JPS60218716A - Oil-impregnated paper condenser bushing - 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 an oil-immersed paper capacitor bushing used for the outlet of oil-immersed electrical equipment such as transformers and reactors.

[Prior art]

Rated voltage 84 for oil-filled electrical equipment such as transformers and reactors
．． Oil-impregnated paper capacitor bushings are often used for bushings of 5 kV or higher, and the one shown in the cross-sectional view of FIG. 1 is common. Below, FIG. 1 will be explained. Center pipe (
1) Wrap kraft insulating paper around the electrode and insert a number of electric field adjustment electrodes in a concentric cylindrical shape in order to uniformly adjust the electric field distribution in the diameter direction and length direction, and increase the capacitance between each electrode. A capacitor part (2) is added, which has a structure in which the voltages are equalized and the voltage is shared equally in each layer, and a mounting flange (3) is added in the middle part.
), an upper insulator tube (4) is arranged at the top, a lower insulator tube (5) is arranged at the bottom, and gaskets (
4a), (4b), (5a).

(6b) is interposed, a support metal fitting (6) is screwed and fixed to the center pipe (1) at the lower end, and sealed by a method such as soldering, and an expansion tube (7) is provided at the upper end. As shown in the figure, a strong compression spring (8) is housed in the inner diameter part, and a spring stopper plate (9) is placed above it, and the center pipe (1) is used as a tensile strength member to compress the compression spring (8) and tighten the outer periphery. A strong compressive force is applied to the upper insulator tube (4), the mounting flange (3), and the lower insulator tube (5) of the section and fixed with a ring nut αQ to ensure mechanical strength as a bushing.The upper end of the expansion tube (7) A bellows θυ with a base for fixing the air terminal Q is provided between the center pipe (1) and the center pipe (1), and the joints with the center pipe (1) and the expansion tube (7) are connected by soldering or other methods. As a jointed and sealed structure, even if there is a difference in the expansion and contraction of the outer peripheral upper insulator tube (4), mounting flange (3), lower insulator tube (5) and center pipe (υ) due to temperature changes during use of the bushing, the bellows αυ The structure is such that a sealed structure can be ensured through deformation.
The upper end is connected to the air terminal (
6) Install. Then, pump the vacuumed insulating oil αQ from the valve (141) installed at the position shown on the mounting flange (3) to the expansion cylinder at the head (7) to the vicinity of the center of the oil level gauge (7a) installed. Fill up to the oil level (15a) and
15a) is assembled by sealing an inert gas Qfj such as nitrogen gas into the interior of the expansion cylinder (7) from the valve α♦ at an appropriate pressure. For high-voltage products with a rated voltage of 115 kV or higher, insulating paper is wrapped around a core metal as shown in the figure to alleviate electric field concentration around the lower support metal fitting (6) and increase insulation strength. Oil shield Q
η is provided. Such a structure is called a center clamp method. When installed in oil-filled electrical equipment, cut the connection lead from the coil to an appropriate length, connect the terminal end α field to the end by brazing or crimping, and connect it to the inner diameter of the center pipe (1). Connect to the air terminal (
6) Connect by screwing to the bottom surface. This type of connection method is called a pipe type. If the current capacity is large, there is a famous method in which it is connected to the lower support metal fitting (6) and the center pipe (1) is energized inside the bushing.In this case, the center pipe (1) is called the center conductor, and this The method is called the stud method.

The center clamp type oil-immersed paper capacitor bushing with this configuration has the feature that the height of the insulator tube is the same as the insulation length, and since the insulator tube itself does not come with any fixing fittings, the diameter is small and the size is very compact. have However, when installed on the equipment, the diameter of the support metal fitting (6) that becomes the live part at the bottom or the submerged oil shield (Q7 for 115 kV or more) is large enough to ensure the required insulation distance between the equipment and the tank wall. In this case, the size of the tank becomes considerably large. If the diameter of the live part can be reduced, the size of the tank can be reduced, and the device can be made smaller and lighter. In addition, complex and expensive metal fittings such as the compression spring (8) 9 for the center clamp system, the support metal fitting (6) that supports strong compression force, and the bellows Qυ to ensure a sealed structure even if expansion and contraction occur due to temperature changes are used. However, it is not necessarily advantageous in terms of cost. [Summary of the Invention] This invention was made with the aim of improving this drawback, and the upper insulator tube on the air side, which is not very relevant to equipment design, is made of porcelain, has flanges at the upper and lower ends, and is fixed with fixing metal fittings. The upper part of the lower insulator tube is fixed to the lower part of the body of the mounting flange, and the lower part is supported so as to be slidable in the axial direction via a ring-shaped gasket disposed around the outer periphery of the center conductor. By doing so, the expansion and contraction caused by temperature changes in the outer periphery and the center conductor is absorbed by the sliding action between the gasket and the lower insulator tube, eliminating the support metal fittings and reducing the diameter of the live part, making it possible to reduce the size and weight of the equipment. The present invention provides an oil-immersed paper capacitor bushing.

(]Embodiment 1 of the invention Hereinafter, embodiments of the invention will be explained with reference to the drawings.Second
The figure is a sectional view showing an oil-immersed paper capacitor bushing in an embodiment of the present invention. In the figure, Ql is the center conductor, (II is the capacitor part, good is the mounting flange, Upper insulator made of porcelain with a tsuba,
(21a) and (21b) are lower and upper gaskets for ensuring the sealing structure of the end face of the upper insulator tube eυ;
c) , (21d) are lower and upper fixing fittings, (2)
is a lower insulator tube made of epoxy casting resin, etc., with the lower end of the cylindrical body (20a) integrally joined with the mounting flange embedded in the upper end, and the inner diameter of the lower part is smooth to ensure a tight seal. It is finished. In addition, the torso (20
The upper end of a) is joined to the mounting flange 4 by welding.

(22a) is a ring-shaped gasket installed around the outer periphery of the center conductor (G) to maintain a seal between the lower insulator tube (2) and the center conductor Oal; The cylinder, (28a) is the oil level gauge, (c) is the end plate screwed onto the upper end of the center conductor U barrel and welded at the boundary, (24)
a) is a gasket that maintains a seal between the top surface of the expansion tube (2) and the end plate (to), and 2) is an air terminal. The terminal end a, valve a, insulating oil αQ1 oil level (15a), and inert gas Utt are the same as before.

To obtain an oil-immersed paper capacitor bushing with such a structure, first, the cylindrical body (20a) is embedded in the position shown in the figure, the lower insulator tube (2) is molded with epoxy casting resin, etc., and the mounting flange 4 is placed in the position shown in the figure. Weld and join.

Next, fit the gasket (22a) into the lower end of the center conductor (G) around which the capacitor part QI is wound, and
) into the inner diameter of the integrated mounting flange 4, place the gasket (21a) on the top surface of the mounting flange), insert the upper insulator pipe Qv, and fix it to the mounting flange 4 using the fixing metal fitting (210). A gasket (2
1b) and insert the expansion tube (to) as shown in the figure, and connect the upper insulator tube Qυ and expansion tube 4 using the fixing fitting (21d). Next, attach the gasket to the top surface of the expansion tube (24a).
), lift the center conductor (G) slightly upwards, attach the end plate (C) to the top of the center conductor by screwing it, and seal the boundary with the center conductor (G) by welding or other method. After securing the structure, fix the end plate to the top of the expansion tube with bolts.

Next, the valve Q41 provided on the mounting flange is evacuated, and insulating oil C15 is filled up to the oil level (15a) at the head, and then an inert gas a1 such as nitrogen gas is filled to a predetermined pressure. The gas should be sealed at a pressure that does not rise to a very high pressure (below 2 kg-g/ctA) at the highest temperature in use, and does not result in negative pressure even at the lowest temperature (-20°C or less). . When attaching the bushing to the transformer body, cut the connection lead to an appropriate length, connect it to the terminal end a by brazing or crimping, and screw it into place from the bottom of the air side terminal 4.

For rated voltages of 115 kV or higher, an oil-submerged shield (2) is used as shown in Figure 8 to alleviate the electric field concentration at the bottom.
is installed. By adopting such a structure, even if expansion and contraction occurs due to temperature changes between the insulator tube (υ(2)) and the mounting flange (■) on the outer periphery and the center conductor (7), the gasket (22a) on the lower end ) can be slid and the sealed structure can be maintained.

In oil-immersed paper capacitor bushings with this type of structure, the diameter of the live part at the lower end on the oil side is extremely small, and even if the insulation distance from the equipment tank wall is maintained, the equipment as a whole can be made smaller and lighter. effective. Also, the fixing fittings (21C) for the upper insulator tube c2v.

(21d) is required, but since the number of metal fittings on the head is small and the shape is simple, the weight can be reduced even if there are many bushings, which is advantageous in terms of manufacturing cost.

FIG. 4 is a sectional view showing an oil-immersed paper capacitor bushing in another embodiment of the present invention. The difference from the previous embodiment is that the lower insulator pipe (2) is attached to the body part (7) of the flange (7).
20a). That is, in this embodiment, a flange is provided at the upper end of the lower insulator tube, and a gasket (22b) is inserted into the upper end surface of the flange to open the body (2 oa
) is bent as shown in the figure, and the gasket (22b) on the joint surface is compressed to an appropriate amount to seal. With such a configuration, the structure on the oil side becomes even simpler.

FIG. 5 is a sectional view showing an oil-impregnated paper capacitor bushing in still another embodiment of the present invention.

Below, a lower insulator tube (A) and a body part (2) different from each of the above embodiments will be explained.
The structure of fixing with 0a) will be explained. (, gOb) is a ring for pressing and fixing the lower insulator tube (2), (20c) is the support and ring attached to the inside of the mounting flange (1), (2oa) is the lower insulator tube (2) (22C) applies force to the lower insulator tube (2) by applying force to the lower insulator tube (2). 2)
The cushion (22d) inserted between the upper end surface and the pressing ring (20b) is connected to the body (20a) and the lower insulator tube (20b).
2) is a gasket that maintains a sealing structure between the

' To use an oil-impregnated paper capacitor bushing with such a configuration, first attach the gasket (22d) to the lower insulator tube (2), insert it into the body part (2oa) of the mounting flange up to the position shown in the figure, and then insert the cushion (22c). For pressing, insert the ring (20b) and install the support ring (20C) inside the mounting flange (E) at the position shown in the figure. For pressing, assemble the lower insulator pipe @ro mounting flange (E) into one piece.

The above configuration also provides the same effects as those of the embodiments described above.

In addition, in the above, the upper insulator tube C2]) is fixed using the fixing fitting (2).
1C), (2ta), we explained the method of clamping at the brim of the 2nd upper insulator tube Qυ, but the upper insulator tube Qυ
It goes without saying that a similar effect can be obtained by fixing ring-shaped flanges to the upper and lower ends with cement and fixing them to the mounting flange (2) and the expansion cylinder (5). In addition, as shown in Figure 6, the inner diameter of the upper surface of the expansion tube ■ and the center conductor (
If the upper end of (g) is made into a jointed and sealed structure by brazing or welding, the end plate (c) shown in FIG. 2 will be unnecessary and the cost will be further reduced.

〔Effect of the invention〕

As explained above, in this invention, the upper insulator tube is made of porcelain, has flanges at the upper and lower ends, and is fixed with fixing metal fittings, and the lower insulator tube has its upper part fixed to the lower part of the body of the mounting flange, and its lower part Since the center conductor is supported slidably in the axial direction via a ring-shaped gasket placed around the outer periphery, expansion and contraction due to temperature changes between the outer periphery and the center conductor is prevented by sliding between the gasket and the lower insulator tube. It is possible to eliminate absorbing and supporting metal fittings, and the diameter of the live part is reduced, which has the effect of making it possible to make the device smaller and lighter.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing a conventional oil-immersed paper capacitor bushing, FIG. 2 is a cross-sectional view showing a Burmese paper-immersed capacitor bushing according to an embodiment of the present invention, and FIG. 8 is a cross-sectional view showing a conventional oil-immersed paper capacitor bushing. FIG. 4 is a cross-sectional view showing an oil-immersed paper capacitor bushing according to another embodiment of the present invention, and FIG. A sectional view showing an oil-immersed paper capacitor bushing, FIG. 6 is an enlarged sectional view of the upper part of the bushing with the end plate omitted. In the figure, 9 o'clock is the insulating oil, (to) is the center conductor, θ is the capacitor part, ni) is the mounting flange, (20a) is the body, 01) is the upper insulator tube, (21c)
(21d) is the fixing metal fitting, (a) is the lower insulator tube, (22a)
is a gasket, and kan is an expansion tube. Note that the same reference numerals in the figures indicate the same or equivalent parts. Agent Masuo Oiwa Figure 1 Figure 2 Figure 4 Figure 5 Figure 6

Claims (1)

[Scope of claims] The lower end of the center conductor and the lower end of the mounting flange are surrounded by a lower insulator tube and the inside is filled with insulating oil (1. The upper insulator tube is made of porcelain and has flanges at the upper and lower ends. The upper part of the lower insulator tube is fixed to the lower part of the body, and the lower part of the lower insulator tube is fixed in the axial direction through a ring-shaped gasket provided around the outer periphery of the center conductor. An oil-impregnated paper capacitor bushing characterized in that it is slidably supported. (2) A patent claim characterized in that the lower insulator tube is an epoxy cast resin molded product with the body of the mounting flange embedded in the upper part. (3) The lower insulator tube is fixed to the body of the mounting flange by bending the lower end of the body of the mounting flange. Oil immersed paper capacitor bushing.