JPS63169008A - Foil wound transformer - Google Patents

Abstract

PURPOSE:To improve the cooling performance and the insulating performance of a foil wound transformer by insulating a lead pipe of a cooling duct with synthetic resin. CONSTITUTION:The lead pipe 18 of a cooling duct is formed of thermoplastic or thermosetting synthetic resin, such as epoxy resin, polyester resin, etc., and formed by an integral injection molding or molding with metal of an attachment 17. The synthetic resin is a high molecular weight substance having high insulating performance, high heat resistance and high coolant resistance. Thus, since the loss of the pipe 18 is largely reduced, its temperature rise is remarkably improved to avoid a decrease in its cooling performance and to eliminate a problem, such as a decrease in the insulating performance.

Description

[Detailed Description of the Invention] [I-', 1st aspect of the invention] (Industrial Application Field) The present invention relates to a 55-turn transformer comprising a hollow cooling duct built into a foil winding. In particular, it relates to a foil-wound transformer that prevents overcurrent caused by leakage magnetic flux.

(Prior Art) A foil-wound transformer has a good winding space factor, so it has the feature of being able to realize a smaller size and lighter fj. Therefore, small 8th transformers with a relatively low voltage of several KV to several 100 KVA with η have been put into practical use and are widely available on the market.

J! In view of its superior merits, it has become even more popular.
Research is underway to expand its application to large capacity ΔV transformers, such as 275KV and 300MV. In order to realize the great value and simplicity of such a foil transformer, we improved the cooling capacity and added high insulation capacity to the windings. In addition, it is required to improve the resistance to radial mechanical force due to short circuit accidents.

In view of these demands, conventionally developed foil-wound transformers have a cooling duct built into the winding, and a coolant with excellent insulation properties (1) is fed into the cooling duct to reduce winding loss. The so-called He-1-Pi-1 method, which uses the latent heat of vaporization of the refrigerant to cool the heat generated by the refrigerant, is well known. It is seen as promising.

Figure 3 shows a known example of this 4F heat pipe type 9) capacity pressure vessel.

In FIG. 3, 1 is an iron core leg, 2 is a metal seat 1 to . 3
is an insulating sheet, which is wound around the core leg portion 1 to form a low-voltage winding 4 and a discretionary winding 5.

A cooling duct 6 is wound inside each winding 1.5, and a pump 7 circulates a refrigerant such as Freon R113 or Fluoriner 1-75 in the cooling duct 1-6. Rust, the heat generation in the winding is taken away by the latent heat of vaporization of the refrigerant, and the vapor is cooled in the cold 7JJ water cabinet 9 in the condenser 8! It seems to be condensed. The liquefied refrigerant is stored in a refrigerant tank 10 and fed into the windings by a circular pump 17.

The refrigerant pipe 11 that constitutes the 4F cooling system is made of Suanres exclusive metal, and this refrigerant pipe 11 and the cold J
, 0 ducts I to 6 are connected by an insulating pipe 12, and the refrigerant path 11 is also connected to the ground potential of a tank 13 and the like. On the other hand, since the cooling duct 6 is built into the winding, it is electrically connected to the same potential as the winding that approaches it. Insulating Li in each part of the winding, insulating oil or S[-6 gas sealed in the tank 13, etc. The medium 14 is arranged in rows 4T.

The 51-turn transformer described above is generally called a lever-type foil-wound transformer because the cooling system in which the refrigerant circulates and the insulation scum of the windings are completely separated.

By the way, the shape of the cooling duct 1-6 built into the winding of the foil-wound transformer as shown in FIG. 4 is as shown in the perspective view of FIG. That is, the cold 1JJ duct 6 has a cylindrical shape or a divided cylindrical shape along the winding direction of the winding, and has a cold FJI panel section 15 into which the refrigerant is sent, and a cooling panel section 15 that has a cylindrical shape along the winding direction of the winding wire or a divided cylindrical shape. Collecting and sending out the flowing refrigerant, or 4. L. In order to send refrigerant to the cooling panel section 15, the upper and lower outlet pipe sections 16 are connected to the insulating pipes 12 on each side, and are arranged between the two sections,...! Mounting part 17
It is composed of. Normally, the outlet pipe portion 16 of the cooling duct 6 is made of metal, and its surface is subjected to an insulation treatment such as 2]-tinguya taping with paint.

However, in the cooling duct 6 configured as described above, ff1t is generated by the current flowing through the nine windings.
1 of the metal conductor of the 1-output pipe portion 16 due to the leakage magnetic flux 1? An overcurrent layer proportional to Sano 2 East occurs, and the load? In addition to the resistance loss due to the ri current, the temperature] = PI becomes [1
I'm tripping over it. This temperature rise! l) The incoming current and the 't+ winding transformer at - can be harmful to improving cooling efficiency, leading to insulation deterioration due to poor cooling, and short circuits or inciting small accidents during long-term operation. There is a risk that it may provoke

(1711 problems to be solved by the invention) As mentioned above,
Conventional foil-wound transformers have had the problem that the temperature rises due to overcurrent layers and resistance losses in the outgoing pipe portion of the cooling duct, resulting in a decrease in cooling performance and a deterioration in insulation.

/N invention (Yo, this was proposed to resolve such problems, and the purpose is to improve the tX of cold 1Jl duct
+ By improving the outlet pipe section and preventing temperature rise, we have improved cooling performance and created foil-wound transformers with high insulation reliability that will not cause short circuits or explosions even during long-term operation. It is to provide.

[41 Compositions of the Invention] (Means for Solving the Problems) The sake roll machine of the present invention includes an L1 outlet pipe section made of thermoplastic or thermosetting synthetic resin in the cooling duct of the cold J, 11 system. It is characterized by the following:

(Function) The present invention has the following configuration, so that the synthetic resin forming the outlet pipe part of the cooling device 1- has a convex shape with high insulation t'l ability, heat resistance t4, and refrigerant resistance. Since it is made of molecular material, loss in the interlayer can be reduced, and the temperature upper limit can be prevented by 1F.

(Example) DT", the first implementation of the f-transformer according to the present invention.
This will be explained with reference to FIGS. J3, Figure 3.

Components that are the same as those in the prior art shown in FIG. 4 are designated by the same reference numerals, and their explanation will be omitted.

■First Embodiment In the embodiment shown in FIG. 1, the outlet pipe section 18 to the cooling duct 1 is made of thermoplastic or thermosetting synthetic resin such as epoxy resin or polyester resin. = J part 17
It is formed by integral molding or molding with metal. These synthetic resins have excellent insulation performance, heat resistance f] and refrigerant resistance ↑1
It is generally well known that the polymer '1'1 has a high molecular weight of 1.

In the core-wound transformer of this embodiment having the above configuration, the loss in the outlet pipe section 18 is significantly reduced compared to the conventional technology in which metal is used for the outlet pipe section. Temperature rise is also significantly improved, and a decline in cooling performance can be avoided. 1 Therefore'/l(!2 Edge t'
There is no problem of decreased performance. Also, since the lead pipe part is made of insulator, the insulation distance from ground to ground is reduced to 1 (J), which has the effect of downsizing the foil-wound transformer and downsizing the shield.

■Da! Embodiment 2 In the embodiment shown in FIG. 2, the pipe section 19 of the cold IJJ duct 6 is made of insulation 1 (e.g. epoxy resin or polynisdel resin 5, which avoids inorganic or organic fibers). It is a molded or cast product, and is bonded to the metal of the mounting portion 17 with a polymer adhesive 20.

In this embodiment, which completely reverses the above configuration, the η1
In addition to the same effect as in the first embodiment, there are also the following effects: 3, 43, and 43, which have the effect that the decrease in mechanical strength due to the fiber assembly built in the outlet pipe section 19 during the period of operation causes discoloration. It is not surprising that in one embodiment, it is also possible to insert fibers into the outlet pipe 18.

[Effect of explanation] As explained above, in the present invention, 1. By improving the simple structure of insulating the outlet pipe part of the cooling duct with synthetic resin, various problems related to electrical insulation are solved, and the temperature due to loss is reduced. Since the upper limit can be prevented, the cooling performance and insulation performance can be improved, and therefore, an excellent F1 voltage transformer with high insulation reliability can be used even during long-term operation.

[Brief explanation of the drawing]

1 and 2 are enlarged sectional views of the outlet pipe portion of a cooling duct without showing different embodiments of the foil-wound transformer according to the present invention, and FIG. 3 shows an example of a conventional foil-wound transformer. The sectional view and FIG. 4 are perspective views showing the cooling duct. DESCRIPTION OF SYMBOLS 1... Iron core leg, 2... Metal sheet, 3... Insulating sheet, 4... Low voltage winding, 5... High voltage winding, 6-...
・1 gukt for cold, 7...pump, 8...condenser, 9
... Cooling water pipe, 10 ... Refrigerant tank, 11 ... Refrigerant pipe line, 12 ... Insulated pipe, 13 ... Tank, 1
4... Insulating medium, 15... Cooling panel section, 16...
・Outlet pie 1 part, 17...Mounting part, 18.19...
・"1 outgoing pipe part, 20...polymer adhesive. Figure 2 Figure 3 Figure 4

Claims (3)

[Claims] (1) A foil winding made by overlapping a metal sheet and an insulating sheet and winding it around the legs of an iron core is stored in a transformer tank together with an insulating medium, and a hollow cooling duct is installed in the foil winding. In the foil-wound transformer, the cooling system is constructed in such a way that the cooling system is separated from the insulating medium by circulating the refrigerant cooled by a condenser installed outside the tank through the refrigerant pipe in the cooling duct. A foil-wound transformer characterized in that lead pipe parts made of thermoplastic or thermosetting synthetic resin are provided at the upper and lower parts of the cooling duct. (2) The foil-wound transformer according to claim 1, wherein the outlet pipe portion of the cooling duct is made of epoxy resin or polyester resin. (3) The foil-wound transformer according to claim 1, wherein the outlet pipe portion of the cooling duct incorporates an insulating inorganic or organic fiber.