JPH01258402A - Lightning arrestor - Google Patents

Abstract

PURPOSE:To make the title device substantially small in size by a method wherein a capacitor is almost densely taken into the area of tabular non-linear resistance element so that its outside appearance makes a true roundness substantially. CONSTITUTION:A tabular non-linear resistance element 41 is formed into a doughnut shape having a rectangular cross section, and a capacitor 6b, to be used for pressure equalization, is arranged in the cavity part located in the center. Accordingly, the electrode plates 41a-51c, attached to both end faces of the elements of a set of two, the projection to be used for the pressure- equalizing capacitor 6b is unnecessitated, and the element 41 can be formed in true roundness. Therefore, the inside diameter of a container, which is determined by the size of an insulating plate 21a, can be made small sharply when compared with the device heretofore in use, and the container is made small in size remarkably.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention is directed to stacking a plurality of plate-shaped nonlinear resistance elements each having contact surfaces on both sides in a container, and stacking a plurality of pressure equalizing capacitors in the container. are arranged in the direction in which the non-device type resistance elements are stacked and electrically connected in series, and the connection point is electrically connected to the contact surface located in the middle of the stack of the non-wire resistance elements to form each non-linear resistance element. The present invention relates to a lightning arrester that equalizes voltage sharing among resistive elements.

[Conventional technology]

Examples of conventional configurations of this type of lightning arrester are shown in FIGS. 5 and 6, where FIG. 5 is a side view of the top of the lightning arrester housed in a container, It is a cross-sectional view seen in the direction of the arrow at the -X position.

As seen in FIG. 5, nitrogen oxide 2. (A disc-shaped nonlinear resistance element 4 (hereinafter referred to as an element) is made of a powder of any metal oxide as a main component and has contact surfaces formed on both sides by a method such as thermal spraying after being compressed, molded, and sintered. Stack them one by one,
In between, sandwich the electrode 5b, and also on the upper surface and the lower end surface respectively! Pole plate 5a.

Apply 5C and turn the electrodes 5a and 5b+ 5b and 5
There are pressure equalizing capacitors 6a and 6b between the
The kR3 & stud 3 and the nut 1 are tightened so that the whole unit is integrated with the insulating plates 2g and 2b from both upper and lower sides with the kR3 and stud 3 in electrical contact with each other. The main part of the lightning arrester is formed. Here, the capacitance of the voltage equalizing capacitor is determined by the unevenness of the shared voltage of each element when there is no voltage equalizing capacitor, the variation in the characteristics of the element itself, and the fact that each element is connected to the metal part of the container, that is, the container is insulated. This inter-container capacitance is generated based on the capacitance of the metal cap that closes both end faces in the case of a cylinder, and the capacitance of the capacitor formed between the container and the entire container if the container is made of metal. By using a capacitance that is sufficiently larger than , and whose reactance is sufficiently smaller than the resistance value exhibited by the element under normal use, and which is larger than the capacitance between both contact surfaces of the element,
The shared voltages of each element are made uniform.

(Problems to be Solved by the Invention) Problems with the conventional lightning arrester configured as described above are as follows. That is, as mentioned above, the voltage equalizing capacitor connected in parallel with the element must have a large capacitance in order to ensure its pressure equalizing effect, and its diameter cannot be reduced below a certain limit. Therefore, if these were arranged as shown in Fig. 5-6 and housed in a normally cylindrical container, the inner diameter of the container would be significantly large, and this would result in a closed type gas insulated switchgear that has been widely used in recent years. This has the disadvantage that it hinders miniaturization of the device and is also expensive.

An object of the present invention is to provide a lightning arrester structure that eliminates the above-mentioned drawbacks of conventional lightning arresters of this type and minimizes the size of a container that accommodates an element and a voltage equalizing capacitor connected in parallel. That's true.

[Means to solve the problem]

In order to achieve the above object, according to the present invention, a plurality of plate-shaped nonlinear resistance elements having contact surfaces formed on both sides are stacked in a container, and a plurality of pressure equalizing capacitors are connected to the nonlinear resistance elements in the container. A lightning arrester is electrically connected to the contact surface of the resistive element to equalize voltage sharing among each non-linear resistive element, and the plate-shaped non-linear resistive element covers the capacitor almost closely within its area. It is assumed that the outer shape is formed into a substantially perfect circle.

[For production]

This invention provides the following features:
In addition to focusing on the existence of large wasted spaces, we are developing manufacturing techniques that allow the characteristics to be uniform over the entire area, no matter how the shape of the element is formed. In order to reduce the height, the elements are formed into a partial circle or fan shape and arranged in the circumferential direction, and the lower surface of one element and the upper surface of the next element are connected in series one after another using a conductor. This was developed based on a manufacturing technology that allows the distribution of through-break locations to be similar to that of a normal fully circular element when an impact current exceeding its discharge capacity is applied to the fan-shaped element. If the lightning arrester is configured as in the present invention, even if the diameter of the voltage equalizing capacitor increases as a single unit due to the capacitance required for its voltage equalizing effect, it is still small compared to the diameter of the element. Even if the element is formed so that the outer shape is substantially a perfect circle, the maximum diameter of the element does not become very large, and the container can be made smaller.

〔Example〕

A first embodiment of the present invention is shown in FIGS. 1 and 2. FIG. Here, FIG. 1 is a side partial sectional view of the main parts of the lightning arrester housed in a container, and FIG. 2 is a cross-sectional view taken along the line XX in FIG. 1 in the direction of the arrow.

In these figures, the same members as in FIGS. 5 and 6 are designated by the same reference numerals, and explanations thereof will be omitted.

As seen in FIG. 1, the element 41 is formed into a donut shape with a rectangular cross section, and the pressure equalizing capacitor 6 is disposed in the central cavity. Therefore, the electric scraping plates 51a and 51b are applied to both end surfaces of each pair of elements.

51c does not require a protrusion for a pressure equalizing capacitor as shown in FIG. 6, and can be formed in a perfect circle shape.

In this case, the outer diameter of the element 41 is a dimension that provides an area approximately equal to the sum of the area of the conventional element 4 (FIG. 6) and the cross-sectional area of the pressure equalizing capacitor 6 al 6 b. Although it is larger than the diameter of the element, the difference is small.Also, in this case, the insulating plate 21a is also larger than before, but the difference is small, so the inner diameter of the container, which is determined by the size of the insulating plate, is smaller than before. becomes significantly smaller,
The container is significantly smaller.

3 and 4 show the second embodiment of the present invention, the same members as in FIGS. 1.2 and 5.6 are given the same reference numerals, and their explanations are omitted. This example shows a configuration example to facilitate disassembly work when checking or inspecting the characteristics of the element and the pressure equalization capacitor separately.As shown in FIG. It is formed in a shape having an arc-shaped notch on the outer periphery, and pressure equalizing capacitors 6a and 6b are fitted into this notch.

The maximum diameter of the element 42 at this time is almost equal to the outer diameter of the element 41 in the first actual MH example, and the difference from the conventional element is small. The size of the perfectly circular electrode plate and the size of the insulating plate are also approximately the same as in the first embodiment, and the container is greatly miniaturized.

〔Effect of the invention〕

As described above, the present invention focuses on the existence of a large wasted space inside the container in the conventional lightning arrester of this type, and also uses conventionally established manufacturing techniques to reduce the characteristics of the element over its entire area. Focusing on the fact that it can be formed into any shape without having to worry about it, we formed the element so that the pressure equalizing capacitor was almost completely incorporated into the element so that the entire element was a perfect circle.This enabled the container to be significantly smaller, making it possible to create a hermetic seal that has become popular in recent years. This has the effect of making it possible to downsize the gas switchgear and also to reduce its own costs.

[Brief explanation of the drawing]

FIG. 1 is a side partial sectional view showing the configuration of the main parts of the lightning arrester according to the first embodiment of the present invention, and FIG. 2 is a Y--
FIG. 3 is a cross-sectional view of the main part of the lightning arrester according to the embodiment shown in FIG. 2, and FIG. Fig. 5 is a side view showing the configuration of the main parts of a conventional lightning arrester, and Fig. 6 is a cross-sectional view of the main parts seen in the direction of the arrow at position X-X in Fig. 5. It is a front view. 4.41.42: Element (nonlinear resistance element), 6a
, 6b: Figure 1, Figure 2, Figure 3, Figure 5

Claims (1)

[Claims] 1) A plurality of plate-shaped nonlinear resistance elements with contact surfaces formed on both sides are stacked in a container, and a plurality of pressure equalizing capacitors are arranged in the container in the stacking direction of the nonlinear resistance elements to electrically In the lightning arrester in which the non-linear resistance elements are connected in series and the connection point is electrically connected to the contact surface located in the middle of stacking the non-linear resistance elements to equalize voltage sharing among the non-linear resistance elements, the plate-shaped 1. A lightning arrester characterized in that a non-linear resistance element is formed so that the capacitor is almost completely enclosed within its area so that the outer shape is substantially perfect circular.