JPH07272823A - Arrester - Google Patents

Abstract

PURPOSE:To provide an arrester element which can easily enlarge the amperage tolerance of the resultant lightning arrester. CONSTITUTION:An arrester element 2 is formed columnarly, and electrodes 21, 22 are provided at the bore and the periphery, respectively, and an insulative layer 23 is provided on a circular plane on each side. A conductor 25 is inserted in a through hole in which the electrode 21 is installed so that it works as a terminal conductor of electrode 21. If the axial length of the arrester element 2 is enlarged, the electrode area can be enlarged easily. Because the amperage tolerance of the resultant lightning arrester depends upon the electrode area, use of this type of element allows accomplishment of a lightning arrester having a large amperage tolerance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lightning arrester provided in a power distribution system or the like for overvoltage protection, and more particularly to a lightning arrester provided in a relatively low voltage system such as a power distribution system and required to have a large current withstanding capability.

[0002]

2. Description of the Related Art A lightning arrester has a lightning element as a non-linear element as a main constituent element. This lightning element is formed by sintering a material containing zinc oxide as a main component into a predetermined shape and then forming a metal such as aluminum. Is sprayed on the surface to form a pair of electrodes. FIG. 6 is a perspective view of a lightning arrester element of a conventional lightning arrester.
As shown in the figure, the lightning protection device 1 is in the shape of a thick disk, and the electrodes 11, 12 formed by blowing aluminum are provided on the circular flat surfaces on both sides of the lightning protection device 1. The curved surface is covered with insulating tape. The insulating layer 13 is formed by being turned.

In the case of a lightning arrester provided in a high-voltage power system, a large number of lightning arresters 1 are axially stacked so that their electrodes 11 and 12 are in contact with each other. Current capacity is electrode 1
It is determined by the area of 1,12, and the withstand voltage is determined by the axial length. FIG. 7 is a perspective view showing a lightning arrester element of a conventional lightning arrester having a configuration different from that of FIG. 6, and a component having the same function as that of FIG. Lightning arrester 1A
A through hole 14 is provided in the through hole 14, and as described above, when a plurality of lightning arrester elements 1A are stacked, a tightening bolt is passed through the through hole 14 to tighten the lightning arrester elements 1A for integration. Figure 6
In the case of the lightning protection element 1, the plurality of tightening bolts are arranged outside the stacked lightning protection elements 1.

[0004]

In a relatively low voltage electric system, a single lightning arrester element can provide sufficient voltage withstand capability, but current withstand capability is sometimes insufficient. As described above, the current withstand capability is proportional to the area of the electrodes 11, 12, 11A, 12A, but the diameter of the lightning protection element 1, 1A cannot be made too large due to manufacturing restrictions. There is a problem that there is an upper limit to the current capacity. In order to fabricate a lightning arrester with a current withstanding capacity higher than this upper limit, it is necessary to adopt a configuration in which multiple lightning arresters 1, 1A are connected in parallel, but the lightning arrester 1 having the shape shown in the figure is connected in parallel. Has a problem that the connection structure is complicated and the size of the arrester is large, which is not practical.

An object of the present invention is to solve such problems and to provide a lightning arrester having a lightning arrester capable of easily increasing the withstand current.

[0006]

In order to solve the above problems, according to the present invention, in a lightning arrester including a lightning arrester containing zinc oxide as a main component and a pair of electrodes, the lightning arrester has a cylindrical shape. It is formed, and electrodes are provided on the inner diameter surface and the outer diameter surface, respectively. Further, it is assumed that at least two lightning protection elements are electrically connected to each other on the inner diameter surface and on the outer diameter surface.

[0007]

In the structure of the present invention, the lightning protection element is formed in a cylindrical shape, and electrodes are provided on the inner diameter surface and the outer diameter surface, respectively, so that the electrode area can be easily increased by increasing the axial length of the lightning protection element. Can be large. Further, when the electrodes on the inner diameter surface and the electrodes on the outer diameter surface of at least two lightning protection elements are electrically connected to each other and the lightning protection elements are connected in parallel, the electrode area becomes twice as many as the single lightning protection element in parallel. Therefore, even when the electrode area required to obtain the desired current withstand capability cannot be obtained with one lightning protection element, the required electrode area can be easily obtained.

[0008]

EXAMPLES The present invention will be described below based on examples.
1 is a perspective view of a lightning arrester showing an embodiment of the present invention, and FIG.
FIG. 2 is a circuit diagram of a lightning arrester using the lightning arrester of FIG.
In these figures, the lightning arrester element 2 is formed by forming zinc oxide into a cylindrical shape and spraying aluminum on its inner and outer diameter surfaces to form electrodes 21 and 22, and insulating layers are formed on the circular planes on both sides. Formed 23. A conductor 25 is inserted into a through hole provided with the electrode 21 and electrically connected to the electrode 21. The conductor 25 has a function of a terminal conductor, and since the detailed structure is omitted, the lightning protection element 2 is fixed. It also has the function of a fixing bracket. The conductor 26 shown in FIG. 2 as a terminal connected to the electrode 22 on the outer diameter side is not shown in FIG.

Since the electrode 21 is on the inner diameter side and therefore has a smaller area than the electrode 22, the current withstand capability of the lightning arrester element 2 is determined by the area of the electrode 21. The area S of the electrode 21 is S = 2πrb, where r is the inner radius of the lightning protection element 2 and b is the axial length.
As described above, r has an upper limit in relation to the outer diameter dimension due to the restrictions when sintering zinc oxide, but since the length dimension b can be increased, the electrode area S is set to the upper limit value of the conventional lightning protection device. It is relatively easy to make larger than.

The withstand voltage of the lightning protection element 2 is determined by the value of (R-r) where R is the radius of the outer diameter. If this value is large, the radius r of the inner diameter must be reduced, and the electrode area S cannot be increased. Therefore, in such a case, since it is difficult to secure the electrode area S required to obtain the current withstanding capability, it is appropriate to adopt the lightning protection device 1, 1A having the conventional configuration shown in FIGS. 6 and 7. . On the other hand, when the withstand voltage is small, the radius r can be set to a large value close to the radius R, so that it is easy to secure a large electrode area S.

It is possible to easily form the lightning arrester element 2 into a cylindrical shape by a conventional technique as shown in the lightning arrester element 1A of the conventional lightning arrester of FIG. The through hole 14 for the tightening bolt of FIG. 7 and the through hole for the electrode 21 of FIG. 1 differ only in their dimensions. That is, from the viewpoint of performance as a lightning arrester, it is preferable that the through hole of the lightning arrester element 1A is small and that of the lightning arrester element 2 is large.

FIG. 3 is a perspective view of only the lightning arrester element of the lightning arrester showing another embodiment of the present invention, FIG. 4 is a sectional view taken along a plane including the axis of symmetry of FIG. 3, and FIG. 5 is a circuit diagram of the lightning arrester element of FIG. And
The same components as those in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted. In these figures, three lightning arresters 2A, 2B, 2C each corresponding to the lightning arrester of FIG. 1 are stacked in the axial direction. A round bar-shaped conductor 33 is commonly connected to the lightning protection elements 2A, 2B, 2C and is electrically connected to the electrode 21 on the inner diameter side through the through hole. It is provided so as to cover the outer diameter side and is electrically connected to the electrode 22 on the outer diameter side. Therefore, as shown in FIG. 5, lightning protection devices 2A, 2B, 2C
Are electrically connected in parallel, their current capacity is three times that of a single lightning protection device. Lightning element 2
There is also an upper limit on the axial dimension of A, 2B, and 2C alone. The lightning protection elements 2A, 2B, 2C may be stacked in the axial direction.

The number of lightning protection devices connected in parallel is not limited to three, and may be two or four or more. Further, the shapes and configurations of the conductors 25, 33, 34 are not limited to those described above.

[0014]

As described above, according to the present invention, the lightning protection element is formed into a cylindrical shape, and electrodes are provided on the inner diameter surface and the outer diameter surface of the lightning protection element, thereby increasing the axial length of the lightning protection element. The area can be easily increased. Since the current withstanding capability of the lightning arrester is proportional to the area of the electrode, a lightning arrester with a large current withstanding capability can be obtained by using this lightning arrester. Further, when a plurality of such lightning protection elements are stacked in the axial direction and electrodes on the inner diameter surface and electrodes on the outer diameter surface are electrically connected to each other so that the respective lightning protection elements are connected in parallel, It is possible to easily obtain a lightning arrester having a desired current withstand capability even when the current withstand capability is insufficient with the individual lightning arresters.

[Brief description of drawings]

FIG. 1 is a perspective view of a lightning arrester element of a lightning arrester showing an embodiment of the present invention.

FIG. 2 is a circuit diagram of a lightning arrester using the lightning arrester of FIG.

FIG. 3 is a perspective view showing only a lightning arrester element of a lightning arrester showing another embodiment of the present invention.

4 is a cross-sectional view of the lightning protection device of FIG. 3 taken along a plane including an axis of symmetry.

5 is a circuit diagram of a lightning arrester using the lightning arrester of FIG.

FIG. 6 is a perspective view of a lightning arrester element of a conventional lightning arrester.

FIG. 7 is a perspective view of a conventional lightning protection device having a configuration different from that of FIG.

[Explanation of symbols]

 1,1A, 2,2A, 2B, 2C… Lightning arrester 21,22,21A, 22A… Electrode 25,26,33,34… Conductor

Claims (2)

[Claims] 1. A lightning arrester comprising a lightning arrester mainly composed of zinc oxide and provided with a pair of electrodes, wherein the lightning arrester is formed in a cylindrical shape, and electrodes are provided on an inner diameter surface and an outer diameter surface respectively. Lightning arrester, which is characterized by 2. The lightning arrester according to claim 1, wherein at least two lightning arresting elements are electrically connected to each other on the inner diameter surface and on the outer diameter surface.