JP2017224772A - Structure of iron core joint of electromagnetic equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure for reducing a loss generated in a fastening metal fitting without increasing the height of an iron core.SOLUTION: The transformer iron core structure is so configured that, in a stationary induction electric magnetic steel sheet or a stacked iron core laminated with an amorphous ribbon, a horizontal maximum dimension of a cross section of a yoke arranged in the horizontal direction of the upper part of the iron core is larger than the maximum dimension of a horizontal method of a cross section of a vertical leg wrapping winding of the iron core.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an iron core structure of a stationary induction device among electromagnetic devices.

  A static induction device is a device that changes the voltage by using a magnetic field or a reactor that adjusts impedance by using the action of a magnetic field. This is largely composed of an iron core and windings. The iron core is a part related to the basic specifications such as the number of windings, depending on the magnetic flux density and cross-sectional area. As the structural material, an electromagnetic steel plate or a magnetic ribbon is used. The materials can be selected depending on the application. For example, power transformers such as transformers and pole transformers used in substations use an iron core having a structure in which electromagnetic steel sheets or iron-based amorphous layers are laminated. In the inner iron type transformer, the portions arranged in the horizontal direction at the upper and lower portions of the iron core are called upper and lower yokes, and the portions where the windings are arranged perpendicular to the axial direction of the winding are called legs. In order to maintain the shape of the iron core as a structure, there are a metal metal fitting for fastening the upper and lower yokes, a stat bolt connected to both of the metal fittings for fastening, and other metal fittings for providing the lower iron core. In particular, the fastening metal fittings are located above and below the winding in the axial direction, and an AC magnetic flux (hereinafter referred to as leakage magnetic flux) generated from the winding acts on them. Eddy current) occurs. Due to this current, Joule heat loss occurs in the fastening metal fitting, resulting in deterioration of efficiency. For this reason, in order to reduce the loss of the transformer, a device for suppressing the Joule heat loss in the fastening metal fitting is made.

  JP-A-2014-216524 (Patent Document 1) is known as a prior art. Patent Document 1 proposes a structure that prevents leakage magnetic flux from winding from entering the fastening bracket by inserting a magnetic material block between the fastening bracket and the coil to form a magnetic path to the iron core. doing. This suppresses the occurrence of loss in the fastening hardware.

JP-A-2014-216524

  However, when the magnetic material block is arranged between the winding and the fastening metal fitting, it is necessary to secure a space for arranging the magnetic material block, and there is a problem that the height of the iron core becomes high. In view of this, the present invention provides a structure that reduces the loss generated in the fastening hardware without increasing the height of the iron core.

  In order to solve the above-described problems, the present invention provides a leg that is an iron core region around which a winding is wound and a yoke that is disposed in a horizontal direction, wherein the cross-sectional shape of the yoke is longer in the horizontal direction than the cross-sectional shape of the leg. Utilizing an iron core structure characterized by Thereby, since a yoke is arrange | positioned at the coil | winding upper part, the loss which generate | occur | produces with the metal fitting for clamping can be reduced.

  According to the present invention, the iron core is characterized in that, in a leg serving as an iron core region around which the winding is wound and a yoke arranged in the horizontal direction, the cross-sectional shape of the yoke is longer in the horizontal direction than the cross-sectional shape of the leg. The structure has the effect of reducing the loss generated in the fastening hardware.

It is explanatory drawing which shows the form of this invention. It is explanatory drawing of the iron core of the form of this invention. It is explanatory drawing of the conventional iron core. It is explanatory drawing of the conventional iron core and peripheral structure. It is explanatory drawing of the conventional iron core and peripheral structure. It is explanatory drawing which shows the 2nd Embodiment of this invention.

  Examples of the present invention will be described below.

  First, the structure of the transformer will be described. Fig. 3 shows the iron core of the transformer. The iron core 40 of the transformer is formed by laminating electromagnetic steel plates or amorphous ribbons. The upper and lower portions of the iron core disposed in the horizontal direction are referred to as an upper yoke 41 and a lower yoke 43, and the portions of the winding disposed perpendicular to the axial direction of the winding are referred to as legs 43. Fig. 4 shows the structure of the transformer. In the transformer, a low-voltage winding 15 and a high-voltage winding 16 are wound around an iron core 14 formed by laminating electromagnetic steel plates or amorphous ribbons. In addition, although a winding is not shown in the figure, there are some composed of two or more such as a low-voltage winding, a high-voltage winding, a tap winding. In order to maintain the shape of the iron core, a fastening metal fitting 17 is provided. The fastening bracket 17 is disposed so as to compress the stacking direction of the upper yoke of the iron core 14. Further, as a structure for holding the windings 15 and 16, an insulator 18 is disposed on the upper and lower portions of the winding, and a push bolt 19 provided on the fastening bracket 17 is used via a highly rigid component 20 such as metal. Is done. The iron core 14 and the windings 15 and 16 thus configured are placed in a tank 20 and impregnated with oil and covered with a tank cover 21.

  Next, the loss generated in the fastening hardware 17 will be described. When a current flows through the windings 15 and 16 of the transformer configured as described above, a leakage flux 21 is generated. The leakage magnetic flux 21 diffuses into the space and generates an eddy current in the metal object according to the law of electromagnetic induction. Joule heat loss due to this eddy current is one factor of transformer loss. In particular, the fastening bracket 17 is a structure close to a winding and is greatly affected by this, so that countermeasures are taken as shown in FIG. As a countermeasure, a block 30 made of a magnetic material is provided between the fastening bracket 32 and the parts 31 arranged above and below the winding. The block 30 is generally constructed by laminating silicon steel plates. By adopting such a structure, the leakage magnetic flux 35 generated from the windings 33 and 34 flows into the iron core 36 without reaching the fastening fitting 32. That is, it is possible to suppress a loss that occurs in the fastening hardware 32.

  Next, the 1st Embodiment of this invention is shown in FIG.1 and FIG.2. FIG. 1 is an explanatory diagram of the first embodiment. This embodiment has a structure that reduces the loss of the fastening hardware without increasing the height of the iron core. The iron core 1 differs in the stacking direction width between the upper yoke 50 and the leg 51. Specifically, the thickness L1 of the upper yoke in the stacking direction and the leg L2 are in the relationship of equation (1). Although not shown, the lower yoke of the iron core is also formed with the same width L1 as that of the upper yoke 50 in the stacking direction.

L1> L2 (1)
As a result, the upper yoke 50 exists above the windings 2 and 3. An insulator 5 and a high-rigidity component 6 are disposed above the windings 2 and 3. The highly rigid component 6 holds the winding with a push bolt 7 provided on the clamp 4 of the upper yoke. With such a structure, the leakage magnetic flux generated in the windings 2 and 3 can flow directly into the iron core 1. Although not shown, the lower yoke of the iron core 1 has the same structure. FIG. 2 shows a three-phase iron core structure. As described above, in the iron core 10, the relationship between the width L1 in the stacking direction of the upper yoke 11 and the lower yoke 12 and the width L2 in the stacking direction of the legs 13 is the same as in the formula (1). The same applies to the structures of the three-phase five-legged device and the single-phase device.

  In the present embodiment configured as described above, the structure shown in FIGS. 1 and 2 can eliminate the magnetic block 30 of FIG. 5 which is a conventional structure. The space for arranging the blocks 30 can be reduced. As a result, it is possible to provide an iron core structure that can reduce the dimension in the height direction of the iron core.

  Next, a second embodiment of the present invention is shown in FIG. This example is different from the first embodiment in the structure of the iron core. Since the volume of the upper yoke 63 that absorbs the leakage magnetic flux generated from the windings 61 and 62 in the iron core 60 is less effective in the upper region of the upper yoke 63, it is possible to provide an insulator 64 in this region. . An insulator 67 and a highly rigid component 68 are disposed above the windings 61 and 62. The highly rigid component 68 holds the windings 61 and 62 with a push bolt 69 provided on the fastening yoke 65 of the upper yoke. In this case, the portion where the width of the upper yoke 63 in the stacking direction is the maximum is L1, and the relation with the width L2 of the stacking direction of the legs is the same as in the formula (1). By setting it as such a structure, the quantity of a silicon steel plate can be decreased.

  In the present embodiment configured as described above, the structure shown in FIGS. 1 and 2 can eliminate the magnetic block 30 of FIG. 5 which is a conventional structure. The space for arranging the blocks 30 can be reduced. As a result, it is possible to provide an iron core structure capable of reducing the height dimension of the iron core.

1 .... Iron core
2. Low voltage winding
3. High voltage winding
4. ・ Fastening bracket
5. ・ Insulator
6. Highly rigid parts
7 ・ ・ Push bolt
11. ・ Upper yoke
12. ・ Lower yoke
13.Leg
20 ・ ・ Tank
21 ・ ・ Tank cover
22. ・ Leakage magnetic flux
30 ・ ・ Block of insulation

Claims (3)

  In a stacked iron core laminated with electromagnetic steel plates or amorphous ribbons of static induction electric appliances, the maximum horizontal dimension of the cross section of the core yoke arranged horizontally in the upper part of the iron core is the vertical core leg around which the core winding is wound. Transformer iron core structure characterized by being larger than the maximum horizontal dimension of the cross section.   2. The transformer core structure according to claim 1, wherein an insulator is included in an upper portion of the yoke in an area of the yoke larger than a maximum dimension of the core leg.   A transformer core structure according to claim 2, a fastening metal fitting for holding the iron core yoke, an insulator disposed on an upper part of a winding provided on the fastening metal fitting, and a pressing part for pressing the insulation material. A transformer core structure characterized by that.

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