Online monitoring device and monitoring method for metallic oxide arrester

Abstract

The invention discloses an online monitoring device and a monitoring method for a metallic oxide arrester. The device comprises a main control chip, a data acquisition module for acquiring leakage current signals and voltage signals, a background algorithm processing module for receiving the data of the data acquisition module, calculating the value of a resistive current and transmitting the value to the main control chip, and a man-machine interaction assembly in interactive connection with the main control chip. The data acquisition module comprises a voltage and current measuring module for measuring the voltage at the two ends of the metal oxide arrester and the leakage current of the metal oxide arrester, a filtering module for receiving the signal of the voltage and current measuring module and performing the filtering treatment, and a conversion module for receiving the signal of the filtering module and performing the AD conversion. Based on the online monitoring device and the monitoring method for the metallic oxide arrester, the influence of harmonic waves in the voltage on the resistive current extraction is fully considered. Meanwhile, the interference caused by the harmonic voltage on the resistive current extraction can be well reduced. Moreover, the efficiency and the accuracy of online monitoring are improved.

Description

technical field [0001] The invention relates to the technical field of electrical equipment testing, in particular to an online monitoring device and a monitoring method for a metal oxide arrester. Background technique [0002] Metal Oxide Arrester (MOA) has excellent characteristics such as good nonlinear characteristics, large flow rate, and excellent protection performance. It is the main device for relay protection in power systems. The long-term online work of MOA is affected by factors such as thermal damage, transient state, harmonic overvoltage impact, and internal moisture, which accelerates the aging and deterioration of the metal oxide arrester arrester, resulting in damage to the arrester, and eventually the arrester loses its protective effect. Therefore, monitoring the surge arresters in operation is an important guarantee for the safe and reliable operation of the power system. Many research results at home and abroad point out that the leakage current will i...

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Problems solved by technology

[0003] The classical capacitive current compensation method cannot remove the harmonic component in the capacitive current, and such harmonic component will be mixed into the resistive current, which will cause an error in the resistive current of the algorithm, thereby affecting the extraction accuracy of the resistive current, which is easy to Causes misjudgment of the state of the metal oxide arrester

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