JP2023134957A - Stationary electromagnetic device - Google Patents

Abstract

To provide stationary electromagnetic device capable of suppressing the reduction of power efficiency and the increase of cost.SOLUTION: A thin stationary electromagnetic device is formed by laminating multiple sheets of magnetic material. The stationary electromagnetic device is constituted of multiple wound cores 1 and 2 that are formed by lap-joining both ends of the magnetic material to form a closed magnetic path and one or more windings 3 wound around multiple winding cores 1 and 2. The multiple winding cores 1 and 2 are hybrid wound cores constituted of at least a winding core 1 (first winding core) located on the outer circumference and a winding core 2 (second winding core) located on the inner peripheral side of the winding core 1. The winding core 1 is made of an iron-based amorphous alloy, and the winding core 2 is made of a grain-oriented electrical steel sheet.SELECTED DRAWING: Figure 1

Description

The present invention relates to stationary electromagnetic equipment such as transformers.

Stationary electromagnetic equipment such as transformers used for converting power transmission and distribution voltages in power systems and electrically insulating between electric wires in two systems is made of iron-based grain-oriented silicon steel sheets, amorphous alloys, nanocrystalline alloys, etc. Two systems of windings, a high-voltage side and a low-voltage side, are wound around the magnetic legs of an iron core made of a conductive soft magnetic material or a non-conductive soft magnetic material such as ferrite.

Currently, grain-oriented electrical steel sheets are mainly used for the iron cores of distribution transformers with a power capacity of approximately 2MVA or more, which are used in distribution substations, etc., in consideration of the balance between mechanical strength, cost, and power efficiency. ing. On the other hand, an amorphous core made of laminated ribbon-shaped amorphous alloys whose main component is iron has less than half the magnetic loss of grain-oriented electrical steel sheets, and is extremely useful for increasing the efficiency of stationary electromagnetic equipment. It is mainly used in small-capacity static electromagnetic equipment of 2 MVA or less.

The thickness of the thin strip-shaped amorphous alloy is 20 to 30 um, which is about one-tenth that of grain-oriented electrical steel sheets, so its mechanical strength is low. A separate structure is required. For example, Patent Document 1 discloses a hybrid core in which an amorphous core is incorporated into a winding together with a supporting member, and a laminated core made of grain-oriented electrical steel sheets is provided on a side surface of the amorphous core and used as part of the support structure. The structure and manufacturing method of stationary electromagnetic equipment to which this is applied are disclosed. Furthermore, in Patent Document 2, in a three-phase tripod type stationary electromagnetic equipment core, two inner wound cores are made of a ribbon-shaped amorphous alloy, and one outer core surrounding the two inner wound cores is A structure is disclosed in which the amorphous wound core is protected by a wound core made of a magnetic steel plate or a laminated core having a step-lap joint.

Patent No. 6963493 Japanese Patent Application Publication No. 8-88128

The technique described in Patent Document 1 is manufactured by placing a large amorphous wound core on a metal support member and inserting it into a winding that is erected using a crane or the like. In this technique, the above-mentioned support member remains in the completed stationary electromagnetic device. Therefore, the leakage magnetic field from the energized windings interlinks the supporting members, generating eddy currents, reducing the power efficiency of stationary electromagnetic equipment due to additional power losses (stray losses). There is also the issue of increased costs.

In addition, in the structure of the three-phase three-legged core disclosed in Patent Document 2, only the center of the three magnetic legs around which the three-phase winding is wound is made of an amorphous wound core. The two magnetic legs at both ends are a hybrid of amorphous and grain-oriented electrical steel sheets, requiring measures to maintain the balance of magnetic properties between the three-phase system, which poses the problem of increased costs.

An object of the present invention is to provide a stationary electromagnetic device that suppresses a decrease in power efficiency and an increase in cost.

In order to achieve the above object, the present invention provides a plurality of wound iron cores formed by laminating and molding a plurality of thin plate-like magnetic materials, and forming a closed magnetic path by lap-joining both ends of the magnetic materials; In a stationary electromagnetic device composed of one or more windings wound around a wound core, the plurality of wound cores include at least a first-volume core located on the outer circumferential side and an inner portion of the first-volume core. It is a hybrid-wound core composed of a second-wound core located on the circumferential side, wherein the first-wound core is made of an iron-based amorphous alloy, and the second-wound core is made of a grain-oriented electrical steel sheet. .

According to the present invention, it is possible to provide a stationary electromagnetic device that suppresses a decrease in power efficiency and an increase in cost.

1 is a front perspective view of a stationary electromagnetic device S showing a first embodiment of the present invention. FIG. 2 is a sectional view taken along the line II-II shown in FIG. 1. FIG. 1 is a perspective view of a three-phase five-legged transformer according to Example 1 of the present invention. It is a figure which shows the manufacturing method of the iron core of stationary electromagnetic equipment S based on Example 1 of this invention. FIG. 2 is a perspective view of a single-phase, two-legged transformer according to a second embodiment of the present invention. FIG. 7 is a front perspective view of a stationary electromagnetic device according to a third embodiment of the present invention. 7 is a sectional view taken along the line VII-VII shown in FIG. 6. FIG.

Embodiments of the present invention will be described below with reference to the accompanying drawings. Similar components are given the same reference numerals, and similar descriptions will not be repeated.

The various components of the present invention do not necessarily have to exist independently, and one component may be made up of multiple members, multiple components may be made of one member, or a certain component may be different from each other. It is allowed that a part of a certain component overlaps with a part of another component, etc.

Example 1 of the present invention will be described using FIGS. 1 to 4. FIG. 1 is a front perspective view of a stationary electromagnetic device S showing a first embodiment of the present invention. FIG. 2 is a cross-sectional view taken along the line II--II shown in FIG.

As shown in FIGS. 1 and 2, the stationary electromagnetic device S of Example 1 is made by laminating and molding a plurality of thin plate-shaped magnetic materials, and forming a closed magnetic path by lap-joining both ends of the magnetic materials. It is composed of wound cores 1 and 2, and one or more windings 3 wound around the plurality of wound cores 1 and 2. The plurality of wound cores 1 and 2 are hybrid wound cores that include a wound core 1 located on the outer peripheral side and a wound core 2 located on the inner peripheral side of this wound core 1.

In Example 1, a winding core 1 (first winding core) in which a plurality of thin ribbons made of an iron-based amorphous alloy are laminated is provided on the outer peripheral side, and a winding in which a plurality of thin plate-like magnetic materials made of grain-oriented electromagnetic steel sheets are laminated. It is a hybrid-wound core with an iron core 2 (second-wound iron core) on the inner circumferential side. That is, the hybrid wound core is composed of a plurality of wound cores 1 and 2. The cut ends of the respective magnetic materials of the wound cores 1 and 2 are connected to each other at lap joints 1a and 2a, forming a hybrid wound core formed into a substantially rectangular shape. A plurality of hybrid wound cores are prepared and arranged adjacent to each other in the horizontal direction.

One or more systems of windings 3 are wound in an overlapping manner around a magnetic leg portion formed by adjacent wound cores, thereby forming a stationary electromagnetic device S.

The upper and lower parts of the hybrid wound core (wound cores 1 and 2) are exposed from the winding 3. The portion exposed from the winding 3 of the hybrid wound core (the upper and lower parts of the wound cores 1 and 2) is used as a yoke. In order to maintain the structure of the stationary electromagnetic device S, the gap between the upper end of the winding 3 and the inner periphery of the wound core 2, and the gap between the lower end of the winding 3 and the inner periphery of the wound iron core 2, are Each is provided with an insulator 5a (first insulator). That is, the inner peripheral side of the wound core 2 is provided with an insulator 5a that is in contact with the winding 3. In Embodiment 1, the gap between the upper end of the winding 3 and the inner periphery of the yoke (the inner periphery of the wound core 2), and the gap between the lower end of the winding 3 and the inner yoke (the inner periphery of the wound core 2) are each provided with a plurality of insulators 5a.

Furthermore, the upper and lower yokes of the hybrid wound core (wound cores 1 and 2) exposed from the winding 3 are paired with the exposed upper and lower yokes of the hybrid wound core (wound cores 1 and 2). A plurality of metal fasteners 4 are provided so as to sandwich each other. Further, the fasteners 4 are arranged in pairs on the upper and lower sides so as to sandwich the winding 3 from above and below.

As shown in FIG. 2, the fastener 4 has a substantially L-shaped cross section perpendicular to the winding direction of the hybrid wound core (wound cores 1 and 2), and has a vertical portion extending in the vertical direction, and a vertical portion extending from the vertical portion. It has a horizontal portion bent in the horizontal direction. The vertical parts of the fasteners 4 are arranged in pairs to sandwich the plurality of wound cores 1 and 2, and the horizontal parts of the fasteners 4 are arranged in pairs to sandwich the windings 3 from above and below. Further, the fasteners 4 that form a pair at the lower portions of the plurality of wound cores 1 and 2 have a connection portion where the lower portions of the fasteners 4 are connected in a pair direction, and this connection portion is connected to the floor. touch the surface.

The gap between the fastener 4 located at the top of the plurality of wound cores 1 and 2 and the upper end of the winding 3, and the gap between the fastener 4 located at the bottom of the plurality of wound cores 1 and 2 and the lower end of the winding 3. An insulator 5b (second insulator) is provided in each gap.

The vertical portions of the pair of fasteners 4 are in contact with the stacked surfaces of the upper and lower yoke portions of the wound cores 1 and 2, and are connected by horizontal studs 4a. The horizontal portions of the pair of fasteners 4 are connected by a vertical stud 4b. Then, the plurality of wound cores 1 and 2 are tightened and fixed in the horizontal direction and the vertical direction by a plurality of fasteners 4, horizontal studs 4a, and vertical studs 4b, respectively.

Here, the operating state of the stress for supporting the wound core, which constitutes the stationary electromagnetic device S in Example 1, will be explained. In particular, when compressive stress is applied to the amorphous wound core 1 constituting the outer peripheral portion in the direction in which the ribbons are laminated, electrical insulation between the ribbons decreases, eddy current flows, and magnetic loss increases. Therefore, it is necessary to ensure mechanical strength to maintain the structure while suppressing compressive stress on the wound core 1.

The weight of the plurality of wound cores 1 and 2 is supported by the winding 3 via an insulator 5a disposed in the gap between the upper end of the winding 3 and the inner periphery of the wound core 2. Furthermore, the weight of the plurality of wound cores 1 and 2 and the winding 3 is increased by the insulator 5b disposed in the gap between the fastener 4 located at the bottom of the plurality of wound cores 1 and 2 and the lower end of the winding 3. The weight of the stationary electromagnetic device S is supported through the connection portion of the fastener 4 that is in contact with the floor surface. Furthermore, an insulator 5c (third insulator) is provided in the gap between the bottom of the wound core and the lower fastener 4 (connection part). By setting the height and tightening pressure of the insulators at appropriate values for each part, the weight of the wound cores 1 and 2 is supported by being divided between the inner circumference of the upper yoke and the bottom (outer circumference) of the lower yoke. It is possible to minimize the compressive stress acting in the lamination direction of the ribbon-like magnetic material constituting the wound core 1 or the thin plate-like magnetic material constituting the wound core 2.

Next, as an example of the stationary electromagnetic equipment S, the configuration of a three-phase five-legged transformer will be described. FIG. 3 is a perspective view of a three-phase five-legged transformer according to Embodiment 1 of the present invention. Components that are common to FIGS. 1 and 2 are denoted by the same reference numerals, and detailed description thereof will be omitted.

In FIG. 3, a plurality of the above-described hybrid wound cores are arranged adjacent to each other in the horizontal direction. In the example shown in FIG. 3, four sets of hybrid wound cores are arranged adjacent to each other in the horizontal direction. The four sets of hybrid wound cores arranged adjacent to each other in the horizontal direction constitute five magnetic legs.

Two systems of windings are wound one on top of the other on a magnetic leg portion made up of adjacent hybrid wound cores to form a three-phase winding. In FIG. 3, a three-phase five-legged transformer is configured.

Next, a method for producing an iron core for a stationary electromagnetic device S will be explained using FIG. 4. FIG. 4 is a diagram showing a method of manufacturing an iron core of a stationary electromagnetic device S according to the first embodiment of the present invention.

First, as shown in Fig. 4(a), a predetermined length is cut into a predetermined length, bent into an inverted U-shape so as to open downward, and then laminated. Thin strip-shaped amorphous alloys (wound core 1) cut into lengths are placed in the vertical direction in a number corresponding to the designed thickness of the core.

Next, as shown in FIG. 4(b), a suspension means 7 such as a rope or a sling is applied to the top of the grain-oriented electrical steel sheet (wound core 2), and the laminated amorphous alloy (wound core 1) and the laminated directional An electromagnetic steel plate (wound core 2) is lifted up by a suspension means 7 to form an inverted U-shape.

Next, as shown in FIG. 4(c), the ends of the amorphous alloy (wound core 1) and the grain-oriented electrical steel sheet (wound core 2) are joined together to form a substantially rectangular closed magnetic path having lap joints 1a and 2a. Form into an iron core. The stress from casting remains in the magnetic material at this stage, and furthermore, due to the bending process, the original magnetic performance of the magnetic material is impaired. Therefore, annealing is performed while applying a DC magnetic field 11 along the magnetic path of the closed magnetic circuit core (wound cores 1 and 2) to relieve residual stress and restore magnetic performance.

Next, after the annealing treatment, as shown in FIG. 4(d), the lap joints 1a and 2a at both ends of the amorphous alloy (wound core 1) and the grain-oriented electrical steel sheet (wound core 2) are opened, and the suspension means 7 is opened. Then, the joints at both ends of the amorphous alloy (wound core 1) and grain-oriented electrical steel sheet (wound core 2) are returned to an open state in an inverted U-shape. Then, both ends of the amorphous alloy (wound core 1) and grain-oriented electromagnetic steel plate (wound core 2) are inserted into the upright winding 3 that has been prepared in advance. Finally, both ends of the amorphous alloy (wound core 1) and grain-oriented electrical steel sheet (wound core 2) exposed from the bottom of the winding are lap-jointed again to close the magnetic path, thereby creating a hybrid structured wound core. Stationary electromagnetic equipment S is completed.

In Example 1, an amorphous alloy (wound core 1) is placed on top of a grain-oriented electrical steel sheet (wound core 2), and its weight is supported by the grain-oriented electrical steel sheet (wound core 2). A support member for the alloy (wound core 1) is not required, and it is possible to suppress a decrease in power efficiency and an increase in cost of stationary electromagnetic equipment.

Example 2 of the present invention will be described using FIG. 5. FIG. 5 is a perspective view of a single-phase, two-legged transformer according to a second embodiment of the present invention. Components that are the same as those in Example 1 are designated by the same reference numerals, and detailed description thereof will be omitted.

In FIG. 3 of the first embodiment, four wound cores are arranged side by side adjacent to each other in the horizontal direction, but in the second embodiment, one set of hybrid wound cores is used.

In Example 2, a wound core 1 in which a plurality of thin ribbons made of iron-based amorphous alloy are laminated is placed on the outer circumferential portion, and a wound iron core 2 in which a plurality of thin plate-like magnetic materials made of grain-oriented electromagnetic steel sheets are laminated in the inner circumferential portion. One wound core is provided, which is formed by lap-joining the cut ends of each magnetic material and forming it into a substantially rectangular shape. Two systems of windings are wound on top of each other on the two left and right magnetic legs, and both are connected in series to form a single-phase winding.

The method of manufacturing the core of the single-phase bipedal transformer (stationary electromagnetic equipment S) is the same as that shown in FIG. 4.

According to the second embodiment, effects similar to those of the first embodiment can be obtained.

Example 3 of the present invention will be described using FIGS. 6 and 7. Components that are the same as those in Example 1 and Example 2 are designated by the same reference numerals, and detailed description thereof will be omitted.

FIG. 6 is a front perspective view of a stationary electromagnetic device according to Example 3 of the present invention. FIG. 7 is a cross-sectional view taken along line VII-VII shown in FIG.

In Example 3, a wound core 1 in which a plurality of thin ribbons made of iron-based amorphous alloy are laminated is placed on the outer circumferential portion, and a wound iron core 2 in which a plurality of laminated thin strips made of grain-oriented electromagnetic steel sheets are laminated is placed on the inner circumferential portion. A plurality of hybrid wound cores formed by forming a substantially rectangular shape by connecting the cut ends of each magnetic material with lap joints 1a and 2a are arranged adjacent to each other in the horizontal direction.

Here, the width Wa of the wound core 1 made of the amorphous alloy is made smaller than the width Wg of the wound core 2 made of the grain-oriented electrical steel sheet (Wa>Wg). Note that the width Wa and the width Wg are lengths in a direction perpendicular to the winding direction of the hybrid wound core.

Of the upper and lower yokes of the hybrid wound core, the vertical portion of the fastener 4 is in contact with only the laminated surface of the wound core 2 made of grain-oriented electrical steel sheets, and the fastener 4 and the wound core 1 made of an amorphous alloy are in contact with each other. A gap is provided in between. With this structure, the stress acting on the wound core 1 made of amorphous alloy can be further reduced than in Examples 1 and 2, and the power efficiency of the stationary electromagnetic device S can be improved.

Further, in the third embodiment, a sheet-like soundproofing material 6 can be provided in the gap between the wound core 1 made of an amorphous alloy and the vertical part of the fastener 4. As the soundproof material 6, for example, glass wool, rock wool, urethane foam, melamine foam, etc. are used.

According to the third embodiment, in addition to the effects of the first embodiment, the excitation noise generated in the wound core made of an amorphous alloy can be reduced.

As explained above, according to each embodiment of the present invention, when an amorphous core with low mechanical strength is applied to a stationary electromagnetic device with a power capacity exceeding approximately 2MVA, a portion of the weight is replaced by an amorphous core with high mechanical strength. A structure in which the core is supported by a grain-oriented electromagnetic steel sheet core can be realized, and the support member for the amorphous-wound core becomes unnecessary, and stray loss and cost can be reduced. Moreover, the compressive stress acting on the amorphous wound core can be suppressed, and the increase in magnetic loss of the amorphous wound iron core can be minimized. Furthermore, according to each embodiment of the present invention, it is possible to provide a soundproofing material or the like in the yoke part of the amorphous wound core exposed to the outside of the winding, and the material has a magnetostriction about 10 times that of a grain-oriented electrical steel sheet. This has the effect of suppressing the excitation noise generated from the amorphous wound core.

Note that the present invention is not limited to the above-described embodiments, and includes various modifications. For example, the embodiments described above are described in detail to explain the present invention in an easy-to-understand manner, and the present invention is not necessarily limited to having all the configurations described. Furthermore, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Further, it is possible to add, delete, or replace a part of the configuration of each embodiment with other configurations.

DESCRIPTION OF SYMBOLS 1... Winding core (1st volume core), 1a... Lap joint, 2... Winding core (2nd volume core), 2a... Lap joint, 3... Winding, 4... Fastener, 4a... Horizontal stud, 4b ...Vertical stud, 5a... Insulator (first insulator), 5b... Insulator (second insulator), 5c... Insulator (third insulator), 6... Soundproofing material, 7... Suspension means, 11... Direct current magnetic field

Claims (13)

A plurality of wound cores formed by laminating and molding a plurality of sheets of thin plate-shaped magnetic material and lap-joining both ends of the magnetic materials to form a closed magnetic path; and one wound core wound around the plurality of wound cores. In stationary electromagnetic equipment composed of the above windings,
The plurality of wound cores are hybrid wound cores that include at least a first-volume core located on the outer peripheral side and a second-volume core located on the inner peripheral side of the first-volume core,
A stationary electromagnetic device, wherein the first volume core is made of an iron-based amorphous alloy, and the second volume core is made of a grain-oriented electromagnetic steel sheet. In claim 1,
upper and lower portions of the hybrid wound core are exposed from the winding;
A first insulator is provided in the gap between the upper end of the winding and the inner periphery of the second core, and in the gap between the lower end of the winding and the inner periphery of the second core. A stationary electromagnetic device characterized by: In claim 2,
A stationary electromagnetic device characterized in that a plurality of fasteners are provided at the upper and lower parts of the hybrid wound core exposed from the windings so as to form a pair and sandwich the exposed upper and lower parts of the hybrid wound iron core, respectively. device. In claim 3,
The fastener has an L-shaped cross section perpendicular to the winding direction of the hybrid wound core, and includes a vertical portion extending in the vertical direction and a horizontal portion bent in the horizontal direction from the vertical portion,
The vertical portions form a pair and sandwich the exposed upper and lower portions of the hybrid wound core, respectively,
A stationary electromagnetic device characterized in that the horizontal portions form a pair and sandwich the winding from above and below. In claim 4,
In the gap between the fastener located at the upper part of the hybrid wound core and the upper end of the winding, and in the gap between the fastener located at the lower part of the hybrid wound core and the lower end of the winding, a second Stationary electromagnetic equipment characterized by being equipped with an insulator. In claim 5,
A stationary electromagnetic device, wherein the vertical portions of the pair of fasteners are connected by a horizontal stud. In claim 6,
A stationary electromagnetic device, wherein the horizontal portions of the pair of fasteners are connected by a vertical stud. In claim 7,
The fasteners forming a pair at a lower position of the hybrid wound core are in contact with a floor surface and have a connection portion where the lower parts of the fasteners are connected in a pair direction,
The weight of the hybrid-wound core is supported by the winding through a first insulator disposed in a gap between the upper end of the winding and the inner periphery of the second-wound core, and the weight of the hybrid-wound core is The weight of the winding is applied to the connecting portion in contact with the floor surface through a second insulator located in a gap between a clamp located at a lower part of the hybrid wound core and a lower end of the winding. A stationary electromagnetic device characterized by: In any one of claims 1 to 8,
The hybrid wound core includes four sets of the hybrid wound core arranged in a horizontal direction,
A stationary electromagnetic device characterized in that a three-phase five-legged transformer is constructed by winding the winding around a magnetic leg portion formed by the adjacent hybrid wound cores. In any one of claims 1 to 8,
A stationary electromagnetic device characterized in that the hybrid-wound core comprises a single-phase two-legged transformer by winding the windings around the left and right magnetic legs of a pair of the hybrid-wound core. In any one of claims 1 to 8,
The stationary electromagnetic device is
An iron-based amorphous alloy cut to a predetermined length and laminated is placed on top of a grain-oriented electrical steel sheet that is cut to a predetermined length, bent into an inverted U shape, and laminated. A suspension means is applied to lift the laminated grain-oriented electrical steel sheets and the laminated iron-based amorphous alloy into an inverted U-shape, and both ends of the grain-oriented electrical steel sheets and the iron-based amorphous alloy are joined to form a rectangular shape. The closed magnetic path iron core is formed into a closed magnetic path iron core, and annealed while applying a direct current magnetic field to the closed magnetic path iron core. After the annealing treatment, the joints at both ends of the grain-oriented electrical steel sheet and the iron-based amorphous alloy are opened and the suspended lifting the grain-oriented electrical steel sheet and the iron-based amorphous alloy by a means, inserting both ends of the grain-oriented electrical steel sheet and the iron-based amorphous alloy into the winding wire, and lap-joining both ends of the grain-oriented electrical steel sheet and the iron-based amorphous alloy exposed from the lower part of the winding wire. Stationary electromagnetic equipment characterized by being manufactured by In any one of claims 4 to 8,
The width of the first volume iron core is made smaller than the width of the second volume iron core,
A stationary electromagnetic device, further comprising a gap between the first volume iron core and the vertical portion of the fastener. In claim 12,
A stationary electromagnetic device characterized in that a soundproofing material is provided in a gap between the first volume iron core and the vertical portion of the fastener.

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