JPS594000A - High voltage testing shield room - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a shielded room for high-voltage testing, and more specifically, to a shielded room for high-voltage testing that is used for withstanding voltage testing of high-voltage electrical equipment.

The reliability of high-voltage electrical equipment is verified through a withstand voltage test. At this time, it is often necessary to perform a so-called partial discharge test, which determines whether there is a faulty part by detecting the weak partial discharge that occurs from the faulty part. many. During such tests, external electromagnetic waves in space, such as radio broadcast waves, are
This weak discharge detection results in unnecessary electrical noise, which must be kept as small as possible. Therefore, the ceiling, side walls, floor, etc. of a shield room used for such high voltage tests are usually constructed to shield the external electromagnetic waves, and the ceiling, side walls, floor, etc. are covered with metal plates or mesh. Efforts are being made to mechanically connect them to form a structure that is as electrically seamless as possible.

In general, external electromagnetic waves such as broadcast waves arrive from all directions around a shielded room, but the direction of arrival of the one with the maximum intensity that determines the required shielding performance of the shielded room can be easily determined using a field strength meter. can.

The purpose of this invention is to obtain a shielded room for high-voltage testing that maximizes the shielding effect against kneading by measuring the arrival direction of external electromagnetic waves with the maximum intensity at the point where the shielded room is constructed. That is.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

Figure 1 fa) + (b), fc) schematically shows this type of shield room. . The shield room l has a roof, side walls 3. It is made of a plurality of metal plates or folded plates thereof, and the ends of the seven straws are wrapped. Further, as described above, in order to increase the shielding effect, the connecting portions between these members are often joined together at a constant pitch by welding or the like.

B indicates the groundwater table.

This invention shows how to roof the outer panel material with the maximum strength that penetrates through the gaps between the members forming the shield room, where A indicates the maximum strength and Aa is for explanation. Showing virtual external electromagnetic waves. Roofing materials 2a and 2b constituting the roof.

2c is roofed from core a to 2C, the lap parts are stacked on top in this order, and the external opening /2a of the gap 7.2 in the lap part is in a direction almost opposite to the arrival direction A of external electromagnetic waves. It's open. By forming the roof in this way, even if the external electromagnetic waves A are reflected by the metal surface, the intrusion into the interior of the shield room L through the gaps is minimized,
The shielding effect of the shield room/is significantly improved.

If the roof is installed in the opposite way to the above, the direction of arrival of the external electromagnetic wave with the maximum intensity will be hypothetically shown as Aa, and it is clear from the figure that the internal pressure of the shield room l will easily enter through the gap between the lap parts of the parts. .

This was also confirmed experimentally. Sunawachi, as shown in Figure 3 (a), when iron plate F is wrapped and electromagnetic wave EO is applied from the direction perpendicular to iron plate F, the transmitted electric field strength E/
As shown in FIG. 6(b), the results of measuring the distribution of the electromagnetic waves show that the electromagnetic waves pass through the gap between the lap parts from the left front force to the right rear.

Side wall 3. The floor V may also be configured in exactly the same way as above. That is, as shown in FIGS. 2(b) and 2(c), the external opening /3a of the lap part of the wall materials 3a, 3b, and 3c is the gap /3, and the floor material ea.

Gap between lap parts of Ilb and Fc/external opening of da/4'
a to the side wall 3.a so that both sides are substantially opposite to the arrival direction A of the external electromagnetic waves. Form the floor. However, in the case of sleeping floor materials, external electromagnetic waves are reflected from the underground water table B, etc., and come from underground to above, so in reality, the end of the material is It is different from the case of other members that they are wrapped in order.

FIGS. 1 and 2 show four other embodiments of the present invention, respectively. In the figure, 6 is a welded wire mesh, 7 & is a so-called exno-kunded metal made by enlarging a metal plate with broken lines. These are used as flooring materials. For the floor of a large-scale shield room, it is necessary to integrate concrete above and below the shield member due to foundation work, and meshes as shown in Figures D and S are often used instead of metal plates. In the case of a mesh, the shielding effect is highest when the direction in which the external electromagnetic waves arrive is from the direction where the pitch of the mesh is minimum, as shown by A in the figure. According to experiments, the shielding effect in the direction A is several dB to about 10 dB higher than in the case Aa. Therefore, the maximum shielding effect can be achieved by measuring the arrival direction of the highest intensity external electromagnetic waves at the shield room construction point and laying the flooring mesh in such a direction that they all arrive from direction A. become. For this reason, there are cases where members are laid diagonally to the building.

By the way, in the above explanation, the case of a shielded room where the present invention is used for testing high voltage electrical equipment was described.
Needless to say, it can be used as a shield room for other purposes.

As explained above, this invention has a simple structure in which members are arranged so that the shielding effect against kneading is maximized after knowing the direction of arrival of the maximum intensity external electromagnetic waves at the construction point of the high voltage test shield room. According to
It is possible to realize an economical and high shielding effect by using ordinary construction materials.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram of an embodiment of the present invention, where (a) is a plan view, (b) is a plan view, (c) is a side view, and FIG. ((2) are also partial sectional views, FIGS. 3(a) and 3(b) are explanatory diagrams and characteristic diagrams of transmitted electric field strength, respectively, and FIGS. They are a plan view and a perspective view of /...shield room, co...roof 1.2a, Jb. J, c--roofing material, 3...side wall, 3a, 3b,...?
C...wall material, da...floor, da a, da b, da C...floor material, l
λ, /3. /'I--gap, /λa, /3a. /IIa...External opening, 6...Welded wire mesh, Ri...Extracted metal. In each figure, the same reference numerals indicate the same or corresponding parts. Agent Shin Kuzuno - 427

Claims (1)

[Claims] (1) Consisting of a plurality of metal plates whose ends are lapped together and the external opening of the gap formed in the lapped portion is oriented almost opposite to the direction in which the external electromagnetic waves of maximum intensity arrive. A shielded room for high voltage testing characterized by having a roof and side walls. (g) A shielded room for high voltage testing according to claim 1, wherein the metal plate is a folded plate. (3) A patent claim comprising a floor made of a plurality of metal plates whose ends are lapped together and the external opening of the gap formed in the lapped portion is oriented substantially opposite to the arrival direction of the maximum intensity of external electromagnetic waves. A shielded room for high voltage testing as described in item 1. (i) A shielded room for high voltage testing according to claim 7, comprising a floor having a metal mesh arranged so that the mesh pitch in the direction perpendicular to the arrival direction of external electromagnetic waves is minimized.