JPH02267906A - Tap winding of transformer - Google Patents

Abstract

PURPOSE:To prevent the generation of local excessive heating of an iron core and an iron core clamping fittings by making the total current of lead wires be cancelled as a whole. CONSTITUTION:A tap winding is divided into an inner layer tap winding 3A and an outer layer tap winding 3B; lead wires 6A, 7A are led out from the upper part and the lower part of the inner layer tap winding 3A and the outer layer tap winding 3B whose directions of winding are mutually inverse. In order to be able to alternately use each tap of the inner layer tap winding 3A and the outer layer tap winding 3B, the upper lead wires 6A (13', 15', 17', 19', 13, 15, 17, 19) and the lower lead wires 7A (12, 14, 16, 18, 14', 16', 18', 20) are wound in the manner in which the inner layer tap winding 3A and the outer layer tap winding 3B are alternately connected in order. By this constitution, the lead wire current of the inner layer tap winding 3A and the lead wire current of the cuter layer tap winding 3B become inverse in direction, so that the total currents of the lead wires are cancelled as a whole. Thereby the tap winding of a transformer, wherein the generation of local excessive heating of an iron core 1 and iron core clamping fittings 8, 9 is prevented, can be obtained.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to tap windings for transformers.

[Conventional technology]

The tap winding of a large capacity transformer with many tap points is usually 1.
The number of turns per tap is reduced to 4 to 5 turns. When the tap winding is placed inside due to impedance specifications, a cylindrical winding with a winding structure in which multiple conductors are arranged in the axial direction and wound into a cylindrical shape is used.

This tap winding has a structure in which lead wires are pulled out from above and below the tap winding, and the upper and lower lead wires are sequentially connected outside the tap winding and connected to the tap changer. When the line is at the highest or lowest voltage, current flows through all of the multiple conductors that make up the tap winding, so current flows in the same direction in each of the upper and lower solar wires.
The total current reaches 20 to 30 kA. Due to this current.

There was a problem in that local overheating occurred in metal structures such as the iron core and iron core clamping fittings near the lead wire, and at the same time, stray loss increased.

For tap windings in which the number of turns per tap is large, the conductor size is small in small capacity transformers, and the winding lead part does not become large, Japanese Patent Laid-Open No. 55-46532 and Japanese Patent Laid-Open No. 62-12112 As described in the publication, by using a two-stage cylindrical winding structure with an outlet on either the upper or lower side of the tap winding, the current in the outlet wire is canceled and local overheating occurs in structures near the first outlet wire. A structure that prevents this can be adopted.

However, in the case of a large capacity transformer with many tap points, this structure cannot be adopted, so a tap winding structure as shown in FIGS. 5 and 6 is adopted. That is, as shown in FIG. 5, the low voltage winding 2. Tap winding 3. In the case of an inner tap winding structure in which a medium voltage winding 4 and a high voltage winding 5 are wound concentrically in that order, this tap winding 3 adopts a winding structure as shown in FIG. ing.

The upper and lower lead wires 6 and 7 are connected alternately in the upper and lower positions as shown in FIG. 6 at the 0 position shown in FIG. That is, the upper and lower lead lines 13', 13.14', 14.15' and 15,1
6' and 16.17' and 17.18' and 18.19' and 1
9 are connected, respectively, and taps Nos. 12a to 20a are drawn out.

If the winding equipped with such tap winding 3 has the highest voltage or the lowest voltage, tap No. 12 in FIG.
Since a to 20a is used, the upper and lower lead lines 13' to 1
9' and 20. 12 to 19 are the same as shown by the arrows.
Current flows in this direction, causing local overheating in the core 1 and the upper and lower core fasteners 8 and 9 (both shown in FIG. 5) near the lead wire 9.

In order to prevent local overheating, it is necessary to increase the distance between the lead wires 13' to 19' and 20. There were problems such as increased size and increased costs.

[Problem to be solved by the invention]

The tap winding in the above conventional technology does not take into account the prevention of local overheating, and when the transformer capacity is large,
There was a problem that localized overheating occurred in the core and core clamping fittings.

The present invention has been made in view of the above points.

The object of the present invention is to provide a tap winding for a transformer that makes it possible to prevent local overheating of the core and core fastening fittings.

[Means to solve the problem]

The above purpose is to divide the tap winding into an inner layer tap winding and an outer layer tap winding, and to draw out lead wires from above and below the outer layer tap winding among the nine windings that are wound in opposite directions.
This is achieved by sequentially and alternately connecting the inner layer tap winding and the outer layer tap winding to both the upper and lower lead wires so that the inner layer tap winding and the outer layer tap winding can be used alternately one tap at a time. Further, the tap winding is divided into an inner layer tap winding, an intermediate layer tap winding, and an outer layer tap winding, and the winding direction of the intermediate layer tap winding is opposite to that of the inner layer tap winding and the outer layer tap winding.

And lead wires are drawn out from the top and bottom of these wound inner, middle, and outer layer tap windings, and the wires are drawn out in the following order: inner layer tap winding, middle layer tap winding, outer layer tap winding, middle layer tap winding, and inner layer tap winding. This is achieved by connecting the outlet gland for use.

[Effect]

Since the above means is provided, the lead wire current of the inner layer tap winding, the lead wire current of the outer layer tap winding, the lead wire current of the inner layer tap winding, the intermediate layer tap winding, and the outer layer tap winding are in opposite directions. From the perspective of the entire outlet section, the current is canceled out, and local overheating of the core and core clamping fittings can be prevented.

〔Example〕

The present invention will be described below based on two illustrated embodiments. An embodiment of the invention is shown in FIGS. 1 and 2. FIG. Note that parts that are the same as those in the prior art are denoted by the same reference numerals, so explanations will be omitted. In this embodiment, the tap winding is replaced by the inner layer tap winding 3.
A, inner and outer layer tap windings 3A and 3I divided into outer layer tap windings 3B and wound with each winding direction opposite to each other.
Upper lead wire 6A and lower lead wire 7 are drawn out from the top and bottom of 3, and upper lead wire 6A and lower lead wire 7 are drawn out so that inner layer tap winding 3A and outer layer tap winding 3B can be used alternately one tap at a time.
In both A and A, the inner layer tap winding 3A and the outer layer tap winding 3B were sequentially and alternately connected. By doing this, the lead wire current of the inner layer tap winding 3A and the lead wire current of the outer layer tap winding 3B are in opposite directions, so that the currents are canceled out in the two outlet sections as a whole, and the iron core 1 and iron core fastening fitting 8
.

That is, the tap winding is divided into an inner layer tap winding 3A and an outer layer tap winding fi3B. The inner layer tap winding 3A and the outer layer tap winding 3B are wound in opposite directions as shown in FIG. 2, and have nine lead wires 13', 15',
17', 19', 13.15.17.19 are 9 lead wires 12, 1 from the top of each tap winding 3A, 3B.
4.16.18.14', 16', 18', 20
is drawn out from the bottom of each tap winding 3A, 3B, and connects the upper lead wire 6A and the lower lead wire 7A at points M and N in FIG. 1 as shown in FIG.

In other words, the inner layer tap winding 3A and the outer layer tap winding 3B are
Upper lead wire 6A (
13', 15', 17', 19', 13.15
．． 17゜19), lower lead wire 7A (12, 14, 1
6, 18, 14'.

16', 18', 20) both inner layer tap winding 3A,
The outer layer tap windings 3B are sequentially and alternately connected. That is, the upper lead lines 6A are 13', 13.15' and 15.17'.
and 17°19' and 19 are connected, and the lower lead wire 7A is 14 and 14'.

16 and 16' and 18 and 18' are connected.

When the winding including such tap windings 3A and 3B has the highest voltage or the lowest voltage, tap numbers 12a to 20a shown in FIG.
2.20 and pulled out from the respective connections), the upper lead wires 13', 15', 17', 19' of the tap winding RjA3A and the tap winding 3
Upper lead line of B 13.15.17.19. The lower lead wires 12, 14, 16, 18 of the tap winding 3A and the lower lead wires 14', 16', 18 of the tap winding 3B.
', 20, respectively, as indicated by the arrows,
Lead wire current of inner layer tap winding 3A and outer layer tap winding 3
The direction of the lead wire current of B is reversed. Therefore, the magnetic field due to the lead line current in the lead line segment portion can be reduced to almost zero. Therefore, local overheating does not occur in the iron core 1 or the iron core fastening fittings 8 and 9, and stray loss can be reduced.

As described above, according to this embodiment, since the magnetic field due to the lead wire current of the tap winding can be reduced to almost zero, local overheating of the iron core, core clamping fittings, etc. near the lead wire 9 can be prevented. :A It is possible to reduce play loss.

Furthermore, there is no need to take special measures against overheating in two localized areas, making it possible to downsize the transformer and reduce costs.

Another embodiment of the invention is shown in FIG.

In this embodiment, a semi-hard copper wire was used as the conductor of the outer layer tap winding 3B. That is, the force generated in the radial direction during a short circuit is larger in the outer tap winding 3B than in the inner tap winding 3A, and the conductor size of the tap winding is determined from the outer tap winding 3B rather than the short circuit mechanical force.

Therefore, by using semi-hard copper wire for the conductor of the outer layer tap winding 3B, the cap W2 of the outer layer tap winding 3B can be made smaller than the width W1 of the inner layer tap winding 3A, and the transformer winding as a whole can be made smaller.

FIG. 4 shows yet another embodiment of the invention. In this embodiment, the tap winding is divided into an inner layer tap winding 3A, an intermediate layer tap winding 3C, and an outer layer tap winding 3B, and the winding direction of the intermediate layer tap winding 3C is changed from the inner layer tap winding 3A to the outer layer tap winding The winding direction was opposite to that of wire 3B. And these inner, middle and outer layer tap windings 3A, 3G, 3I3
Pull out the lead wires from the top and bottom of the inner layer tap winding 3A.

The lead wires were connected so that the intermediate layer tap winding 3G, the outer layer tap winding 3B, the intermediate layer tap winding 1%3C, and the inner layer tap winding 3A could be used in this order. By doing this, the lead wire currents of the inner layer tap winding 3A, the intermediate layer tap winding 3C, and the outer layer tap winding 3B are in opposite directions, resulting in the same effect as in the case of FIGS. 1 and 2 described above. It can be effective.

〔Effect of the invention〕

As described above, the present invention provides a tap winding for a transformer, which prevents local overheating of the core and core fasteners. Obtainable.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the winding configuration of one embodiment of the tap winding of the transformer of the present invention, FIG. 2 is a connection diagram showing the connection of the lead wire of the same embodiment, and FIG. 3 is the diagram of the present invention. FIG. 4 is an explanatory diagram showing the winding configuration of another embodiment of the tap winding of the transformer according to the present invention. FIG. ! Explanatory diagram showing groove formation. FIG. 5 is an explanatory diagram showing the winding configuration of a tap winding of a conventional transformer, and FIG. 6 is an explanatory diagram showing the same conventional lead wire connection. 3A...Inner layer tap winding, 3B...Outer layer tap winding. 3C: Intermediate layer tap winding, 6A: Upper lead wire. 7A...Lower lead wire 2nd Figure 1Figure 13A...3B...6A...7A...Inner layer tap windingOuter layer tap windingUpper lead wireLower lead wireCurrent cancellation chartFig. Diagram

Claims (3)

[Claims] 1. In the tap winding of a transformer with a cylindrical winding structure in which a plurality of conductors are arranged in the axial direction and wound in a cylindrical shape, the tap winding is divided into an inner layer tap winding and an outer layer tap winding, and the winding direction is The lead wires are drawn out from above and below the inner and outer layer tap windings, which are wound in opposite directions, and both the upper lead wire and the lower lead wire are drawn out so that each tap of the inner layer tap winding and the outer layer tap winding can be used alternately. A transformer tap winding characterized in that an inner layer tap winding and an outer layer tap winding are sequentially and alternately connected. 2. The tap winding for a transformer according to claim 1, wherein the outer layer tap winding uses a semi-hard copper wire as a conductor. 3. In the tap winding of a transformer with a cylindrical winding structure in which a plurality of conductors are arranged in the axial direction and wound in a cylindrical shape, the tap winding is divided into an inner layer tap winding, an intermediate layer tap winding, and an outer layer tap winding. At the same time as dividing, the winding direction of the intermediate layer tap winding is opposite to the winding direction of the inner layer tap winding and the outer layer tap winding, and lead wires are installed from above and below the wound inner, intermediate, and outer layer tap windings. A transformer tap characterized in that the lead wire is connected so that it can be used in the order of drawer, inner layer tap winding, intermediate layer tap winding, outer layer tap winding, intermediate layer tap winding, and inner layer tap winding. winding.