JP2024013843A - Three-phase tripod-wound core and three-phase tripod-wound core transformer using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a three-phase tripod-wound core that uses a grain-oriented electromagnetic steel sheet that has been subjected to magnetic domain refining treatment by introducing thermal strain as a core material, and has excellent iron loss reduction effects and noise reduction effects.

SOLUTION: A three-phase tripod-wound core consists of two adjacent inner cores 10 and one outer core 12 surrounding the two inner cores 10, made of grain-oriented electromagnetic steel sheets as a raw material. The three-phase tripod wound core has a region formed of a grain-oriented electromagnetic steel sheet that has been subjected to magnetic domain refining treatment by introducing thermal strain and a region formed of a grain-oriented electromagnetic steel sheet that has not been subjected to magnetic domain refining treatment by introducing thermal strain, and has a region 5 formed of the grain-oriented electromagnetic steel sheet that has not been subjected to magnetic domain refining treatment by introducing thermal strain in a region 4 where magnetic flux crossing occurs between the outer core 12 and the inner cores 10 between legs when viewed from the side.

SELECTED DRAWING: Figure 2

COPYRIGHT: (C)2024,JPO&INPIT

Description

本発明は、三相三脚巻鉄心およびこれを用いた三相三脚巻鉄心変圧器に関し、特に方向性電磁鋼板を用いて製造される変圧器用の三相三脚巻鉄心および前記巻鉄心を用いた三相三脚巻鉄心変圧器に関するものである。 The present invention relates to a three-phase tripod-wound core and a three-phase tripod-wound core transformer using the same, and particularly to a three-phase tripod-wound core for a transformer manufactured using grain-oriented electrical steel sheets and a three-phase tripod-wound core using the above-described core. This relates to a phase tripod wound core transformer.

鉄の磁化容易軸である＜００１＞方位が鋼板の圧延方向に高度にそろった結晶組織を有する方向性電磁鋼板は、特に電力用変圧器の鉄心材料として用いられている。方向性電磁鋼板に求められる第一の特性としては、励磁された際の損失である鉄損が小さいことである。鉄損を低減する技術として、磁区細分化がある。磁区細分化は、レーザーやプラズマジェット、電子ビームなどを鋼板表面に照射することで、鋼板の表面に還流磁区と呼ばれる磁区を発生させ、鉄損を低減する技術である。還流磁区は、電磁鋼板の磁化容易方向に沿って生じる。通常＜００１＞方位は圧延方向に集積しているが、その方位と等価で、直交している＜１００＞、＜０１０＞方位も磁化容易方向である。これら２つの方位は圧延直交方向及び板厚方向の合成成分となっている。還流磁区はこれらの方位に沿って発生するため、還流磁区は、圧延直交方向及び板厚方向の成分を持った磁区となっている。 Grain-oriented electrical steel sheets, which have a crystal structure in which the <001> orientation, which is the axis of easy magnetization of iron, is highly aligned in the rolling direction of the steel sheet, are particularly used as core materials for power transformers. The first property required of a grain-oriented electrical steel sheet is that the iron loss, which is the loss when excited, is small. Magnetic domain refinement is a technique for reducing iron loss. Magnetic domain refining is a technology that reduces iron loss by generating magnetic domains called return magnetic domains on the surface of a steel sheet by irradiating the surface of the steel sheet with a laser, plasma jet, electron beam, etc. The reflux magnetic domain occurs along the direction of easy magnetization of the electrical steel sheet. Generally, the <001> orientation is concentrated in the rolling direction, but the <100> and <010> orientations, which are equivalent to and perpendicular to this orientation, are also directions of easy magnetization. These two orientations are composite components of the rolling direction and the plate thickness direction. Since the reflux magnetic domain is generated along these directions, the reflux magnetic domain has components in the direction perpendicular to rolling and in the thickness direction.

変圧器は、その鉄心構造から巻鉄心変圧器と積鉄心変圧器に大別される。巻鉄心変圧器とは、鋼板を巻き重ねて鉄心を形成するものである。一方、積鉄心変圧器とは、所定の形状に切断した鋼板を積層することで鉄心を形成するものである。変圧器鉄心として要求される特性は種々あるが、特に重要なことは鉄損が小さいことと、騒音が小さいことである。 Transformers are broadly classified into wound core transformers and stacked core transformers based on their core structure. A wound core transformer is one in which the core is formed by winding steel plates one on top of the other. On the other hand, a stacked core transformer has an iron core formed by stacking steel plates cut into a predetermined shape. There are various characteristics required of a transformer core, but the most important are low iron loss and low noise.

変圧器鉄損を小さくするためには、一般には、鉄心素材である方向性電磁鋼板の鉄損（素材鉄損）を小さくすればよいと考えられる。磁区細分化が施された電磁鋼板を鉄心素材に用いることで、変圧器鉄損も小さくなる。しかし、変圧器鉄心、特に電磁鋼板を三脚及び五脚有する三相励磁の巻鉄心変圧器では、素材鉄損と比べて変圧器における鉄損が大きくなることが知られている。変圧器の鉄心として電磁鋼板が使用された場合の鉄損値（変圧器鉄損）を、エプスタイン試験あるいは単板磁気測定試験（ＳＳＴ試験）で得られる素材の鉄損値で除した値を、一般に、ビルディングファクター（ＢＦ）と呼ぶ。つまり、三脚または五脚を有する三相励磁の巻鉄心変圧器では、ＢＦが１を超えるのが一般的である。 In order to reduce the transformer iron loss, it is generally considered that the iron loss (material iron loss) of the grain-oriented electrical steel sheet that is the core material should be reduced. By using magnetic steel sheets with magnetic domain refining as the core material, transformer iron loss is also reduced. However, it is known that in a three-phase excited wound core transformer having three or five legs of a transformer core, particularly an electromagnetic steel plate, the core loss in the transformer is larger than the core loss of the material. The value obtained by dividing the iron loss value (transformer iron loss) when a magnetic steel sheet is used as the core of a transformer by the iron loss value of the material obtained by the Epstein test or single plate magnetic measurement test (SST test) is Generally, it is called building factor (BF). That is, in a three-phase excitation wound core transformer with three or five legs, BF generally exceeds 1.

一般的な知見として、巻鉄心変圧器における変圧器鉄損が素材鉄損に比べて増加する要因として、主に磁路長の違いにより生じる内側鉄心への磁束の集中が指摘されている。図１に、三脚巻鉄心変圧器を三相励磁し、左の脚と中央の脚のみが励磁された瞬間の磁束の流れの模式図を示す。内側鉄心１と外側鉄心２が、ともに励磁されている時、外側鉄心２に比べて内側鉄心１の磁路が短いため、内側鉄心１に磁束が集中する。励磁磁束密度が比較的大きくなると、内側鉄心１だけでは励磁を担えなくなり、外側鉄心２にも多くの磁束が通るようになり、磁束の集中は緩和する。但し、図１に示すように、外側鉄心２を通る磁束は、励磁されていない右の脚に向けて流れ、励磁されている中央の脚に戻ろうとする際に、内側鉄心１に磁束が渡るようになり、内側鉄心１と外側鉄心２の間に、層間の磁束渡り３が生じるようになる。面直方向に磁化が生じることにより、面内渦電流損が生じることとなり、変圧器鉄損が増加する。 As a general knowledge, it has been pointed out that the main reason for the increase in transformer iron loss in wound core transformers compared to the material iron loss is the concentration of magnetic flux on the inner core caused by the difference in magnetic path length. FIG. 1 shows a schematic diagram of the flow of magnetic flux at the moment when a tripod wound core transformer is excited in three phases and only the left leg and the center leg are excited. When both the inner core 1 and the outer core 2 are excited, the magnetic flux concentrates on the inner core 1 because the magnetic path of the inner core 1 is shorter than that of the outer core 2. When the excitation magnetic flux density becomes relatively large, the inner core 1 alone cannot carry out the excitation, and a large amount of magnetic flux also passes through the outer core 2, so that the concentration of magnetic flux is alleviated. However, as shown in Figure 1, the magnetic flux passing through the outer core 2 flows toward the unexcited right leg, and when it returns to the excited center leg, the magnetic flux passes to the inner core 1. As a result, interlayer magnetic flux crossing 3 occurs between the inner core 1 and the outer core 2. Magnetization in the direction perpendicular to the plane causes in-plane eddy current loss, which increases transformer iron loss.

変圧器の騒音の由来として、一般的には電磁鋼板を磁化した際の歪みである磁歪、鉄心の固有振動、磁化された鋼板による電磁振動が挙げられる。このうち、磁化された鋼板による電磁振動とは、交流励磁の場合、時間変化とともに磁化が変化し、積層された鋼板間の吸引力も時間とともに変化することで発生する微小振動のことである。内側鉄心１と外側鉄心２の間に生じる層間の磁束渡り３のような面内方向の磁化によっても鋼板間の吸引力が変化し、電磁振動が生じ、変圧器の騒音の原因の一つとなっている。 The sources of transformer noise generally include magnetostriction, which is distortion caused when magnetic steel sheets are magnetized, natural vibrations of the iron core, and electromagnetic vibrations caused by magnetized steel sheets. Of these, electromagnetic vibrations due to magnetized steel plates are minute vibrations that occur when the magnetization changes with time and the attractive force between the laminated steel plates also changes with time in the case of AC excitation. Magnetization in the in-plane direction, such as interlayer magnetic flux crossing 3 that occurs between the inner core 1 and outer core 2, also changes the attractive force between the steel plates, causing electromagnetic vibration, which is one of the causes of transformer noise. ing.

こういった変圧器鉄損、変圧器騒音の増加要因に対する定性的な理解をもとに、変圧器鉄損、変圧器騒音を低減させる方策として、例えば以下のような提案がされている。 Based on this qualitative understanding of the factors that increase transformer iron loss and transformer noise, the following proposals have been made, for example, as measures to reduce transformer iron loss and transformer noise.

特許文献１では、磁路長が短く磁気抵抗が小さい内周側に、外周側よりも磁気特性の劣る電磁鋼板を、磁路長が長く磁気抵抗が大きい外周側には、内周側よりも磁気特性の優れた電磁鋼板を配置することで、変圧器鉄損が効果的に低減することが開示されている。特許文献２では、方向性けい素鋼板を巻回した巻鉄心を内側部分に配置し、この巻鉄心の外側に該方向性けい素鋼板より低磁歪の磁性材料を巻回して組合せ鉄心とすることで、変圧器騒音を効果的に低減できることが開示されている。特許文献３では、ラップ部を設けて積層及び巻回した変圧器鉄心のラップ部にのみ磁区細分化処理を施すことで、鉄損を低減できる技術について開示されている。また、特許文献４では、鉄心材料を個別に折り曲げ、組み付けることで鉄心の歪を軽減し、鉄心形成後に行う歪取り焼鈍を不要とすることで、鉄心素材として熱歪を導入し低鉄損化した磁区細分化材を用いることができるユニコアと呼ばれる巻鉄心に関する技術について開示されている。 In Patent Document 1, an electromagnetic steel plate with inferior magnetic properties than the outer circumferential side is used on the inner circumferential side where the magnetic path length is short and the magnetic resistance is low, and an electromagnetic steel sheet is used on the outer circumferential side where the magnetic path length is long and the magnetic resistance is large compared to the inner circumferential side. It is disclosed that transformer iron loss can be effectively reduced by arranging electrical steel sheets with excellent magnetic properties. In Patent Document 2, a wound core having grain-oriented silicon steel sheets wound thereon is arranged in the inner part, and a magnetic material having lower magnetostriction than the grain-oriented silicon steel sheets is wound around the outside of the wound core to form a combination core. It is disclosed that transformer noise can be effectively reduced. Patent Document 3 discloses a technique that can reduce iron loss by performing magnetic domain refining processing only on the lap portions of a transformer core that is laminated and wound with a wrap portion. In addition, in Patent Document 4, the strain of the core is reduced by individually bending and assembling the core material, and by eliminating the need for strain relief annealing performed after the core is formed, thermal strain is introduced into the core material to reduce core loss. A technology related to a wound core called Unicore that can use a magnetic domain refining material has been disclosed.

特開２０１０－８７５３６号公報Japanese Patent Application Publication No. 2010-87536 特開平３－２６８３１１号公報Japanese Patent Application Publication No. 3-268311 国際公開第２０２０／１２１６９１号International Publication No. 2020/121691 特開２０２１－１６３９４３号公報Japanese Patent Application Publication No. 2021-163943 特開２０１１－７５２９７号公報Japanese Patent Application Publication No. 2011-75297

特許文献１、２に開示されているように、内側鉄心へ磁束が集中することを利用し、内側鉄心と外側鉄心に異なる素材を適用することで、効率的に変圧器特性を改善することができる。しかし、特許文献３に開示されているように、励磁磁束密度が大きくなると、損失が大きい鉄心の外側にも磁束が流れるようになり、変圧器特性の改善効果は小さくなる。また、この時に、外側鉄心を通る磁束は、内側鉄心へ渡るようになり、この層間の磁束渡りによって層間磁束渡り部の渦電流損のみならず、素材である鋼板間の電磁振動により騒音も増加し、変圧器特性が著しく劣化する。特許文献４のように鉄心素材に低鉄損な磁区細分化材を用いたとしても、三相三脚の巻鉄心になると前記した層間の磁束渡りによって鉄心の鉄損は大きくなる。 As disclosed in Patent Documents 1 and 2, it is possible to efficiently improve transformer characteristics by utilizing the concentration of magnetic flux on the inner core and applying different materials to the inner core and outer core. can. However, as disclosed in Patent Document 3, when the excitation magnetic flux density increases, the magnetic flux also flows outside the iron core where the loss is large, and the effect of improving transformer characteristics becomes smaller. Also, at this time, the magnetic flux passing through the outer core begins to pass to the inner core, and this interlayer magnetic flux transfer not only increases eddy current loss at the interlayer magnetic flux transfer section, but also increases noise due to electromagnetic vibration between the steel plates that are made of the material. However, the transformer characteristics deteriorate significantly. Even if a magnetic domain refining material with low core loss is used as the core material as in Patent Document 4, in the case of a wound core for a three-phase tripod, the core loss increases due to the above-mentioned magnetic flux crossing between layers.

そこで、本発明は、熱歪み導入による磁区細分化処理が施された方向性電磁鋼板を鉄心素材として用いた三相三脚巻鉄心であって、鉄損の低減効果及び騒音の低減効果に優れる三相三脚巻鉄心を提供することを目的とする。 Therefore, the present invention provides a three-phase tripod-wound core that uses grain-oriented electrical steel sheets that have been subjected to magnetic domain refining treatment by introducing thermal strain as the core material, and which has excellent iron loss and noise reduction effects. The purpose is to provide a phase tripod wound core.

三相三脚巻鉄心変圧器では、鉄心素材として磁区細分化処理が施された低鉄損材料を用いることで変圧器鉄損が低減できるが、磁束渡りの発生に代表される鉄心内の複雑な磁化状態によって、変圧器鉄損は劣化し、磁区細分化による鉄心素材の鉄損の改善よりも変圧器鉄損の改善は小さくなる。外側鉄心から内側鉄心への磁束渡りを抑え、渦電流損の発生を抑制することで、この改善代の差を小さくし、変圧器鉄損をさらに低下でき、さらに変圧器騒音を抑えることができる可能性があり、その方法について検討した。 In three-phase tripod-wound core transformers, the transformer core loss can be reduced by using low core loss materials that have undergone magnetic domain refining treatment as the core material. The transformer core loss deteriorates depending on the magnetization state, and the improvement in the transformer core loss is smaller than the improvement in the core material core loss by magnetic domain segmentation. By suppressing the flow of magnetic flux from the outer core to the inner core and suppressing the occurrence of eddy current loss, the difference in improvement margin can be reduced, transformer core loss can be further reduced, and transformer noise can be further suppressed. This is a possibility, and we have considered ways to do so.

磁束渡りは、三相三脚巻鉄心変圧器の外側鉄心から内側鉄心への板厚方向への磁束の渡りであるので、磁束渡りが生じる部分に流れる板厚方向の磁束量を減らすことで、磁束渡りが抑えることができるのではないかと考えた。そこで本発明者らは、変圧器鉄心の外側鉄心から内側鉄心へ渡る磁束を減らすことを試みた。 Magnetic flux crossing is the passing of magnetic flux in the plate thickness direction from the outer core to the inner core of a three-phase tripod wound core transformer, so by reducing the amount of magnetic flux flowing in the plate thickness direction in the area where magnetic flux crossing occurs, the magnetic flux can be reduced. I thought it might be possible to suppress migration. Therefore, the present inventors attempted to reduce the magnetic flux passing from the outer core of the transformer core to the inner core.

熱歪み導入による磁区細分化処理が施された方向性電磁鋼板では、前記したように、熱歪み導入部に、圧延直交方向及び板厚方向の成分を持つ還流磁区が形成される。還流磁区によって鋼板全体としては低鉄損化がなされているが、変圧器用の鉄心素材として考えると、板厚方向への磁化である磁束渡りを還流磁区が促進しており、局所的に変圧器鉄損を増加させているという問題がある。そこで、還流磁区の磁束渡りへの影響を調査するために、変圧器鉄心において磁束渡りが発生する層間磁束渡り部にのみ、熱歪み導入による磁区細分化処理を施していない素材を用いて三相三脚巻鉄心を作製し、磁束渡り部の鉄損、及び、変圧器鉄損、変圧器騒音について実験を行い調査した。以下に実験の詳細を説明する。 In a grain-oriented electrical steel sheet subjected to magnetic domain refining treatment by introducing thermal strain, as described above, a reflux magnetic domain having components in the direction perpendicular to rolling and in the thickness direction is formed in the thermal strain introduced portion. Although the iron loss of the steel sheet as a whole is reduced by the return magnetic domain, when considered as an iron core material for a transformer, the return magnetic domain promotes magnetic flux passage, which is magnetization in the thickness direction of the plate, and locally the transformer There is a problem that iron loss is increased. Therefore, in order to investigate the influence of the freewheeling magnetic domain on the magnetic flux crossing, we used a material that has not undergone magnetic domain refining treatment by introducing thermal strain only in the interlayer magnetic flux crossing section where magnetic flux crossing occurs in the transformer core. A tripod-wound core was fabricated, and experiments were conducted to investigate the iron loss in the magnetic flux crossing section, transformer iron loss, and transformer noise. The details of the experiment will be explained below.

鋼帯幅１５０ｍｍでレーザーを鋼板表面に照射することで熱歪み導入による磁区細分化処理を施した８００Ａ／ｍにおける磁束密度Ｂ８が１．９２Ｔの方向性電磁鋼板を鉄心素材として用いて、図２に示す巻鉄心形状にて三相三脚巻鉄心を作製した。この三相三脚巻鉄心は、前記鉄心素材を用いて構成された隣接する２つの内側鉄心１０と前記２つの内側鉄心１０を囲む１つの外側鉄心１２とからなる。また、各コーナー部に折り曲げ部（屈曲部）を有するユニコアである。なお、前記熱歪み導入による磁区細分化処理は、鋼板の板幅の全部（全幅）に施した。また、前記鉄心素材のうち、巻鉄心に組み上げた際に、脚と脚の間の、外側鉄心と内側鉄心間の磁束渡りが生じる領域（層間磁束渡り部）４において、後述する非処理部５を形成する領域には、熱歪み導入による磁区細分化処理を施さなかった。図２に示すように、本発明において、層間磁束渡り部４は、巻鉄心を側面視した場合に、隣接する脚６と脚６の間（隣接する脚６間）の領域である。より具体的には、層間磁束渡り部４の長さｆは、隣接する脚６間の長さと定義する。また、層間磁束渡り部４の厚さｇは、隣接する脚６間の中心位置（脚間中心位置）７上で内側鉄心１０と外側鉄心１２が接する箇所である隣接部８から外側方向への外側鉄心の厚さｅと、前記隣接部８から内側方向への内側鉄心の厚さｅ’との合計と、同じ厚さと定義する。なお、本明細書において、側面視とは、巻鉄心を方向性電磁鋼板の巻回方向と垂直な方向、すなわち、巻鉄心を構成する長尺状の方向性電磁鋼板の幅方向に視ることをいう。 A grain-oriented electrical steel sheet with a magnetic flux density B8 of 1.92T at 800 A/m, which has been subjected to magnetic domain refining treatment by introducing thermal strain by irradiating the steel sheet surface with a laser beam with a steel strip width of 150 mm, is used as the iron core material. A three-phase tripod wound core was fabricated using the wound core shape shown in the figure. This three-phase tripod-wound core consists of two adjacent inner cores 10 made of the core material and one outer core 12 surrounding the two inner cores 10. Moreover, it is a unicore having a bent part (bending part) at each corner part. Note that the magnetic domain refining treatment by introducing thermal strain was applied to the entire width of the steel plate (full width). In addition, in the region (interlayer magnetic flux crossing portion) 4 where magnetic flux crosses between the outer core and the inner core between the legs when the core material is assembled into a wound core, a non-treated portion 5 to be described later No magnetic domain refining treatment by introducing thermal strain was applied to the region forming the . As shown in FIG. 2, in the present invention, the interlayer magnetic flux crossing portion 4 is a region between adjacent legs 6 (between adjacent legs 6) when the wound core is viewed from the side. More specifically, the length f of the interlayer magnetic flux crossing section 4 is defined as the length between adjacent legs 6. Further, the thickness g of the interlayer magnetic flux crossing portion 4 is determined from the adjacent portion 8, which is the point where the inner core 10 and the outer core 12 touch on the center position 7 between the adjacent legs 6 (the center position between the legs), in the outward direction. The thickness is defined to be the same as the sum of the thickness e of the outer core and the thickness e' of the inner core inward from the adjacent portion 8. In this specification, side view refers to the direction in which the wound core is viewed in a direction perpendicular to the winding direction of the grain-oriented electrical steel sheet, that is, in the width direction of the elongated grain-oriented electrical steel sheet that constitutes the wound core. means.

そして、層間磁束渡り部４中に、熱歪み導入による磁区細分化処理が施されていない方向性電磁鋼板により形成された領域（本明細書において「非処理部」ともいう）５を形成した。具体的には、前記非処理部５は、外側鉄心と内側鉄心の隣接部８から外側方向にＬの厚さとなる領域と、前記隣接部８から内側方向にＭの厚さとなる領域（図２中、ハッチングで示された領域）である。非処理部５のＬの厚さとＭの厚さは、熱歪み導入による磁区細分化処理が施されていない領域を有する鉄心素材の巻鉄心厚さ方向への積み重ね数を変更することで調整した。そして、非処理部５のＬの厚さとＭの厚さを変更した三相三脚巻鉄心変圧器を作製し、５０Ｈｚ、１．７Ｔの三相励磁を行い、それぞれの三脚巻鉄心変圧器について、鉄損測定、騒音測定を行った。鉄損測定と同時に、特許文献５に開示されているように、赤外線カメラにより励磁中の鉄心端面のうち、層間磁束渡り部４の平均温度上昇量を測定し、実際にこの層間磁束渡り部４で局所的に鉄損が増加していることを確認し、そのうえで層間磁束渡り部４の局所鉄損を測定した。 Then, in the interlayer magnetic flux crossing section 4, a region 5 (also referred to as an "untreated section" in this specification) formed of a grain-oriented electrical steel sheet that has not been subjected to magnetic domain refining treatment by introducing thermal strain was formed. Specifically, the untreated portion 5 includes a region having a thickness of L in the outward direction from the adjacent portion 8 of the outer core and the inner core, and a region having a thickness of M in the inward direction from the adjacent portion 8 (FIG. 2 (middle, area indicated by hatching). The thickness of L and the thickness of M of the untreated portion 5 were adjusted by changing the number of stacks of the core material in the thickness direction of the core material having a region not subjected to magnetic domain refining treatment by introducing thermal strain. . Then, a three-phase three-legged wound core transformer was created in which the thickness of L and M of the non-processing section 5 were changed, three-phase excitation was performed at 50Hz and 1.7T, and for each three-legged wound core transformer, Iron loss and noise measurements were performed. At the same time as the iron loss measurement, as disclosed in Patent Document 5, the average temperature rise of the interlayer magnetic flux crossing section 4 of the end face of the core during excitation is measured using an infrared camera, and the average temperature rise of the interlayer magnetic flux crossing section 4 is actually measured. It was confirmed that the iron loss locally increased, and then the local iron loss of the interlayer magnetic flux crossing section 4 was measured.

変圧器騒音については、作製したそれぞれの巻鉄心変圧器に対し、励磁中に、鉄心高さｄの１／２の位置で、巻鉄心変圧器の表面から３０ｃｍの距離で、巻鉄心変圧器を囲むようにした８点の位置で測定し、その平均値を変圧器騒音とした。 Regarding transformer noise, for each wound core transformer that was fabricated, during excitation, the wound core transformer was energized at a position of 1/2 of the core height d, at a distance of 30 cm from the surface of the wound core transformer. Measurements were taken at eight surrounding points, and the average value was taken as the transformer noise.

変圧器鉄損は、作製したそれぞれの三相三脚巻鉄心の各脚に１次側、２次側共に５０ターンの巻き線を施し、励磁最大磁束密度が１．７Ｔ、周波数５０Ｈｚの条件で三相励磁を行い、１次電流と２次電圧を電力計にて測定し、無負荷損失を計算し、鉄心重量で除することで算出した。表１に、非処理部５のＬの厚さとＭの厚さを変更して作製した各巻鉄心変圧器における変圧器鉄損、変圧器騒音、及び、層間磁束渡り部４の鉄損（層間磁束渡り部４の鉄損平均）の値を示す。 The transformer iron loss was determined by winding each leg of each three-phase tripod core with 50 turns on both the primary and secondary sides, and under the conditions that the maximum excitation magnetic flux density was 1.7T and the frequency was 50Hz. Phase excitation was performed, the primary current and secondary voltage were measured with a wattmeter, and the no-load loss was calculated by dividing by the iron core weight. Table 1 shows the transformer core loss, transformer noise, and core loss of the interlayer magnetic flux crossing section 4 (interlayer magnetic flux The average iron loss of the transition section 4 is shown.

層間磁束渡り部４に熱歪み導入による磁区細分化処理が施されていない方向性電磁鋼板により形成された領域（非処理部）５を設けることで、鉄心全体を熱歪み導入による磁区細分化処理が施された方向性電磁鋼板で構成した巻鉄心変圧器（表１のＮｏ．１）と比べ、変圧器鉄損、変圧器騒音、および層間磁束渡り部鉄損が顕著に減少することが分かった。特に、非処理部５の厚さが、外側鉄心及び内側鉄心の厚さに対して、ともに２０％以上となる場合、層間磁束渡りを抑えたことによる効果がより高められ、変圧器鉄損、変圧器騒音の低減効果が、ともにより高められることが分かった。層間磁束渡り部４の鉄損の低下は、層間磁束渡り部４での磁束渡り量の減少を反映した結果であると推察している。 By providing a region (untreated portion) 5 formed of a grain-oriented electrical steel sheet that has not been subjected to magnetic domain refining treatment by introducing thermal strain to the interlayer magnetic flux crossing portion 4, the entire core can be subjected to magnetic domain refining treatment by introducing thermal strain. Compared to a wound core transformer constructed from grain-oriented electrical steel sheets (No. 1 in Table 1), it was found that the transformer core loss, transformer noise, and interlayer magnetic flux crossover core loss were significantly reduced. Ta. In particular, when the thickness of the non-treated portion 5 is 20% or more of both the thickness of the outer core and the inner core, the effect of suppressing interlayer magnetic flux crossing is further enhanced, and the transformer iron loss is reduced. It was found that the effect of reducing transformer noise was further enhanced in both cases. It is presumed that the decrease in iron loss in the interlayer magnetic flux crossing section 4 is a result of reflecting a decrease in the amount of magnetic flux passing through the interlayer magnetic flux crossing section 4.

三相三脚巻鉄心においては、磁路が長い外側鉄心の内側から、磁路が短い内側鉄心の外側に向けて磁束渡りが生じる。方向性電磁鋼板は、圧延方向の透磁率を高め、圧延方向の磁化にのみ特化した材料であるので、板厚方向への磁化である磁束渡りは、方向性電磁鋼板において透磁率が低い方向への磁化であるため鉄損は増加する。また、方向性電磁鋼板の圧延面に渦電流が流れることで渦電流損の増加にもつながる。磁区細分化により形成される還流磁区は、方向性電磁鋼板の板厚方向成分を持つため、板厚方向の透磁率を高める働きがあり、層間磁束渡りを促進する。外側鉄心から内側鉄心へ流れ込もうとする磁束量は、外側鉄心の磁束渡り部の板厚方向の透磁率が高いと増加し、内側鉄心の板厚方向の透磁率が高ければ、内側鉄心が受け入れられる渡り磁束の量が増える。そこで、外側鉄心において磁束渡りが生じる領域に、熱歪み導入による磁区細分化処理を施していない素材を適用することで、透磁率の増加を抑制し、内側鉄心へ流れ込もうとする磁束を抑え、また内側鉄心において磁束渡りが生じる領域に、熱歪み導入による磁区細分化処理を施していない素材を適用することで、同様に、内側鉄心が受け入れられる磁束量が減少し、これら両方の効果によって層間磁束渡りを抑えることができたと考えられる。従って、変圧器鉄損の低下は、層間磁束渡り部の鉄損が、層間磁束渡りが抑えられることで低下し、その影響で変圧器鉄損が低下したと推察される。また、非処理部の厚さが、内側鉄心中および外側鉄心中で、それぞれの鉄心の厚さの２０％以上である条件では、変圧器鉄損がより改善された。これは、非処理部の厚さが大きくなることで、磁束渡りを抑える効果がより高められ、磁束渡り抑制による鉄損の低下が、鉄心素材に熱歪み導入による磁区細分化処理を施さないことによる鉄損増加を大きく上回ることができたためだと推察される。 In a three-phase tripod-wound core, magnetic flux crosses from the inside of the outer core, where the magnetic path is long, to the outside of the inner core, where the magnetic path is short. Grain-oriented electrical steel sheets are materials that have high magnetic permeability in the rolling direction and are specialized only for magnetization in the rolling direction, so the magnetic flux transfer, which is magnetization in the thickness direction, is in the direction of low magnetic permeability in grain-oriented electrical steel sheets. Iron loss increases because of the magnetization. Furthermore, eddy currents flowing through the rolling surface of grain-oriented electrical steel sheets also lead to an increase in eddy current loss. The reflux magnetic domain formed by magnetic domain refining has a component in the thickness direction of the grain-oriented electrical steel sheet, so it has the function of increasing magnetic permeability in the thickness direction and promotes interlayer magnetic flux crossing. The amount of magnetic flux that attempts to flow from the outer core to the inner core increases when the magnetic flux crossing section of the outer core has a high magnetic permeability in the thickness direction. The amount of flux that can be accepted increases. Therefore, by applying a material that has not undergone magnetic domain refining treatment by introducing thermal strain to the area where magnetic flux crosses in the outer core, we suppress the increase in magnetic permeability and suppress the magnetic flux that attempts to flow into the inner core. In addition, by applying a material that has not undergone magnetic domain refining treatment by introducing thermal strain to the area where magnetic flux crosses in the inner core, the amount of magnetic flux that the inner core can accept similarly decreases, and due to both of these effects, It is thought that the interlayer magnetic flux crossing could be suppressed. Therefore, it is inferred that the transformer iron loss is reduced because the iron loss in the interlayer magnetic flux crossing section is suppressed because the interlayer magnetic flux crossing is suppressed, and the transformer iron loss is reduced due to this influence. Further, under the condition that the thickness of the untreated portion in the inner core and the outer core is 20% or more of the thickness of each core, the transformer core loss was further improved. This is because the effect of suppressing magnetic flux transfer is further enhanced by increasing the thickness of the untreated portion, and the reduction in iron loss due to suppression of magnetic flux transfer is achieved by not performing magnetic domain refining treatment by introducing thermal strain into the core material. This is thought to be due to the fact that the increase in iron loss was greatly outweighed by the increase in iron loss.

変圧器騒音は、非処理部を有する全ての巻鉄心変圧器で低下が認められた。特に非処理部のＬの厚さが外側鉄心の厚さに対して２０％以上で、かつ、非処理部のＭの厚さが内側鉄心の厚さの２０％以上の条件で、顕著に変圧器騒音の改善が認められた。通常、磁区細分化材を用いて巻鉄心変圧器を作製した場合、その変圧器騒音は、磁区細分化処理を施していない鉄心素材を用いて作製した巻鉄心変圧器に比べて大きくなることが知られている。そのため、巻鉄心変圧器中の非処理部領域の増加により、変圧器の騒音は低下する。しかし、その領域が、外側鉄心および内側鉄心それぞれの厚さの２０％以上で変圧器騒音が顕著に減少したことは、前述した理由に加えて、層間磁束渡りが減少することによる面内方向の磁化による電磁振動の抑制によるものが大きいと推察される。 A reduction in transformer noise was observed for all wound core transformers with untreated sections. In particular, if the thickness of L in the untreated part is 20% or more of the thickness of the outer core, and the thickness of M in the untreated part is 20% or more of the thickness of the inner core, the transformation will be noticeable. Improvement in instrument noise was observed. Normally, when a wound core transformer is manufactured using magnetic domain refining material, the transformer noise is likely to be louder than a wound core transformer manufactured using core material that has not undergone magnetic domain refining treatment. Are known. Therefore, the noise of the transformer is reduced by increasing the non-treated area in the wound core transformer. However, in addition to the above-mentioned reasons, the reason that the transformer noise was significantly reduced in the region of 20% or more of the thickness of each of the outer core and inner core is that the in-plane direction due to the decrease in interlayer magnetic flux transfer It is presumed that this is largely due to the suppression of electromagnetic vibrations caused by magnetization.

上記の実験事実及び推定をもとに、三相三脚巻鉄心変圧器における変圧器鉄損及び変圧器騒音を小さくするためには、層間磁束渡り部の磁束渡りを小さくすることが肝要であると知見した。さらに、層間磁束渡り部の磁束渡りを小さくするためには、層間磁束渡りが生じる領域に、熱歪み導入による磁区細分化処理を施していない方向性電磁鋼板で形成された領域（非処理部）を設け、それ以外の領域を、熱歪み導入による磁区細分化処理を施した方向性電磁鋼板で形成することが有効であることも知見した。さらに、非処理部の領域が内側鉄心および外側鉄心それぞれの厚さの２０％以上である場合、層間磁束渡りの抑制効果が大きくなり、変圧器鉄損、変圧器騒音ともにより大きな改善を示すため、非処理部の領域は、内側鉄心、外側鉄心、それぞれの厚さの２０％以上（２０～１００％）にすることが特に好適であることを知見した。 Based on the above experimental facts and estimates, in order to reduce transformer iron loss and transformer noise in a three-phase tripod wound core transformer, it is important to reduce the magnetic flux transfer in the interlayer magnetic flux transfer section. I found out. Furthermore, in order to reduce the magnetic flux crossing in the interlayer magnetic flux crossing part, it is necessary to create an area (untreated part) in the area where the interlayer magnetic flux crossing occurs using grain-oriented electrical steel sheets that have not been subjected to magnetic domain refining treatment by introducing thermal strain. It has also been found that it is effective to form the other regions with grain-oriented electrical steel sheets that have been subjected to magnetic domain refining treatment by introducing thermal strain. Furthermore, if the area of the untreated portion is 20% or more of the thickness of the inner core and outer core, the effect of suppressing interlayer magnetic flux crossing will be greater, and both transformer iron loss and transformer noise will show greater improvement. It has been found that it is particularly preferable that the area of the untreated portion be 20% or more (20 to 100%) of the thickness of each of the inner core and outer core.

以上の知見を基に、本発明の完成に至った。すなわち、本発明は以下の構成を備える。
［１］方向性電磁鋼板を素材として構成された隣接する２つの内側鉄心と前記２つの内側鉄心を囲む１つの外側鉄心からなる三相三脚巻鉄心であって、
前記三相三脚巻鉄心は、
熱歪み導入による磁区細分化処理が施された方向性電磁鋼板により形成された領域と、熱歪み導入による磁区細分化処理が施されていない方向性電磁鋼板により形成された領域を有し、
巻回方向と垂直な方向からの側面視において、脚と脚の間の、前記外側鉄心と前記内側鉄心間の磁束渡りが生じる領域に、前記熱歪み導入による磁区細分化処理が施されていない方向性電磁鋼板により形成された領域を有する、三相三脚巻鉄心。
［２］巻回方向と垂直な方向からの側面視において、前記熱歪み導入による磁区細分化処理が施されていない方向性電磁鋼板により形成された領域が、脚と脚の間、かつ、前記外側鉄心と前記内側鉄心の隣接部から外側方向に前記外側鉄心の厚さの２０～１００％の領域と、前記隣接部から内側方向に前記内側鉄心の厚さの２０～１００％の領域である、［１］に記載の三相三脚巻鉄心。
［３］前記熱歪み導入による磁区細分化処理が、鋼板の板幅の全部または一部に施された、［１］または［２］に記載の三相三脚巻鉄心。
［４］前記［１］または［２］に記載の三相三脚巻鉄心を用いた三相三脚巻鉄心変圧器。
［５］前記［３］に記載の三相三脚巻鉄心を用いた三相三脚巻鉄心変圧器。 Based on the above findings, the present invention has been completed. That is, the present invention includes the following configuration.
[1] A three-phase tripod-wound core consisting of two adjacent inner cores and one outer core surrounding the two inner cores made of grain-oriented electromagnetic steel sheets,
The three-phase tripod wound core is
A region formed by a grain-oriented electrical steel sheet that has been subjected to magnetic domain refining treatment by introducing thermal strain, and a region formed by a grain-oriented electrical steel sheet that has not been subjected to magnetic domain refining treatment by introducing thermal strain,
In a side view from a direction perpendicular to the winding direction, the magnetic domain refining process by introducing thermal strain is not applied to a region between the legs where magnetic flux crosses between the outer core and the inner core. A three-phase tripod-wound core with a region formed by grain-oriented electrical steel sheets.
[2] In a side view from a direction perpendicular to the winding direction, the region formed by the grain-oriented electrical steel sheet that has not been subjected to the magnetic domain refining treatment by introducing thermal strain is between the legs and A region of 20 to 100% of the thickness of the outer core in an outward direction from an adjacent portion of the outer core and the inner core, and a region of 20 to 100% of the thickness of the inner core in an inward direction from the adjacent portion. , the three-phase tripod wound core according to [1].
[3] The three-phase tripod-wound core according to [1] or [2], wherein the magnetic domain refining treatment by introducing thermal strain is applied to all or part of the width of the steel plate.
[4] A three-phase three-phase three-legged core transformer using the three-phase three-legged core described in [1] or [2].
[5] A three-phase three-phase three-legged core transformer using the three-phase three-legged core described in [3].

本発明によれば、熱歪み導入による磁区細分化処理が施された方向性電磁鋼板を鉄心素材として用いた三相三脚巻鉄心であって、鉄損の低減効果及び騒音の低減効果に優れる三相三脚巻鉄心を提供することができる。 According to the present invention, there is provided a three-phase tripod-wound core that uses grain-oriented electrical steel sheets that have been subjected to magnetic domain refining treatment by introducing thermal strain as the core material, and which has excellent iron loss reduction effects and noise reduction effects. A phase tripod wound core can be provided.

本発明によれば、熱歪み導入による磁区細分化処理が施された方向性電磁鋼板（非耐熱型磁区細分化材）を適用した三相三脚巻鉄心の内側鉄心と外側鉄心が接する磁束渡り部に、非耐熱型の磁区細分化処理を施さない領域を形成することで、変圧器鉄損と変圧器騒音が低減された三相三脚巻鉄心および三相三脚巻鉄心変圧器を提供することができる。
本発明によれば、特に非耐熱型磁区細分化材を適用したユニコアにおいて、励磁磁束密度が比較的高い状態でも、層間磁束渡りを抑制できることで、優れた鉄損低減効果と騒音低減効果を得ることができる。 According to the present invention, the magnetic flux crossing portion where the inner core and the outer core of a three-phase tripod-wound core are made of a grain-oriented electrical steel sheet (non-heat-resistant magnetic domain refining material) subjected to magnetic domain refining treatment by introducing thermal strain In addition, it is possible to provide a three-phase tripod-wound core and a three-phase tripod-wound core transformer in which transformer iron loss and transformer noise are reduced by forming a region that is not subjected to heat-resistant magnetic domain refining treatment. can.
According to the present invention, especially in a unicore to which a non-heat-resistant type magnetic domain refining material is applied, interlayer magnetic flux crossing can be suppressed even when the excitation magnetic flux density is relatively high, thereby achieving excellent iron loss reduction effects and noise reduction effects. be able to.

図１は、三相三脚巻鉄心において、外側鉄心から内側鉄心へ生じる層間の磁束渡りを模式的に示す図（側面図）である。FIG. 1 is a diagram (side view) schematically showing magnetic flux transfer between layers occurring from an outer core to an inner core in a three-phase tripod-wound core. 図２は、実験で作製した三相三脚巻鉄心の構成を示す側面図である。FIG. 2 is a side view showing the configuration of a three-phase tripod wound core produced in an experiment. 図３は、実施例で作製した三相三脚巻鉄心の構成を示す側面図である。FIG. 3 is a side view showing the configuration of the three-phase tripod wound core produced in the example.

以下、本発明を具体的に説明する。 The present invention will be explained in detail below.

図２を用いて本発明の一実施形態に係る三相三脚巻鉄心の製造方法について説明する。 A method for manufacturing a three-phase tripod wound core according to an embodiment of the present invention will be described with reference to FIG.

材料となる方向性電磁鋼板の表面に、レーザーやプラズマジェット、電子ビームなどを照射することで、前記鋼板に、熱歪みが導入され磁区細分化処理が施されて、前記鋼板が低鉄損化される。このレーザー等の照射による磁区細分化処理は、鉄心素材となる方向性電磁鋼板の全長に施すのではなく、巻鉄心に組み上げた際に、脚と脚の間の鉄心の接合部（磁束渡りが生じる領域）となる鋼板の領域には前記照射を施さないようにする。前記方法で作製した鉄心素材を用いて巻鉄心を組み上げるが、本発明を適用できる巻鉄心として好適なものとして、鉄心を組み上げた際に鉄心に入る歪みが少ない鉄心であるユニコアが挙げられる。 By irradiating the surface of grain-oriented electrical steel sheet, which is the material, with a laser, plasma jet, electron beam, etc., thermal strain is introduced into the steel sheet and magnetic domain refining treatment is performed, resulting in a low core loss of the steel sheet. be done. This magnetic domain refining treatment by laser irradiation is not applied to the entire length of the grain-oriented electrical steel sheet that is the core material, but rather to the joints of the core between the legs (where magnetic flux is The above-mentioned irradiation is not applied to the area of the steel plate that will be the area where the irradiation occurs. A wound core is assembled using the core material produced by the above method, and a suitable wound core to which the present invention can be applied is Unicore, which is an iron core that causes less distortion when assembled.

ユニコアは、鉄心素材である方向性電磁鋼板を鉄心の各層の長さになるように切り出した後、折り曲げ巻回することで作製される。上記方法で作製した鉄心素材では、鉄心を組み上げた際に脚と脚の間に当たる部分には熱歪みが導入されていないため、図２のような非処理部５を持つ三相三脚巻鉄心を作製することができる。この熱歪みについては材料である方向性電磁鋼板の板幅（鋼帯幅）の全部（全幅）に導入することが低鉄損化の観点で最も好ましいが、板幅（鋼帯幅）の一部のみに熱歪みを導入した鉄心素材であっても、本発明の効果は発揮され、鉄損が低減された鉄心を提供できる。また、本発明は、ユニコアに適用することが好適であるが、ユニコアに限定されず、他の鉄心においても好適に適用できる。例えば鋼帯を巻回したトランコと呼ばれる鉄心においても好適に適用できる。 Unicore is manufactured by cutting grain-oriented electrical steel sheets, which are the core material, to the length of each layer of the core, and then bending and winding the sheets. In the core material produced by the above method, thermal strain is not introduced in the portion between the legs when the core is assembled, so a three-phase tripod-wound core with an untreated portion 5 as shown in Fig. 2 is not introduced. It can be made. Regarding this thermal strain, it is most preferable to introduce it into the entire width (full width) of the grain-oriented electrical steel sheet (steel strip width), which is the material, from the viewpoint of reducing core loss. Even with an iron core material in which thermal strain is introduced only in a portion, the effects of the present invention can be exhibited, and an iron core with reduced iron loss can be provided. Further, although the present invention is preferably applied to Unicore, it is not limited to Unicore and can be applied suitably to other iron cores. For example, it can be suitably applied to an iron core called a tranco wound with a steel strip.

次に、本発明における各構成の限定理由について説明する。 Next, reasons for limiting each configuration in the present invention will be explained.

三相三脚巻鉄心変圧器の変圧器鉄損には、励磁されていない脚から励磁されている脚に戻ろうとする磁束の流れが生じ、これが外側鉄心から内側鉄心への磁束渡りとなり、また磁束渡りが変圧器鉄損を増加させる一因となっていることが明らかとなった。 The transformer core loss of a three-phase tripod wound core transformer involves a flow of magnetic flux that tries to return from the non-excited leg to the energized leg, which results in flux crossing from the outer core to the inner core, and the magnetic flux It has become clear that crossings are a factor in increasing transformer iron loss.

そこで、磁束渡りは、外側鉄心と内側鉄心が接している部分を介して発生する現象であり、板厚方向への磁化であることから、磁束渡りが生じる領域に対し、磁束渡りを抑えることを目的として、熱歪み導入による磁区細分化処理を施さない方向性電磁鋼板により形成された領域（非処理部）を設けることで、鉄心全体を熱歪み導入による磁区細分化処理を施した方向性電磁鋼板で構成した変圧器鉄心に比べて低鉄損化が達成された。なお、鉄心に対し、鉄心形成後に歪み取り焼鈍を行うと、鉄心全体から熱歪み導入による磁区細分化効果が除かれるため、本発明は、鉄心形成後に歪み取り焼鈍を実施しない変圧器および鉄心に対して適用可能である。このときの非処理部の厚さは、前記した実験結果より、外側鉄心および内側鉄心の厚さに対しそれぞれ２０％以上とすることが、特に優れた鉄損低減効果を得る点から好ましい。熱歪み導入による磁区細分化処理を施すことで、レーザー等の照射部直下に鋼板の板厚方向を向いた還流磁区と呼ばれる磁区が形成される。前記還流磁区は、板厚方向を向いているため、この磁区が磁束渡り部にあることで磁束渡りが促進されて変圧器鉄損の増加を招く。本発明では、鉄心中に非処理部を設け、還流磁区を局所的に除くことで磁束渡りを抑えているため、磁束渡り部以外の箇所に導入される磁区細分化の手法は、熱歪みによって還流磁区が導入される方法であれば特に限定されない。 Therefore, since magnetic flux crossing is a phenomenon that occurs through the part where the outer core and the inner core are in contact, and is magnetization in the thickness direction, it is necessary to suppress magnetic flux crossing in the area where magnetic flux crossing occurs. The purpose is to create a region (untreated area) formed of grain-oriented electrical steel sheet that has not been subjected to magnetic domain refining treatment by introducing thermal strain. Lower core loss has been achieved compared to transformer cores made of steel plates. Note that if the iron core is subjected to strain relief annealing after core formation, the effect of magnetic domain refining due to introduction of thermal strain is removed from the entire core. It is applicable to From the above-mentioned experimental results, it is preferable that the thickness of the untreated portion at this time be 20% or more of the thickness of the outer core and the inner core, respectively, in order to obtain a particularly excellent iron loss reduction effect. By performing magnetic domain refining treatment by introducing thermal strain, a magnetic domain called a reflux magnetic domain, which is oriented in the thickness direction of the steel plate, is formed directly under the irradiation area of a laser or the like. Since the return magnetic domain is oriented in the plate thickness direction, the presence of this magnetic domain in the magnetic flux crossing portion promotes magnetic flux crossing, leading to an increase in transformer iron loss. In the present invention, magnetic flux crossing is suppressed by providing an untreated part in the iron core and locally removing the reflux magnetic domain. Therefore, the method of magnetic domain refining introduced in places other than the magnetic flux crossing part is based on thermal distortion. The method is not particularly limited as long as it introduces a reflux magnetic domain.

また、本明細書中では特定の形状の三相三脚型の巻鉄心における特性について記述しているが、その他の三相巻鉄心変圧器で磁束渡りが発生するすべての三相巻鉄心に対して本発明は好適であり、その形状、寸法は限定されない。 In addition, although this specification describes the characteristics of a three-phase tripod-type wound core with a specific shape, it applies to all three-phase wound cores in which magnetic flux crossing occurs in other three-phase wound core transformers. The present invention is suitable, and its shape and dimensions are not limited.

また、本発明に適用する鉄心素材としては、特に限定されず、例えば耐熱型磁区細分化処理材に熱歪みを導入した材料を用いることもできる。また、母材のゴス粒の配向性の大小の影響も受けず、任意の方向性電磁鋼板を材料として用いることができる。 Further, the core material to be applied to the present invention is not particularly limited, and for example, a material obtained by introducing thermal strain into a heat-resistant magnetic domain refining treated material can also be used. Furthermore, any grain-oriented electrical steel sheet can be used as the material without being affected by the orientation of Goss grains in the base material.

本発明の三相三脚巻鉄心を用いた三相三脚巻鉄心変圧器とすることで、変圧器鉄損、変圧器騒音が低下する。この変圧器の形状や特性は限定されず、任意の巻鉄心変圧器に対し本発明を適用することができる。 By providing a three-phase three-phase three-legged core transformer using the three-phase three-legged core of the present invention, transformer core loss and transformer noise are reduced. The shape and characteristics of this transformer are not limited, and the present invention can be applied to any wound core transformer.

［実施例１］
表２に示す８００Ａ／ｍにおける磁束密度Ｂ８が異なる方向性電磁鋼板を材料とし、これにレーザー照射（熱歪み導入による磁区細分化処理）を施して鉄心素材とした。そして、前記鉄心素材を用いて、図３に示す鉄心形状のユニコアを作製し、１次、２次ともに５０ターンの巻き線コイルを取り付けて、三相三脚巻鉄心変圧器を作製した。励磁磁束密度１．７Ｔ、周波数５０Ｈｚの条件で励磁し、変圧器鉄損及び変圧器騒音を上述の方法で測定した。なお、前記レーザー照射は、鋼板の板幅の全部（全幅）に施した。また、前記鉄心素材のうち、巻鉄心に組み上げた際に、脚と脚の間の、外側鉄心と内側鉄心間の磁束渡りが生じる領域（層間磁束渡り部）に対応する領域には、レーザー照射を施さないようにして、前記磁束渡りが生じる領域に非処理部を設けた。さらに、レーザー照射を施していない領域を有する鉄心素材の巻鉄心厚さ方向への積み重ね数を変更することで、非処理部のＬの厚さとＭの厚さを変更した巻鉄心を作製した。ただし、一部の巻鉄心については、巻鉄心全体を、熱歪み導入による磁区細分化処理が施されていない領域を有する鉄心素材を用いずに、すなわち、熱歪み導入による磁区細分化処理が施された鉄心素材のみで構成し、巻鉄心中に非処理部を設けなかった（表２中、Ｌの厚さとＭの厚さが共に０％の巻鉄心）。 [Example 1]
Grain-oriented electrical steel sheets with different magnetic flux densities B8 at 800 A/m shown in Table 2 were used as materials, and were subjected to laser irradiation (magnetic domain refining treatment by introducing thermal strain) to obtain iron core materials. Then, a unicore having the core shape shown in FIG. 3 was produced using the above-mentioned core material, and a 50-turn winding coil was attached to both the primary and secondary to produce a three-phase three-legged core transformer. It was excited under the conditions of an excitation magnetic flux density of 1.7 T and a frequency of 50 Hz, and the transformer iron loss and transformer noise were measured by the above-mentioned method. Note that the laser irradiation was applied to the entire width (full width) of the steel plate. In addition, when the core material is assembled into a wound core, a region corresponding to a region where magnetic flux crosses between the outer core and the inner core occurs between the legs (interlayer magnetic flux cross section) is irradiated with a laser. An untreated portion was provided in the area where the magnetic flux crossing occurred so that the magnetic flux was not applied. Furthermore, by changing the number of stacks of core materials having regions that were not irradiated with laser in the thickness direction of the core, a wound core was produced in which the thickness of L and the thickness of M in the non-treated portion were changed. However, for some wound cores, the entire wound core is not subjected to magnetic domain refining treatment by introducing thermal strain without using a core material that has a region that has not been subjected to magnetic domain refining treatment by introducing thermal strain. The wound core was made of only the same core material, and no untreated portion was provided in the wound core (in Table 2, the wound core in which both the thickness of L and the thickness of M were 0%).

変圧器鉄損及び変圧器騒音の測定結果を表２中に示す。本発明の適合例（発明例）では、層間磁束渡り部に非処理部を設けることで、非処理部を有さない変圧器巻鉄心に比べて、変圧器鉄損、変圧器騒音が共に良好であり、優れた変圧器特性を示すことが判明した。 The measurement results of transformer iron loss and transformer noise are shown in Table 2. In an example of adaptation of the present invention (invention example), by providing an untreated portion in the interlayer magnetic flux crossing portion, both transformer iron loss and transformer noise are better than a transformer wound core that does not have an untreated portion. It was found that it exhibited excellent transformer characteristics.

１、１０ 内側鉄心
２、１２ 外側鉄心
３ 層間の磁束渡り
４ 層間磁束渡り部
５ 非処理部
６ 脚
７ 脚間中心位置
８ 隣接部 1, 10 Inner core 2, 12 Outer core 3 Interlayer magnetic flux transfer 4 Interlayer magnetic flux transfer portion 5 Untreated portion 6 Leg 7 Center position between legs 8 Adjacent portion

Claims (5)

方向性電磁鋼板を素材として構成された隣接する２つの内側鉄心と前記２つの内側鉄心を囲む１つの外側鉄心からなる三相三脚巻鉄心であって、
前記三相三脚巻鉄心は、
熱歪み導入による磁区細分化処理が施された方向性電磁鋼板により形成された領域と、熱歪み導入による磁区細分化処理が施されていない方向性電磁鋼板により形成された領域を有し、
巻回方向と垂直な方向からの側面視において、脚と脚の間の、前記外側鉄心と前記内側鉄心間の磁束渡りが生じる領域に、前記熱歪み導入による磁区細分化処理が施されていない方向性電磁鋼板により形成された領域を有する、三相三脚巻鉄心。 A three-phase tripod-wound core consisting of two adjacent inner cores made of grain-oriented electromagnetic steel sheets and one outer core surrounding the two inner cores,
The three-phase tripod wound core is
A region formed by a grain-oriented electrical steel sheet that has been subjected to magnetic domain refining treatment by introducing thermal strain, and a region formed by a grain-oriented electrical steel sheet that has not been subjected to magnetic domain refining treatment by introducing thermal strain,
In a side view from a direction perpendicular to the winding direction, the magnetic domain refining process by introducing thermal strain is not applied to a region between the legs where magnetic flux crosses between the outer core and the inner core. A three-phase tripod-wound core with a region formed by grain-oriented electrical steel sheets. 巻回方向と垂直な方向からの側面視において、前記熱歪み導入による磁区細分化処理が施されていない方向性電磁鋼板により形成された領域が、脚と脚の間、かつ、前記外側鉄心と前記内側鉄心の隣接部から外側方向に前記外側鉄心の厚さの２０～１００％の領域と、前記隣接部から内側方向に前記内側鉄心の厚さの２０～１００％の領域である、請求項１に記載の三相三脚巻鉄心。 In a side view from a direction perpendicular to the winding direction, a region formed by the grain-oriented electrical steel sheet that has not been subjected to magnetic domain refining treatment by introducing thermal strain is between the legs and with the outer core. A region of 20 to 100% of the thickness of the outer core in an outward direction from an adjacent portion of the inner core, and a region of 20 to 100% of the thickness of the inner core in an inward direction from the adjacent portion. The three-phase tripod wound core described in 1. 前記熱歪み導入による磁区細分化処理が、鋼板の板幅の全部または一部に施された、請求項１または２に記載の三相三脚巻鉄心。 The three-phase tripod-wound core according to claim 1 or 2, wherein the magnetic domain refining treatment by introducing thermal strain is applied to all or part of the width of the steel plate. 請求項１または２に記載の三相三脚巻鉄心を用いた三相三脚巻鉄心変圧器。 A three-phase tripod-wound core transformer using the three-phase tripod-wound core according to claim 1 or 2. 請求項３に記載の三相三脚巻鉄心を用いた三相三脚巻鉄心変圧器。 A three-phase three-phase three-legged core transformer using the three-phase three-legged core according to claim 3.

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