JPH04125433U - Current transformer - Google Patents

Abstract

(57) [Summary] [Purpose] To absorb changes in the length of the primary conductor due to temperature changes and to be able to firmly support the primary conductor. [Configuration] Primary conductor support device 2 that supports the lower end of the primary conductor 5
Set 0. This primary conductor support device includes a receiving plate 21 that receives the lower end of the primary conductor, and springs 2 at both ends of the receiving plate 21.
Fixing fittings 23a, 23 connected via 2a, 22b
b, and the fixing fittings 23a, 23b are attached to the tank 1.
Fixed against. The upper end of the primary conductor 5 is connected to primary terminals 9a, 9 by rigid connecting conductors 27a, 27b.
Connect to b.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

The present invention relates to a power current transformer installed in a substation or the like.

0002

[Conventional technology]

A current transformer with a relatively large current rating has a primary conductor and a The secondary winding wound around the provided iron core is stored in a tank filled with insulating oil. It has a unique structure. The primary conductor through which a large current flows is quite large, so Its length changes considerably under the influence of the heat generated by it and the ambient temperature. Therefore, the primary It is necessary to support the conductor while taking into account changes in length due to thermal expansion and contraction.

0003 Figure 3 shows the general structure of a 3000A class current transformer. part tank, 2 is an insulator pipe whose lower end is connected to the top of the lower tank 1, and 3 is an insulator pipe whose lower end is connected to the upper end of the insulator pipe 2. The connected upper tank has an oil-tight structure with the lower tank 1, insulator pipe 2 and upper tank 3. A built-in tank 4 is constructed.

0004 5 is a ring-shaped core linkage part (ring-shaped part) 5A, and a core linkage part 5A formed in a ring shape. A so-called eyebolt-shaped primary having a rising portion 5B rising upward from the It is a conductor. In the rising part 5B, conductors 501 and 502 are arranged concentrically, and the inner The conductor 501 passes through the inside of the outer conductor 502 to reach the core linkage portion 5A, and The conductor 502 is wound around the outside of the rising portion 5B by winding one turn or several turns at the It's flowing. Insulating paper is wrapped around the outer surface of the primary conductor 5, and the insulating paper allows Main insulation 5C is configured to provide insulation between the primary conductor and ground. The primary conductor 5 is made of copper or It consists of an aluminum pipe, with an oil channel formed inside.

[0005] The primary conductor 5 is placed in a tank with its lower end core linking portion 5A located in the lower tank 1. The core linkage portion 5A is housed in the tank 4, and the core linkage portion 5A is attached to a support stand 6 provided in the lower tank 1. It is placed on tapered surfaces 6a1 and 6b1 provided on a and 6b. Iron core linkage part 5 A cushion 7 made of corrugated pressboard or the like is provided between A and the support stands 6a and 6b. It's trapped.

[0006] The conductors 501 and 502 protrude upward from the upper end of the rising portion 5B of the primary conductor 5. Terminal connection parts 5a and 5b are provided at the ends (terminal parts of the primary conductor), and the upper tank 3 A primary terminal 9a is connected to the opposing side walls 3a, 3b via a pair of insulating members 8a, 8b. , 9b are attached. Terminal connection parts 5a and 5b are flexible connection conductors 1 0a, 10b to corresponding primary terminals 9a, 9b.

[0007] An annular core 11 is arranged so as to interlink with a core linkage portion at the lower end of the primary conductor 5, A secondary winding 12 is distributed around the iron core 11 in a toroidal manner.

[0008] The iron core 11 and the secondary winding 12 are supported at the bottom of the lower tank via an insulating support 13. has been done.

[0009] Above the upper tank 3 is a feeding tank (oil amount adjustment) consisting of bellows etc. tank) 14 is arranged, and the feeding tank is connected to the upper tank via a connecting pipe 15. Connected within link 3. The feeding tank 14 is fixed to the upper tank 3. It is covered with a covered cover 16. Tank 4 is filled with insulating oil, The oil volume change due to thermal expansion and contraction is absorbed by the ding tank 14. ing.

0010 Although not shown, a secondary terminal connected to the secondary winding is provided on the side of the lower tank 1. A secondary terminal board is provided.

[0011]

[Problem that the idea aims to solve]

In current transformers with high current ratings, the primary conductor is formed by copper or aluminum pipe. However, this primary conductor expands and contracts due to the heat generated by the current and changes in ambient temperature. and its length changes. For current transformers rated at 275KV class or higher, the length is 1 It has been confirmed that there is a change of more than 0 mm. Therefore, conventionally, as shown in Figure 3, Then, the lower core linkage portion 5A of the primary conductor 5 is placed on the support stands 6a, 6 via the cushion 7. At the same time, the terminal connecting parts 5a and 5b provided at the upper terminal part are placed on the flexible cable. Connect to the primary terminals 9a, 9b via flexible connection conductors 10a, 10b, and Due to the deformation of the bodies 10a and 10b, the elongation of the primary conductor is absorbed and the main insulation 5C is I tried not to apply any force to it.

0012 However, with such a support structure, the fault current of the system is transferred to the primary conductor of the current transformer. When the flow flows in, the flexible connecting conductor vibrates greatly, causing the upper end of the primary conductor to There was a risk that the position would shift. In addition, the primary conductor is sufficiently fixed to prevent vibrations during transportation. Since it cannot be said that it is a there were.

[0013] The purpose of this invention is to support the primary conductor more firmly than before. Our purpose is to provide current transformers.

[0014]

[Means to solve the problem]

The present invention has an iron core linkage part at the lower end that interlinks the iron core, and the end connected to the primary terminal. A primary conductor having a terminal end at the upper end, and a primary conductor arranged so as to interlink with the core interlocking part of the primary conductor. The secondary winding wound around the iron core is stored in a tank filled with an insulating medium. , has a structure in which the terminal of the primary conductor is connected to the primary terminal provided at the top of the tank. This is related to current transformers.

[0015] In the present invention, a primary conductor receiving plate and a spring are connected to both ends of the primary conductor receiving plate. A primary conductor support device with connected fixing fittings is provided at the bottom of the tank, and this Fix the fixing fittings of the primary conductor support device to the tank. Iron core at the lower end of the primary conductor The interlinking portion is placed on the primary conductor receiving plate, and the primary conductor is supported by the receiving plate. primary The terminal portion of the conductor is connected to the primary terminal via a rigid connecting conductor.

[0016]

[Effect]

As mentioned above, connect the terminal end of the primary conductor to the primary terminal via a rigid connecting conductor. This will prevent the connected conductor from vibrating greatly when fault current flows into the grid. Therefore, the position of the upper end of the primary conductor does not shift.

[0017] In addition, since the primary conductor support device is equipped with a spring, the temperature can be controlled by the spring. Changes in the length of the primary conductor due to changes can be absorbed.

[0018] Furthermore, by appropriately setting the strength and amount of expansion and contraction of the spring of the primary conductor support device, strengthens the primary conductor against the tank without affecting the main insulation on the primary conductor. It can be fixed firmly.

[0019]

【Example】

Figure 1 shows an example in which the present invention is applied to the current transformer shown in Figure 3. In the figure, parts equivalent to those in FIG. 3 are given the same reference numerals.

[0020] In this embodiment, a primary conductor support device 20 is provided to support the primary conductor 5. . As shown in FIG. 2, this primary conductor support device 20 includes a ring at the lower end of the primary conductor. A strip-shaped primary conductor receiving plate 21 curved along the lower surface of the core linkage portion 5A. , a fixing fitting 2 connected to both ends of the primary conductor receiving plate via springs 22a and 22b. 3a, 23b, and the fixing fittings 23a, 23b are attached to opposite sides of the lower tank 1. It is fixed with bolts 25 to bosses 24a and 24b welded to 1a and 1b. Ru. In FIG. 2, 26 is between the head of the bolt 25 and the fixing fittings 23a and 23b. This is a spring washer that is inserted. For passing bolts through the fixing fittings 23a and 23b A large number of holes 23a1, 23b1 are provided, and the fixing fittings 23a, 23b can be attached to the bolts. When fixing, the primary conductor can be improved by selecting the hole through which the bolt will pass based on the actual item. The dimensional tolerances of the body 5 and the insulator tube 2 are accommodated.

[0021] The primary conductor 5 has its lower end core linkage portion 5A placed on the primary conductor receiving plate 21. The terminal connection parts 5a and 5b provided at the upper end of the primary conductor 5 are The primary terminals 9a, 9b. The connection conductors 27a and 27b have sufficient thickness. An L-shaped strip of copper or aluminum may be used.

[0022] At both corners of the lower end of the lower tank 1, when installing the primary conductor 5 into the tank, Support stands 28a and 28b that temporarily support the lower ends of the conductors are welded to each other. Also these By welding the support base, the volume inside the lower tank is reduced and the amount of oil is saved. It is. When the primary conductor 5 is supported by the support device 20, the primary conductor 5 and the support A gap is formed between the holders 28a and 28b. This gap is caused by a change in temperature. Set it to be larger than the amount of expansion and contraction of the conductor. Other points are the same as shown in Figure 3. It is.

[0023] With the above configuration, when the primary conductor 5 expands and contracts due to temperature changes, the spring 2 2a and 22b expand and contract to absorb changes in the length of the primary conductor. Also, springs 22a, 2 By setting the strength of 2b appropriately, the primary conductor can be protected from electromagnetic vibration and vibration during transportation. It can be strongly supported against motion. The upper end of the primary conductor is a rigid contact. Since it is connected to the primary terminal by connecting conductors 27a and 27b, electromagnetic vibration etc. The position of the top end of the primary conductor does not change. Also, due to vibration, the lower end of the primary conductor Even if it swings, it will return to its original position due to the restoring force of the springs 22a and 22b, so the primary conductor The position of the body does not shift.

[0024] In the above embodiment, the core intersection at the lower end of the primary conductor is formed into a ring shape. However, when a hairpin-shaped primary conductor is used in which the core intersection at the lower end is formed into a U-shape, The present invention can be similarly applied to such cases.

[0025] In the above embodiment, as shown in FIG. 2, two springs 22a and two springs 22b are provided. However, more springs can also be provided.

[0026] In addition, in order to relieve the electric field near the springs 22a, 22b and the fixing fittings 23a, 23b, A shield can also be provided for this purpose.

[0027]

[Effect of the idea]

As described above, according to the present invention, the terminal portion of the primary conductor is connected to a rigid connecting conductor. Since it is connected to the primary terminal through the This can prevent the upper end of the primary conductor from shifting due to movement or the like.

[0028] In addition, since the primary conductor support device is equipped with a spring, the temperature can be controlled by the spring. Changes in the length of the primary conductor due to changes can be absorbed.

[0029] Furthermore, by providing a spring in the primary conductor support device, the lower end of the primary conductor is Even if it shakes, its position can be automatically restored to its original position. Mechanical design that eliminates the risk of misalignment of the primary conductor due to electromagnetic vibration or vibration during transportation. You can get a strong current transformer.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention.

FIG. 2 is a perspective view showing a primary conductor support device used in an embodiment of the present invention.

FIG. 3 is a longitudinal sectional view showing a conventional current transformer.

[Explanation of symbols]

1...Lower tank, 2...Insulator pipe, 3...Upper tank, 4...Tank, 5...Primary conductor, 5A...Iron core linkage part, 5B...Rising part, 5a, 5b...Provided at the terminal part of the primary conductor Terminal connection part, 9a, 9b...Primary terminal, 11...Iron core, 12...Secondary winding, 20...Primary conductor support device, 21...Primary conductor receiving plate, 22a, 22b...Spring, 23a, 23b...Fixing Metal fittings, 27a, 27b...connecting conductors having rigidity.

Claims (1)

[Scope of utility model registration request] [Claim 1] A primary conductor having a core linkage portion interlinking with the iron core at the lower end and having a terminal portion connected to the primary terminal at the upper end, the primary conductor interlinking with the iron core linkage portion of the primary conductor. A secondary winding wound around an iron core arranged as shown in FIG. In the connected current transformer, a primary conductor support device comprising a primary conductor receiving plate and fixing fittings connected to both ends of the primary conductor receiving plate via springs is provided at a lower part in the tank. and the fixing fittings of the primary conductor support device are fixed to the tank, and the primary conductor is supported with its lower end core linkage portion placed on the primary conductor receiving plate, A current transformer, wherein an end portion of the primary conductor is connected to the primary terminal via a rigid connecting conductor.