report, from 2005 to 2010, power grid outage accidents caused by power transmission and transformation equipment failures in my country accounted for 37% to 48% of the total accidents in that year, ranking first in the cause of failure. The overvoltage signal has a huge impact on the safe operation of the power grid. How to correctly analyze the cau...

AI Technical Summary

Problems solved by technology

[0004] Overvoltage monitoring methods and devices at home and abroad are mainly focused on the monitoring of internal overvoltage, and there are few monitoring devices for lightning overvoltage, and most of them are expensive

The surge of lightning overvoltage is steep, which requires a higher sampling frequency and frequency response; at the same time, arresters in different states have different transient residual voltage parameters, and it is difficult to determine the latent fault of the arrester, and often such latent faults eventually develop into Weak points in insulation lead to failure

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