JPS5896711A - Foil winding transformer - Google Patents

Abstract

PURPOSE:To prevent local heating by current concentration around a lead out conductor by a method wherein the lead out conductor fixed to the end section of a foil winding is formed in hollow shape and is composed to circulate an insulating medium in the inside of the conductor. CONSTITUTION:A hollow-shaped lead out conductor 14 is fixed to the end section of metal foil. The upper end section of the conductor 14 is connected to one end of a line end bushing 19 installed at a transformer tank by an insulating lead 20. In a foil winding transformer composed in this way, an insulating medium filled in the transformer tank is naturally circulated in the conductor as shown in dashed line arrows. Therefore, the current flowed by dispersing throughout the whole width of the metal foil concentrates at the conductor 14 part, and the heat is immediately cooled by the insulating medium even if heat is generated. Therefore, local heating around the conductor 14 can be prevented. This can prevent a decrease in insulating dielectric strength due to the carbonization of an insulator.

Description

[Detailed Description of the Invention] Technical Field of the Invention - 1 The present invention relates to a foil-wound transformation in which metal foil or other insulating sheets are layered and wound: a foil-shaped winding is used and the winding is cooled with a refrigerant. It has to do with vessels.

Technical background of the invention A to capacity 'l vessel kl space factor force J, t/' (7)
It has the characteristics of being small in size and able to realize liV IN 11. Comparison of several KV and several 100 KVA culms 11
The low-intensity, small-capacity transformer has been put into practical use and is widely available on the market. 1. Recently, the advantages of A/: Considering the advantages, J, high voltage, large capacity (D example engineering L; f 27
Expansion of application to 5K V, 300M VA class transformer F1 is being investigated (σ1C), but the biggest key is how cold 741
It all depends on whether we can improve the performance and add high insulation ability to the windings. Such high-voltage, large-capacity transformers have not yet been put into practical use, but they have a built-in cold 741 duct inside the winding. This cooling U1 duct: - A refrigerant with excellent insulation properties is sent into the tank, or a refrigerant is sent together with an insulating medium into the tank, and this refrigerant is lost to the windings, resulting in loss in the windings. There is a gas insulated transformer that directly cools the heat.

-2- = Problems with back shadow technology This type of transformer [,1] Since it utilizes the latent heat of vaporization of the refrigerant, it can be expected to have excellent cooling characteristics, and there is a high demand for personnel transformers. However, in actual use, C has the following problems.

In other words, the ``l'' of the foil winding is a linear [
Connect the 1-output conductor, and uniformly draw out the 1-output conductor to the outside of the transformer tank through the line end lancing. On the other hand, the current flowing across the entire width of the foil winding concentrates at the connection point, causing local heating in that area and carbonization of the insulation near the connection point and lead conductor, resulting in dielectric strength. This may cause a decrease in the VAM of the device.

OBJECT OF THE INVENTION The present invention has been made in view of point i.
The purpose of the present invention is to provide a highly reliable foil-wound transformer that is free from accidents caused by it.

The foil-wound transformer of the present invention has a hollow lead conductor fixed to the end of the foil winding, and an insulating medium such as insulating oil or gas is naturally circulated inside the coil. The structure is such that the area near the conductor 171 is cooled.

Examples of the invention Embodiments of the present invention will be described below with reference to the drawings.

A low voltage winding 4 and a high voltage winding 5 are formed by wrapping metal foils 2 and 3 around an insulating sheet 1 on the leg part 1 of the iron core, and a hollow cooling duct 1- is formed between these windings. 6 is built-in. This cooling duct 1-6 has a cylindrical shape along the winding direction of the winding wire or a divided cylindrical shape. C7
5 and 14 refrigerants are used. This refrigerant [yo,
J to the pump 7 of the cooling device which is connected to the outside of the transformer.
The heat generated within the windings is removed by the latent heat of vaporization of the refrigerant, and the vapor is condensed in the water-cooled 7J1 pipe 9 (Par-cooled II) in the condenser 8 of the cooling M1 device. The refrigerant number is stored in the refrigerant tank 10 and is sent back to the refrigerant 111 duct 1-6 in the winding by the pump 7, making up 11 circuits. 1. In this case, refrigerant line pipe 11△, 11B made of metal such as stainless steel 11
1 duct h 6 is connected with insulated pipes 12A, 12B, refrigerant line pipes 11△, 11B are connected to the ground potential of tank 13, etc., and cold 711 duct 6 is built into winding 4゜5. Above, the same type as the adjacent winding (electrically connected to f/.Furthermore, the insulation of each part of the winding 4.5 is an insulating medium such as insulating oil or SR gas sealed in the tank 13). It is secured by

In the transformer of this embodiment configured in this way, a hollow lead conductor 14 is provided at the end of the metal foil 2, as shown in FIG.
It is fixed by welding or crimping. The upper end of this 1-1 lead conductor 11 is formed into a cylindrical shape, and the portion that contacts the gold B foil 2 is pressed into a substantially circular shape. This lead-out lead (4114) is fixed to the beginning of winding the metal foil 2, but in that case,
As shown in FIG. 4, the winding of metal i2 (=j
There is a hole 18 in the lower end of the lead conductor 14 so as not to prevent i:J. I heard that it was -1.

Furthermore, this 1] upper end of the output conductor 14 and the change 1. - One end of one of the track end bushings attached to the T-equipment tank is connected by an insulated lead 20, and in this case, these are connected so as to be expandable and retractable by a sliding type connector h21.

In the foil-wound transformer of this embodiment having such a configuration, the inside of the hollow 11-output conductor 14 fixed to the end of the metal foil 2 is connected to the transformer as shown by the broken line arrow in FIG. The insulating medium filled in the tank circulates naturally.

Therefore, the current that was distributed over the entire width of the metal foil 2 is now
Even if heat is generated in a concentrated manner at the lead-out conductor 14, the heat is immediately cooled down by the insulating medium, which prevents local heating near the lead-out conductor and prevents carbonization of the insulator. Preventing the dielectric strength from decreasing due to the conductor part 11 (see Figure 5).

In this embodiment, the hollow 1-1 conductor 14 fixed to the end of the metal foil 2 is connected to the hollow insulating leat 20 at the 10th end of the metal foil 2. 2
1. In addition, as in the above embodiment, 1-
Instead of providing a hole 1B at one end of the 1-output conductor 11, a hole 18 is provided near each connection point of each line end notch connected to the hollow insulated lead 20. .

In the foil-wrapped converter constructed in this manner, the hollow conductor 17 is fixed to the end of the metal foil 2. The insulating medium flowing from the lower end 11 part 17 of 1-] outgoing conductor 1/I and the insulating wire 2 as shown by the broken arrow in the figure
Natural circulation is carried out by flowing into the tank 13 through the hole 18 which passes through the inside of the line (and is installed near one end of the line end 1 shinging 19) and covers the tank 13. Therefore, the output conductor 1 (1 as in the above embodiment)
This not only prevents local heating due to current concentration in the vicinity, but also prevents heating of the insulated lead 20 itself connected to the line end bushing 19, making it possible to create a highly reliable foil-wound transformer. can be provided.

In the illustrated embodiments, the insulating medium and the refrigerant are separated and circulated; however, the present invention is not limited to this, and the refrigerant may be mixed with the insulating medium. It can also be applied to so-called semi-boole type or spray type transformers in which spray is applied to the foil winding.

As explained above, the present invention has a hollow lead-out conductor that hardens at the end of a foil winding, and an insulating medium is circulated inside the lead-out conductor.
Since it is b that the -1 outgoing conductor is cooled,
[There is no local heating of the I-out conductor, there is no risk of dielectric strength reduction due to carbonization of the insulator, and the reliability is improved.
This has the effect of making it possible to install a high-performance transformer.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view schematically showing one embodiment of the foil-wound transformer of the present invention, Fig. 2 is a perspective view of the 1] outgoing conductor portion, and -8- Fig. 3 is a cross-sectional view of the 11 outgoing conductor and metal foil. Cross-sectional view of the fixed part,
Figure 4 1; & [Cross section 1 of the 1-output conductor and insulated lead part
81 and 5j are cross-sectional views of the lead conductor and insulated lead portion according to another embodiment of the present invention. 1... Iron core leg, 2... Metal foil, 3... Insulating sheet 1
~． 4...Low voltage winding, 5...High voltage winding, 6...Cold f, l] duct, 7... Bon l, 8... Condenser, 9
...Water cooling w pipe, 10...Refrigerant tank, 11A, II
B... Refrigerant pipe, 12A, 12B... Insulated pipe,
13...Tank, 14...Leading conductor, 15...
Insulating tube, 16...Groove, 17...11 parts between, 18...
・Hole, 19...Bushing, 20...Insulated lead,
21...Slide type 2 l contact. 7317 Attorney Kensuke Chika (1 idiot) -9-

Claims (1)

[Claims] (1) The contents of a transformer are constituted by wrapping a foil winding made of overlapping metal foil and an insulating sheet around the legs of an iron core, and storing the contents of the transformer together with an insulating medium in a tank. In a foil-wound transformer configured such that at least the foil winding is cooled by a refrigerant cooled by a cooling device disposed outside the tank, a lead-out conductor having a hollow interior is provided at the end of the metal foil. A foil-wound transformer, characterized in that the lead conductor is connected to a line end bushing via an insulated lead, and the insulating medium is circulated at least within the lead conductor. 2) The foil-wound transformer according to claim 1, wherein the insulating lead is hollow, and the insulating medium circulates through the lead conductor and the insulating lead.