JPS61172311A - Three-phase transformer - Google Patents

Abstract

PURPOSE:To simplify the lead-out structure of a lead wire by a method wherein, using foil-like windings as the winding of each set, the lead wires coming from each winding are provided on the shorter side of a transformer tank, and the lead wires are constituted in such a manner that they are led out collectively from a three-phase spacer. CONSTITUTION:The lead wires 4 coming from the foil-like windings 2, 2' and 2'' of each set are led out to outside a transformer tank from a three-phase type spacer 5 provided on the side of the shorter side of the transformer tank 1. The cooling device 7, which is an accessory part of the transformer, is ar ranged on the longer side of the transformer tank 1. As the outermost side of the foil-like windings 2, 2' and 2'' are all equipotential, the lead wire 4 can be led out of any position of the winding, the connection of the three-phase spacer 5 located on the side of the shorter side of the tank can be facilitated, and the arrangement and the insulative constitution of the spacer 5 can also be simplified. On the three-phase transformer, as the lead wire 4 for three phases can be led out of the spacer 5, the connection with the other gas insulated machine can be performed easily.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a three-phase transformer having a built-in winding formed by winding a metal sheet and an insulating sheet inside a tank.
In particular, the present invention relates to a three-phase transformer that has an improved structure for drawing out lead wires from the windings of each phase.

[Technical Background of the Invention] In recent years, due to soaring land prices and other reasons, substations have become more compact and are increasingly being installed inside buildings or underground. For such substations, the transformer is directly connected to gas insulated equipment using SFB gas, etc., and the transformer itself is also insulated with insulating gas such as SF6 gas for safety reasons such as fire. A so-called gas insulated transformer is used to provide insulation.

An example of a connection structure between this type of transformer and gas insulated equipment such as a circuit breaker is shown in FIG.

In FIG. 2, 1 is a transformer tank which houses windings 2 and an insulating medium 3 inside. The long side of the tank 1 is a lead wire through hole, and for example, the lead wire 4 extending from the high voltage winding of each phase is connected to the gas insulated bus 6 via a spacer 5 provided on the long side of the tank. External devices such as a lightning arrester and a circuit breaker (not shown) are connected to the gas insulated bus 6.

It is also attached to the long side of the opposite side of the low voltage transformer tank 1 by the same means as the high voltage side. A cooling device 7 for cooling such a transformer is arranged between each gas insulated bus bar 6.

[Problems of Background Art] However, the lead wire extraction structure of the conventional three-phase transformer having the above-mentioned configuration has the following problems.

(2) Since single-phase gas insulated busbars 6 are arranged over the entire sides of both sides of the transformer tank 1, the installation area at the substation becomes large, and a large space is required.

(2) Since the cooling device 7 is provided in the middle of the gas insulated bus bar 6, its size is limited.

- The cross members supporting the gas insulated bus bar 6 must be attached from the ground, which requires a large amount of cross members and is expensive.

■ Since the lightning arrester attached to the transformer is attached to the end of the gas-insulated busbar, the distance from the transformer winding becomes long and may not be sufficient to protect the winding.

In order to solve the above-mentioned problems with conventional three-phase transformers, it is theoretically possible to use a three-phase bulk spacer to facilitate the connection between the transformer tank and gas-insulated equipment. I can't stand it. However, with conventional transformers wound with rectangular copper wire, the direction of lead wire is limited, so the insulation configuration becomes complicated when the lead wire runs up to the three-phase spacer, making it difficult to use a three-phase spacer. The advantages of this were lost and it was not practical.

[Object of the Invention] The present invention was proposed in view of the problems of the prior art as described above, and its purpose is to simplify the structure for drawing out lead wires from the windings of each phase, and to provide a three-phase type An object of the present invention is to provide a three-phase transformer in which the structure of the transformer tank is simplified and the transformer and its accessories are made more compact by using the spacer.

[Summary of the Invention] The three-phase transformer of the present invention uses so-called foil windings made of metal sheets and insulating sheets as the windings for each phase housed in the transformer tank. The drawing direction of the lead wires from each winding can be freely set, and the connection structure of the lead wires between the windings of each phase and the three-phase spacer is simplified.

Furthermore, in the three-phase transformer of the present invention, by providing a three-phase spacer on the short side of the rectangular transformer tank, sufficient space can be secured without placing a gas-insulated bus bar on the long side of the tank. This makes it possible to rationally arrange transformer accessory parts such as cooling devices and cross members.

[Embodiment of the Invention] Hereinafter, an embodiment of the present invention will be described in detail with reference to FIG. Note that the same parts as those of the conventional transformer shown in FIG. 2 are denoted by the same reference numerals, and explanations thereof are omitted.

In this embodiment, the transformer tank 1 is rectangular in size so that the windings of each phase accommodated therein can be arranged linearly. The windings of each phase housed in the transformer tank 1 are foil windings made by overlapping and winding metal sheets and insulating sheets.
It has been described in many publications including 2@ gazette and is already well known.

The lead wires 4 of the foil windings 2a, 2b, 2c of each phase are drawn out from a three-phase spacer 5 provided on the short side of the transformer tank 1 to the outside of the tank. A cooling device @7, which is an accessory part of the transformer, is arranged on the long side of the transformer tank 1.

The effects of the three-phase transformer of this embodiment having such a configuration are as follows.

■ Since the foil winding has the same potential on the outermost side of the winding, the lead wire can be pulled out from any position on the winding, and the connection to the three-phase spacer on the short side of the tank is easy. It is easy to use, and insulation configuration can be easily achieved by crawling up to the spacer.

■ In a three-phase transformer, the lead wires can be taken out from one spacer for each of the three phases, making it easy to connect to other gas-insulated equipment.

■ Since the three-phase spacer is installed on the short side of the tank, the cooling device for cooling the transformer can be placed all at once on the long side of the tank, eliminating any particular restrictions on its size and shape, and improving performance. In addition to making it possible to use a good cooling device, the area required for installation can also be reduced, and the substation itself can be made more compact.

■ When the insulating medium inside the transformer is an insulating gas such as S Fs gas, the tank is usually manufactured as a pressure tank, but since the lead wire outlet is only on a part of the short side of the tank, concentrated stress is generated. This makes it possible to provide an economical transformer tank with excellent mechanical strength and a low cost transformer.

[Effects of the Invention] As described above, the present invention uses a three-phase spacer in which foil windings are used as the windings of each phase and the lead wires from each winding are provided on the short side of the transformer tank. The simple structure of pulling out all at once simplifies the lead wire exit structure.
This has the effect of making it possible to obtain a compact three-phase transformer that allows for rational arrangement of accessory parts such as a cooling device.

[Brief explanation of drawings]

FIG. 1 is a plan view schematically showing an embodiment of a three-phase transformer according to the present invention, and FIG. 2 is a plan view showing an example of a conventional three-phase transformer. DESCRIPTION OF SYMBOLS 1... Transformer tank, 2.2a, 2b, 2C... Winding wire, 3... Insulating medium, 4... Lead wire, 5... Spacer, 6... Gas insulated bus bar, 7 ···Cooling system.

Claims (1)

[Claims] In a three-phase transformer that has a built-in winding made of an insulating sheet and a metal sheet wound inside the tank, the windings of each phase are arranged in a straight line inside the rectangular tank, and the short side of the rectangular tank is A three-phase transformer characterized in that a three-phase spacer is provided in the tank, and the lead wires extending from the windings of each phase are drawn out from the three-phase spacer to the outside of the tank.