JPH0561854B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an insulating spacer used mainly in a gas-insulated switchgear using SF ₆ gas as an insulating medium, such as in a conduit aerial power transmission device.

[Technical Background of the Invention] Many insulating spacers are used in gas-insulated switchgears and pipeline aerial power transmission devices to insulate and support high-voltage conductors within grounded metal containers. This insulating spacer supports a high voltage conductor at the center of a cone-shaped insulating spacer body made of epoxy resin, as shown in, for example, Japanese Patent Publication No. 54-44106 and Japanese Patent Application Laid-open No. 55-155512. Fittings for mounting bolts are attached to the flange on the outer periphery of the spacer. Furthermore, the insulation performance of SF ₆ gas tends to deteriorate due to unequal electric fields, so as a countermeasure to this, it is common to embed shield electrodes in the circumferential direction on the high voltage and ground sides.

FIG. 4 shows a longitudinal cross-sectional view of a conventional insulating spacer. In the figure, 1 is a high voltage conductor, 2 is an insulating gas, 3 is a grounding container, and 4 is a cone-shaped insulating spacer body. The current-carrying member 41 that connects adjacent high-voltage conductors 1 to each other is cast integrally with the insulating spacer main body 4, and a high-voltage shield 41a is integrally formed on the outer peripheral surface thereof to protrude. 6 is a metal flange integrally cast on the outer periphery of the insulating spacer body 4;
By sandwiching this metal flange 6 between flanges 31 provided at the ends of the grounded metal container 3 and fastening them with bolts 7, the adjacent grounded metal containers 3 and high voltage conductor 1 are joined to each other. At the same time, the high voltage conductor 1 is insulated and supported by the insulating spacer 40.

Further, 71 is a conductive ring integrally cast into the insulating spacer body 4, and this conductive ring 7
1 is always grounded to alleviate the electric field at the junction between the container 3 and the insulating spacer 40, contributing to improving insulation performance.

[Problems with Background Art] However, the conventional insulating spacer as described above has the following drawbacks.

That is, the high voltage shield 41 provided on the current carrying member 41
Since the amount of protrusion toward the insulating spacer 40 side is small in a, the electric field of the creeping direction component near the current-carrying member 41 becomes high on the concave side of the insulating spacer 40, and as a result, particles, for example, metal particles, are slightly generated in this part. However, if it adheres, the original insulation performance of the insulating spacer will deteriorate. In order to prevent this, it is possible to increase the size of the insulating spacer body to improve insulation performance, but increasing the size of the insulating spacer increases the cost due to larger equipment and an increase in the amount of epoxy resin used for the insulating spacer. connection,
Not the preferred method.

For these reasons, there has been a desire for an insulating spacer that exhibits excellent insulation performance against metal particles and the like without changing the size of the insulating spacer body.

[Object of the Invention] The present invention was proposed in order to solve the above-mentioned problems, and its purpose is to improve the concave surface of the insulating spacer body by a simple means of devising the shape of the high-voltage shield. Another object of the present invention is to provide an insulating spacer which alleviates the creeping electric field near a high voltage conductor on a convex surface and is strengthened against metal particles and the like.

[Summary of the invention] The insulating spacer of the present invention has vertical creeping parts perpendicular to the high voltage conductor or current-carrying member near the center of the concave and convex surfaces of the cone-shaped insulating spacer body, and high voltage is applied to these parts. In the insulating spacer in which a shield is embedded, the diameter of the tip of the high voltage shield is set to be larger than the diameter of the vertical creeping portion of the concave surface of the insulating spacer body and smaller than the diameter of the vertical creeping portion of the convex surface. It has the above characteristics.

With this configuration, the electric field in the vertical creeping parts of both the concave and convex surfaces is relaxed, preventing metal particles from adhering to these parts, and even if they do, dielectric breakdown can easily occur. I made it seem like it wasn't there.

[Embodiments of the Invention] *Representative Examples Representative embodiments of the present invention will be described below with reference to FIGS. 1 and 2. Note that since the gist of the present invention is the positional relationship of the high-voltage shield embedded in the insulating spacer, other parts will be explained in the fourth section.
The illustration is simplified compared to the conventional type shown in the figure.

In this embodiment, the diameter of the high voltage shield 41a
D ₁ is the current-carrying conductor 4 on the concave side of the insulating spacer 40
It is set larger than the diameter D ₃ of the vertical creeping surface formed near the conductor 41 on the convex side, and smaller than the diameter D ₂ of the vertical creeping surface formed near the current-carrying conductor 41 on the convex side. Also, the thickness d of this high voltage shield 41a
is 1/2 to 2/3 of the thickness t of the insulating spacer 40 at the current-carrying conductor 41 portion.

In the insulating spacer of this example with such a configuration, the vertical creeping electric fields on the concave side and the convex side are respectively
When E ₁ and E ₂ are used, the electric field strengths E ₁ and E ₂ are
The relationship among the diameter D ₁ of the high voltage shield 41a, the diameter D ₃ of the vertical creeping surface on the concave side, and the diameter D ₂ of the vertical creeping surface on the convex side is shown in FIG.

As is clear from Figure 2, the electric field E ₁ on the convex side is
As the value of D ₁ /D ₂ increases, it decreases, while the electric field E ₂ on the concave side increases as the value of D ₁ /D ₃ increases. Therefore, as in this embodiment, D ₁ >D ₃ ,
If D ₁ > D ₂ , both the electric field E ₁ on the convex side and the electric field E ₂ on the concave side will be in a low range, so it is possible to reduce the electric field on both the vertical creeping sides of the concave side and the convex side. .

Since the electric field of the creeping direction component of this insulating spacer becomes the dominant electric field for the conductive metal particles, the insulating spacer of this example in which the electric field of this creeping direction component is relaxed is effective against metal particles, etc. The insulation properties will be strengthened accordingly.

*Other embodiments In the above embodiment, the high voltage shield 41a is embedded in the insulating spacer body 4 in contact with the high voltage conductor or its current-carrying member, but as shown in FIG. The present invention can also be applied to an insulating spacer embedded in the insulating spacer body 4 with the shield 41a separated from a high voltage conductor or the like.

[Effects of the Invention] As explained above, according to the present invention, the shape of the high voltage shield embedded inside the insulating spacer body is
The present invention has the effect of providing an excellent insulating spacer with enhanced insulation properties against conductive metal particles, etc., with a simple configuration that is appropriately set according to the creeping shape of the insulating spacer.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view showing a typical embodiment of the insulating spacer of the present invention, FIG. 2 is a graph showing the relationship between the electric field strength of each part of the insulating spacer of FIG. 1 and the shape of the insulating spacer, and FIG. 4 is a longitudinal sectional view showing another embodiment of the present invention, and FIG. 4 is a longitudinal sectional view showing an example of a conventional insulating spacer. DESCRIPTION OF SYMBOLS 1... High voltage conductor, 2... Insulating gas, 3... Grounding container, 4... Insulating spacer main body, 40... Entire insulating spacer, 41... Current carrying member, 41a... High voltage shield, 6... Flange, 7...Bolt, 7
1... Conductive ring. D ₁ ... Diameter of high voltage shield, D ₂ ... Diameter of vertical creepage on convex side, D ₃ ... Diameter of vertical creepage on concave side.

Claims (1)

[Claims] 1. An insulating spacer having a cone-shaped insulating spacer body that insulates and supports a high-voltage conductor or current-carrying member at the center, and a high-voltage shield embedded in the circumferential direction near the high-voltage conductor in the insulating spacer body. In this case, a vertical creeping portion perpendicular to the high voltage conductor or current-carrying member is provided near the center of the concave surface and convex surface of the cone-shaped insulating spacer body, respectively, and the diameter of the tip of the high voltage shield is equal to the diameter of the insulating spacer body. An insulating spacer characterized in that the diameter is set to be larger than the diameter of the vertical creeping portion of the concave surface and smaller than the diameter of the vertical creeping portion of the convex surface. 2. The thickness of the high-voltage shield embedded inside the insulating spacer body is set to 1/2 to 2/3 of the thickness of the insulating spacer body at the high-voltage conductor or current-carrying member portion. Insulating spacer.