JP2013038104A - Transformer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the size of a transformer by reducing the size of a tap changeover section.SOLUTION: A transformer comprises: a plurality of tap terminals 15a-c provided to a tap winding 5; common terminals 17 provided to the side of the tap terminals 15a-c, to which any one of the tap terminals is connected with a tap changeover connection terminal 16; a first common terminal surface 20c; a second common terminal surface 20b extending downward from the tip of the first common terminal surface; and a third common terminal surface 20a extending from the lower end of the second common terminal surface, in parallel with the first common terminal surface 20c. Each of the tap terminals 15a-c has a vertical section shifted to the end of the tap winding 5 in the winding radial direction and drawn out from the same position in the circumferential direction, and has a tap terminal surface horizontally extending in the outer direction of the winding diameter from the tip of the vertical section and formed to be flush with any one of the first to third common terminal surfaces 20a-c. The common terminal surface and the tap terminal surface, which are formed to be flush with each other, are bolt-connected with the tap changeover connection terminal 16 to change over among the taps.

Description

  The present invention relates to a transformer, and more specifically, to a structure of a tap switching unit of a transformer having tap windings.

  In a molded transformer or the like, a flat conductor (hereinafter referred to as a bus bar) is used as a lead conductor having a large current capacity, for example, at the start and end of winding of a secondary winding. When the lead conductor is formed of a bus bar, for example, in a three-phase Δ-connection molded transformer, the lead conductor at the start and end of winding of each phase is bolted by a connection bus bar. In addition, since the bolt fastening portions of the lead conductors at the beginning and end of winding are overlapped with each other in the horizontal direction, the depth dimension of the lead conductor fastening portion becomes large, and the external dimensions of the transformer become large. was there.

  In order to solve such a problem, Patent Document 1 discloses that the position of the bolt fastening portion of the lead conductor at the start of winding and the position of the bolt fastening portion of the lead conductor at the end of winding are shifted in the height (up and down) direction. It has been proposed to reduce the outer dimensions of the transformer by shortening the depth dimension so that the positions of the fastening portions do not overlap each other in the horizontal direction. Moreover, since the position of a bolt fastening part does not mutually overlap in a horizontal direction, since an impact wrench can be used for bolt fastening, it is said that workability | operativity can be improved.

Patent No. 3011520

  However, Patent Document 1 does not consider the structure of the tap switching unit of the transformer including the tap winding. That is, the transformer including the tap winding is configured to supply a predetermined voltage by switching the tap terminal of the tap winding in response to the voltage fluctuation. Also in this case, when the current capacity is large, the conductor drawn from the tap winding is formed by a bus bar, and the plurality of tap terminals are also formed by a flat bus bar. In addition, tap switching is performed by switching connection between a desired one tap terminal and a main winding or an external line via a common terminal (common terminal) formed of a bus bar.

  However, since the connection between the tap terminal and the common terminal is performed by bolting the tap terminal and the common terminal with a tap switching connection terminal formed of a bus bar, depending on the structure of the tap switching part, the depth dimension becomes large, There is a problem that the outer dimension of the transformer becomes large.

  For example, the plurality of tap terminals are formed in a flat plate shape that is parallel to the axial direction of the tap winding from the upper end portion of the tap winding, shifted outward in the winding diameter direction, and drawn upward from the same circumferential position. The vertical part is provided. On the other hand, it is conceivable that the common terminal connected to the main winding or the external line is also provided by being drawn upward from the same position in the circumferential direction as the tap terminal in parallel to the vertical portion of the tap terminal from the upper end of the tap winding. In this case, since each tap terminal and the common terminal extend in parallel upward, the tap switching connection terminal bolted to the common terminal is bent into an inverted U shape and bolted to an arbitrary tap terminal. According to this, the tap terminal protrudes greatly outward from the outer peripheral surface of the tap winding, and there are problems that the external dimensions of the transformer are increased and the appearance is poor. In addition, since the inverted U-shaped tap switching connection terminal is required to have flexibility, it is necessary to use a flexible conductor in which metal foils are overlapped or thin wires are formed in a net-like shape. There is a problem that it takes.

  The problem to be solved by the present invention is to reduce the size of the transformer by reducing the size of the tap switching portion of the tap winding.

  In order to solve the above-described problems, the present invention provides a plurality of tab-shaped tap terminals each drawn from a tap winding, and a common terminal connected to a main winding or an external line, and any of the plurality of tap terminals. In the transformer comprising a tap switching connection terminal for connecting one, the common terminal is formed by a flat plate and is provided at intervals beside the plurality of tap terminals along a circumferential direction of the tap winding. A first common terminal surface formed to be insulated and supported by the fixed portion, and a second common terminal surface formed by bending downward from the tip of the first common terminal surface; A third common terminal surface formed to bend and extend from the tip of the second common terminal surface to the fixed portion side in parallel to the first common terminal surface, and the first to third common terminals Bolt holes on each side The plurality of tap terminals are pulled out from the end of the tap winding in the axial direction of the tap winding, shifted vertically in the winding diameter direction, and pulled out from the same position in the circumferential direction. And a plurality of the first and third common terminal surfaces of the common terminal that are bent from the tip of the vertical portion and extended in the outer direction of the winding diameter. A tap terminal surface is formed, a bolt hole is formed in each tap terminal surface, and the common terminal surface of any one of the first to third common terminal surfaces of the common terminal and the common The tap switching connection terminal is passed to the tap terminal surface formed flush with the terminal surface, and fastened with bolts inserted through the bolt holes.

  According to the present invention, the common terminal has the first to third common terminal surfaces and is formed in a J shape or a U shape, and the plurality of tap terminals are formed on the first to third common terminal surfaces of the common terminals. Since the plurality of tap terminal surfaces are formed on the same common terminal surface, the first common terminal surface to the third common terminal surface located on the same surface, corresponding to these. The tap can be switched by bringing the tap switching connection terminal into contact with any one of the tap terminal surfaces, inserting the bolt into the bolt hole, and fastening with the nut. As a result, according to the present invention, since the tap switching connection terminal can be formed using a rectangular flat plate, the horizontal dimension of the tap terminal can be minimized, and the depth dimension of the transformer can be reduced. . Further, since the common terminal is formed in a U-shape, the dimension in the height direction can be minimized.

  Furthermore, as a specific aspect of the present invention, the plurality of tap terminals include at least first to third tap terminals, and the first tap terminal is horizontally disposed from a tip of the vertical portion of the tap terminal. The first tap terminal surface is formed so as to extend to the height, and the height of the vertical portion is formed such that the first tap terminal surface and the third common terminal surface of the common terminal are flush with each other. And the second tap terminal is positioned between the height of the vertical portion of the tap terminal and the height of the vertical portion of the tap terminal. A second tap terminal surface extending horizontally from the tip and bent downward; the second tap terminal surface and the second common terminal surface of the common terminal are formed flush with each other; 3 tap terminal is the tip of the vertical portion of the tap terminal A third tap terminal surface formed to extend horizontally, and the height of the vertical portion is such that the third tap terminal surface and the first common terminal surface of the common terminal are flush with each other. Can be formed.

  Here, the number of tap terminals is determined according to the required transformer specifications, that is, the voltage fluctuation range and the allowable fluctuation range. However, in general, the rated voltage is adjusted within a range of ± n · ΔV (n is a natural number) with respect to the reference, so that at least three tap terminals are provided. In addition, five tap terminals may be provided. In view of this, the present invention considers the case where four to six tap terminals are provided as needed, and the fourth to sixth provided on the opposite side of the first to third tap terminals across the common terminal. The fourth to sixth tap terminals are formed in the same manner as the first to third tap terminals. When there are two fourth to sixth tap terminals, the fifth tap terminal corresponding to the second tap terminal among the fourth to sixth tap terminals can be omitted.

  In addition, this invention is applicable to any tap winding of a single phase transformer and a three-phase transformer. In the case of a three-phase transformer, it is preferable to form the common terminals for each phase in the same shape.

  According to the present invention, the size of the tap switching portion of the tap winding can be reduced, and the transformer can be miniaturized.

It is a perspective view which shows the structure of the tap switching part of one Embodiment of this invention. It is the perspective view which looked at a part of structure of the tap switching part of embodiment of FIG. 1 from a different angle. It is a perspective view which shows the internal structure of the transformer of embodiment of FIG. It is a circuit diagram of the main winding which has the tap winding of the transformer of embodiment of FIG.

  Hereinafter, the transformer of the present invention is explained based on an embodiment. The transformer of one embodiment of the present invention is a three-phase molded transformer having the structure shown in the internal structure diagram of FIG. As illustrated, the windings 1 </ b> A to 1 </ b> C of each phase are wound around an iron core provided upright on the base member 2. The windings 1A to 1C of each phase include a secondary winding 3 wound around the center, a primary winding 4 wound coaxially around the outer side of the secondary winding, and an outer side of the primary winding. And a tap winding 5 wound coaxially therewith. A flat lead-out conductor 6 drawn in the vertical direction from the winding end of each phase of the primary winding 4 is horizontal to the outside in the winding diameter direction of the winding, as shown in FIG. It is formed to have a terminal surface 7 which is formed by being bent into a shape. An external terminal 8 formed by bending the terminal surface 7 into an L shape is fastened by a bolt. The external terminal 8 is fixed to the upper support member 9 via an insulating material 10. In addition, the lead conductor (not shown) drawn from the winding end of each phase of the secondary winding 3 is formed by bending horizontally outside the winding diameter direction of the winding, like the primary winding. An external terminal 11 having a terminal surface and bent into an L-shape is bolted to the terminal surface, and the external terminal 11 is fixed to the upper support member 9 via an insulating material.

  In this embodiment, as shown in FIG. 4, the tap winding 5 includes three tap terminals 15a to 15c for each phase, and one of these tap terminals (for example, 15a) is connected to tap switching. The terminal 16 is connected to the common terminal 17. The common terminal 17 of each phase is connected to the lead conductor 6 or the external terminal 8 of the primary winding 4 of another adjacent phase.

  Here, with reference to FIG. 1A and FIG. 2, an example of the structure of the tap switching unit of the present embodiment, which is a feature of the present invention, will be described. The three tap terminals 15a to 15c formed by the flat plate of the present embodiment are each drawn from the end of the tap winding 5 in the axial direction of the winding and shifted in the winding diameter direction (winding depth direction). And vertical portions 25a to 25c drawn from the same position in the circumferential direction (tangential direction of the winding).

  On the other hand, the common terminal 17 formed of a flat plate is spaced along the left side of the three tap terminals 15a to 15c, that is, along the circumferential direction of the tap winding 5 (the tangential direction of the winding). Is provided. The common terminal 17 includes a base 18 that is supported by an upper support member 9 that is a fixing portion via an insulating material 10, a horizontal portion 19 that is bent from the lower end of the base 18 and extends in a horizontal direction, and a horizontal portion 19 A first common terminal surface 20c is formed at the tip. Further, a second common terminal surface 20b is formed in a hanging portion that is bent from the tip of the first common terminal surface 20c and is hung downward. Further, a third common terminal surface 20a is formed by extending from the tip of the second common terminal surface 20b to the base 18 side in parallel with the first common terminal surface 20c. In the first to third common terminal surfaces 20a to 20c, two bolt holes 23 are formed side by side in the width direction of each terminal surface.

  Each of the tap terminals 15 a to 15 c has a tap terminal surface that is flush with any one of the first to third common terminal surfaces 20 a to 20 c of the common terminal 17. That is, each tap terminal 15a to 15c is formed with a horizontal portion that is bent from the tip of the vertical portion 25a to 25c and extends outward in the winding diameter. Tap terminal surfaces 26a and 26c are formed on the horizontal portions of the tap terminals 15a and 15c, respectively. Further, the tap terminal 15b provided between the tap terminals 15a and 15c has a tap terminal surface 26b formed at a hanging portion formed by bending downward from the tip of the horizontal portion. That is, the tap terminals 15a to 15c have tap terminal surfaces 26a to 26c formed flush with different common terminal surfaces of the first to third common terminal surfaces 20a to 20c of the common terminal 17, respectively. Has been. In each of the tap terminal surfaces 26a to 26c formed in this way, two bolt holes 23 are formed side by side in the width direction of each terminal surface.

  With this configuration, according to the present embodiment, any one of the first to third common terminal surfaces 20a to 20c of the common terminal 17, for example, as shown in FIG. By passing the tap switching connection terminal 16 to the common terminal surface 20b and the tap terminal surface 26b formed flush with the common terminal surface, and fastening with bolts and nuts 27 inserted into the respective bolt holes 23, The common terminal 17 can be switched and connected to an arbitrary tap terminal.

  Further, the arrangement and connection of the lead conductors 31 to 33 shown in FIG. 4 connected to the lead conductor 6 or the external terminal 8 of the primary winding 4 of the other phase adjacent to the common terminal 17 of each phase is shown in FIG. This will be described with reference to FIG. The connection between the lead conductor 6 and the external terminal 8 of the primary winding 4 of each phase is such that the external terminal 8 formed by bending the terminal surface 7 of the lead conductor 6 into an L-shape is a bolt as shown in these drawings. -It is fastened by a nut 27. On the other hand, two bolt holes 23 are formed side by side in the width direction on the base 18 side of the horizontal portion 19 of the common terminal 17. For example, the lead conductor 6 or the external terminal 8 of each phase is connected to the common terminal 17 by horizontally arranging the flat surfaces of the lead conductors 31 to 33 formed in a flat plate shape. The two bolt holes 23 drilled at both ends are aligned with the bolt holes 23 of the common terminal 17, the lead conductor 6 and the external terminal 8, and are fastened by bolts and nuts 27.

  According to this embodiment, the common terminal 17 has the first to third common terminal surfaces 20a to 20c, is formed in a J shape or a U shape, and the tap terminal surfaces of the plurality of tap terminals 15a to 15c. 26a to 26c are formed on the same common terminal surface of each of the first to third common terminal surfaces 20a to 20c, so that the common terminal surfaces located on the same surface and the taps corresponding thereto The tap can be easily switched by bringing the tap switching connection terminal 16 into contact with the terminal surface and fastening with the bolt and nut 27.

  Thereby, according to this embodiment, since the tap switching connection terminal 16 can be formed using a rectangular flat plate, the horizontal dimension of the tap terminals 15a to 15c can be minimized, and the depth dimension of the transformer can be reduced. Can be small. In addition, since the common terminal is formed in a U-shape and the three common terminal surfaces 20a to 20c are formed, the dimension in the height direction can be minimized.

  In the above embodiment, the number of tap terminals 15 is three. However, the present invention is not limited to this, and the number of tap terminals is not limited to the required transformer specification, that is, the voltage fluctuation range and the allowable fluctuation. It can be changed according to the width. However, in general, the rated voltage is adjusted within a range of ± n · ΔV (n is a natural number) with respect to the reference, and therefore at least three tap terminals or five tap terminals are often provided. In this regard, according to the present invention, four to six tap terminals can be provided as necessary. In this case, in place of the embodiment shown in FIG. 1 and the like, for example, a maximum of three tap terminals similarly formed can be provided on the opposite side of the three tap terminals 15a to 15c with the common terminal 17 interposed therebetween. According to this, it is possible to configure a tap switching unit of a maximum of 6 tap tap windings by simply shifting the fastening position of the tap switching connection terminal 16. In the case of 5 taps, the fifth tap terminal corresponding to the second tap terminal 15b among the first to third tap terminals 15a to 15c can be omitted, and can be easily realized.

  Moreover, although the said embodiment demonstrated the three-phase transformer, this invention can be applied also to the switching connection part of the tap winding of a single phase transformer.

3 Secondary winding 4 Primary winding 5 Tap winding 6 Lead conductor 8 External terminal 10 Insulating material 15a to 15c Tap terminal 16 Tap switching connection terminal 17 Common terminal 18 Base 19 Horizontal part 20a to 20c Common terminal surface 23 Bolt hole 26a-26c Tap terminal surface 27 Bolt / Nut 31-33 Lead conductor

Claims (4)

A plurality of tab-shaped tap terminals each drawn from the tap winding, and a tap switching connection terminal for connecting any one of the plurality of tap terminals to a common terminal connected to the main winding or the external line In the transformer
The common terminal is formed of a flat plate and is provided at intervals along the circumferential direction of the tap winding with a space between the plurality of tap terminals. 1 common terminal surface, a second common terminal surface formed by bending downward from the tip of the first common terminal surface, and parallel to the first common terminal surface from the tip of the second common terminal surface A third common terminal surface formed to bend and extend to the fixed portion side, and a bolt hole is formed in each of the first to third common terminal surfaces,
The plurality of tap terminals are pulled out from the end of the tap winding in the axial direction of the tap winding, shifted in the winding diameter direction, and pulled out from the same position in the circumferential direction; and A plurality of tap terminal surfaces that are bent from the tip of the vertical portion and extend outward in the winding diameter and are formed on the same common terminal surface of the first to third common terminal surfaces of the common terminal. A bolt hole is formed in each tap terminal surface,
The tap switching connection terminal is passed to any one common terminal surface of the first to third common terminal surfaces of the common terminal and the tap terminal surface formed flush with the common terminal surface. A transformer characterized in that it is fastened with a bolt inserted into a bolt hole. The plurality of tap terminals have at least first to third tap terminals,
The first tap terminal has a first tap terminal surface formed to extend horizontally from the tip of the vertical portion of the tap terminal, and the height of the vertical portion is the first tap terminal surface. Formed so that the third common terminal surface of the common terminal is flush with the surface,
The second tap terminal is located between a height of the vertical portion of the tap terminal and a height of the vertical portion of the first and third tap terminals. A second tap terminal surface extending horizontally and bent downward, the second tap terminal surface and the second common terminal surface of the common terminal are formed flush with each other;
The third tap terminal has a third tap terminal surface formed to extend horizontally from the tip of the vertical portion of the tap terminal, and the height of the vertical portion is the third tap terminal surface. The transformer characterized in that it is formed at a height that is flush with the first common terminal surface of the common terminal.   In addition to the first to third tap terminals, the plurality of tap terminals further includes fourth to sixth taps provided on the opposite side of the first to third tap terminals with the common terminal interposed therebetween. 3. The transformer according to claim 2, further comprising at least two terminals, wherein the fourth to sixth tap terminals are formed in the same manner as at least two of the first to third tap terminals. vessel. The transformer according to any one of claims 1 to 3, wherein the main winding and the tap winding are provided for three phases, and the common terminals of each phase are formed in the same shape. .

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