JP2022112780A - Stationary induction device - Google Patents

Abstract

To provide a stationary induction device by improving the formability of a segment coil used in the stationary induction device, reducing eddy current losses in the coil, and suppressing the effects of skin effects.SOLUTION: The stationary induction device includes an iron core stacked with thin plate soft magnetic material and a coil wound around the iron core. The coil consists of a plurality of U-shaped first segment coil strands (2) that sandwiches sides of the iron core and a plurality of second segment coil strands (4) that connects each of the adjacent U-shaped first segment coil strands. The U-shaped first segment coil strand (2) and the second segment coil strand (4) are divided into a plurality of unit conductors.SELECTED DRAWING: Figure 6

Description

TECHNICAL FIELD The present invention relates to a stationary induction device such as a transformer and a reactor, in which a segment coil formed by joining a plurality of divided strands is wound around an iron core.

Stationary induction devices such as transformers and reactors have windings wound around a circular or rectangular closed iron core, and use electromagnetic induction phenomena to realize functions such as voltage conversion and harmonic signal filtering. . The iron cores of power transmission/distribution and power receiving/distribution transformers, which are mainly connected to electric power systems, are made by laminating and forming multiple thin sheets of soft magnetic materials such as grain-oriented electrical steel sheets and amorphous alloys whose main component is iron. Configured.

As an example, FIG. 1 shows a schematic diagram of a general assembly process of a stationary induction device using a wound iron core made of a thin plate-shaped soft magnetic material. First, thin plate-shaped soft magnetic materials 1a cut to a desired length are laminated in the vertical direction by the number corresponding to the design thickness of the iron core (S101). Next, the iron core 1 laminated with the thin plate-like soft magnetic materials 1a is lifted and bent into an inverted U shape (S102). Subsequently, both ends of the core 1 are joined to form a substantially rectangular closed magnetic circuit core having a lap joint 14 (S103). The soft magnetic material at this stage has residual stress from the time of casting, and the bending process has damaged the original magnetic performance of each soft magnetic material 1a. Therefore, the iron core 1 is annealed while a DC magnetic field 12 is applied along the magnetic path of the iron core 1 to relax the residual stress and restore the magnetic performance. After the annealing treatment, the lap joint 14 is opened to open the iron core 1 again in an inverted U shape, and the open end is inserted into a plurality of previously manufactured continuous winding coils 10 (S104). Finally, the open portion of the core projecting from the lower portion of the winding is lap-joined again to close the magnetic path, thereby completing the static induction device using the wound core having the lap joint 14 (S105). Thus, in a general assembly process, it is necessary to repeat the lapping operation twice.

Here, Japanese Patent Application Laid-Open No. Hei 6-209535 (Patent Document 1) relates to a motor coil as a segment coil technology configured by joining a plurality of split wires. In Patent Document 1, "In-slot coils are stacked and incorporated in slots of a stator core. Inter-slot coils are individually joined to the end surfaces of the in-slot coils. In addition, there are n-1 pieces (n: number of phases) between them. The inter-slot coils are bar-shaped so that the in-slot coils belonging to the spaced slots are connected to each other.Since the space factor is determined by the lamination structure of the in-slot coils in the slots, a plurality of conducting wires are bundled to form a coil. The space inside the slot is no longer idle as in the case, and the space factor is improved.” (See abstract).

JP-A-6-209535

FIG. 2 shows a schematic diagram of an assembly process when a segmented coil structure configured by joining a plurality of divided strands is applied to a stationary induction device. In this case, since the lap joint 14 is not required in the iron core 1, the core 1c is wound while pulling out the soft magnetic material from the base material 1b in which the thin plate-like soft magnetic material is wound into a roll, thereby forming the iron core 1 in a substantially rectangular shape. (S201). Next, annealing is performed while a DC magnetic field 12 is applied along the magnetic path of the core 1 (S202). Subsequently, the stationary induction device is completed by providing the segment coil 2, which is formed by joining a plurality of divided strands, to the magnetic leg portion of the iron core 1 (S203). Therefore, by applying the segment coil structure, the assembly process of the static induction device can be shortened.

However, when the segment coil structure of Patent Document 1 is applied to the static induction device described above, in a static induction device with a large capacity, the wires divided into a plurality of wires become very thick wires, making it difficult to form the segment coil. . In addition, when the coil is composed of a single extra-thick wire, eddy current loss generated in the wire increases. Furthermore, in a high-frequency region, current is concentrated on the surface of the wire due to the skin effect, and no current flows inside the wire.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a static induction device in which the forming workability of a segment coil used in a static induction device is improved, the eddy current loss in the coil is reduced, and the influence of the skin effect is suppressed.

In order to solve the above problems, for example, the configurations described in the claims are adopted.
The present application includes a plurality of means for solving the above problems, and one example is a stationary induction device comprising an iron core laminated with thin plate-shaped soft magnetic materials and a coil wound around the iron core, The coil includes a plurality of U-shaped first segment coil wires sandwiching the side of the core, and a plurality of second coil wires connecting the adjacent U-shaped first segment coil wires. and a segment coil wire, wherein the U-shaped first segment coil wire and the second segment coil wire are divided into a plurality of unit conductors.

ADVANTAGE OF THE INVENTION According to this invention, the formability of the segment coil used for a static induction apparatus can be improved, the eddy current loss of a coil can be reduced, and the influence of a skin effect can be suppressed.

Problems, configurations, and effects other than those described above will be clarified by the following description of the embodiments.

1 is a schematic diagram of an assembly process for a conventional stationary induction device; FIG. It is the schematic of an assembly process at the time of applying a segment coil structure to a stationary induction apparatus. 1 is a perspective view illustrating a portion of a segment coil structure according to Example 1 of the present invention; FIG. 4 is a perspective view illustrating another part of the segment coil structure of Example 1 of the present invention; FIG. FIG. 4 is a perspective view illustrating an intermediate stage of assembly of the segment coil structure according to the first embodiment of the present invention; 1 is a perspective view illustrating a segment coil structure according to Example 1 of the present invention; FIG. FIG. 5 is a cross-sectional view of coil portions of a conventional stationary induction device, a stationary induction device to which a segment coil structure is applied, and a stationary induction device of Example 1; FIG. 5 is a perspective view illustrating a segment coil structure according to Example 2 of the present invention; It is a figure explaining the segment coil structure of the stationary induction apparatus of Example 3 of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention should not be construed as being limited to the contents of the examples described below. Those skilled in the art will easily understand that the specific configuration can be changed without departing from the idea or gist of the present invention.
In the configurations of the invention described below, the same or similar configurations or functions are denoted by the same reference numerals, and redundant description may be omitted.

A stationary induction device according to the first embodiment of the present invention has a segment coil structure by attaching and connecting a plurality of divided segment coil wires to magnetic legs of a substantially rectangular wound iron core as shown in FIG. A coil is provided. The segment coil wire of the first embodiment is composed of a plurality of divided unit conductors, for example, by stacking a plurality of thin plate conductors and integrating them. Here, the segment coil wire is, for example, a U-shaped or bar-shaped member, which is combined and connected to form a coil having a segment coil structure. The divided unit conductors are composed of, for example, thin-plate conductors, and a plurality of the conductors are stacked to form a segment coil wire. That is, for example, by stacking and integrating a plurality of unit conductors composed of thin plate conductors, a U-shaped or bar-shaped segment coil wire is formed, and a U-shaped or bar-shaped segment coil wire is formed. are combined to form a segment coil structure coil. In addition, in the present invention, the U-shape also includes a U-shape.

FIG. 3 shows the U-shaped first segment coil wire 2 of the first embodiment. As shown in FIG. 3(a), the first segment coil wire 2 is constructed by stacking a plurality of U-shaped thin plate conductors, four in the example shown in the figure, and integrating them. In the illustrated example, the lamination direction of the thin plate conductors is the axial direction of the coil, that is, the longitudinal direction of the magnetic legs of the iron core. The thin plate conductor used for the segment coil uses a bare wire of a conductor such as aluminum or copper or a wire with an enamel film to ensure insulation. In the case of aluminum conductors, the insulation may be Al ₂ O ₃ formed on the surface. By dividing the segment coil wire 2 into a plurality of pieces instead of a single extra-thick wire, the formability of the coil is improved. Furthermore, by dividing the segment coil wire 2 into a plurality of thin plates, it is possible to reduce the eddy current loss of the coil and suppress the influence of the skin effect.

As shown in FIG. 3(b), the U-shaped first segment coil wire 2 is wrapped with insulating paper or tape 3 except for the ends to increase the withstand voltage of the coil and ensure insulation performance. do. The insulating paper or insulating tape 3 may be made of mica, for example.

FIG. 4 shows the bar-shaped (rod-shaped) second segment coil wire 4 of the first embodiment. As shown in FIG. 4(a), the second segment coil wire 4 is formed by stacking a plurality of bar-shaped thin plate conductors (four in the example shown) and integrating them. The thin plate conductors forming the second segment coil wires 4 are also bare wires of conductors such as aluminum and copper or electric wires with enamel coating to ensure insulation. In order to connect the second segment coil wire 4 with the adjacent U-shaped first segment coil wire 2, the end of the bar-shaped segment coil wire is shifted by one pitch. Therefore, the second segment coil wire 4 is bent at the central portion. Here, the end of the bar-shaped second segment coil wire 4 is shifted by one pitch. Of course, the ends of the coil wires 2 may be shifted by one pitch.

As shown in FIG. 4(b), the rod-shaped second segment coil wire 4 is also wrapped with insulating paper or tape 5 except for the ends to increase the withstand voltage of the coil and ensure insulation performance.

FIG. 5 shows a state in which a pair of the U-shaped first segment coil wire 2 and the bar-shaped second segment coil wire 4 are assembled. FIG. 5(a) shows a state in which one end of a bar-shaped second segment coil wire 4 is abutted against and joined to the inner end of the U-shaped first segment coil wire 2. FIG. . Coil wire end portions can be joined using, for example, TIG welding, laser welding, electron beam welding, soldering, brazing, or the like.

FIG. 5B shows a state in which the U-shaped first segment coil wire 2 and the bar-shaped second segment coil wire 4 are wrapped with insulating paper or insulating tapes 3 and 5 . The insulating paper or the insulating tapes 3 and 5 are omitted from the subsequent coil drawings because the drawings are complicated.

FIG. 6 shows a state in which two U-shaped first segment coil wires 2 and one bar-shaped second segment coil wire 4 are assembled. FIG. 6(a) shows an assembled state in which one bar-shaped second segment coil wire 4 is joined to two adjacent U-shaped first segment coil wires 2. FIG. . By joining both ends of the bar-shaped second segment coil wire 4, current flows in the direction indicated by the arrow, so it can be seen that a coil is formed.

As shown in FIG. 6(b), the junction between the U-shaped first segment coil wire 2 and the bar-shaped second segment coil wire 4 is coated with an insulator such as powder coating 6. Ensuring the insulation performance of the cover and coil.

FIG. 6 shows a state in which two U-shaped first segment coil wires 2 and one bar-shaped second segment coil wire 4 are assembled. Then, more U-shaped first segment coil wires 2 are arranged adjacent to each other, and bar-shaped second segment coil wires are attached to the adjacent U-shaped first segment coil wires 2, respectively. Wires 4 are spliced to form a coil. Although not shown in FIGS. 5 and 6, an iron core 1 is arranged between the U-shaped first segment coil wire 2 and the bar-shaped second segment coil wire 4. , constitutes a transformer.

The U-shaped first segment coil wire 2 and the bar-shaped second segment coil wire 4 are attached to the iron core 1 by arranging a plurality of U-shaped first segment coil wires 2 side by side. Fixed and unitized. Similarly, a plurality of bar-shaped second segment coil wires 4 are aligned and fixed to form a unit. Then, the iron core is placed in the concave portion of the U-shaped first segment coil unit, and the bar-shaped second segment coil unit is attached and connected so as to surround the iron core.

FIG. 7 shows cross-sectional views of coil portions of a conventional static induction device, a static induction device to which a segment coil structure is applied, and a static induction device of Example 1 for comparison. These cross-sectional views are cross-sectional views perpendicular to the winding direction of the coil along the longitudinal direction of the magnetic leg portion of the iron core. The figure shows one half from the iron core.

FIG. 7(a) is a cross-sectional view of a conventional transformer with continuous winding coils. A low-voltage winding 20 made of a sheet-shaped conductor is provided outside the iron core 1 with one turn in a plurality of layers. A high-voltage winding 30 is provided on the outside thereof in a plurality of layers with a plurality of turns.

FIG. 7(b) is a cross-sectional view of a transformer in which a segment coil structure is applied to the low-voltage winding. A low-voltage winding 22 made of a single extra-thick wire is provided on the outside of the iron core 1 with a plurality of turns. A high-voltage winding 30 is provided on the outside thereof in a plurality of layers with a plurality of turns.

FIG. 7(c) is a cross-sectional view of the transformer of Example 1, in which the segment coil of the low-voltage winding is divided into a plurality of conductors. Outside the iron core 1, a low-voltage winding 24 composed of a segment wire obtained by stacking a plurality of divided unit conductors, for example, thin plate conductors, is provided with a plurality of turns in one layer. A high-voltage winding 30 is provided on the outside thereof in a plurality of layers with a plurality of turns.

According to this embodiment, the U-shaped first segment coil wire and the second segment coil wire that connects the ends of the adjacent U-shaped first segment coil wires, Since the segment-structured coil wound around the iron core is formed, the assembly process of the stationary induction device can be shortened. In addition, since the segment coil wire is configured by stacking a plurality of divided unit conductors, for example, a plurality of thin plate conductors, the forming workability of the segment coil is improved, the eddy current loss of the coil is reduced, and the influence of the skin effect is improved. can be suppressed.

FIG. 8 shows the segment coil structure of Example 2 of the present invention. In Example 1, a bar-shaped wire was used as the second segment coil wire, but in this example, a U-shaped wire is used.

FIG. 8A shows an assembled state in which one U-shaped second segment coil wire 7 is joined to two adjacent U-shaped first segment coil wires 2′. indicates By joining the outer end portion of the U-shaped second segment coil wire 7 to the inner end portion of the U-shaped first segment coil wire 2', current flows in the direction indicated by the arrow. , becomes a coil.

As shown in FIG. 8(b), the junction between the U-shaped first segment coil wire 2' and the U-shaped second segment coil wire 7 is coated with powder coating 6' or the like. Cover with an insulator to ensure the insulation performance of the coil. Although not shown, the U-shaped first segment coil wire 2′ and the U-shaped second segment coil wire 7 are wrapped with insulating paper or insulating tape except for the ends. are integrated.

According to this embodiment, by making the second segment coil wire U-shaped, the inside of the end portion of the U-shaped first segment coil wire 2' and the U-shaped second segment coil wire Since the joint area with the outside of the end portion of the coil wire 7 can be increased, the electric resistance of the joint portion can be reduced and the joint strength can be increased.

FIG. 9 shows the segment coil structure of the stationary induction device of Example 3 of the present invention. The figure is a cross-sectional view of the segment coil attached to the iron core, viewed in the longitudinal direction of the iron core.

In this embodiment, in the segment structure of Embodiment 1, a notch portion for positioning the second segment coil wire is provided inside the end portion of the U-shaped first segment coil wire. . In this embodiment, first, a U-shaped first segment coil wire 2 is arranged so as to surround the iron core 1 . The U-shaped first segment coil wire 2 is formed with notches 8 inside both ends thereof. Next, the bar-shaped second segment coil wire 4 is aligned with the notch 8 and attached.

As the second segment coil wire, the upper end portion of the U-shaped second segment coil wire 7 of Example 2 is bent outward, and the notch portion 8 of the first segment coil wire You may make it position.

According to the present embodiment, in addition to the effects of the first embodiment, since the notch portion for positioning is provided, attachment of the second segment coil wire is facilitated. In addition, since the notched portion widens the bonding area between the first segment coil wire and the second segment coil wire, the electrical resistance of the bonding portion can be reduced, and the bonding strength can be increased. can be done.

In each of the above embodiments, the present invention has been described with respect to the wound core type static induction device shown in FIG. 2, but the present invention can also be used for a stacked core type static induction device. In a stacked core type stationary induction device, members in which magnetic thin plates such as electromagnetic steel plates are stacked are combined to form a rectangular core, and coils of the segment coil structure of the present invention are provided on the legs of the core.

1 Iron core 1a Thin plate-like soft magnetic material 1b Base material 1c in which a thin plate-like soft magnetic material is wound in a roll shape Winding cores 2, 2' U-shaped segment coil wire 3 Insulating paper or insulating tape 4 Bar shape (bar shape) Segment coil wire 5 Insulating paper or insulating tape 6, 6' Powder coating 7 U-shaped segment coil wire 8 Positioning notch 10 Continuous winding coil 12 DC magnetic field 14 Lap joint 20 Voltage winding 22 Low-voltage winding 24 applying segment coil structure Low-voltage winding 30 of the present invention High-voltage winding

Claims (10)

A stationary induction device comprising an iron core laminated with a thin plate-shaped soft magnetic material and a coil wound around the iron core,
The coil is
a plurality of U-shaped first segment coil wires sandwiching the side of the iron core;
and a plurality of second segment coil wires that connect the adjacent U-shaped first segment coil wires,
A stationary induction device, wherein the U-shaped first segment coil wire and the second segment coil wire are divided into a plurality of unit conductors. In the stationary induction device according to claim 1,
The first segment coil wire and the second segment coil wire are integrated by stacking thin plate conductors and wrapping insulating paper or insulating tape around the outer periphery except for the ends. stationary induction equipment. In the stationary induction device according to claim 1,
A stationary induction device, wherein each of the plurality of unit conductors is covered with an insulator. In the stationary induction device according to claim 1,
A static induction device, wherein the first segment coil wire and the second segment coil wire are divided into a plurality of unit conductors in the axial direction of the coil. In the stationary induction device according to claim 1,
A stationary induction device, wherein a junction between the first segment coil wire and the second segment coil wire is covered with an insulator. In the stationary induction device according to claim 1,
A stationary induction device, wherein the second segment coil wire is bar-shaped. In the stationary induction device according to claim 1,
A stationary induction device, wherein the second segment coil wire is U-shaped. In the stationary induction device according to claim 1,
A notch for positioning is provided inside the end of the U-shaped first segment coil wire, and the end of the second segment coil wire is arranged in the notch for positioning. A stationary induction device characterized by: In the stationary induction device according to claim 1,
A stationary induction device, wherein the first segment coil wire and the second segment coil wire are joined by TIG welding, laser welding, electron beam welding, soldering, or brazing. In the stationary induction device according to claim 1,
A stationary induction device, wherein the iron core is a laminate of amorphous alloy ribbons and grain-oriented electrical steel sheets.

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