JP2019029553A - Amorphous Transformer - Google Patents

Abstract

To solve a problem in which the short-circuit strength improves as the coil shape of a transformer approaches a circular shape, however, the cross-sectional shape of an amorphous core is rectangular, and in the case of a circular coil, a large space occurs between an iron core and a coil.SOLUTION: A transformer according to an embodiment of the present invention includes at least a coil formed by winding a conductor a plurality of times and an iron core inserted into the inner periphery of the coil. The iron core is formed by laminating a plurality of ribbon layers made of one or a plurality of amorphous ribbons, and from among the plurality of ribbon layers, the even number ribbon layer is stacked on the odd number ribbon layers so as to be shifted from the odd number ribbon layers in the same direction as the width direction of the iron core.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an amorphous transformer.

  The transformer includes a coil (a primary coil and a secondary coil) and an iron core inserted in the inner periphery of the coil as main components. There are several types of coil shapes used in the transformer, but a circular coil shape is preferable in terms of improving short-circuit strength.

  When a circular coil is employed in the transformer, for example, as shown in Patent Document 1, an iron core inserted in the inner periphery has a cross-sectional shape in order to reduce a space generated between the coil and the iron core. An iron core that is close to a circle (close to the inner peripheral shape of the coil) is employed.

JP 54-142520 A

  In recent years, an iron core formed by laminating a plurality of amorphous ribbons is often used for a transformer. However, since an amorphous ribbon is very thin and difficult to mold, it is common to laminate amorphous ribbons having the same width to form a wound core. Therefore, in general, the cross-sectional shape of the amorphous iron core is rectangular, and in the case of a circular coil, a large space is created between the iron core and the inner wall of the coil. The split coil in this space becomes large. In addition, the short-circuit mechanical force generated when the transformer is short-circuited causes the coil wire to drop into the space, causing an increase in impedance.

  In order to manufacture an iron core having a cross-sectional shape close to the shape of the inner circumference of the coil, such as the iron core disclosed in Patent Document 1, it is necessary to stack a plurality of amorphous ribbons having different widths. However, this requires preparation of a plurality of amorphous ribbons having different widths, resulting in an increase in work man-hours and costs.

  An amorphous transformer according to an embodiment of the present invention includes at least a coil formed by winding a conductor a plurality of times and an iron core inserted into the inner periphery of the coil. The iron core is an iron core formed by laminating a plurality of ribbon layers composed of one or a plurality of amorphous ribbons, and among the plurality of ribbon layers, even-numbered ribbon layers are odd-numbered ribbon layers. On the other hand, the iron cores are laminated so as to be shifted in the same direction in the width direction.

  According to the present invention, the space generated between the amorphous iron core and the coil can be reduced with a small number of work steps. Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

1 is a schematic cross-sectional view of an amorphous iron core used in an amorphous transformer according to Example 1. FIG. It is the cross-sectional schematic which inserted the amorphous iron core in the coil. It is the schematic which shows the content structure of a transformer. It is a cross-sectional schematic diagram of an iron core coil of a conventional amorphous transformer. It is a figure which shows the example of the coil of a three-phase transformer, and the iron core inserted in the coil.

  Embodiments of the present invention will be described below with reference to the drawings. The transformer according to the embodiment described below is an amorphous transformer using an amorphous iron core formed by laminating a plurality of amorphous ribbons. Hereinafter, the transformer is simply referred to as a “transformer”. In the following embodiments, the direction of the iron core will be described. The direction in which a plurality of amorphous ribbons are laminated is referred to as the “thickness direction” or “lamination direction” of the iron core. The direction perpendicular to the thickness direction of the iron core and the longitudinal direction of the iron core (or amorphous ribbon) is referred to as the “width direction” of the iron core.

  FIG. 3 is a diagram showing the content structure of a transformer, particularly a single-phase transformer. The transformer is composed of a coil 1 and an iron core 2 arranged so as to penetrate the coil. The example shown in FIG. 3 is an example of a transformer that employs a cylindrical coil 1.

  FIG. 4 is a cross-sectional view of a conventional coil in which an amorphous iron core is inserted, and represents a cross section taken along the line AA of FIG. As is well known, the short-circuit strength improves as the coil shape of the transformer approaches a circle. Since amorphous ribbons are very thin and difficult to form, it is common to laminate amorphous ribbons of the same width into a wound core shape. Therefore, the cross-sectional shape of the amorphous iron core is rectangular, and in the case of a circular coil, a large space 3 is created between the iron core and the inner wall of the coil. The split coil in this space becomes large. Moreover, the electric wire of a coil falls in the space 3 by the short circuit mechanical force which arises at the time of a transformer short circuit, and becomes a cause of an impedance increase.

  FIG. 1 is a schematic cross-sectional view of an iron core used in the transformer according to the present embodiment. The amorphous iron core 2 is formed by laminating amorphous ribbons 4. The amorphous iron core 2 (hereinafter also abbreviated as “iron core 2”) used in the transformer according to the present embodiment is arranged in the width direction by one or several sheets so that the amorphous ribbon 4 overlaps the central portion. It is formed by laminating while shifting alternately.

  An example of a method for stacking the amorphous ribbon 4 will be described with reference to FIG. In FIG. 1, the amorphous ribbons 4-2, 4-3. . . Are stacked. Here, amorphous ribbons 4-1, 4-2, 4-3. . . Each may be a single amorphous ribbon, or may be a layer composed of n (n is an integer of 1 or more) amorphous ribbons. Further, amorphous ribbons 4-1, 4-2, 4-3. . . The width of each is the same. In the present specification, a layer composed of one or a plurality of amorphous ribbons is referred to as a ribbon layer, and the amorphous ribbons 4-1, 4-2, 4-3. . . Each of these is also a ribbon layer. Moreover, the number (number of lamination | stacking) of the thin ribbon layer which comprises the iron core 2 is not limited to a specific number, It is good to determine the number of lamination | stacking suitably according to the kind and characteristic of the transformer to be used.

  In FIG. 1, the amorphous ribbon 4-2 is laminated to the amorphous ribbon 4-1 while being shifted to the left by a distance d (d is a positive value) (in FIG. Direction (left-right direction) is the width direction of the iron core 2), and the amorphous ribbon 4-3 is shifted leftward by a distance −d with respect to the amorphous ribbon 4-2 (in other words, rightward by the distance d). Are stacked). Similarly, the amorphous strips 4-3 and subsequent layers are laminated by alternately repeating the steps of laminating the layers by shifting the distance d in the left direction and laminating the layers by shifting the distance d by the distance d in the right direction. Thus, the iron core 2 is formed in which the amorphous ribbon 4- (2k) is laminated with a distance d shifted to the left in the width direction of the iron core 2 with respect to the amorphous ribbon 4- (2k-1). (Where k is an integer greater than or equal to 1). Here, the example in which the amorphous ribbons 4-2 and 4-3 are stacked in the upper direction of the amorphous ribbon 4-1 has been described, but the amorphous ribbons stacked in the lower direction of the amorphous ribbon 4-1 are described. 4 is also laminated in the same procedure. In this way, when the amorphous ribbons 4 are laminated one by one (or in units of n) while being alternately shifted in the width direction, the iron core 2 having a width larger than the width of the amorphous ribbon 4 is obtained. In addition, the thickness of the overlapping portion at the center of the iron core 2 obtained here is twice that of both end portions, and the cross section of the completed amorphous iron core 2 is not rectangular but approaches an octagon or an ellipse.

  Here, the distance d may be appropriately determined according to the shape of the inner periphery of the coil 1 into which the iron core 2 is inserted. However, since the plurality of amorphous ribbons 4 are stacked so that there are portions that overlap each other, the distance d is smaller than the width of the amorphous ribbon 4.

  FIG. 2 is a schematic sectional view in which the amorphous iron core 2 of FIG. 1 is inserted into a circular coil 1. The coil 1 is formed by winding a conductor such as a copper wire a plurality of times in the same manner as a coil used in a known transformer. By making the coil 1 circular, the short-circuit strength of the coil 1 is improved. Since the cross section of the amorphous iron core 2 approaches an elliptical shape, the space 3 between the amorphous iron core 2 and the inner wall of the circular coil 1 can be reduced. Since the space 3 is reduced, the coil size can be reduced, and the amount of electric wires used can be reduced. Therefore, the transformer can be reduced in size, cost, and load loss. Moreover, the space where a coil electric wire falls by the mechanical force generated at the time of a short circuit is reduced, and the short circuit strength of a transformer improves. Therefore, large-capacity models with a large electromagnetic mechanical force at the time of a short circuit, which was difficult to manufacture with conventional technology, can be manufactured with amorphous iron core transformers.

  The shape of the coil 1 is not limited to a circle, and the space 3 between the coil 1 and the iron core 2 can be reduced even in the case of an ellipse, an octagon, or the like.

  There are only several kinds of width dimensions of the amorphous ribbon, and the design value of the width dimension of the amorphous core 2 is limited in the conventional iron core forming method. However, according to the present invention, it is possible to manufacture the amorphous iron core 2 having an arbitrary width dimension by adjusting the shift amount and the overlap margin of the amorphous ribbon.

  Although the shape of the iron core 2 described in the first embodiment is a vertically symmetric shape, the shape of the iron core 2 may be vertically asymmetric. Example 2 describes such an example. FIG. 5 shows an example of a coil of a three-phase transformer and an iron core inserted into the coil.

  In the three-phase transformer, two iron cores (2a, 2b) are inserted into one coil 1. In this case, if the shape of the two iron cores (2a, 2b) is a vertically symmetric octagonal shape as described in the first embodiment, the space between the coil 1 and the iron cores 2a, 2b becomes large. .

  Therefore, when two iron cores (2a, 2b) are inserted into one coil 1 as shown in FIG. 5, the shapes of the iron cores 2a, 2b are made asymmetric in the vertical direction, as shown in FIG. It is good to have a substantially hexagonal shape. The iron core 2a is amorphous thin so that the width of the surface (hereinafter referred to as "the bottom surface of the iron core 2a") located at the center of the coil 1 is the largest, and the bottom surface of the iron core 2a is flat. The band 4 is preferably laminated. Similarly, with respect to the iron core 2b, the width of the surface (bottom surface of the iron core 2b) located at the center of the coil 1 should be maximized, and the bottom surface of the iron core 2b should be flat.

  In the case of a three-phase transformer, the space formed between the iron core 2 (2a, 2b) and the inner wall of the coil 1 can be reduced by making the cross-sectional shape of the iron core 2 (2a, 2b) in this way. Is possible.

1 ... Coil, 2 ... Amorphous iron core, 3 ... Space generated between iron core and coil, 4 Amorphous ribbon

Claims (4)

A coil formed by winding a conductor multiple times;
An iron core inserted into the inner periphery of the coil;
Have
The iron core is formed by laminating a plurality of ribbon layers composed of one or more amorphous ribbons,
Among the plurality of the ribbon layers, the even-numbered ribbon layers are laminated with being shifted in the same direction in the width direction of the iron core with respect to the odd-numbered ribbon layers,
An amorphous transformer characterized by that. The thickness of the central portion of the iron core is twice the thickness of both end portions of the iron core.
The amorphous transformer according to claim 1, wherein: The shape of the inner periphery of the coil is circular or elliptical.
The amorphous transformer according to claim 2, wherein: Two iron cores are inserted into the inner circumference of the coil,
The width of each of the iron cores is configured such that the width of the bottom surface that is a portion located in the center of the coil is the largest,
The amorphous transformer according to claim 3, wherein: