Vacuum switchgear

Abstract

The invention relates to a vacuum switch device, which reduces the cost and improves the reliability by simplifying the signal processing circuit of the vacuum pressure diagnosis device. The vacuum switching device is composed of a floating potential metal container (12), two insulating sleeves, and a pair of electrodes capable of contacting and separating. The measuring terminal (50) for vacuum pressure diagnosis is arranged opposite to the metal container (12). The metal container (12) and the measuring terminal (50) are casted by an insulator (20) such as epoxy, and the outer periphery of the insulator (20) is The portion is provided with a grounded conductive coating (21). Through the grounded conductive coating (21), the ground capacity of the metal container (12) is increased, so the potential of the metal container (12) during operation is close to the ground potential. When the vacuum pressure deteriorates, if a discharge occurs between the main circuit and the metal container (12), the potential of the metal container (12) is equal to the system potential, so it can be detected based on the potential rise of the system frequency occurring on the metal container (12). Deterioration of vacuum pressure.

Description

technical field [0001] The present invention relates to a vacuum switchgear, and more particularly to a vacuum switchgear equipped with a function of diagnosing vacuum pressure tightness during normal operation. Background technique [0002] The electrical resistance performance and shutoff performance of the vacuum switchgear depend on the pressure (vacuum pressure) inside the vacuum vessel. FIG. 9 is a so-called Paschen curve showing discharge characteristics in vacuum, showing the correlation between the product of pressure and distance and discharge voltage. As shown in the figure, when the vacuum pressure rises above a certain value, the insulation performance drops sharply. In the vacuum switchgear, in addition to breakage failures, there may be deterioration of the vacuum pressure due to long-term leakage of the gas medium, so periodic inspections are required. [0003] Generally, the way to detect vacuum pressure tightness is to take the vacuum switchgear out of th...

AI Technical Summary

Problems solved by technology

[0004] However, when using this diagnostic method, since the discharge pulse used for diagnosis is a high-frequency signal, the detection circuit is complicated, and because a discrimination function for distinguishing electrical noise from the surrounding environment is required, the cost has to be increased objectively.

[0005] In the above-mentioned prior art, because high-frequency discharge pulses are used to diagnose vacuum pressure, it is necessary to additionally have complex signal processing functions and circuits such as a pulse detection circuit and a function of distinguishing external noise.

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