JPH08264052A - Partial conductive-glazed insulator - Google Patents

Abstract

PURPOSE: To provide a partial conductive-glazed insulator capable of sufficiently preventing the occurrence of a corona discharge or RIV under severe operating conditions. CONSTITUTION: A pin metal 21 and a cap metal 22 are connected to a insulator main body 11 made of glazed porcelain serving as an insulation section via Portland cement 18. Conductive glaze layers 19, 20 are formed in the boundary region between the insulating glaze layer 15 of the insulator main body 11 and the Portland cement 18. The conductive glaze layers 19, 20 are made gradually thinner toward a shade section 12 side. The surface resistance of the conductive-glaze layers 19, 20 is within the range of 100-800MΩon the pin side 19 and to the range of 20-1000MΩ on the cap side 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a partially conductive glazed insulator in which a conductive glaze layer (a conductive glaze layer) is provided in a boundary region between an insulating surface of an insulator body and a cement material.

[0002]

2. Description of the Related Art For example, in a suspended insulator, a pin metal fitting on the power supply side and a cap metal fitting on the grounding side are joined to each other on both the inner and outer surfaces of an insulating part made of glazed porcelain via cement material, and these metal fittings are mutually connected. It is insulated. These members have different electrical characteristics, such as surface resistance, so that electric field concentration occurs in the boundary region between these members during power application. Here, when an electric field concentration exceeding the dielectric strength of air occurs, corona discharge occurs due to partial insulation breakdown of air,
Radio interference voltage (RIV) is generated.

In order to prevent the occurrence of corona discharge and RIV, for example, a partial conductive glazed porcelain in which a conductive glaze in which a metal oxide such as iron oxide is mixed with a general glaze is applied to a boundary region where electric field concentration is likely to occur is known. Are known. Generally, the surface resistance value of the conductive glaze layer is 100 MΩ or less. For example, in the suspension insulator of USP 3,243,505,
A conductive glaze layer made of blue titania is formed in the boundary region between the insulating material of the insulator body where the electric field is likely to concentrate and the cement material. The surface resistance value of this conductive glaze layer is 0.2 to
It is in the range of 20 MΩ. The conductive glaze layer reduces the electric field concentration and prevents corona discharge and RIV.

[0004]

For example, when the sending voltage is high, the voltage shared by the insulator is high, and the electric field concentration is large in the boundary region of each constituent material of the insulator. Further, in an environment such as a high altitude area where discharge is likely to occur, even a slight electric field concentration may cause corona discharge or RIV. However, under such a severe use condition, the conventional partial conductive glazed insulator has a problem that the electric field concentration is not sufficiently mitigated, so that the electric field concentration cannot be fully mitigated and corona discharge or RIV occurs. .

An object of the present invention is to provide a partially conductive glaze insulator capable of sufficiently preventing corona discharge and RIV generation even under severe use conditions.

[0006]

In order to achieve the above-mentioned object, in the invention of claim 1, the surface resistance of the conductive glaze layer on the voltage application side is 100 to 800 MΩ and the surface resistance of the conductive glaze layer on the ground side. Is set to 20 to 1000 MΩ.

According to the second aspect of the present invention, the surface resistance of each of the conductive glaze layers is gently changed so that there is a difference in height between the insulating surface of the insulator body and the cement material. is there.

According to the third aspect of the present invention, the surface resistance distribution is formed so as to be higher on the insulating surface side and lower on the cement material side.

[0009]

According to the invention of claim 1, the corona extinction voltage level of the partially conductive glaze can be set in a high range.
Therefore, corona discharge does not occur up to a high voltage level, and it is possible to withstand a larger electric field concentration.

According to the second aspect of the invention, the drop in surface resistance between the insulating surface of the insulator main body where the electric field concentration is likely to occur and the boundary region of the cement material can be smoothed through the conductive glaze layer.

According to the invention of claim 3, a surface resistance distribution is formed along the tendency of the surface resistance from the cement material side having a relatively low surface resistance to the insulating surface of the insulator main body having a high surface resistance. It Therefore, the difference in surface resistance between the insulating surface of the insulator body and the cement material becomes more gentle, and the electric field concentration is alleviated.

[0012]

EXAMPLE An example in which the present invention is embodied in a suspended-type insulator (hereinafter, referred to as a partially conductive glaze insulator) will be described with reference to the drawings. As shown in FIG. 1, a plurality of pleats 13 are integrally formed in an annular and concentric shape on the inner surface of the cap portion 12 of the insulator body 11. A cylindrical head portion 14 having a lid is integrally formed on the central upper portion of the cap portion 12. Further, the entire surface of the insulator body 11 is coated with a general glaze (hereinafter referred to as insulating glaze) containing silicon oxide and aluminum oxide having an insulating property as main components, and the insulating glaze layer 1 as an insulating surface is formed.
It is 5. Porcelain pieces are fixed to the outer peripheral surface and the inner peripheral surface of the head portion 14 to form a sand layer 16. On the outer surface and the inner surface of the head 14 of the insulator main body 11, a grounding side cap fitting 22 is provided with a Portland cement 18 interposed.
And the pin metal fitting 21 on the power supply side are joined and fixed. Therefore, the cap fittings 22 and the pin fittings 21 are located at both ends of the insulator body 11.

A fitting recess 22a is formed on the upper portion of the cap member 22 for engaging the pin member 21 of the other partial conductive glazed insulator immediately above. In addition, the lower end of the pin fitting 21 is engaged with the fitting recess 22a of the other partial conductive glaze insulator immediately below. As described above, a plurality of partially conductive glazes are used by being connected in series.

As shown in FIG. 2, conductive glaze layers 19 and 20 are formed on the inner surface and outer surface of the insulator body 11 in a boundary region between the insulating glaze layer 15 of the insulator body 11 and the Portland cement 18 over a width of 30 mm. ing. The conductive glaze layers 19 and 20 are formed so that the thickness thereof is gradually reduced from the Portland cement 18 side to the cap portion 12 side. The conductive glaze layers 19 and 20 are formed on the insulating glaze layer 15 of the insulator main body 11 by applying an iron-based semiconductive glaze with a brush so as to have a predetermined width and thickness. In addition,
The iron-based semiconductive glaze has a composition of general glaze to which 15 wt% of iron oxide and 8 wt% of chromium oxide are added.

In FIG. 1 and FIG. 2, the insulating glaze layer 15 and the conductive glaze layers 19 and 20 are drawn thicker than they actually are to facilitate understanding. Next, the conductive glaze layers 19 and 20
The relationship between the surface resistance value of and the corona extinction voltage level will be described.

FIG. 3 shows the pin side conductive glaze layer 19 in FIG.
3 shows the voltage level at which the corona discharge disappears under the condition that the surface resistance value of the cap side conductive glaze layer 20 is variously changed. As shown in FIG. 3, the resistance value of the conductive glaze layer 20 on the cap side is 10 MΩ or less, or 1000 to 50.
In the range of 00 MΩ, the corona extinction voltage level hardly changes over the entire surface resistance value of the pin-side conductive glaze layer 19 of 1 to 1000 MΩ. On the other hand, the surface resistance value of the cap side conductive glaze layer 20 is 20 to 1000 MΩ.
In the range of, the surface resistance value of the pin side conductive glaze layer 19 is 100.
In the range of up to 800 MΩ, the conventional double conductive glaze layer 19,
Compared with the case where the surface resistance of 20 is 100 MΩ or less,
High corona extinction voltage levels were observed. That is, by setting the surface resistance values of the pin-side conductive glaze layer 19 and the cap-side conductive glaze layer in this range, it is possible to prevent corona discharge to a higher voltage level than that of the conventional partial conductive glaze insulator. That is, the optimum range of the surface resistance value of the conductive glaze layers 19 and 20 is 20 to 1000 MΩ on the cap side and 100 to 800 MΩ on the pin side.
Here, when the surface resistance values of the conductive glaze layers 19 and 20 are less than or equal to this optimum range, the conductive glaze layers 19 and 20 and the insulating glaze layer 15
Corona discharge may occur at the boundary between and. On the other hand, when the surface resistance values of the conductive glaze layers 19 and 20 are above the optimum range, corona discharge may occur at the boundary between the conductive glaze layers 19 and 20 and the Polland cement 18.

Further, as shown in FIG. 4, since the conductive glaze layer is formed by coating with a brush, a slight variation is observed in the surface resistance value. However, there is a certain relationship between the thickness of the conductive glaze layer and the surface resistance value in the average value. That is, the thicker the conductive glaze layer, the lower the surface resistance value, and the thinner the thickness, the higher the surface resistance value. Therefore, the surface resistance value of the conductive glaze layers 19 and 20 can be defined by its thickness. Here, in this embodiment,
The thickness of each of the pin-side conductive glaze layer 19 and the cap-side conductive glaze layer 20 is approximately 0.14 to 0.23 mm and 0.14 to 0.33 m so that the surface resistances thereof fall within the above-mentioned optimum range.
It is configured to change within the range of m.

According to this embodiment constructed as described above, the insulating glaze layer 1 of the insulator body 11 where electric field concentration is likely to occur
Conductive glaze layers 19 and 20 are formed in a boundary region between the No. 5 and the Portland cement 18. The surface resistance value of the pin side conductive glaze layer 19 is in the range of 100 to 800 MΩ, and the surface resistance value of the cap side conductive glaze layer 20 is 20 to 1000 MΩ.
It is formed to be in the range of Ω. Moreover, the conductive glaze layers 19 and 20 are formed so as to have a gentle thickness from the Portland cement 18 side to the cap portion 12 side. Therefore, as shown in FIG. 4, the conductive glaze layer 1
Since the smaller the thickness of 9 and 20, the higher the surface resistance value, the surface resistance distribution in each conductive glaze layer 19 and 20 is
It gradually rises from the Portland cement 18 side to the cap 12 side.

As shown in FIG. 5, in general, the surface resistance value of 18 layers of Portland cement is about 1 MΩ, while the surface resistance value of the insulating glaze layer 15 is about 10000 MΩ. Here, in the partially conductive glazed insulator of the present embodiment, the two layers 15, 1 are provided via the conductive glazed layers 19, 20 having the above-mentioned configuration.
Since 8 is bonded, the difference in surface resistance between the two layers 15 and 18 is reduced, and the electric field concentration is reduced. Moreover, in accordance with the tendency of the surface resistance of the two layers 15 and 18 to be high or low, the gradient of the surface resistance in the conductive glaze layers 19 and 20 is the approximate line α on the pin side and the approximate line β on the cap side in FIG. 5, respectively. It changes smoothly along the line, and the electric field concentration is further alleviated. Therefore, the voltage level at which corona discharge of the partially conductive glaze is generated can be improved, and corona discharge and RIV can be achieved even under severe use conditions such as high voltage voltage application and high altitude areas.
Is sufficiently prevented.

Further, the conductive glaze layers 19 and 20 are formed such that an iron-based semiconductive glaze has a predetermined width and thickness on the upper surface of the insulating glaze layer 15 which is glazed on the entire outer peripheral surface of the insulator body 11. Since it only needs to be applied, it is easy to process and is advantageous in manufacturing.

The present invention can be modified and embodied as follows. (1) In FIG. 2, the thickness of the conductive glaze layers 19 and 20 should be changed more gently.

With this structure, the electric field concentration can be further alleviated. (2) In FIG. 5, the gradients of the approximate lines of the surface resistance changes of the conductive glaze layers 19 and 20 are made different within the respective allowable ranges.

Even with this structure, the electric field concentration can be alleviated. (3) In FIG. 5, the gradient of the approximate line β of the surface resistance change of the cap-side conductive glaze layer 20 is made to coincide with the approximate line α of the pin-side conductive glaze layer 19 surface resistance change.

With this structure, both conductive glaze layers 19,
The thicknesses of 20 can be matched, which is advantageous in manufacturing. (4) In FIG. 5, the gradients of the approximate lines of the surface resistance changes of the conductive glaze layers 19 and 20 are reversed within their respective allowable ranges. That is, in FIG. 2, it should be formed so that it is higher toward the end of the cement material 18 and lower toward the insulating surface 15.

(5) Change the metal oxide of the conductive glaze applied to the conductive glaze layers 19 and 20 to tin oxide, titanium oxide or the like. (6) As the conductive glaze layers 19 and 20, a plurality of conductive glazes (for example, iron-based, titanium-based, tin-based conductive glaze) layers having different kinds of metal oxides are concentrically arranged in a row, and the surface resistance is increased. To make changes.

(7) The conductive glaze layers 19 and 20 are attached to the insulator body 11
Apply directly to the porcelain surface of. Even with the above configuration,
The electric field concentration can be relaxed. (8) The present invention is applied to the boundary area between the insulating material of the station post insulator and the line post insulator and the cement material.

Next, the technical idea grasped by the above embodiment will be described. (1) A partially conductive glazed porcelain according to any one of claims 1 to 3, wherein a porcelain surface serving as an insulating surface of the porcelain insulator body 11 is provided with an insulating glaze, and conductive glaze is provided on the insulating surface to provide conductive glaze layers 19 and 20.

In the case of such a structure, the conductive glaze layer 19,
The formation of 20 is only required to be applied to the surface of the insulator main body 11 with a conductive glaze at a predetermined position so as to have a predetermined width and thickness.

[0029]

As described in detail above, according to the present invention, the following excellent effects are exhibited. According to the invention of claim 1,
It is possible to improve the electric field concentration resistance of the partially conductive glaze insulator,
Corona discharge does not occur up to high voltage levels.
Therefore, even under severe usage conditions, corona discharge and R
It is possible to prevent the generation of IV.

According to the second and third aspects of the present invention, the electric field concentration in the boundary area between the insulating surface of the insulator body and the cement material is alleviated, so that corona discharge or RIV is less likely to occur.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view showing an embodiment of a partially conductive glaze insulator of the present invention.

FIG. 2 is an enlarged partial sectional view showing a main part of FIG.

FIG. 3 is a graph showing the relationship between the surface resistance of the conductive glaze layer and the corona extinction voltage level.

FIG. 4 is a graph showing the relationship between the thickness of the conductive glaze layer and the surface resistance.

FIG. 5 is a conceptual diagram showing the surface resistance near the conductive glaze layer.

[Explanation of symbols]

11 ... Insulator main body, 15 ... Insulating glaze layer as insulating surface, 1
8 ... Portland cement as cement material, 19 ...
Pin-side conductive glaze layer as a conductive glaze layer on the power-supply side, 20 ... Cap-side conductive glazed layer as a ground-side conductive glaze layer, 21 ... Pin metal fittings as metal fittings on the power-supply side, 22 ... Metal fittings on the ground side Cap metal fittings.

Claims (3)

[Claims] 1. Partial conductivity in which metal fittings on the power-supply side and the grounding side are joined to both ends of the insulator body via cement material, and a conductive glaze layer is provided in a boundary region between the insulating surface of the insulator body and the cement material. In the glaze insulator, the surface resistance of the conductive glaze layer on the voltage-applying side is set to 100 to 800 MΩ,
Also, the surface resistance of the conductive glaze layer on the ground side is 20 to 1000 MΩ.
Partially conductive glaze insulator set to. 2. The portion according to claim 1, wherein the surface resistance of each of the conductive glaze layers is gently changed so that there is a difference in height between the insulating surface of the insulator body and the cement material. Conductive glaze insulator. 3. The surface resistance is higher on the insulating surface side,
The partially conductive glazed insulator according to claim 2, which is formed so as to be lower on the cement material side.