Lightning arrester performance parameter detecting device

Abstract

The invention discloses a lightning arrester performance parameter detecting device which comprises a current monitor which is used for carrying out collection and harmonic analysis compensation calculation on the resistive current and capacitive current of an MOA lightning arrester and outputting a calculated value to a current monitor of an MOA lightning arrester state online monitoring centralized control terminal, the MOA lightning arrester state online monitoring centralized control terminal used for transmitting a monitored value to a computer after data processing, and the computer used for checking and controlling a current monitor of the MOA lightning arrester remotely, wherein the MOA lightning arrester is connected with a plurality of current monitors which are connected with the MOA lightning arrester state online monitoring centralized control terminal, and the MOA lightning arrester state online monitoring centralized control terminal is connected to the computer. According to the lightning arrester performance parameter detecting device, by means of the triple harmonic analysis method and the unique compensation calculation technique, the change of the resistive current and the capacitive current is calculated to judge the early-stage fault of the MOA lightning arrester, real-time central monitoring of all MOA lightning arresters in a transformer substation is achieved, the operation is simple, safety and reliability are achieved, and cost performance is high.

Description

technical field [0001] The invention relates to a detection device for a lightning arrester in a power system, in particular to a detection device for a performance parameter of a lightning arrester. Background technique [0002] The detection device for parameters such as arrester current is mainly used for online monitoring of arresters in substations, and the installation method adopts the traditional counter installation method. [0003] At present, there are mainly the following methods for arrester monitoring at home and abroad: [0004] 1. On-line monitoring of arresters based on optical fiber transmission [0005] Its working principle converts the full current (leakage current) measured by the arrester with a monitor into an optical pulse signal, which is transmitted by optical fiber and then transformed into a 485 bus by a photoelectric converter to realize the remote transmission function. Its working process is MOA arrester The full current of the capacitor cha...

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Problems solved by technology

[0006] This method does solve the problem of remote data transmission, but there are many problems in the practical process, and some of them cannot work normally after less than half a year of installation

[0007] (1) In the voltage-frequency circuit, the capacitance value of the capacitor is very unstable due to the change of the ambient temperature. After testing, the detected current display value and the remote signal are very unstable when the ambient temperature is below 5 degrees or above 30 degrees. When the ambient temperature is below zero, the detection current display value and remote transmission cannot work. The photodiode initial current in the voltage-frequency circuit has a large dispersion, resulting in instability of measurement results and remote transmission signals;

[0008] (2) The optical fiber is easily affected by external factors, such as: the wind causes the beam of the optical fiber connector to deviate from the original position, causing the system to be intermittent; the outer skin of the optical fiber cannot resist ultraviolet rays in the sun for a long time, and the aging of the outer skin of the optical fiber appears locally Receiving external light after the crack point causes abnormal transmission

[0009] (3) The optical interface on the monitor leaks more seriously and the photoelectric converter also has poor sealing, which cannot meet the waterproof level requirements

[0017] Although the isolation transformer is used for sampling, there will still be a hidden danger to the power grid. In case of a short circuit caused by signal sampling, the PT will be abnormal. With the continuous implementation of the smart grid, the PT is also required to be intelligent and adopt digital transmission. It is no longer possible to take the voltage signal from the PT

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