Design of Defect Identification and Location System for UHV AC Surge Arrester

Abstract

Ultra high voltage (UHV) metal oxide arrester (MOA) is prone to problems such as resistance sheet aging and moisture exposure during long-term operation. Due to the larger size and more complex structure of the UHV arrester, the full current, resistive current and internal and external temperature change rates of the main body are smaller than that of the 500 kV arrester after defects. The objective of this paper is to simulate the working conditions of 1000 kV UHV AC surge arrester with defects in different sections. And the tests proved that the existing surge arrester live detection and online monitoring methods are difficult to judge the operation status of UHV surge arrester. Based on the experimental findings, humidity levels exceeding 70% indicate that the lightning arrester is damp. Additionally, when the current reading surpasses twice the standard’s required normal value, and the humidity remains within acceptable limits, it suggests that there is an aging issue with the resistor in the lightning arrester’s current path. A method of judging the type of defects by using the leakage current inside the arrester and the change of temperature and humidity is proposed a wireless sensor that can be placed in the arrester for a long time can be designed to accurately detect the defect and locate the defect node. The measurement error for the full current is not exceed 1%. It is given by theoretical analysis and experiment. The judgment basis of the internal defect type and fault warning, the test shows that the arrester defect identification and positioning system meets the accuracy requirements of the arrester state assessment.

Keywords

• UHV
• AC surge arrester
• defect identification
• current supply
• wireless communication