A fully sealed electromagnetic shielding impedance box

Abstract

The invention relates to a novel full-sealed electromagnetic shielding impedance box. The novel full-sealed electromagnetic shielding impedance box comprises a box body and a foundation, wherein the outer side of the foundation is respectively provided with a grounding end, a foundation outer side measurement end coaxial cable jack and a foundation outer side signal end coaxial cable jack in a circumference direction, the box body comprises an electric field shielding cover and a magnetic field shielding cover which are sleeved with an interval, the electric field shielding cover is arranged at the outer side of the magnetic field shielding cover, intervals are arranged between the top portion and circumference of the magnetic field shielding cover and the electric field shielding cover, and bottom portions of the electric field shielding cover and the magnetic field shielding cover are respectively provided with an opening. The method is more applicable to AC high voltage signal measurement in complex on-site test environments and can realize long-time measurement without influence of external factors such as, an electromagnetic environment, rain, snow, dust storm, on-site wiring and disposing position.

Description

technical field [0001] The invention relates to the field of test devices for measuring AC high-voltage signals, in particular to a test device for measuring AC high-voltage signals for substation system debugging. Background technique [0002] At present, the high-voltage signal measurement generally adopts a complete set of resistive voltage divider, capacitive voltage divider or resistive-capacitive voltage divider device manufactured by the manufacturer. Practical experience shows that resistive voltage dividers have high requirements for the quality of resistive components. Even if a surface discharge occurs on the resistive film of the components, the overall resistance or failure of the resistive voltage divider will result in poor long-term stability and high manufacturing costs. And the higher the voltage level is, the worse the response characteristics are, and it is rarely used now; for the capacitive voltage divider, it basically does not consume the AC active po...

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Problems solved by technology

[0003] In addition, according to the actual needs of on-site measurement, sometimes it is necessary to take voltage signals from the end screens of multiple transformer bushings, the end of capacitive voltage transformers, multiple lines or the first ends of multiple dry-type shunt reactors, which cannot be used in many cases. A complete set of voltage divider measuring devices is used for measurement. Therefore, many scientific and technological testing institutions mostly use self-designed and custom-made suitable impedance boxes to form a measurement circuit with the test product. signal measurement

Generally, the custom-made impedance box adopts a single-layer design, and the sealing performance is poor. It is greatly affected by the surrounding electromagnetic field environmental factors and weather factors. It is not suitable for long-term signal acquisition. It is not easy to place due to the influence of wiring and geographical environment during measurement. The reliability is poor, which is not conducive to the promotion and use in the power system

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