JP2007005470A - Three-phase wound core and three phase transformer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To manufacture a three-phase wound iron core without deteriorating workability, and assemble a three-phase transformer by dividing a three-phase outer iron core with long circumference, while suppressing the cut length of an iron core and lightening the weight of one block of an iron core, in order to cope with the increase in manufacturing processes and upsizing of manufacturing equipments when such a large-sized model as a three-phase transformer is manufactured by winding cores. <P>SOLUTION: The three-phase wound iron core is constituted of a first inner iron core 1 and a second inner iron core 2, and an outer iron core 3 arranged in the shape of a nearly rectangle arranged on the perimeter of the inner iron core. The first inner iron core 1 and the second inner iron core 2 are respectively coupled by one inner iron core joining parts 4 and 5. The outer iron core 3 is divided into a plurality of pieces, in such a way that the iron core 3 manufactured by joining them at two or more outer iron core joining parts 6 and 7 located in an almost rectangular shaped upper and lower yoke or a corner. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a stationary induction device such as a three-phase transformer using a three-phase wound iron core made of a silicon steel plate.

  As an iron core used for a three-phase transformer, a stacked iron core and a wound iron core are known, and the loaded iron core is applied to a relatively large transformer. As shown in FIG. 7, the iron core includes coil leg portions 1 a to 1 c and yoke portions 2 a and 2 b, and the joint portion of each element is cut at 45 °. In the case of a three-phase core, there are six butted locations 3d, and the shape of the joint greatly affects the characteristics. The smaller the number of joints, the better the characteristics. Further, since the magnetic flux of the transformer does not flow much outside the iron core, the corner portion uses the iron core in vain. Even in the manufacturing process of the core, there are many types of shapes such as the upper iron part 2a, the lower iron part 2b, the U-phase leg part 1a, the V-phase leg part 1b, and the W-phase leg part 1c. Cost a lot. Moreover, many man-hours are required also for the operation | work which laminates | stacks one silicon steel sheet at a time in the case of iron core formation after a cutting | disconnection.

On the other hand, in the case of the wound core of the three-phase transformer shown in FIG. 8, the stacking direction of the silicon steel sheet is different from that of the stacked core, and the shape is in line with the flow of magnetic flux. As a result, the amount of core used can be reduced. Further, after the laminated silicon steel plates are laminated as they are to form an annular shape, they can be formed into a rectangular shape by using a forming die and can be transferred to an annealing process. This process is easy to mechanize and can be manufactured at low cost because it requires less manual work than the core. Further, there are many advantages because there are few butted portions 3d and the iron core loss is reduced.
However, when manufacturing large-sized wound cores, it is difficult to manufacture wound cores because the equipment in each process of the silicon steel sheet cutting process, round winding process, rectangular forming process, and annealing process is enlarged. In the case of large size, transformers are often made with iron cores.

As other conventional examples of three-phase wound cores, those having structures shown in Patent Documents 2 to 4 below are known. 9 to 11 show conventional examples of the structure of the three-phase wound core described in Patent Document 2 to Patent Document 4. FIG.
In the conventional example of the three-phase wound core shown in FIG. 9, the first wound body 14 and the second wound body 15 are arranged on the outer periphery of the two inner wound cores 13, 13 arranged outside. A wound iron core 16 is formed. In this case, both the inner wound core 13 and the outer wound core 14 each have one cut portion 17.
Further, in the conventional example of the three-phase tripod-shaped wound core 20 shown in FIG. 10, outer wound cores 23, 23 are arranged on the outer periphery of the pair of inner wound cores 21, 21, and the inner wound core is also the outer wound core. Also has two seam portions 24, 24. Moreover, the outer periphery winding core 27 is arrange | positioned at the outer periphery of said pair of outer winding cores 23 and 23, and has the joint part 28 and 28 of each two inclined surfaces. In the three-phase wound core shown in FIG. 10, since the joint portion is located on the leg portion, noise due to high-frequency vibration is generated, and in order to suppress this noise, it is necessary to fix it with a cover plate or a band. It is.
Further, in the conventional example of the three-phase tripod wound core illustrated in FIG. 11, three inner cores 2 arranged adjacent to the wound core and an outer core 3 surrounding the outer periphery of these inner cores 2 are provided. It has a phase tripod wound core structure, and the outer core 3b is formed by dispersing the lap joint 5b over the entire area of the yoke straight portion of the outer core 3b. The two inner iron cores have one joint portion, and the outer iron core has one joint portion dispersed throughout the straight portion.

Moreover, the thing of the following patent documents 4 and 5 is known as a prior art example of the structure of a single phase wound iron core.
12 and 13 show conventional examples of the structure of these single-phase wound cores.
In the conventional example of the structure of the single-phase wound core shown in FIG. 12, the inner circumference side wound core block has one butt joint for every turn, and the outer circumference side core block is every turn. Two butt joints are provided, and two butt joints of the outer peripheral side iron core block are arranged on the legs near the corners of the wound core.
Further, in the conventional example of the structure of the single-phase wound core shown in FIG. 13, there is a single-phase wound core having two outer peripheral blocks 5 of the wound core 2 and having joints at two corners of the wound core. Are listed.
JP-A-5-101943 JP 2001-284136 A JP 2005-72161 A Japanese Utility Model Publication No. 62-12914 JP 2000-188219 A

  In order to reduce the size of a large static induction device, the use of a wound iron core is an effective means, but it leads to an increase in manufacturing processes and an increase in size of manufacturing equipment. As a solution to this, it is useful to divide a three-phase outer core having a long circumference. This reduces the cutting length of the iron core and reduces the weight of one iron core block by dividing it, so that the iron core can be manufactured without deteriorating workability. It is effective for. Moreover, it becomes a subject to make it not affect a product characteristic also about the form of the junction part.

In order to cope with an increase in the size of the wound core, the present invention cuts the three-phase outer core in two in the wound core manufacturing process and arranges the outer core joint at the upper and lower yokes or corners of the outer core. While shortening the length, it is possible to manufacture using the same equipment as a small wound core.
Moreover, the deterioration of the iron core characteristics is suppressed by considering the shape and method of the joint. In addition, depending on the form of the iron core joint, the dimensions of the transformer are also affected. For example, if the joint is a step lap method, the outer dimensions of the iron core will not change, but the loss of the iron core will increase. On the other hand, if the overlap method is used, the loss of the iron core will improve, but the size of the joint will increase. This affects the product dimensions.
The present invention provides a three-phase wound core and a three-phase transformer in consideration of workability, product characteristics, and dimensions by combining two joint portions of a three-phase outer core and the above-described two joint forms.

  According to the present invention, the amount of iron core material used can be reduced, and a compact three-phase wound core and three-phase transformer can be manufactured and costs can be reduced.

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

FIG. 1 shows a first embodiment of the present invention. As shown in FIG. 1, a three-phase wound iron core is formed by combining a first inner iron core 1, a second inner iron core 2 and an outer iron core 3. Since the magnetic flux density distribution of the transformer core is concentrated on the inner core, the inner core does not divide the inner core joint 4 and the inner core joint 5 in order to suppress the core loss. It is desirable to have one place for each of the two. Further, in the case of the inner iron core, since the cutting length of the silicon steel sheet is relatively short, it is preferable to join at one place because it is not subject to any special restrictions in the manufacturing process.
On the other hand, if the outer iron core has a single joint, the cutting length becomes long, and if the outer iron core is arranged and molded in a rectangular shape, the outer dimensions become large and the equipment is easily restricted. Therefore, the outer iron core is divided into two parts, the circumference is shortened, and an iron core that can be manufactured without deteriorating the workability without being restricted by facilities is supplied.
Moreover, by providing the outer iron core joint portions 6 and 7 in the upper and lower yoke portions of the outer iron core, the state of the joint portion can be confirmed and defects can be made obvious. In addition, since the outer core joint is not located on the leg, no fixing member such as a cover plate or a band is required to suppress noise due to high frequency vibration. Also, the outer core joints 7 and 8 are By adopting a step wrap method in which the gaps are joined in a staircase pattern, an increase in the thickness of the outer iron core joint can be suppressed, and the lower surface of the lower iron part can be formed flat.

  FIG. 2 shows a second embodiment of the present invention. The outer lap joint of the step wrap method shown in the first embodiment can suppress the size of the joint, but it tends to hinder the flow of magnetic flux and increases the loss of the iron core. Therefore, loss is suppressed by making at least one of the outer iron core joints overlap. In the case of FIG. 2, an increase in transformer size can be reduced by disposing the overlapped outer core connecting portion 7 in the upper yoke portion. This is because there is a gap between the upper metal fitting and the upper end of the outer iron core, and the terminal for connection is arranged at the upper part, so that the increase in the size of the overlap joint can be accommodated within this size range. .

Furthermore, as shown in FIG. 3, if both the upper and lower outer core joints 6 and 7 are joints of an overlap system, the loss of the outer core can be further suppressed.
Here, since the dimension of the connecting portion of the outer iron core joint formed in the lower iron portion is increased, the iron core is not stable. In order to ensure stability, it is desirable to insert a spacer having the same thickness as the size increase of the lower wrap portion.

  As shown in FIG. 4, by arranging the outer iron core joints 6 and 7 at the corners on the rectangular diagonal line of the outer iron core 3, it is possible to suppress an increase in product size due to overlap.

  Further, as shown in FIG. 5, the outer core joints 6, 7, 8, and 9 are dispersed using four corner portions, and a layer having the outer core joint portion and an outer core joint portion are formed in one corner portion. If the outer core joints 6, 7, 8, 9 are arranged so that there are no layers, the presence of the outer core joints will less affect the outer dimensions of the core.

The example of the external appearance of the three-phase transformer which employ | adopted the three-phase wound core of said each Example is shown in FIG.
In FIG. 6, the three-phase transformer is configured by combining the three-phase wound core of each of the above embodiments and a plurality of coils mounted on a tripod of the three-phase wound core.

  Although the present invention has been described with reference to a three-phase wound core of a three-phase transformer as an example, the three-phase wound core of the present invention is not limited to a three-phase transformer, and electrical equipment that requires a wound core made of a silicon steel plate Available to all.

The figure which shows the 1st Example of this invention. The figure which shows the 2nd Example of this invention. The figure which shows the 3rd Example of this invention. The figure which shows 4th Example of this invention. The figure which shows 5th Example of this invention. The figure which shows the example of an external appearance of the three-phase transformer using the three-phase wound iron core of this invention. The figure which shows the prior art example of a three-phase product core. The figure which shows the prior art example of a three-phase wound iron core. The figure which shows the other conventional example of a three-phase wound iron core. The figure which shows the other conventional example of a three-phase wound iron core. The figure which shows the other conventional example of a three-phase wound iron core. The figure which shows the prior art example of the connection part of a single phase wound iron core. The figure which shows the prior art example of the connection part of a single phase wound iron core.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a Stack iron core U-phase leg 1b Stack iron core V-phase leg 1c Stack iron core W-phase leg 2a Stack iron core upper relay part 2b Stack iron core lower yoke part 3d Iron core butting part 1 1st inner core 2 2nd inside Iron core 3 Outer core 4 Inner core joint 5 Inner core joint 6 Outer core joint 7 Outer core joint 8 Outer core joint 9 Outer core joint

Claims (7)

In a three-phase wound core consisting of a first inner core and a second inner iron core, and an outer iron core arranged in a substantially rectangular shape on the outer periphery of the inner iron core,
Each of the first inner core and the second inner core is joined at one inner core joint, and the outer core is divided into a plurality of parts, and the substantially rectangular upper and lower yokes or corners. A three-phase wound core, characterized by being joined at a plurality of outer core joints located in the center.   The three-phase wound core according to claim 1, wherein the outer core joint is a step lap or overlap joint.   3. The three-phase wound core according to claim 2, wherein the step wrap type outer iron core joint is located in a succeeding iron portion of the outer iron core.   The overlap type outer iron core joint is located in a succeeding iron part of the outer iron core, and a spacer having the same thickness as the size increase of the overlap type outer iron core joint is installed. Item 3. A three-phase wound iron core according to item 2.   3. The three-phase wound core according to claim 2, wherein the overlapped outer core joint is located at a corner portion on a diagonal line of the outer core arranged in a substantially rectangular shape.   A part of the overlapped outer core joint is located at each corner on one diagonal of the outer core arranged in a substantially rectangular shape, and the other part of the outer core joint is substantially rectangular. 6. The three-phase wound core according to claim 5, wherein the three-phase wound core is located at each corner portion on the other diagonal line of the arranged outer core.   A three-phase transformer comprising the three-phase wound core according to any one of claims 1 to 6 and a plurality of coils attached to legs of the three-phase wound core.

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