JPH0232844B2 - DODENSEIRYUSHIHOKAKUSOCHI - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a conductive particle trapping device that is attached to a gas-insulated electrical device and traps conductive particles that enter the device and trigger dielectric breakdown.

Below, Gas Insulated Bus:
This will be explained using a conductive particle capture device attached to a GIB (Gib) as an example.

Fig. 1A is a perspective view showing a partially broken GIB equipped with a conventional conductive particle capture device, Fig. 1B is a cross-sectional view taken along line IB-IB of Fig. 1A, FIG. 1C is a longitudinal sectional view taken along the line IC--IC in FIG. 1B.

In the figure, 1 is a cylindrical GIB container made of a metal material and filled with an insulating gas such as sulfur hexafluoride (SF ₆ ), and 2 is a cylindrical container installed along the central axis of the cylindrical container 1. A high voltage conductor to which a high voltage is applied to the container 1; 3 an insulating spacer made of an insulating material and fixed to a predetermined part of the high voltage conductor 1 surrounding this part; 4, one end of which is the insulating spacer 3; Three metal pins are attached at equal angular intervals of 120 degrees to each other on the outer peripheral surface of the cylindrical container 1, and the other end contacts the inner wall surface of the cylindrical container 1. It consists of a slit-formed metal plate held by two metal pins 4 at a predetermined distance from a predetermined area at the lower part of the inner wall surface of the container 1, and in which a plurality of predetermined slits 5a are formed parallel to each other. This is a conventional conductive particle capture device. The length of the conductive particle capture device 5 in the direction along the high voltage conductor 2 is configured to be longer than the length of the insulating spacer 3 in this direction by a predetermined length on each side thereof.
Note that the potential of the conductive particle capture device 5 is set to the potential of the cylindrical container 1 through the metal pin 4.

Next, the operation of this conventional conductive particle trapping device 5 will be explained with reference to the longitudinal sectional view of FIG. 1C.

Most of the conductive particles (indicated by P in the figure) mixed into the GIS cylindrical container 1 are often attached to the lower part of the inner wall surface of the cylindrical container 1. Such conductive particles P are charged because they are exposed to the electric field created between the high voltage conductor 2 and the inner wall surface of the cylindrical container 1, and due to this electric field, they exert an attractive force in the direction toward the high voltage conductor 2. receive. When the attractive force due to this electric field overcomes the gravity of the conductive particle (P) itself, the conductive particle (P) floats up to the surface of the high voltage suppressor 2, as illustrated by curve A.
approach. When the conductive particles (P) approach the high voltage conductor 2, a discharge occurs between the conductive particles (P) and the high voltage conductor 2, and due to this discharge, the conductive particles (P) are no longer charged. As a result, the conductive particles (P) no longer receive the attractive force due to the electric field.
It falls again onto the inner wall surface of the cylindrical container 1 due to gravity. While repeating such movement, the conductive particles (P) move under the inner wall surface of the cylindrical container 1,
When the particles pass through the slit 5a and reach the area of the inner wall surface of the cylindrical container 1 directly below the conductive particle capture device 5 (hereinafter this area will be abbreviated as the "directly below area"),
Since the cylindrical container 1 and the conductive particle capture device 5 are at the same potential, the electric field in the area directly under the conductive particle capture device 5 is very weak. Therefore, the conductive particles (P) do not move within the area directly under the conductive particle capture device 5 and are captured. In addition, as illustrated by curve B, conductive particles (P)
Even if the particles do not pass through the slit 5a of the conductive particle capture device 5 and directly reach the area immediately below the conductive particle capture device 5, they are captured in the same manner as in the above case. In this way, the conductive particle capture device 5
The conductive particles (P) existing in areas other than the area directly under the conductive particle capture device 5 are sequentially captured and reduced in the area directly under the conductive particle capture device 5. The discharge with P) is the trigger,
It is possible to suppress dielectric breakdown from occurring between the high voltage conductor 2 and the inner wall surface of the cylindrical container 1. Moreover, since the length of the conductive particle trapping device 5 is configured to be longer than the length of the insulating spacer 3 by a predetermined length on each side of the insulating spacer 3 in the direction along the high voltage conductor 2, the conductive particle trapping device 5 is Before (P) adheres to the creeping surface of the insulating spacer 3, it passes through the slit 5a and is captured in the region immediately below the conductive particle capture device 5. Therefore, conductive particles (P) do not adhere to the creeping surface of the insulating spacer 3, and the insulating spacer 3
There is no deterioration in the insulation properties of the

By the way, under an AC electric field where an AC voltage is applied between the cylindrical container 1 and the high voltage conductor 2 of the GIB, an ion current due to the insulating gas filled in the cylindrical container 1 does not flow between them. Under a DC electric field where a DC voltage is applied between these, the situation is significantly different from under an AC electric field, and an ion current due to the insulating gas always flows in the direction from the high voltage conductor 2 toward the inner wall surface of the cylindrical container 1. A wind accompanying this ion flow is blowing as illustrated by curve C in the longitudinal cross-sectional view of FIG. 1C. Therefore, under an alternating current electric field, the conductive particle capture device 5 in which the conductive particles (P) are captured
However, under a DC electric field, the wind accompanying the above-mentioned ion flow causes the conductive particles (P) to fly out of the area directly under the conductive particle capture device 5 in which they are captured. It acts as if it blows out from within the area directly below. Due to this effect, the conventional conductive particle capture device 5 cannot reliably capture the conductive particles (P) in the area directly under the DC electric field, and the high voltage conductor 2 and the cylindrical container There was a problem in that it was not possible to effectively suppress dielectric breakdown caused by the conductive particles (P) between the conductive particles (P) and the inner wall surface of the conductive particles (P).

This invention was made in view of the above-mentioned problems, and is designed to prevent conductive particles from being blown out from the captured area by the action of the wind accompanying the ion flow caused by the insulating gas under both DC electric fields. It is an object of the present invention to provide a conductive particle trapping device that can reliably trap conductive particles even under a direct current electric field as well as under an alternating current electric field.

FIGS. 2A, B, and C are a plan view, a front view, and a side view, respectively, showing a conductive particle trapping device according to an embodiment of the present invention, which is attached to the GIB shown in FIG. 1.

In the figure, 50 is the conductive particle trapping device of this embodiment, and 51 is a plurality of slits 5 of a predetermined width.
1a are metal plates with slits formed parallel to each other and similar to the conventional conductive particle capture device 5 shown in FIG. It is a bowl-shaped metal body with an open end fixed to the periphery of the lower surface. Note that 1 and 2 indicated by dashed lines in FIGS. 2B and 2C represent the cylindrical container and high voltage conductor of the GIB when the conductive particle capture device 50 of this embodiment is attached to the GIB shown in FIG. 1, respectively. is part of.

When the conductive particle capture device 50 of this embodiment is attached to the GIB shown in FIG. 1, since the cylindrical container 1 of the GIB and the conductive particle capture device 50 are at the same potential, The electric field inside 52 and the area immediately below it is very weak. Therefore, as illustrated by curve A in the vertical cross-sectional view of FIG.
Similarly to the example illustrated by curve B in the vertical cross-sectional view of FIG. be done. Under an alternating current electric field, the conductive particles captured in this way are transported from the interior of the bowl-shaped metal body 52 and the area immediately below it to the outside, similar to the conventional conductive particle capture device 5 shown in FIG. There is no such thing as jumping out. Furthermore, under a DC electric field, the conductive particles captured inside the bowl-shaped metal body 52 are blown out to the outside of the bowl-shaped metal body 52 by the action of the wind accompanying the ion flow caused by the above-mentioned insulating gas. Moreover, since there is no wind effect accompanying the ion flow in the area directly under the bowl-shaped metal body 52, the conductive particles captured in the area directly under it will not flow outside this area. There is no chance of being blown out. Therefore, in the conductive particle trapping device of this embodiment, conductive particles can be captured as reliably under a DC electric field as under an AC electric field, so that the conductive particles can be captured at the same height as the inner wall surface of the cylindrical container of the GIB. It is possible to effectively suppress dielectric breakdown caused by conductive particles between the conductor and the voltage conductor.

Although the slit-formed metal plate 51 is used in this embodiment, it is not necessarily limited to the slit-formed metal plate, and other porous metal plates including wire mesh may be used.

Although the conductive particle capture device attached to the GIB of a cylindrical container has been described as an example, the present invention is not limited to this, and it goes without saying that the present invention can be applied to a GIB of a cylindrical metal container other than a cylindrical container. The present invention can be applied to gas-insulated electric devices in general, including a high-voltage conductor provided along the central axis of the cylindrical metal container.

As described above, in the conductive particle capture device of the present invention, the surface of the porous metal plate on the side of the cylindrical metal container that captures the conductive particles mixed in the cylindrical metal container of the gas-insulated electrical equipment is A bowl-shaped metal body whose opening end was fixed and kept at the same potential as the porous metal plate so as to close all the holes in the porous metal plate was provided, so that the inside of the bowl-shaped metal body and the area immediately below it Electric field is very weak. Therefore, the conductive particles passing through the porous metal plate are captured inside the bowl-shaped metal body, and the conductive particles directly reach the area directly under the bowl-shaped metal body without passing through the porous metal plate. Particles are trapped within said area. The conductive particles captured in this manner do not fly out from inside the bowl-shaped metal body and the region immediately below it under an alternating current electric field. Also,
Under a direct current electric field, the conductive particles trapped inside the bowl-shaped metal body are blown out to the outside of the bowl-shaped metal body by the action of the wind accompanying the ion flow caused by the insulating gas. There is no
Since there is no wind effect associated with the ion flow in the region immediately below the bowl-shaped metal body, the conductive particles captured within the region are not blown out to the outside of the region. Therefore, it is possible to reliably capture conductive particles both under an AC electric field and under a DC electric field, thereby effectively suppressing dielectric breakdown caused by conductive particles mixed in the gas-insulated electrical device. Can be done.

[Brief explanation of drawings]

Fig. 1A is a perspective view showing a partially broken GIB equipped with a conventional conductive particle capture device, Fig. 1B is a cross-sectional view taken along line IB-IB of Fig. 1A, Figure 1C is a longitudinal sectional view taken along the IC-IC line in Figure 1B, and Figures 2A, B, and C are a plan view, front view, and side view, respectively, showing a conductive particle trapping device according to an embodiment of the present invention. It is a diagram. In the figure, 1 is a cylindrical container (cylindrical metal container),
2 is a high voltage conductor, 50 is the conductive particle capture device of the above embodiment, 51 is a slit-forming metal plate (porous metal plate), and 52 is a bowl-shaped metal body. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A gas-insulated electrical appliance comprising a cylindrical metal container filled with an insulating gas and a high voltage conductor provided along the central axis of the cylindrical metal container and to which a high voltage is applied to the cylindrical metal container. A porous metal plate is provided in the cylindrical metal container of the device at a predetermined distance from a predetermined region at the bottom of the inner wall surface thereof and has the same potential as that of the cylindrical metal container, and the inner wall surface in which conductive particles mixed into the cylindrical metal container are captured in the predetermined area of the cylindrical metal container, wherein all pores of the porous metal plate are plugged on the surface of the porous metal plate facing the cylindrical metal container. A conductive particle trapping device characterized in that it is provided with a bowl-shaped metal body whose opening end is fixed and kept at the same potential as the porous metal plate.