High voltage lightning arrester upper segment leakage current testing device and testing method

Abstract

The invention discloses a high voltage lightning arrester upper segment leakage current testing device and testing method. The device comprises an interception umbrella and a leakage current testing assembly, wherein the interception umbrella is electrically connected with the leakage current testing assembly, the leakage current testing assembly, the interception umbrella is connected with a high voltage lightning arrester in a detachable manner, the interception umbrella is arranged between a middle segment flange and a grading ring of the high voltage lightning arrester, the middle segment flange is positioned at a minimum distance from an upper segment of the high voltage lightning arrester, and the interception umbrella is arranged on an insulating sleeve of the high voltage lightning arrester; when the high voltage lightning arrester upper segment leakage current testing device is used, the interception umbrella is mounted on the insulating sleeve of the upper segment of the high voltage lightning arrester, a current formed on the interception umbrella via stray capacitance caused by the grading ring can be measured, a numeric value of the current equals a numeric value of an interference current in the lightning arrester, the numeric value of the current is subtracted from measurement data when the measurement data is processed, accurate data of a leakage current can be obtained, the high voltage lightning arrester upper segment leakage current testing device is convenient to use because the interception umbrella is connected with the high voltage lightning arrester in a detachable manner, and measurement workloads are reduced.

Description

technical field [0001] The invention relates to the field of leakage current testing, in particular to a leakage current testing device and a testing method for an upper section of a high-voltage arrester. Background technique [0002] The high-voltage surge arrester is connected between the cable and the earth, and is usually connected in parallel with the protected equipment. The core component of the high-voltage surge arrester is a varistor, which has a nonlinear volt-ampere curve characteristic. Under normal operating voltage, the resistance of the varistor is very large, and the current passing through the varistor is only a few hundred microamperes. When the excessive voltage invades, the varistor is approximately short-circuited, so that the overvoltage is quickly introduced to the ground through the grounding wire, and at the same time the amplitude of the system voltage is limited, and then the varistor quickly returns to the high-resistance state to protect the eq...

AI Technical Summary

Problems solved by technology

The insulation of the high-voltage arrester is mainly determined by the value of the leakage current of the high-voltage arrester. The high-voltage arrester is generally equipped with a voltage equalizing ring on the upper section, but due to the short distance between the voltage equalizing ring and the upper section of the high-voltage arrester, there will be stray capacitance. An interference current is formed in the upper circuit of the arrester. During the experiment, the interference current caused by the equalizing ring is measured together with the leakage current of the upper segment, resulting in a relatively large current in the upper segment during on-site measurement, which makes it difficult to accurately reflect the insulation of the high-voltage arrester. The main measures to avoid the interference of the equalizing ring are: 1. Remove the equalizing ring during the test. This method requires a lot of work, requires special equipment and has certain risks; 2. Shielding. The high-voltage shielding effect is not good, and the low-voltage shielding cannot be realized. ; 3. Artificial estimation, the environment of the high voltage arrester is different, and the estimation error is large

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