JPS61167314A - Gas insulating electric device - 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 (Industrial Application) The present invention relates to a gas insulated electrical device installed in power generation and substations, etc.

(Conventional technology) The configuration of electrical equipment installed at power generation and substations is conventional.

The air insulation method was the mainstream, but in recent years, GIS (Gas Insulating
System) method is the mainstream. This method is
Since it is used as a SFsF2 gas edge medium with high withstand voltage characteristics, miniaturization and high voltage can be easily achieved.

A conventional gas insulated electrical device will be explained based on the drawings. Fourth
The figure is a sectional view of a specific example of a conventional gas-insulated electric device, FIG. 6 is a detailed enlarged view of the dotted line (c) in FIG.
A sectional view taken along the line ■-■ in the figure, and FIG. 7 is a perspective view of the insulating collar.

In the figure, (1), (2), and (8) have a flange part (4) formed at each end and SFsF inside.
The tanks (5) and (6) filled with two gases are sandwiched from both sides by the flange part (4), and the tanks (1) and (
2), (8) a disc-shaped insulating spacer that insulates between;
(7) is the central conductor (8), (9) which penetrates the center part of the insulating spacer (5), (6) and is supported and placed inside the tank (1), (2), <8). QQ is a bolt and nut that is fitted into the bolt (8) to electrically insulate the tanks (1) and (2). Hollow and bolt.

(IJ is a grounding bar electrically connected between the tank (2) and the grounding mesh 4).

A conventional gas-insulated electric device is constructed as described above, and an induced current (it) is generated in the tank (1), (powder, (8)) by the current (17) flowing through the center conductor (7).
, (iz).

(i3) is for each tank (1), (2),
The length of (8) is suppressed to 8 to 100 m by insulating sections with insulating collars and insulating spacers (5) and (61).

Further, the grounding bar port is electrically connected to the grounding mesh of the substation and the tank (2) at low impedance so that the potential of the tank (2) does not rise. Usually, tanks (2
) to prevent an induced current (i!) from flowing in the tank (2).

(Problem to be solved by the invention) Normally, when a commercial frequency voltage is applied to the center conductor (7) Iζ, the tank (1), <23, (8)
Almost no voltage is generated between the adjacent flange parts (4).However, voltage such as commercial frequency is not necessarily applied to the center conductor (7); Switching surges due to switch operation, or center conductor (
A surge overvoltage, such as a lightning surge caused by a lightning strike, is also applied to an overhead power transmission line (not shown) electrically connected to Cζ.

When such a surge overvoltage enters a gas-insulated electrical device and propagates through the center conductor (7) at almost the speed of light, it also causes damage to the tanks (1), (2), and (8) of the center conductor (7). A surge voltage (v) corresponding to surge overvoltage closure occurs,
It also propagates at almost the speed of light. However, the tank (,1
), (2).

(8) Between 1 and 2, the surge voltage (v) propagating through the tank (2) is blocked by the insulating collar (IQ) due to the presence of the insulating collar CIG for suppressing the induced current mentioned above. Surge overvoltage (V
, ) occurs. Research has shown that this surge overvoltage (v3) has a frequency of 50 to 10 megahertz (MHz).
The maximum voltage is the surge overvoltage of the center conductor (7) (approximately 2
There was a problem in that it reached 0% and threatened the insulation of the insulation collar, causing creepage failure and penetration failure of the insulation collar 〇〇.

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, it is an object of the present invention to provide a highly reliable gas-insulated electric device that suppresses surge overvoltage generated in the collar.

(Means for Solving the Problems) A gas insulated electrical device according to the present invention includes a plurality of cylindrical tanks each having a flange formed at each end and arranged in series, and each of the adjacent flange portions. a disk-shaped insulating spacer that is sandwiched between the insulating spacers and insulating the tanks; and a central conductor that is supported at the center of the insulating spacer and penetrates the inside of the tanks.

A non-linear voltage limiting means is provided which is interposed between the adjacent flange parts and electrically connected to limit the surge voltage between the flange parts.

(Operation) In this invention, a voltage limiting means having a non-linear voltage limiting characteristic such that the voltage does not change much in a predetermined current range with current-voltage characteristics is electrically connected between adjacent flange portions. This prevents the surge overvoltage from propagating and passing between the flanges, and the insulating spacer interposed between the flanges suppresses the overvoltage. Prevent creepage breakdown and through-hole breakdown.

[Embodiments] Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 8. FIGS. 1 and 2 are partial sectional views of an embodiment of the present invention, which correspond to conventional FIGS. 6 and 6, and FIG. 8 is an explanatory diagram of voltage limiting characteristics.

In the figure, tanks (1), (2), flange part (4)
, insulating spacer (5), center conductor (7), bolt (8)
, nut (9), and insulating collar CI+) are the same as the conventional ones shown in FIGS. 4 to 7. The opening is fitted into the bolt (8) as shown in Figure 1, and is made of zinc oxide (ZnO) with four insulating collars arranged diagonally and on the same circumference as shown in Figure 2. Bismuth oxide (
BizOa) - It is formed of a zinc oxide sintered body mixed with a small amount of metal oxide such as antimony oxide (SbzOa), granulated, molded, and sintered. Its current-voltage characteristics are the second
As shown in the figure, it has significant nonlinearity.

When a normal commercial frequency voltage is applied to the center conductor (7), the voltage applied to the insulation collar 〇〇, CLI (
VA) is at most IOV, and the characteristic point of A shown in Figure 8 (
FA). On the other hand, the surge overvoltage (
(not shown) and a surge overvoltage (not shown) occurs in the insulation collar 4 due to the intrusion.

Since the insulation collar has the current-voltage characteristics shown in FIG. 8, the characteristic point (PB), that is, the voltage, can be suppressed to vB.

In this way, the insulation collar screams to surge overvoltage (not shown)
is applied, the ζ surge voltage is limited due to the non-linear current-voltage characteristics of the zinc oxide sintered body, and no overvoltage is applied to the conventional insulating collar αQ, and there is no overvoltage applied between the flanges of adjacent tanks. No creeping breakdown or penetration breakdown occurs. Note that the insulating collar □□□ is made of zinc oxide sintered body, so it is mechanically weaker than the conventional insulating collar (1G), but only four of them are arranged diagonally as shown in the above example. However, even if the rest remains the conventional insulating collar CIG, the entire gas insulated electrical device maintains sufficient mechanical strength.

In addition, in the above embodiment, the insulating collar side is formed of zinc oxide sintered body, but some of the bolts (8),
A part of the insulating collar 4 may be omitted by forming the nut (9) from a zinc oxide sintered body, which is normally an insulator, and becomes a voltage limiter when a surge overvoltage occurs. Also,
A resistance element formed of a zinc oxide sintered body may be connected between adjacent flange portions by a lead wire.

[Effects] As explained above, this invention electrically connects adjacent tanks using a member with voltage limiting characteristics, thereby preventing creeping dielectric breakdown and penetration breakdown between tank flanges. This has the effect of improving the reliability of the device.

[Brief explanation of drawings]

1 and 2 are partial sectional views of a gas insulated electrical device according to an embodiment of the present invention, FIG. 8 is an explanatory diagram of voltage limiting characteristics, and FIG. 4 is a sectional view of a conventional gas insulated electrical device. 5 is a detailed enlarged view of the dotted line (c) in FIG. 4, FIG. 6 is a sectional view taken along line Vl-11 in FIG. 4, and FIG. 7 is a perspective view of the insulating collar. (1) , (2)...Tank, (4)...Flange, (5)--Insulation spacer, (7)...Center conductor, +81-...Bolt, +9)... Natsuto,
. Shout, sauce... Insulation color. In each figure, the same reference numerals indicate the same or corresponding parts.

Claims (6)

[Claims] (1) A plurality of cylindrical tanks each having a flange formed at each end and arranged in a row, and a disc-shaped insulating spacer that is held between each of the adjacent flange parts and insulates the tanks; A central conductor supported at the center of the insulating spacer and penetrating through the tank, and a non-linear electrical conductor that is electrically connected between the adjacent flange parts and limits the surge voltage between the flange parts. A gas insulated electrical device characterized in that it is provided with a limiting means. (2) Adjacent flanges are fastened with bolts and nuts together with insulating spacers, and the bolt has an insulating collar with a flange formed at the end that connects at least one of the flange parts with the bolt or the nut. 2. A gas-insulated electrical device according to claim 1, wherein the gas-insulated electrical device is fitted in such a manner as to electrically insulate the gas-insulated electrical device. (3) The gas insulated electrical device according to claim 2, wherein the collar is formed of a zinc oxide sintered body and also serves as voltage limiting means. (4) The gas insulated electrical device according to claim 1, wherein the adjacent flange portions are fastened with insulating bolts and nuts together with insulating spacers. (5) The gas insulated electrical device according to claim 4, wherein the bolt and nut are made of zinc oxide sintered body and also serve as voltage limiting means. (6) The voltage limiting means is a resistance element formed of a zinc oxide sintered body, and adjacent flange portions are connected by a lead wire. Gas insulated electrical equipment.