JPH0538008A - Detecting device for ground fault of gas-insulated switchgear - Google Patents

Abstract

PURPOSE:To perform work of maintenance inspection for an arc light receiving part without withdrawing insulation gas in a closed vessel. CONSTITUTION:A gas valve 6 is connected to a closed vessel 2 filled with insulation gas 1, and an arc light receiving part 3 for detecting arc light 5 generated by grounding 4, is provided in an opposite closed vessel side of the gas valve 6 and connected to a photoelectric conversion device 8 through an optical fiber 7. The arc light 5, passing through the gas valve 6 by reflecting parts formed in an internal wall surface of the closed vessel 2 and an external surface of a conductor 18, is detected by the arc light receiving part 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ground fault accident detection device for a gas insulated switchgear, and more particularly to a ground fault accident detection device for detecting arc light generated during a ground fault accident.

[0002]

2. Description of the Related Art Generally, a gas-insulated switchgear is constructed by forming a plurality of gas compartments by an insulating spacer in a metal container filled with an insulating gas, and accommodating an electric device in each gas compartment. When a ground fault occurs in a closed container, it is not possible to easily know in which gas compartment it occurred by visual inspection. Therefore, paying attention to the fact that each gas compartment is equipped with a pressure detector that monitors the filling pressure of the insulating gas, etc. Attempts have been made, but it was not possible to accurately detect a ground fault because the pressure rise differs depending on the breaking current. On the other hand, Japanese Patent Laid-Open No. 56-29423 proposes a ground fault accident detection device that detects arc light when a ground fault occurs in each gas section.

[0003]

The conventional ground fault detection device in the gas-insulated switchgear has been able to improve the accuracy of ground fault detection by monitoring the arc light as described above, but it is hermetically sealed. Since the inspection window was formed in the container and the arc light receiving part was attached to the back side of the lid plate that hermetically seals it, the lid plate must be removed in order to inspect or replace the arc light receiving part. In each case, the operation of the apparatus had to be stopped and the insulating gas in the closed container had to be collected before the operation.

An object of the present invention is to provide a ground fault accident detection device for a gas insulated switchgear capable of performing maintenance and inspection of the arc light receiving portion without recovering the insulating gas in the closed container.

[0005]

In order to achieve the above-mentioned object, the present invention is to connect an end of a gas valve to an airtight container filled with an insulating gas and to detect an arc light at the other end of the gas valve. It is characterized in that a light receiving portion is provided.

[0006]

Since the ground fault detection device for the gas insulated switchgear according to the present invention has the above-described structure, the insulating gas in the closed container is recovered by closing the gas valve when inspecting the arc light receiving portion. It can be carried out by gas-separating the arc light receiving part from the closed container without using any gas valve.If this gas valve is attached to the closed container for each gas compartment and used for filling the insulating gas, , An arc light receiving part is provided on the side opposite to the closed container of this gas valve, and arc light is generated due to a ground fault, and this arc light is detected by the arc light receiving part through the gas valve. According to experiments by the inventor, accurate detection could be performed even using the above-mentioned ordinary gas valve.

[0007]

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a vertical sectional front view showing a main part of a ground fault accident detection device for a gas insulated switchgear according to an embodiment of the present invention. The closed container 2 forming one gas compartment is hermetically sealed at its ends by insulating spacers 17A and 17B, and is filled with the insulating gas 1. Insulating spacers 17A, 17
The opposite sides of the central conductor of B are connected by a conductor 18 forming a main circuit, and the opposite side is connected to another device having the same structure. One end of a gas valve 6 for filling the insulating gas 1 is connected to the closed container 2, and an arc light receiving portion 3 is provided on the other end side of the gas valve 6. The arc light receiving portion 3 is connected to the photoelectric conversion device 8 via the optical fiber 7, and the optical signal detected by the arc light receiving portion 3 is converted into an electric signal by the photoelectric conversion device 8 and output.

FIG. 2 is an enlarged view of the gas valve 6, in which a series of flow holes 11 can be sealed by a valve body 10 by operating a handle 9. The flow hole 11 has a bent shape as shown in the figure. However, in the case of a dedicated gas valve for detecting arc light, the flow hole 11 should be formed as linear as possible, and the flow hole including the existing reflecting surface 12 should be formed. The inner wall surface forming the hole 11 is preferably mirror-finished.

Now, when a ground fault 4 occurs in the closed container 2, an arc light 5 is generated, and this arc light 5 is introduced into the gas valve 6 by reflection as shown by an arrow on the inner wall surface of the closed container 2. Is detected by the arc light receiving unit 6. Even if the gas valve 6 is normally used, the arc light 5 reaches the arc light receiving portion 3 through the flow hole 11 in FIG. 2 and is accurately detected. This optical signal is transmitted to the photoelectric conversion device 8 via the optical fiber 7 and outputs the occurrence of a ground fault as an electric signal.

When the arc light receiving portion 3 is to be inspected or replaced, the handle 9 of the gas valve 6 is operated to seal the flow hole 11 with the valve element 10, and the arc light receiving portion 3 on the lower end side of the gas valve 6 is closed. Remove and do. At this time, since the inside of the closed container 2 is closed by the gas valve 6,
It is not necessary to collect the insulating gas 1 inside, and it is not necessary to stop the operation of the apparatus each time the arc light receiving portion 3 is inspected, unlike the conventional case.

FIG. 3 is a vertical sectional front view showing a main part of a ground fault accident detecting device of a gas insulated switchgear according to another embodiment of the present invention. The internal structure of the closed container 2 is the same as that of the embodiment shown in FIG. 1, and the closed container 2 includes a gas valve 6 and a gas pipe 1.
A gas pressure monitoring device 14 having one end connected via 5, an arc light receiving portion 3, and a photoelectric conversion device 8 connected to the arc light receiving portion 3 via an optical fiber 7 are provided.

According to this embodiment, the gas pressure can be monitored by the gas pressure monitoring device 14 when the insulating gas is filled in the closed container 2 or thereafter, and the gas pressure in the closed container 2 is raised. The ground fault can be monitored by the arc light receiving unit 3. By constructing the arc light receiving section 3 on the side of the gas valve 6 provided for gas pressure monitoring that is opposite to the closed vessel 2, the gas valve 6 is closed when the arc light receiving section 3 is inspected and maintained. It is possible to perform inspections while maintaining the operating state of the gas valve 6
The configuration can be simplified by also using

In carrying out the present invention, the closed container 2
In the vicinity of the mounting portion of the gas valve 6, for example, the inner wall surface of the closed container 2 on the side facing the gas valve 6 or the outer surface of the conductor 18 on the side facing the gas valve 6 is made into a mirror surface by polishing or polishing, Form a reflection part of the arc light 5 by coating paint, and the arc light 5 is reflected by this reflection part.
To improve the detection accuracy of the arc light receiving portion 3 by reflecting the light to accelerate the entry into the gas valve 6 or by using the entire inner wall surface of the closed container 2 or the entire outer surface of the conductor 18 as a reflecting portion. be able to.

[0014]

As described above, according to the present invention, since the arc light receiving section is provided on the side of the gas valve connected to the closed container opposite to the closed container, the arc light introduced through the gas valve can be detected. The gas valve can be closed to perform maintenance and inspection of the arc light receiving portion, and there is no need to recover the insulating gas or stop the operation of the device as in the conventional case.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view showing a main part of a ground fault accident detection device of a gas insulated switchgear according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view showing an enlarged gas valve, which is a main part of FIG.

FIG. 3 is a vertical sectional front view showing a main part of a ground fault accident detection device of a gas insulated switchgear according to another embodiment of the present invention.

[Explanation of symbols]

1 Insulating gas 2 closed container 3 Arc light receiver 6 gas valves 11 distribution holes 14 Gas pressure monitor 18 conductors

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yukinori Yamaoka             1-1-1 Kokubuncho, Hitachi-shi, Ibaraki Stock             Hitachi, Ltd. Kokubu factory

Claims (5)

[Claims] 1. A ground fault detection of a gas-insulated switchgear in which a conductor is arranged in an airtight container filled with an insulating gas, and an arc light receiving section detects arc light in the airtight container. In the device, a gas valve is connected to the closed container, and the arc light receiving section is provided on the side of the gas valve opposite to the closed container. 2. The ground fault accident detection device for a gas insulated switchgear according to claim 1, wherein the inner wall surface forming the through hole of the gas valve is a mirror surface. 3. The ground fault detection of a gas-insulated switchgear according to claim 1, wherein the arc light reflecting portion is formed on at least the inner wall of the closed container facing the gas valve. apparatus. 4. The ground fault accident detection device for a gas insulated switchgear according to claim 1, wherein a reflecting portion for the arc light is formed on at least a surface of the conductor facing the gas valve. . 5. The ground fault accident detection device for a gas insulated switchgear according to claim 1, wherein a gas pressure monitoring device is connected to the side of the gas valve opposite to the closed container.