JPH0541122A - Lighting arrester insulator - Google Patents

Abstract

PURPOSE:To manufacture and install a resistor device unit easily without making the unit large and heavy, lower the cost of a lightning arrester insulator, and improve electric reliability. CONSTITUTION:While being piled in series, divided resistor device simples 11 are coated with a thermally shrinkable and elastic tube 12 to obtain a resistor device simples-piled unit 14 and a plurality of resistor device simples-piled units 14 are bundled to give a resistor device unit 4. Consequently, discharging capacity against lightning surge current is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ground fault in which, when a surge current caused by a lightning strike enters an electric line, it is quickly discharged to the ground, and the subsequent current at a commercial frequency generated is suppressed and cut off. The present invention relates to a lightning protection insulator that can prevent the above.

[0002]

2. Description of the Related Art Conventionally, the problems to be solved by the invention
As a lightning arrester, a resistance element mainly composed of zinc oxide having a non-linear voltage-current characteristic and having a columnar shape is housed in series inside a cylindrical withstand voltage insulating cylinder. There is one in which cap-shaped electrode fittings are fitted and fixed to both ends of the pressure-proof insulating cylinder, and a rubber insulating jacket is molded on the outer peripheral surface of the pressure-proof insulating cylinder.

The capacity (current cross-sectional area) and length of the resistance element are set according to the expected surge current at the time of lightning stroke and the voltage class to which the lightning protection insulator is applied. Compared to the transmission line with an overhead ground fault, in a transmission line without an overhead ground line, surge current due to lightning strikes the transmission line directly, so the energy of the lightning surge current is Increased compared to lightning surge current. For this reason, it becomes necessary to use a resistance element housed in the lightning protection insulator that has a large capacity to withstand it. Further, when the voltage class of the transmission line becomes large, it is necessary to withstand the operating voltage when processing a lightning surge. For example, in a 66 KV class electric line, 20 resistance elements are used alone, and in the 154 KV class, the same element is used as 4 units.
It is necessary to lengthen the connection length of the resistance elements according to the voltage, such as connecting 0 in series.

In response to this demand, conventionally, a plurality of resistance elements 31 connected in series as shown in FIG. 8 are covered with a heat-shrinkable elastic tube 32, which is housed inside a pressure-resistant insulating tube 33. .. The structure of this resistance element unit has the advantage that the lightning arrester can be miniaturized because the storage space is the smallest because the dimension in the radial direction is shortened. However, if the resistance element 31 having a single structure has a large diameter, and the current manufacturing technology for firing increases the diameter of a single resistance element, the material and size of the resistor element are likely to vary in the firing process. It was extremely difficult to manufacture such a thing. Therefore, the applicant of the present application has proposed the following as a lightning protection insulator that solves such a problem.

(1) The arrangement configuration of the resistance elements shown in FIG.
The cylindrical resistance element 31 is divided into a plurality of pieces, which are arranged in parallel at, for example, three locations. However, in the structure having a plurality of resistance element rows, it is necessary to increase the diameter of the withstand voltage insulating cylinder 33, and the insulating jacket molded on the outer periphery of the withstand voltage insulating tube 33 is naturally large in size and heavy in weight. Since the insulator as a whole is extremely large and heavy, there are problems in terms of applicability to existing lines, pillar work and manufacturing costs.

In order to solve this, the applicant of the present application has further proposed the following. (2) As shown in FIG. 10, in the state where the resistance element unit 34 divided into three is arranged in a columnar shape as a whole, each element unit 34 is adhered and fixed by an adhesive 35 having elasticity and heat conductivity. A plurality of resistance elements 31 are connected in series. (See Japanese Patent Laid-Open No. 1-216504) In the conventional resistance element 31, since each resistance element unit 34 is combined, the problem in manufacturing technology is solved. However, not only the assembling work is troublesome, but also a dimensional error occurs in each resistance element unit 34 during the firing process, and the end face of the resistance element 31 is not flat due to the difference in the vertical length of each element unit 34. Therefore, when each resistance element 31 is assembled, there is a problem that a gap is generated at the contact interface, and as a result, electrical reliability is reduced.

Further, when the material and size of the resistance element unit 34 are varied, a potential difference is generated between the resistance element units 34 and a discharge occurs between the resistance element units 34, and the resistance element 31 is deteriorated early. There was also a problem that it was easy to invite.

The present invention has been made in order to solve the above-mentioned conventional problems, and its object is to greatly improve the discharge capacity against lightning surge without increasing the size and weight of the lightning protection insulator. It is an object of the present invention to provide a lightning protection insulator capable of easily manufacturing and assembling a resistance element, reducing the cost of the product, and further improving the electrical reliability.

[0009]

In order to achieve the above object, the present invention joins a plurality of resistance elements having a non-linear voltage-current characteristic in series inside an insulating jacket and integrating them with an insulating coating. In the lightning protection insulator, in which the resistance element unit configured as described above is housed, and electrode fittings are fitted to both ends of the insulation jacket, the resistance elements are divided into a plurality of pieces along a plane parallel to the axis of the insulation jacket. Then, each of the divided resistive elements in the same column is enclosed by an insulating coating to form a resistive element single unit, and the resistive element unit is configured by converging a plurality of the resistive element single units with a converging means. I am taking it.

[0010]

According to the present invention, since the resistance element alone divided into small pieces is fired, the variation in quality and size can be reduced, and the resistance element can be easily manufactured.

Further, according to the present invention, a resistance element single unit is formed by enclosing a divided resistance element single body in series in a state of being laminated with an insulating coating, and the resistance element single unit is converged by a plurality of converging means. Since the element unit is assembled, the assembly work is facilitated, and the cost of the product can be reduced.

Further, according to the present invention, since each resistance element single unit is insulated by the insulating coating, even if a potential difference occurs between the units, no discharge occurs between the units, and therefore the resistance element is deteriorated. Can be suppressed and electrical reliability can be improved.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment embodying the present invention will now be described with reference to FIG.
~ It demonstrates based on FIG. Fiber reinforced synthetic resin (FR
An insulating jacket 2 made of EPDM, silicon rubber or the like is formed on the outer peripheral surface of the pressure-resistant insulating cylinder 1 made of P), and a large number of pleats 3 are integrally formed on the outer peripheral surface.
A resistance element unit 4 which will be described in detail later and is made of, for example, zinc oxide having a non-linear voltage-current characteristic is housed inside the withstand voltage insulating cylinder 1, and metal such as aluminum or copper is provided at both upper and lower ends thereof. Made of cylindrical spacers 5, 6
Are joined or opposed. An elastic current-carrying member 7 described later is interposed between the resistance element unit 4 and the spacer 5. The outer diameters of the spacers 5 and 6 are formed to have substantially the same dimensions as the inner diameter of the pressure-proof insulating cylinder 1. Further, cap-shaped electrode fittings 8 and 9 are fitted to the upper and lower ends of the pressure-proof insulating cylinder 1, respectively. Then, the inner peripheral surfaces of the cylindrical caulking portions 8a and 9a of the electrode fittings 8 and 9 are
It is fixed by caulking to the outer peripheral surface of the withstand voltage insulating cylinder 1 toward the spacers 5 and 6.

An insulating filler 10 such as silicon rubber is filled between the inner peripheral surface of the pressure-resistant insulating cylinder 1 and the outer peripheral surface of the resistance element unit 4. The pressure-proof insulating cylinder 1 has a pressure-release hole 1 for releasing a high-temperature, high-pressure gas to the outside due to an internal arc in the event that the resistance element unit 4 is conductively broken.
a is formed. In addition, screw holes 8b and 9b are formed in the electrode fittings 8 and 9, and the screw hole 8b is used for attaching the lightning protection insulator to a support arm of a steel tower or the like.
Are used to support a discharge electrode (not shown).

Next, a method of manufacturing the resistance element unit 4 will be described with reference to FIGS. First, as shown in FIG. 2, a large number of resistive element single bodies 11 each having a fan-shaped plane are formed, and the element single bodies 11 are heat-shrinkable elastic tubes 12 as an insulating coating made of EPDM rubber or silicon.
They are housed in series in a laminated state. At this time, a conductive adhesive may be applied to the joint end surface of each element single body 11 and the respective element single bodies 11 may be connected to each other. The elastic tube 1 is moved to the inside of a heating device (not shown) while being placed on the element receiving jig 13 and heated to a predetermined temperature.
2 is shrunk, and a large number of element single bodies 11 are tightly packed in the elastic tube 12 to form a single element single layer unit 14.

Next, a plurality of similarly formed element unit laminate units 14 (four in this embodiment) are assembled and combined so as to form a columnar shape as a whole as shown in FIG. Further, the outer peripheral portion of the plurality of element-only laminated units 14 is covered with a heat-shrinkable elastic tube 15 as another cylindrical thin focusing means, so that each element-only laminated unit 1
4 is contracted and brought into close contact with the outer peripheral surface of 4, and each unit 14 is tightly wrapped in a columnar shape as a whole.

Finally, a reinforcing insulating band 16 made of a heat-shrinkable polymer or FRP is wound around the outer peripheral surface of the heat-shrinkable elastic tube 15 to complete the manufacture of the non-linear resistance element unit 4. ..

Next, the elastic current-carrying member 7 will be described with reference to FIG.
A plurality of short-circuit conductors 1 for electrically connecting the coil-shaped compression spring 18 inserted through the through-hole 17a formed therein, each element-unit laminated unit 14 and the upper spacer 5 respectively.
9 and 9. Further, the lower end surface of the resistance element unit 4 is pressed against the upper surface of the lower spacer 6 by the elastic force of the compression spring 18 so as to be electrically conducted.

The process of assembling the lightning protection insulator constructed as described above will be briefly described. A lower electrode metal fitting 9 is fitted to the lower end of the pressure-resistant insulating cylinder 1, and a lower spacer 6 is housed inside the pressure-resistant insulating cylinder 1 to form a caulking cylinder (not shown).
By pressing the outer peripheral surface of the caulking portion 9a of the lower electrode metal fitting 9 toward the center of the spacer 6 at a plurality of points, and caulking the caulking portion 9a of the electrode metal fitting 9 to the spacer 6 while crimping the end portion of the pressure-proof insulating cylinder 1. Fix it. In this step, the airtightness may be improved by applying a resin-based or rubber-based adhesive in advance on the interface between the pressure-resistant insulating cylinder 1 and the electrode fitting 9.

Further, the resistance element unit 4, the elastic current-carrying member 7, and the upper spacer 5 are sequentially accommodated in the pressure-resistant insulating cylinder 1, and the upper electrode metal fitting 8 is fitted to the outer peripheral portion of the pressure-resistant insulating cylinder 1. In this state, the caulking portion 8 of the electrode fitting 8
The outer peripheral surface of a is pressed by a caulking cylinder (not shown) to be caulked and fixed.

Finally, the pressure-proof insulating cylinder 1, both electrode fittings 8, 9
In a state of being housed in a molding die (not shown), molten rubber is injected into the cavity of the molding die to be cured, and
The insulating jacket 2 is molded on the outer peripheral surface of the. At this time, the insulating jacket 2 includes the pressure-proof insulating cylinder 1 and the crimped portions 8a, 9
It is vulcanized and adhered to the outer peripheral surface of a. Further, the molten rubber enters the inside of the pressure-proof insulating cylinder 1 through the pressure release hole 1 a and becomes the insulating filler 10.

The lightning protection insulator constructed as described above is
For example, it is applied to a power line supporting insulator device, and the lower electrode fitting 9
A discharge electrode (not shown) on the ground side is supported by the. Then, a discharge electrode (not shown) on the power supply side supported on the transmission line side flows over the air discharge gap to the discharge electrode on the ground side, and then passes through the resistance element unit 4 of the lightning protection insulator, and then the upper electrode metal fitting. It flows from 8 to the support arm of the steel tower and is discharged to the ground. Further, the subsequent current generated thereafter is suppressed and cut off by the restoration of the air discharge gap and the resistance value of the resistance element unit 4, thereby preventing a ground fault accident.

In this embodiment, the resistive element unit 11 is laminated and joined in series to form the heat-shrinkable elastic tube 12.
In the state in which a plurality of element unit units 14 are bundled into a columnar shape as a whole and further wrapped with a heat-shrinkable elastic tube 15, the individual resistance element units are adhered to each other. In comparison, the manufacturing and assembling operations can be performed quickly and easily, and the cost of the product can be reduced.

Further, each resistance element single body 11 is adjacent to each resistance element single body 11 due to a dimensional error in manufacturing or a variation in material.
Even if a potential difference occurs between them, since they are insulated from each other by the insulating tube 12, no discharge occurs between the element unit units 14 and deterioration of the element is suppressed to improve durability. Reliability can be improved.

Next, another embodiment of the present invention will be described with reference to FIGS.
It will be explained based on. (1) Instead of the heat-shrinkable elastic tube 12, as shown in FIG. 6, an insulating housing cylinder 21 as an insulating coating for housing the element unit 11 made of an insulating material is formed in advance, and the housing cylinder 21 is A single element element 11 is stacked in series inside the accommodation space 21a and accommodated therein. Further, a plurality of the insulation accommodation cylinders 21 are bundled and integrally connected by an insulation band 16 or the like to form a cylindrical resistance element unit. Make up 4. In this embodiment, an adhesive is used to prevent the resistance element single body 11 from coming off from the accommodation space 21a.

(2) In another embodiment shown in FIG. 7, a housing space 22a for housing the fan-shaped resistive element single body 11 in series is housed in an insulating housing cylinder 22 made of synthetic resin which also serves as an insulating coating and a focusing means. Are formed at a plurality of locations to form a cylindrical resistance element unit 4. In this embodiment, an adhesive is used in order to prevent the resistance element single body 11 from coming off from the accommodation space 22a.

[0027]

As described in detail above, according to the present invention, the resistance element unit can be easily manufactured and assembled without increasing the size and weight of the resistance element unit, and the cost of the lightning protection insulator can be reduced. Moreover, there is an effect that the electrical reliability can be further improved.

[Brief description of drawings]

FIG. 1 is a fragmentary perspective view showing an embodiment embodying a lightning protection insulator of the present invention.

FIG. 2 is a perspective view showing a single resistive element laminated unit.

FIG. 3 is a vertical cross-sectional view showing the entire lightning protection insulator.

4 is a cross-sectional view of the lightning protection insulator of FIG.

FIG. 5 is a partially exploded perspective view of the vicinity of a holding metal fitting.

FIG. 6 is a partial perspective view of a resistance element unit showing another example of the present invention.

FIG. 7 is a partial perspective view of a resistance element unit showing another example of the present invention.

FIG. 8 is a transverse cross-sectional view showing a relationship between a resistance element of a conventional lightning protection insulator and a withstand voltage insulating cylinder.

FIG. 9 is a transverse cross-sectional view showing a relationship between a resistance element of a conventional lightning protection insulator and a withstand voltage insulating cylinder.

FIG. 10 is a perspective view showing a resistance element of a conventional lightning protection insulator.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Withstand voltage insulation cylinder, 2 Insulation outer shell, 4 Resistance element unit, 8 Upper electrode metal fittings, 9 Lower electrode metal fittings, 11 Resistance element single body, 12 Heat shrink elastic tube as an insulation coating, 14 Single element laminated unit, 15 As focusing means Heat-shrinkable elastic tube, 21 Insulation container as insulation coating, 21a accommodation space, 22 Insulation container made of synthetic resin that also serves as insulation coating and focusing means, 22a accommodation space.

Claims (1)

[Claims] 1. A resistance element unit in which a plurality of resistance elements having a non-linear voltage-current characteristic are connected in series inside an insulating jacket and integrated by an insulating coating is accommodated, and both ends of the insulating jacket are accommodated. In the lightning insulator in which the electrode fittings are fitted to the respective parts, the plurality of resistance elements are divided into a plurality of pieces along a plane parallel to the axis of the insulating jacket, and each divided resistance element in the same row is individually insulated by an insulating coating. A lightning arrester characterized in that a resistance element single unit is formed by enclosing the resistance element single unit, and a plurality of the resistance element single units are converged by a converging means to form the resistance element unit.