JPS6237891A - Arrestor for gas insulation neutral point - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a lightning arrester, and more particularly to a gas-insulated neutral point lightning arrester used for neutral point protection of a stage-insulated transformer.

[Technical background of the invention and its problems] As is well known, lightning arresters limit the peak value of shocking abnormal voltages caused by lightning and the opening and closing of circuits by shunting the accompanying current, thereby preventing the occurrence of electricity in power systems. It is used to protect electrical equipment such as substations. As one such lightning arrester, a neutral point protection lightning arrester, which is installed in the neutral point grounding circuit of a stage isolation transformer (hereinafter simply referred to as a transformer), has been adopted as one such lightning arrester. ing.

Figure 5 shows a front view of this type of neutral point protection lightning arrester installed on a transformer, and Figure 6 shows a neutral point protection lightning arrester connected to a transformer. This figure shows a single-line connection diagram. In the figure, 1 is a transformer, 2 and 3 are its primary and secondary connections, 6 and 7 are primary and secondary cables connected to the primary and secondary connections 2 and 3, respectively; is a primary neutral point bushing installed on the top of the tank of transformer 1, and 4 is a primary neutral point lightning arrester that is also installed on the top of the tank of transformer 1 and electrically connected to the primary neutral point bushing. .

By the way, a primary neutral point lightning arrester 5, which is a neutral point protection lightning arrester, is attached to the upper part of the tank of the transformer 1, as shown in FIG. For this reason, if the transformer has a configuration in which the secondary side and secondary side main circuits are not exposed, installing the secondary neutral point lightning arrester 5 on the top of the tank of the transformer 1 will not expose the main circuit. I can't. On the other hand, as a method to solve this problem, a method is being considered to adopt gas-insulated switchgear consisting of a disconnector and lightning arrester, which are part of conventional gas-insulated switchgear, but this is not possible due to the cost. The problem is that it becomes very expensive.

[Object of the Invention] The present invention was made to solve the above-mentioned problems, and its purpose is to integrate a disconnector and a lightning arrester, and to improve the insulation resistance for maintenance and inspection of the lightning arrester. It is an object of the present invention to provide an economically advantageous gas-insulated neutral point lightning arrester that can be extremely easily measured.

[Summary of the Invention] In order to achieve the above object, the present invention provides a neutral point protection lightning arrester that is installed in a neutral point grounding circuit of a transformer to protect the neutral point. The neutral point extraction part is taken out from the neutral point extraction part, and the high voltage side fixed contact connected to the neutral point lead wire of the neutral point extraction part, the grounding side fixed contact connected to the grounding wire, and the insulation resistance measurement. A case part is provided with a fixed contact and an insulating gas is filled inside, and a lightning arrester internal element is housed inside a lightning arrester insulating cylinder, and the high voltage side fixed contact or a fixing for insulation resistance measurement is provided. A lightning arrester section that is housed inside the case section and includes a high-voltage side lightning arrester movable contact that can make contact with and separate from the contact, and a ground side lightning arrester movable contact that can always come into contact with the ground side fixed contact; The present invention is characterized in that it comprises a rotation mechanism part that is mechanically coupled to the lightning arrester part and rotates the lightning arrester part.

[Embodiments of the invention] An embodiment of the present invention shown in the drawings will be described below.

FIGS. 2 and 3 show a side view and a front view, respectively, of a configuration example when the gas-insulated neutral point lightning arrester according to the present invention is applied to a transformer, and show the same parts as FIG. 5. are given the same reference numerals and their explanation will be omitted, and only the different parts will be described here. In other words, in Figures 2 and 3,
A primary neutral point extraction part 8 is taken out from the side of the tongue of the transformer 1, and a gas insulated neutral point lightning arrester 9 of the present invention is attached to this secondary neutral point extraction part 8, and furthermore, this gas insulated neutral point The lightning arrester 9 is placed on a pedestal 10.

FIG. 1 is a sectional view showing an example of the structure of the gas-insulated neutral point lightning arrester 9, and the same parts as in FIGS. 2 and 3 are denoted by the same reference numerals.

That is, this gas-insulated neutral point lightning arrester 9 has lightning arrester internal elements 21. Lightning arrester upper electrode plate 22. Lightning arrester movable contact 2
3. Lightning arrester insulation tube 25. Metal cylinder for protecting the insulation cylinder 26. , sliding ring 27. A surge arrester section having a new circuit function consisting of a surge arrester lower electrode plate 29, and a surge arrester intermediate support 20. Sliding ring presser 281 Rotating rod 30. Lightning arrester mounting plate holder 31. Lightning arrester mounting plate 32, lightning arrester mounting plate 35. Fixing nut 3
6, a rotating mechanism section that enables the lightning arrester section to rotate, and a gas bushing side fixed contactor 24 as a high pressure side fixed contactor. Ground side fixed contact 37. Ground side terminal 38. Fixed contact for insulation resistance measurement 40. A main circuit connection portion consisting of an insulation resistance measurement terminal 42 and a gas-insulated neutral point lightning arrester flange 16. Metal case 18. Gas insulated neutral point lightning arrester bottom plate 19. Gas seal part 33. Protective cover 39. It consists of a case part 6-1, which is made up of a bushing 41 and a protective cover 43, and houses the rotation mechanism part of the lightning arrester part 1 and the main circuit connection part.

First, in the above-mentioned lightning arrester section, the surge arrester internal element 21 is housed inside the surge arrester insulating tube 25, and its upper and lower parts are fixed by the surge arrester upper electrode plate 22 and the surge arrester lower electrode plate 29 as the ground side surge arrester movable contact. There is.

Furthermore, a rod-shaped high-voltage side surge arrester movable contact 23 is mounted and fixed in a substantially horizontal direction on the lightning arrester upper electrode plate 22, and this lightning arrester movable contact 23 is arranged so that the main surge arrester part rotates. As shown in FIG. 4, it is connected to the gas bushing side fixed contact 24 to connect the lightning arrester to the main circuit, or it is connected to the insulation resistance measuring fixed contact 40 to disconnect the lightning arrester. It has become.

Further, the lightning arrester lower electrode plate 29 has a disk shape, and is always in contact with the ground side fixed contact 37 to be electrically connected.

On the other hand, in the rotating mechanism section, the lightning arrester section is fixedly attached to the upper surface side of the lightning arrester mounting plate 32, and the rotating rod 30 is directly connected to the lower surface side. Furthermore, a lightning arrester intermediate support 20 is disposed approximately in the longitudinally intermediate portion of the outer circumferential side of the lightning arrester insulating tube 25 with a predetermined gap as shown in the figure in order to prevent the lightning arrester portion from lateral wobbling due to rotation. has been done. Furthermore, a metal tube 26 for protecting the insulation tube is provided in the gap on the outer peripheral side of the lightning arrester insulation tube 25, and a sliding ring 27 is fixed to the metal tube 26 for protecting the insulation tube. is attached to the lightning arrester intermediate support 20 so as to slide within a sliding ring retainer 28 fixed thereto. Furthermore, the lightning arrester lower holding plate 35 is fixed to the rotating rod 30' by a fixing nut 36, and as the rotating rod 30 rotates, the gas seal portion holding plate 34 slides to prevent vertical vibration of the lightning arrester portion. I try to do that.

Further, in the main circuit section and the case section, the ground side fixed contact 37 is electrically connected to a ground wire (not shown) through a ground side terminal 38. On the other hand, at a corresponding position on the same horizontal plane as the lightning arrester movable contact 23 of the metal case 18, there is a fixed contact 40 for measuring insulation resistance inside the metal case 18.
is attached, and a bushing 4 is attached to the outside of the metal case 18.
1 is set up. Further, an insulation resistance measuring terminal 42 is attached to the bushing 41, and the bushing 41 and the insulation resistance measuring terminal 42 are covered with a removable protective cover 43. Furthermore, the rotating rod 30. Gas seal part presser 34, lightning arrester lower presser plate 35. The fixing nut 36 is covered with a removable protective cover 39, which protects the rotating rod 30 and prevents erroneous operation thereof.

In addition, 11 is a metal case of the primary neutral point extraction part 8, 12 is a neutral point lead wire arranged in the case 11 of this primary neutral point extraction part 8 and connected to the neutral point of the transformer 1, and 13 is a neutral point lead wire of this primary neutral point extraction part 8. Neutral point oil bushing to which neutral point lead wire 12 is connected, 1
4 is the neutral point oil submerged bushing connection part, 15 is the primary neutral point extraction part flange, and 17 is fixed to the primary neutral point extraction part flange 15 and the flange 16 of the gas-insulated neutral point lightning arrester 7. This is a neutral point gas bushing. Also,
Insulating oil is filled inside the secondary neutral point extraction section 8, and insulating gas such as SFs is filled inside the gas-insulated neutral point lightning arrester 9.

In the gas-insulated neutral point lightning arrester of this embodiment configured as described above, first, the movable surge arrester contactor 23 attached to the surge arrester upper electrode plate 22 of the surge arrester section is normally fixed to the gas bushing side as shown in FIG. It is connected to the contactor 24. As a result, the lightning arrester section becomes connected to the main circuit, and the neutral point of the transformer 1 is connected to the neutral point lead wire 12. Neutral point oil bushing 13, neutral point gas bushing 17. Gas bushing side fixed contact 24. Lightning arrester movable contact 23. Lightning arrester internal element 21. Lightning arrester lower electrode plate 29. Ground side fixed contact 3
7. It is grounded via the ground side terminal 38, making it possible to protect the transformer 1.

Next, when disconnecting the lightning arrester section and removing it from the protection of the transformer 1 for maintenance or inspection, first remove the protective cover 39 from the bottom plate 19 of the gas-insulated neutral point lightning arrester, and then use the handle to 30 to the position of the fixed contact 40 for measuring insulation resistance, the movable lightning arrester contact 23
The electrical connection is switched from the gas pushing side fixed contact 24 side to the insulation resistance measuring fixed contact 40 side. Then, by removing the protective cover 43 from the metal case 18 while the main circuit is disconnected, the insulation resistance measuring terminal 42 is opened.
is exposed, so the insulation resistance of the lightning arrester section can be easily measured between the insulation resistance measuring terminal 42 and the ground terminal 38.

In addition, when returning this gas-insulated neutral point lightning arrester 9 to the neutral point protection of the transformer 1 again, use the handle to move the rotating rod 30 to the fixed contact 2 on the gas bushing side in the same way as described above.
By rotating it to position 4, the lightning arrester movable contact 23 is connected to the gas bushing side fixed contact 24, and the main circuit can be easily connected.

From the above, in the gas-insulated neutral point lightning arrester according to this embodiment, the disconnector and the arrester can be integrated to form the arrester section, and the main circuit of the arrester section is disconnected. This makes it extremely easy to measure insulation resistance.

Furthermore, the neutral point protection of the transformer 1, which is the original function, can be reliably performed, making it possible to provide an extremely reliable gas-insulated neutral point lightning arrester.

Note that the present invention is not limited to the embodiments described above, and can be implemented with various modifications without changing the gist thereof.

[Effects of the Invention] As explained above, according to the present invention, in a neutral point protection lightning arrester provided in a neutral point grounding circuit of a transformer to protect the neutral point, The neutral point extraction part is taken out from the neutral point extraction part, and the high voltage side fixed contact connected to the neutral point lead wire of the neutral point extraction part, the grounding side fixed contact connected to the grounding wire, and the insulation resistance measurement. A case part is provided with a fixed contact and an insulating gas is filled inside, and a lightning arrester internal element is housed inside a lightning arrester insulating cylinder, and the high voltage side fixed contact or a fixing for insulation resistance measurement is provided. A lightning arrester section that is housed inside the case section and includes a high-voltage side lightning arrester movable contact that can make contact with and separate from the contact, and a ground side lightning arrester movable contact that can always come into contact with the ground side fixed contact; Since it is composed of a rotation mechanism that is mechanically coupled to the lightning arrester section and rotates the lightning arrester section, it is possible to integrate the disconnector and the lightning arrester, and it is also easy to use for maintenance and inspection of the lightning arrester. It is possible to provide an economically advantageous and highly reliable gas-insulated neutral point lightning arrester that allows very easy insulation resistance measurements.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing one embodiment of the present invention, FIGS. 2 and 3 are side views and front views showing an example of a configuration in which the present invention is applied to a transformer, and FIG. Figure 5 is a front view showing a configuration example when a conventional neutral point protection lightning arrester is attached to a transformer;
FIG. 6 is a single line diagram showing the case where the neutral point protection lightning arrester is connected to the transformer. DESCRIPTION OF SYMBOLS 1...Transformer, 2...-Next side connection part, 3...Secondary side connection part, 4...-Next neutral point bushing, 5...-
Next neutral point lightning arrester, 6...-secondary cable, 7...secondary cable, 8...-secondary neutral point extraction part, 9...gas insulated neutral point lightning arrester, 10... - Frame, 11...-Next neutral point extraction part metal case, 12... Neutral point lead wire,
13... Bushing in neutral point oil, 14... Bushing connection part in neutral point oil, 15... Flange for next neutral point extraction part, 16... Gas insulated lightning arrester for neutral point 7 lunge,
17... Neutral point gas bushing, 18... Metal case, 19... Gas insulated neutral point lightning arrester bottom plate, 20...
...Surge arrester intermediate support, 21...Surge arrester internal element, 22
... Lightning arrester upper electrode plate, 23... Lightning arrester movable contact, 24... Gas bushing side fixed contact, 25...
Lightning arrester insulating tube, 26... Metal tube for protecting the insulating tube, 27.
...Sliding ring, 28...Sliding ring holder, 29...
・Surge arrester lower electrode plate, 30...Rotating rod, 31...
・Surge arrester mounting temporary support, 32...Surge arrester mounting plate, 33...
・Gas seal part, 34...Gas seal part holder, 35.
・・Surge arrester mounting plate, 36・Fixing nut, 37・
...Grounding side fixed contact, 38...Grounding side terminal, 39.
...Protective cover, 40... Fixed contact for measuring insulation resistance, 41... Bushing, 42... Terminal for measuring insulation resistance, 43... Protective cover. Figure 1 Figure 2 Figure 3 Prisoner Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] In a neutral point protection lightning arrester installed in a neutral point grounding circuit of a transformer to protect the neutral point, a neutral point extraction part is taken out from the side of the tank of the transformer, and the neutral point extraction part is taken out from the side of the tank of the transformer. A fixed contact on the high voltage side connected to the neutral point lead wire of the section, a fixed contact on the ground side connected to the grounding wire, and a fixed contact for insulation resistance measurement are provided, and an insulating gas is sealed inside. a case portion consisting of a lightning arrester insulating tube, a high voltage side surge arrester movable contact that stores the internal elements of the lightning arrester inside the lightning arrester insulating tube, and that is capable of coming into and out of contact with the high voltage side fixed contact or the insulation resistance measuring fixed contact; A grounding side lightning arrester movable contact that can be in constant contact with a grounding side fixed contact is provided, and the lightning arrester section is housed inside the case section, and is mechanically coupled to the lightning arrester section to rotate the lightning arrester section. What is claimed is: 1. A gas-insulated neutral point lightning arrester comprising: a rotating mechanism section;