JPH0831663A - Transformer winding - Google Patents

Transformer winding

Info

Publication number
JPH0831663A
JPH0831663A JP16770694A JP16770694A JPH0831663A JP H0831663 A JPH0831663 A JP H0831663A JP 16770694 A JP16770694 A JP 16770694A JP 16770694 A JP16770694 A JP 16770694A JP H0831663 A JPH0831663 A JP H0831663A
Authority
JP
Japan
Prior art keywords
winding
flow
cooling medium
width
duct
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP16770694A
Other languages
Japanese (ja)
Other versions
JP3254914B2 (en
Inventor
Takeshi Sakamoto
健 坂元
Kiyoto Hiraishi
清登 平石
Hiroyuki Fujita
裕幸 藤田
Iwao Umene
▲巌▼ 梅根
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hitachi Ltd
Original Assignee
Hitachi Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hitachi Ltd filed Critical Hitachi Ltd
Priority to JP16770694A priority Critical patent/JP3254914B2/en
Publication of JPH0831663A publication Critical patent/JPH0831663A/en
Application granted granted Critical
Publication of JP3254914B2 publication Critical patent/JP3254914B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Landscapes

  • Coils Of Transformers For General Uses (AREA)

Abstract

PURPOSE:Unify the distribution of flow rate of insulating coolant within a horizontal duct, lower the maximum temperature of a winding, and unify the distribution of temperature rise. CONSTITUTION:A plurality of shunt plates are inserted in the direction of the axis of a disc or helical winding 1 with in a flow bending block. A shunt plate 8 the width of which is smaller than that of the winding 1 is inserted in proximity to the center of the flow bending section in the direction of height in such a way that it projects into the vertical duct 6 on the inlet side. Thus the rate of coolant flowing to a horizontal duct below the shunt plate 8 is increased, and that of coolant flowing to a horizontal duct above the shunt plate 8 is decreased. This unifies the distribution of the flow rate of coolant, and reduces the rise of maximum temperature that will take place without the shunt plate. That also prevents the overcooling of the winding in the upper position, and unifies the distribution of temperature of the winding. In addition, pressure loss within the winding is reduced, and the rate of the circulating flow of coolant is increased.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【産業上の利用分野】本発明は変圧器巻線に係り、特
に、円板状巻線、またはヘリカル状巻線からなり、強制
循環冷却のSF6 ガス絶縁変圧器に好適な変圧器巻線に
関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transformer winding, and more particularly, it is a disc winding or a helical winding, and is suitable for a forced circulation cooling SF 6 gas insulated transformer. Regarding

【0002】[0002]

【従来の技術】都市に設置する変圧器には防災上、不燃
化の要望が強く、また、大容量化,小形化の要求も強
い。不燃性の絶縁冷却媒体を用いた変圧器として、SF
6 ガス絶縁変圧器があるが、SF6 ガスは密度,比熱,
熱伝導率などの、冷却性能に関する物性値が液状絶縁冷
却媒体に比べ小さいために冷却性能が悪く、また、絶縁
耐力も小さい。このため、冷却媒体であるSF6 ガスの
体積流量を多く流す一方、変圧器巻線内の絶縁距離、即
ち、垂直ダクトや水平ダクトなどの絶縁冷却媒体を流す
寸法を大きくしている。
2. Description of the Related Art For disaster prevention, there is a strong demand for non-combustible transformers installed in cities, and there is also a strong demand for larger capacity and smaller size. As a transformer using non-flammable insulating cooling medium, SF
There are 6 gas insulation transformers, but SF 6 gas has density, specific heat,
Since the physical properties of the cooling performance such as thermal conductivity are smaller than that of the liquid insulating cooling medium, the cooling performance is poor and the dielectric strength is also small. Therefore, while the volumetric flow rate of the SF 6 gas, which is the cooling medium, is increased, the insulation distance in the transformer winding, that is, the dimension in which the insulating cooling medium such as the vertical duct or the horizontal duct is passed is increased.

【0003】変圧器巻線の構造として、鉄心の周りに素
線を円板状に巻いた円板巻線、あるいはら旋状に巻いた
ヘリカル巻線の場合は、巻線の半径方向の内側、及び外
側に、絶縁筒に沿って垂直スペーサを配置して垂直ダク
トを設け、また、円板状の巻線の軸方向には巻線各段間
に水平スペーサを挿入して水平ダクトを形成すると共
に、折流板を巻線の軸方向に複数枚挿入して折流区を形
成し、折流板の開口部が巻線の半径方向の内外に交互に
設けられ、冷却媒体は軸方向に流れるに従い、巻線内の
半径方向の流れの向きが折流区ごとに交互に変わるよう
になっている。
As the structure of the transformer winding, in the case of a disk winding in which a wire is wound in a disk shape around an iron core or a helical winding in a spiral shape, the inner side in the radial direction of the winding. , And on the outside, vertical spacers are arranged along the insulating cylinder to provide vertical ducts, and in the axial direction of the disk-shaped winding, horizontal spacers are inserted between the winding stages to form horizontal ducts. In addition, a plurality of folding plates are inserted in the axial direction of the winding to form a folding region, the openings of the folding plates are alternately provided inside and outside in the radial direction of the winding, and the cooling medium is in the axial direction. The flow direction in the radial direction in the windings alternates with each other according to the flow.

【0004】このような構造で冷却媒体の体積流量が多
く、また、冷却媒体の流れる水平ダクトの断面積が大き
いと、折流区内の上方の水平ダクトへ冷却媒体が多く流
れ、下方部の水平ダクトには少なく流れる傾向になる。
このため、巻線の温度上昇分布に大きな差が生じ、巻線
の平均温度上昇に比べて巻線の最高温度上昇が高くなる
傾向がある。
With such a structure, when the volumetric flow rate of the cooling medium is large and the horizontal duct in which the cooling medium flows has a large cross-sectional area, a large amount of the cooling medium flows into the upper horizontal duct in the flow break area, and the lower portion The horizontal duct tends to flow less.
Therefore, there is a large difference in the temperature rise distribution of the winding, and the maximum temperature rise of the winding tends to be higher than the average temperature rise of the winding.

【0005】このようなことから、巻線内のガスの流れ
を改善するために、絶縁筒に沿った垂直ダクトの半径方
向の幅を大きくしたり(特開平4−168707号公報参照)、
また、垂直ダクトの他に巻線の半径方向の中央付近に、
軸方向に貫通する垂直ダクト(ガスダクト)を設けた
り、このダクトの半径方向の寸法や位置を巻線の段ごと
に異ならせる方法もある(例えば、特開昭52−43937号
公報,特開昭53−40820号公報,特開昭54−34025号公報
等)。
From the above, in order to improve the gas flow in the winding, the radial width of the vertical duct along the insulating tube is increased (see Japanese Patent Laid-Open No. 4-168707).
In addition to the vertical duct, near the radial center of the winding,
There is also a method of providing a vertical duct (gas duct) penetrating in the axial direction, and varying the radial dimension and position of this duct for each stage of the winding (for example, Japanese Patent Laid-Open Nos. 52-43937 and 52-43937). 53-40820, JP-A-54-34025, etc.).

【0006】[0006]

【発明が解決しようとする課題】しかし、この構造で
は、流れの抵抗の少ない絶縁筒に沿った垂直ダクト内を
ガスが多く流れ、巻線の半径方向の中央付近の垂直ダク
トや、水平ダクト内を流れるガスの流量は相対的に少な
くなり、巻線温度上昇低減の効果は小さい。また、垂直
ダクトの半径方向の幅を大きくしたり、前記ガスダクト
を設けると、巻線の半径方向の寸法が増大し、全体とし
て変圧器の体積が大きくなる。また、ガスダクトの半径
方向の位置を巻線の段ごとに異ならせると、冷却媒体の
流れに分岐合流箇所が多くなり、冷却媒体の圧力損失が
増大し、冷却媒体の流量が少なくなるか、ヘッドの大き
いブロワが必要となる。
However, in this structure, a large amount of gas flows in the vertical duct along the insulating cylinder having a low flow resistance, and the vertical duct or the horizontal duct near the radial center of the winding. The flow rate of the gas flowing through the coil is relatively small, and the effect of reducing the temperature rise of the winding is small. Further, when the radial width of the vertical duct is increased or the gas duct is provided, the dimension of the winding in the radial direction increases, and the volume of the transformer increases as a whole. Also, if the radial position of the gas duct is made different for each stage of the winding, the number of branching and joining points in the flow of the cooling medium increases, the pressure loss of the cooling medium increases, the flow rate of the cooling medium decreases, or A large blower is required.

【0007】特に、都市部に設置する変圧器には小型化
が強く要求されるため、巻線の小型化が必要となる。
In particular, since transformers installed in urban areas are strongly required to be downsized, it is necessary to downsize windings.

【0008】本発明は上述の点に鑑みなされたもので、
その目的とするところは、水平ダクト内を流れる冷却媒
体流量分布を均一化して局部加熱を防止し、温度上昇分
布を均一化すると共に、巻線全体を小形化し、温度上昇
を低減することのできる変圧器巻線を提供するにある。
The present invention has been made in view of the above points,
The purpose is to make the cooling medium flow rate distribution in the horizontal duct uniform to prevent local heating, to make the temperature rise distribution uniform, and also to make the entire winding compact and reduce the temperature rise. To provide transformer windings.

【0009】[0009]

【課題を解決するための手段】本発明は、軸方向に複数
枚の折流板を挿入し複数の折流区に区分した円板巻線、
あるいはヘリカル巻線において、各折流区の高さ方向中
央付近の巻線間に、折流区に冷却媒体が入る側の垂直ダ
クトにはみ出さすと共に、半径方向の幅を巻線の半径方
向の幅より狭くした絶縁性の材料で成形された分流板
を、水平ダクトの上下に流路を構成するように水平スペ
ーサに挟み、冷却媒体のある割合の流量を分流板により
その下方の水平ダクト内に強制的に分流させるようにす
ることを特徴とする。また、前記分流板は、巻線内で固
定しやすいように、巻線の内側の垂直ダクトにはみ出さ
せるものについては、巻線内側の絶縁筒に付けられた垂
直スペーサを囲うような切欠きを設ける。内外いずれの
垂直ダクトにはみ出す分流板もそれを挟む水平スペーサ
に接着させても良い。また、分流板を乗せる水平スペー
サには分流板の幅に相当する部分は厚さを薄くし、残り
の部分は分流板と同じ高さの支持板を貼り付ける。ま
た、分流板の周方向長さは、複数枚の水平スペーサに相
当する長さとするが、その両端は水平スペーサの中央ま
でとし、水平スペーサの中央で隣りあう周方向の分流板
と突き合わせる。分流板の、垂直ダクト内での突き出す
幅は、垂直ダクト幅の少なくとも半分以上とする。
DISCLOSURE OF THE INVENTION According to the present invention, a disc winding in which a plurality of bent plates are inserted in the axial direction and divided into a plurality of bent regions,
Alternatively, in the helical winding, between the windings near the center in the height direction of each of the winding areas, the windings protrude into the vertical duct on the side where the cooling medium enters the winding area, and the radial width of the winding A flow dividing plate made of an insulating material that is narrower than the width is sandwiched by horizontal spacers so as to form a flow path above and below the horizontal duct, and a certain proportion of the cooling medium is flowed inside the horizontal duct below the flow dividing plate. It is characterized by forcibly diversion. In addition, for the flow dividing plate that extends in the vertical duct inside the winding so as to be easily fixed in the winding, a cutout that surrounds the vertical spacer attached to the insulating cylinder inside the winding is provided. Set up. The flow dividing plates protruding into either the inner or outer vertical ducts may be bonded to the horizontal spacers sandwiching them. Further, on the horizontal spacer on which the flow dividing plate is placed, the portion corresponding to the width of the flow dividing plate is made thin, and the remaining portion is attached with a support plate having the same height as the flow dividing plate. Further, the length in the circumferential direction of the flow dividing plate is set to a length corresponding to a plurality of horizontal spacers, but both ends thereof are set to the center of the horizontal spacer, and they are abutted with the circumferential flow dividing plates adjacent to each other in the center of the horizontal spacer. The projecting width of the flow distributor in the vertical duct shall be at least half the vertical duct width.

【0010】[0010]

【作用】上記構成とすることにより、巻線の各折流区内
の各水平ダクトへの冷却媒体の流量分布は、前記分流板
の無い場合は折流区の上方の水平ダクトへ多く流れ、下
方の水平ダクトへは少なく流れ下方の巻線の温度上昇が
大きくなるが、折流区の高さ方向中央付近に入り口側垂
直ダクトにはみ出して分流板を設けることにより、冷却
媒体の流れの相当部分が、前記分流板に堰き止められ、
分流板の無い場合に比較し分流板の下方の水平ダクトへ
流れる冷却媒体の流量が多くなり、分流板より下方の巻
線の温度上昇は十分小さくなる。
With the above structure, the flow rate distribution of the cooling medium to the horizontal ducts in each of the winding sections of the winding is large in the horizontal duct above the folding section when the flow dividing plate is not provided, Although there is little flow to the lower horizontal duct and the temperature rise in the lower winding increases, the flow distribution of the cooling medium can be reduced by installing a flow divider plate in the vertical duct near the center in the height direction of the flow break area. A part is blocked by the distribution plate,
Compared with the case without the flow dividing plate, the flow rate of the cooling medium flowing to the horizontal duct below the flow dividing plate increases, and the temperature rise of the winding below the flow dividing plate becomes sufficiently small.

【0011】特に、従来の折流区内で最高の温度上昇を
示す折流区下方部の巻線の温度上昇の値は大きく低減で
き、絶縁物の信頼性向上や寿命の延長を図ることができ
る。また、分流板より上方の巻線内水平ダクトへの冷却
媒体の流量は少なくなり、巻線が冷却され過ぎるという
ことが無くなり、冷却媒体の流量を効果的に巻線冷却に
利用させることができる。
In particular, the value of the temperature rise of the winding in the lower part of the current-flowing zone, which shows the highest temperature rise in the conventional current-flowing zone, can be greatly reduced, and the reliability of the insulator can be improved and the life can be extended. it can. Further, the flow rate of the cooling medium to the horizontal duct in the winding above the flow dividing plate is reduced, the winding is not overcooled, and the flow rate of the cooling medium can be effectively used for cooling the winding. .

【0012】さらに、一般に折流板の上方近辺の水平ダ
クトへ流れる冷却媒体の流量は少なく、折流板の下方近
辺の水平ダクトへ流れる冷却媒体の流量は多いが、同様
のことが分流板を挿入した場合でも発生する。しかし、
分流板の半径方向の幅が巻線の半径方向の幅に比べて短
くしてあるので、分流板を通過した後方ではその上下の
流れは合流し、分流板の直上の巻線は適度に冷却され、
大きな温度上昇を示さない。また、分流板によりその上
方へ流れる流量が、分流板の無い場合に比較し大きく減
少するため、冷却媒体の圧力損失は、分流板による抵抗
増加分以上に減少し、折流区当りの流動抵抗は減少す
る。
Further, generally, the flow rate of the cooling medium flowing to the horizontal duct near the upper part of the flow distribution plate is small, and the flow rate of the cooling medium flowing to the horizontal duct near the lower part of the flow distribution plate is large. It occurs even when inserted. But,
Since the radial width of the flow dividing plate is shorter than the radial width of the winding, the flow above and below the flow dividing plate merges behind the flow dividing plate, and the winding immediately above the flow dividing plate is cooled appropriately. Is
No significant temperature rise. Also, since the flow rate above the diversion plate is greatly reduced compared to the case without the diversion plate, the pressure loss of the cooling medium is reduced by more than the resistance increase due to the diversion plate, and the flow resistance per flow section is reduced. Decreases.

【0013】このため、冷却媒体を循環させる同じブロ
ワの循環能力に対して冷却媒体の流量は増加し、巻線の
冷却性能は向上する。
Therefore, the flow rate of the cooling medium is increased with respect to the circulation capacity of the same blower for circulating the cooling medium, and the cooling performance of the winding is improved.

【0014】一方、分流板を巻線内に設定する際、水平
スペーサには垂直スペーサを囲う切欠きがあり、また、
支持板が貼り付けてあるので位置決めは容易である。
On the other hand, when setting the flow dividing plate in the winding, the horizontal spacer has a notch surrounding the vertical spacer, and
Positioning is easy because the support plate is attached.

【0015】[0015]

【実施例】本発明の変圧器巻線の一実施例を図1、及び
図2により説明する。図1は、本発明による巻線部分断
面概略図、図2は本発明による巻線部分斜視図である。
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the transformer winding of the present invention will be described with reference to FIGS. FIG. 1 is a schematic sectional view of a winding part according to the present invention, and FIG. 2 is a perspective view of a winding part according to the present invention.

【0016】図1において、1は巻線、2は絶縁筒、3
は単位巻線で絶縁筒2内に円板状に巻かれている。4は
折流板で、巻線1の軸方向に複数個配置され、折流区を
形成する。この折流板4は半径方向に交互に折流区入口
5を有し、冷却媒体は、この入り口より当該折流区に入
る。ある折流区において巻線の内外両側には入口側垂直
ダクト6,出口側垂直ダクト7があり、また、折流区の
高さ方向中央付近の単位巻線間には、入口側垂直ダクト
6にはみだして分流板8がある。分流板8の半径方向幅
は巻線1の幅より狭く製作される。9は水平ダクトで、
分流板8のある部分では、分流板8の上下に狭い水平ダ
クト9′が形成される。この構成を部分拡大して斜視し
た図2により説明する。
In FIG. 1, 1 is a winding wire, 2 is an insulating cylinder, and 3
Is a unit winding and is wound in a disk shape inside the insulating cylinder 2. Reference numeral 4 denotes a flow fold plate, which is arranged in the axial direction of the winding 1 to form a flow fold section. The fold plate 4 has fold flow zone inlets 5 alternately in the radial direction, and the cooling medium enters the fold flow zone through the inlets. An inlet-side vertical duct 6 and an outlet-side vertical duct 7 are provided on both inner and outer sides of a winding in a certain fold-flow section, and an inlet-side vertical duct 6 is provided between unit windings near the center in the height direction of the fold-flow section. There is a flow dividing plate 8 that protrudes out. The width of the flow distribution plate 8 in the radial direction is made narrower than the width of the winding 1. 9 is a horizontal duct,
A narrow horizontal duct 9 ′ is formed above and below the flow dividing plate 8 at a portion of the flow dividing plate 8. This configuration will be described with reference to FIG. 2, which is a partially enlarged perspective view.

【0017】図2において、内外両側の絶縁筒2の間に
単位巻線3が円板状に巻かれている。単位巻線3が軸方
向に水平スペーサ10を介して積層され、水平ダクト9
を形成する。入り口側垂直ダクト6は、この図の場合巻
線1の内側にあるが、垂直スペーサ11により形成さ
れ、出口(外側)側垂直ダクト7は水平スペーサ10
か、または図示していないが外側絶縁筒に付けられた垂
直スペーサにより形成される。分流板8は水平スペーサ
10の厚さ方向の中央に位置させ、その上下に狭い水平
ダクト9′を作る。
In FIG. 2, a unit winding 3 is wound in a disk shape between the insulating cylinders 2 on the inner and outer sides. The unit windings 3 are stacked in the axial direction with a horizontal spacer 10 interposed therebetween, and the horizontal duct 9
To form. The inlet side vertical duct 6, which is inside the winding 1 in this case, is formed by a vertical spacer 11 and the outlet (outer) side vertical duct 7 is a horizontal spacer 10.
Alternatively, although not shown, it is formed by vertical spacers attached to the outer insulating cylinder. The flow dividing plate 8 is located at the center of the horizontal spacer 10 in the thickness direction, and narrow horizontal ducts 9'are formed above and below the flow dividing plate 8.

【0018】このような構成の巻線において、冷却媒体
は折流区入口5から当該折流区に入り、入口側垂直ダク
ト6を上昇し、分岐して各水平ダクト9を通過し、出口
側垂直ダクト7へ入り上下の単位巻線3を冷却する。こ
こで分流板の無い場合には冷却媒体の各水平ダクトへの
流量分布は、折流区の下方で少なく、上方で多く流れ
る。
In the winding having such a structure, the cooling medium enters the flow diverting zone from the flow diverting zone inlet 5, rises in the vertical duct 6 on the inlet side, branches to pass through each horizontal duct 9, and exits on the outlet side. It enters the vertical duct 7 and cools the upper and lower unit windings 3. Here, when there is no flow dividing plate, the distribution of the flow rate of the cooling medium to each horizontal duct is small in the lower part of the flow diverting section and large in the upper part.

【0019】しかし、本発明では分流板8が入口側垂直
ダクト6にはみだして存在するので、冷却媒体の相当の
部分は、分流板8によりそれより下方の水平ダクトへ流
れるように分流され、分流板の無い場合に比較し、折流
区下方の巻線を多量の冷却媒体で冷却し、巻線の温度上
昇は低くなる。特に、折流区下部の巻線の温度上昇が、
分流板の無い場合に比較し大幅に低減できる。
However, in the present invention, since the flow dividing plate 8 exists in the vertical duct 6 on the inlet side, a considerable portion of the cooling medium is divided by the flow dividing plate 8 so as to flow to the horizontal duct below the flow dividing plate 8, and the flow is divided. Compared to the case without the plate, the winding below the flow-segment is cooled with a large amount of cooling medium, and the temperature rise of the winding is reduced. In particular, the temperature rise of the windings at the bottom of the flow
Significant reduction compared to the case without a flow distributor.

【0020】一方、分流板の上方の水平ダクトへは、分
流板の無い場合に比較し冷却媒体の流量は減少するが、
分流板の無い場合、多量の冷却媒体が流れ必要以上に巻
線を冷却していたのでその欠点が解除され、より均等に
巻線は冷却されることになる。
On the other hand, the flow rate of the cooling medium to the horizontal duct above the flow dividing plate is smaller than that in the case without the flow dividing plate.
In the absence of the flow dividing plate, a large amount of cooling medium flows and the winding is cooled more than necessary, so that the drawback is eliminated and the winding is cooled more uniformly.

【0021】このことを試験データにより示す。図3
は、巻線冷却特性試験装置概略系統図で、巻線モデル2
1を収納した巻線モデル容器22,冷却器23,ブロワ
24,流量計25,流量調整バルブ26を配管27,配
管27′により冷却媒体が循環するように構成されてい
る。流量調整バルブ26は冷却媒体の循環流量を自由に
変化できるように挿入してある。また、冷却媒体の運転
条件を測定するための圧力計28,温度計29が流量計
25の上流側に取り付けられており、また、この系統内
の媒体を冷却媒体であるSF6 ガスに入れ替えるために
真空抜き用配管30,ガス充填用配管31が配管27′
に取り付けられている。また、冷却器には冷却水入り口
32と冷却水出口33が取り付けられており、冷却媒体
を冷却水で冷却する。
This is shown by test data. FIG.
Is a schematic system diagram of the winding cooling characteristic test device.
The winding model container 22 in which 1 is housed, the cooler 23, the blower 24, the flow meter 25, and the flow rate adjusting valve 26 are configured to circulate the cooling medium through the pipes 27 and 27 '. The flow rate adjusting valve 26 is inserted so that the circulating flow rate of the cooling medium can be freely changed. Further, a pressure gauge 28 and a thermometer 29 for measuring the operating conditions of the cooling medium are attached to the upstream side of the flowmeter 25, and in order to replace the medium in this system with SF 6 gas which is the cooling medium. A vacuum vent pipe 30 and a gas filling pipe 31 are attached to the pipe 27 '.
Attached to. A cooling water inlet 32 and a cooling water outlet 33 are attached to the cooler to cool the cooling medium with the cooling water.

【0022】巻線モデル21は、幅6mm,高さ15mmの
銅線内にヒータと熱電対を埋込み、絶縁フィルムを巻い
て模擬導体とし、これを複数本並べて模擬単位巻線と
し、一対の折流板4′からなる折流区あたり10段の模
擬単位巻線を高さ方向に水平スペーサを介して重ねて形
成されている。測定対象の折流区入り口には冷却媒体用
の温度計34を挿入してある。図示してないが模擬垂直
スペーサ間の流路幅は80mmである。
In the winding model 21, a heater and a thermocouple are embedded in a copper wire having a width of 6 mm and a height of 15 mm, and an insulating film is wound to form a simulated conductor. The simulated unit windings of 10 stages are formed by stacking the flow plate 4'in the height direction with a horizontal spacer interposed therebetween. A thermometer 34 for a cooling medium is inserted at the inlet of the measured flow section. Although not shown, the flow path width between the simulated vertical spacers is 80 mm.

【0023】巻線モデル21内に分流板8′を挿入しな
い場合と挿入した場合の冷却特性試験を行った。試験方
法は模擬導体に埋め込まれたヒータに所定の電流を流し
て発熱させ、冷却媒体であるSF6 ガスを、ブロワ24
により循環させ、流量調整バルブ26により種々の流量
に設定して模擬導体の温度を測定した。
A cooling characteristic test was carried out with and without the distribution plate 8'in the winding model 21. In the test method, a heater embedded in the simulated conductor is caused to flow a predetermined current to generate heat, and SF 6 gas, which is a cooling medium, is passed through the blower 24.
Was circulated, and the flow rate adjusting valve 26 was set to various flow rates to measure the temperature of the simulated conductor.

【0024】図4は試験結果の一例を示す温度上昇特性
図で、試験条件は、冷却媒体圧力0.2MPa,流量3
55l/分,巻線表面の熱流束870W/m2、また、
巻線モデルの寸法は、流路長(実変圧器では半径方向の
幅に相当)は80mm,水平ダクト高さ4mm,垂直ダクト
幅20mmである。図4の横軸は折流区入り口ガス温度か
らの各模擬単位巻線の平均温度上昇で、縦軸は巻線モデ
ルの下部折流板からの模擬単位巻線の高さ方向の番号で
ある。図4において白抜き円で示したのは分流板の無い
場合、黒円は分流板を挿入した場合の結果である。分流
板の垂直ダクトにはみ出した寸法は15mm、模擬巻線内
の分流板長さは40mmである。
FIG. 4 is a temperature rise characteristic diagram showing an example of the test results. The test conditions are: cooling medium pressure 0.2 MPa, flow rate 3
55 l / min, heat flux on winding surface 870 W / m 2 ,
Regarding the dimensions of the winding model, the flow path length (corresponding to the radial width in an actual transformer) is 80 mm, the horizontal duct height is 4 mm, and the vertical duct width is 20 mm. The horizontal axis of FIG. 4 is the average temperature rise of each simulated unit winding from the inlet gas temperature of the folded section, and the vertical axis is the number in the height direction of the simulated unit winding from the lower folded plate of the winding model. . The white circles in FIG. 4 show the results when there is no flow dividing plate, and the black circles show the results when the flow dividing plate is inserted. The size of the flow dividing plate protruding into the vertical duct is 15 mm, and the length of the flow dividing plate in the simulated winding is 40 mm.

【0025】図4から明らかなように、分流板の無い場
合に比べて分流板を挿入した場合には、模擬巻線モデル
の最高温度上昇が低下しており、また、全体の平均温度
上昇も10.1℃から9.8℃に下がっており、分流板を
挿入した効果が、特に最高温度上昇に関して顕著である
ことが分かる。また、ガスの圧力を変えたり垂直ダクト
の幅を変えた試験の結果、流量調整バルブを全開にした
場合のガスの循環流量は、分流板の無い場合に対して1
〜7%増加しており、巻線内の圧力損失が小さくなる効
果が有る。圧力損失が低下する理由は、水平ダクトへの
流量配分が均等化され、特にガス流量が多く流れる部所
が無くなるためである。
As is apparent from FIG. 4, the maximum temperature rise of the simulated winding model is lower when the diversion plate is inserted than when there is no diversion plate, and the average temperature rise of the whole is also decreased. The temperature drops from 10.1 ° C to 9.8 ° C, and it can be seen that the effect of inserting the flow dividing plate is remarkable especially with respect to the maximum temperature rise. In addition, as a result of tests in which the gas pressure was changed and the width of the vertical duct was changed, the gas circulation flow rate when the flow rate adjustment valve was fully opened was 1 compared with the case without a flow distributor.
The increase is up to 7%, which has the effect of reducing the pressure loss in the winding. The reason why the pressure loss decreases is that the flow rate distribution to the horizontal ducts is made uniform, and in particular, there is no part where the gas flow rate is large.

【0026】図5は本発明による内側垂直ダクト側には
み出す分流板の設置状況を示す一実施例の平面図であ
る。図5において、1は巻線、2は絶縁筒、6′は内側
垂直ダクト、11は絶縁筒に取り付けられた垂直スペー
サ、8が分流板、10は水平ダクトを形成させる水平ス
ペーサである。分流板8には垂直スペーサを囲うように
切欠き12が周方向に複数設けられており、周方向の位
置決めが容易になる効果が有るとともに組立て工数も低
減できる。また、分流板の周方向端部には、隣りあう分
流板の端部と突きあって垂直スペーサを囲うように半分
の幅の切欠き12′が設けられる。分流板の半径方向の幅
は巻線1の幅より狭く、分流板の上下を通過した冷却媒
体は、その後流で合流し、上下の巻線を冷却することが
できる。
FIG. 5 is a plan view of an embodiment showing the installation state of the flow dividing plate protruding to the inner vertical duct side according to the present invention. In FIG. 5, 1 is a winding wire, 2 is an insulating cylinder, 6'is an inner vertical duct, 11 is a vertical spacer attached to the insulating cylinder, 8 is a flow dividing plate, and 10 is a horizontal spacer forming a horizontal duct. The flow dividing plate 8 is provided with a plurality of notches 12 in the circumferential direction so as to surround the vertical spacers, which has the effect of facilitating the positioning in the circumferential direction and can reduce the number of assembling steps. Further, a notch 12 'having a half width is provided at an end portion in the circumferential direction of the flow dividing plate so as to butt with an end portion of an adjacent flow dividing plate and surround the vertical spacer. The radial width of the flow dividing plate is narrower than the width of the winding 1, and the cooling medium passing above and below the flow dividing plate merges in the subsequent flow to cool the upper and lower windings.

【0027】図6は本発明による一実施例の外側垂直ダ
クト側にはみ出す分流板の形状を示す平面図である。図
6において、1は巻線、2は絶縁筒、7′は外側垂直ダ
クト、8は分流板で、分流板8の外側には絶縁筒に届く
ように支持部13,13′が周方向に複数設けられてい
る。支持部13,13′があるため、半径方向の外側へ
のずれを防止する効果が有る。
FIG. 6 is a plan view showing the shape of the flow dividing plate protruding to the outer vertical duct side according to one embodiment of the present invention. In FIG. 6, 1 is a winding wire, 2 is an insulating cylinder, 7'is an outer vertical duct, 8 is a flow dividing plate, and support portions 13, 13 'are arranged in the circumferential direction on the outside of the flow dividing plate 8 so as to reach the insulating cylinder. There are multiple. Since the support portions 13 and 13 'are provided, there is an effect of preventing the outward shift in the radial direction.

【0028】図7は本発明による一実施例の内側垂直ダ
クトにはみ出す分流板を乗せる水平スペーサを示す部分
斜視図である。水平スペーサ10は下側水平スペーサ1
0′の上に半径方向外側に支持板14を貼り付けてあ
る。支持板14により分流板の半径方向外側へのずれを
防止でき分流板の位置決めが容易となる。なお、分流板
の上下に狭い水平ダクトを形成するため、分流板及び支
持板14の上に下側スペーサ10′と同じ形状の上側ス
ペーサを重ねて分流板を挟むようにする。
FIG. 7 is a partial perspective view showing a horizontal spacer on which a flow dividing plate protruding into an inner vertical duct according to an embodiment of the present invention is placed. The horizontal spacer 10 is the lower horizontal spacer 1.
A support plate 14 is attached on the outer side of 0'in the radial direction. The support plate 14 can prevent the flow diverting plate from being displaced outward in the radial direction, which facilitates the positioning of the flow diverting plate. In order to form narrow horizontal ducts above and below the flow dividing plate, an upper spacer having the same shape as the lower spacer 10 'is placed on the flow dividing plate and the support plate 14 to sandwich the flow dividing plate.

【0029】図8は本発明による一実施例の外側垂直ダ
クトにはみ出す分流板を乗せる水平スペーサを示す部分
斜視図である。水平スペーサ10は下側スペーサ10′
の上に半径方向内側に支持板14′を貼り付けてある。
支持板14′により分流板の半径方向内側へのずれを防
止でき分流板の位置決めが容易となる。
FIG. 8 is a partial perspective view showing a horizontal spacer on which a flow dividing plate protruding to an outer vertical duct according to an embodiment of the present invention is placed. The horizontal spacer 10 is the lower spacer 10 '.
A support plate 14 'is attached on the inside in the radial direction.
The support plate 14 'can prevent the flow diverter from being displaced inward in the radial direction, and the flow diverter can be easily positioned.

【0030】図9は本発明による他の実施例の内側垂直
ダクトにはみ出す分流板の形状を示す平面図である。図
9において、分流板8には外側に伸びた支持部13を設
け、外側端部が外側絶縁筒に接するように長くする。切
欠き12は内側絶縁筒に付いた垂直スペーサを囲うよう
にする。この分流板を図7に示した下側水平スペーサ1
0′の上に乗せると、分流板の位置決めは容易になる。
FIG. 9 is a plan view showing the shape of the flow dividing plate protruding into the inner vertical duct according to another embodiment of the present invention. In FIG. 9, the flow dividing plate 8 is provided with a support portion 13 extending to the outside, and is lengthened so that the outer end portion contacts the outer insulating cylinder. The notch 12 surrounds the vertical spacer attached to the inner insulating cylinder. This flow dividing plate is shown in FIG.
When placed on 0 ', the diversion plate can be easily positioned.

【0031】図10は本発明による他の実施例の外側垂
直ダクトにはみ出す分流板の形状を示す平面図である。
図10において、分流板8には切欠き12を有する内側
に伸びた支持部13″を設け、切欠き12が内側絶縁筒
に付いた垂直スペーサを囲うようにする。図9に示した
場合と同様に、本実施例でも分流板の位置決めは容易に
なる。
FIG. 10 is a plan view showing the shape of the flow dividing plate protruding to the outer vertical duct according to another embodiment of the present invention.
In FIG. 10, the flow dividing plate 8 is provided with an inwardly extending support portion 13 ″ having a notch 12 so that the notch 12 surrounds the vertical spacer attached to the inner insulating tube. As shown in FIG. Similarly, also in this embodiment, positioning of the flow dividing plate becomes easy.

【0032】図11は本発明による他の実施例の巻線部
分断面概略図である。本実施例では、図1に示した場合
の一折流区内の分流板の数を複数枚にした場合で、この
場合も図1と同様に折流区下方部の巻線温度上昇を低減
できるとともに、更に巻線温度上昇分布を均一化できる
効果が有る。
FIG. 11 is a schematic partial sectional view of a winding wire of another embodiment according to the present invention. In the present embodiment, the number of the flow dividing plates in one bent-flow section in the case shown in FIG. 1 is plural, and in this case as well, the winding temperature rise in the lower part of the bent-flow section is reduced as in FIG. In addition to being able to do so, there is an effect that the winding temperature rise distribution can be made uniform.

【0033】[0033]

【発明の効果】以上説明した本発明の変圧器巻線によれ
ば、折流区の高さ方向中央付近に設けられた分流板によ
り、その下方の水平ダクトへの冷却媒体流量が増加し、
分流板の無い場合に比較し折流区下方の巻線の温度上昇
は低減され、特に巻線の最高温度上昇が小さくなる。ま
た、巻線全体の平均温度上昇も低下するし、分流板を挿
入することにより、流量分布が均一化され折流区内の圧
力損失が小さくなり、冷却媒体の循環流量が増加し、巻
線の温度上昇はさらに低下できる効果が有る。
According to the transformer winding of the present invention described above, the flow distribution plate provided in the vicinity of the center in the height direction of the flow diverting section increases the flow rate of the cooling medium to the horizontal duct thereunder,
Compared to the case without the flow distribution plate, the temperature rise of the winding below the flow diverter is reduced, and especially the maximum temperature rise of the winding is reduced. In addition, the average temperature rise of the entire winding decreases, and the flow distribution plate is inserted to make the flow distribution uniform and reduce the pressure loss in the flow divergence area. There is an effect that the temperature rise of can be further decreased.

【0034】また、分流板の周方向の長さを複数の水平
スペーサ分とすることにより、巻線への組込みが容易と
なる。さらに、狭い幅の垂直ダクトの場合でも折流区内
の各水平ダクトへの流量分布を均一化でき、巻線全体の
体積を小形化でき、従って変圧器の大きさを小さくでき
る。
Further, by making the length of the flow distribution plate in the circumferential direction a plurality of horizontal spacers, it becomes easy to assemble it into the winding. Further, even in the case of a vertical duct having a narrow width, the flow distribution to each horizontal duct in the flow divergence section can be made uniform, and the volume of the entire winding can be made small, so that the size of the transformer can be made small.

【図面の簡単な説明】[Brief description of drawings]

【図1】本発明の変圧器巻線の一実施例を示す部分断面
図である。
FIG. 1 is a partial sectional view showing an embodiment of a transformer winding of the present invention.

【図2】本発明の変圧器巻線の一実施例を示す部分斜視
図である。
FIG. 2 is a partial perspective view showing an embodiment of the transformer winding of the present invention.

【図3】本発明の効果を確認するための巻線冷却特性試
験装置概略系統図である。
FIG. 3 is a schematic system diagram of a winding cooling characteristic test device for confirming the effect of the present invention.

【図4】本発明による試験結果の一例を示す温度上昇特
性図である。
FIG. 4 is a temperature rise characteristic diagram showing an example of a test result according to the present invention.

【図5】本発明による内側垂直ダクトにはみ出す分流板
の設置状況を示す平面図である。
FIG. 5 is a plan view showing an installation state of a flow dividing plate protruding to an inner vertical duct according to the present invention.

【図6】本発明による外側垂直ダクトにはみ出す分流板
の形状を示す平面図である。
FIG. 6 is a plan view showing the shape of the flow distribution plate protruding to the outer vertical duct according to the present invention.

【図7】本発明による内側垂直ダクトにはみ出す分流板
を乗せる水平スペーサの斜視図である。
FIG. 7 is a perspective view of a horizontal spacer on which a flow dividing plate protruding into an inner vertical duct according to the present invention is placed.

【図8】本発明による外側垂直ダクトにはみ出す分流板
を乗せる水平スペーサの斜視図である。
FIG. 8 is a perspective view of a horizontal spacer on which a flow dividing plate protruding to an outer vertical duct according to the present invention is placed.

【図9】本発明による他の実施例の内側垂直ダクトには
み出す分流板形状の平面図である。
FIG. 9 is a plan view of a flow diverter plate shape protruding into an inner vertical duct according to another embodiment of the present invention.

【図10】本発明による他の実施例の外側垂直ダクトに
はみ出す分流板形状の平面図である。
FIG. 10 is a plan view of a flow diverting plate shape protruding to an outer vertical duct according to another embodiment of the present invention.

【図11】本発明による他の実施例の巻線部分断面概略
図である。
FIG. 11 is a schematic partial sectional view of windings of another embodiment according to the present invention.

【符号の説明】[Explanation of symbols]

1…巻線、2…絶縁筒、3…単位巻線、4…折流板、5
…折流区入口、6…入口側垂直ダクト、7…出口側垂直
ダクト、8…分流板、9…水平ダクト、9′…狭い水平
ダクト、10…水平スペーサ、11…垂直スペーサ。
1 ... Winding, 2 ... Insulation cylinder, 3 ... Unit winding, 4 ... Folding plate, 5
... Bending section entrance, 6 ... Inlet side vertical duct, 7 ... Outlet side vertical duct, 8 ... Diversion plate, 9 ... Horizontal duct, 9 '... Narrow horizontal duct, 10 ... Horizontal spacer, 11 ... Vertical spacer.

───────────────────────────────────────────────────── フロントページの続き (72)発明者 梅根 ▲巌▼ 茨城県日立市国分町一丁目1番1号 株式 会社日立製作所国分工場内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Umene ▲ Gan ▼ 1-1-1, Kokubuncho, Hitachi City, Ibaraki Prefecture Hitachi Co., Ltd. Kokubun Plant

Claims (5)

【特許請求の範囲】[Claims] 【請求項1】鉄心脚の周りに、絶縁筒を隔壁として円板
状巻線あるいはヘリカル状巻線を水平スペーサにより一
定の間隔を置いて軸方向に積層し、前記巻線と内外両側
の絶縁筒の間に、軸方向の垂直スペーサを挿入して垂直
ダクトを設けると共に、巻線全体の軸方向に、複数枚の
折流板を内外交互に開口部を設けて挿入し複数の折流区
を形成し、絶縁冷却媒体を軸方向にジグザグ状に流すよ
うにした変圧器巻線において、 前記各折流区高さ方向の中央付近の巻線間に、絶縁冷却
媒体の入り口側垂直ダクトに巻線端からはみ出させると
共に、半径方向の幅を前記巻線の半径方向の幅より狭く
した分流板を挿入したことを特徴とする変圧器巻線。
1. A disk-shaped winding or a helical winding having an insulating cylinder as a partition wall around the iron core leg is axially laminated at regular intervals by horizontal spacers to insulate the winding from the inner and outer sides. A vertical duct is inserted between the cylinders by inserting a vertical spacer, and a plurality of folding plates are inserted in the axial direction of the entire winding by alternately opening the inside and outside to insert a plurality of folding regions. In a transformer winding that forms an insulating cooling medium in a zigzag manner in the axial direction, between the windings in the vicinity of the center in the height direction of each of the fold zones, the inlet side vertical duct of the insulating cooling medium is formed. A transformer winding, characterized in that a diversion plate having a width in a radial direction narrower than a width in a radial direction of the winding is inserted while protruding from a winding end.
【請求項2】前記請求項1の変圧器巻線において、各折
流区高さ方向の中央付近の巻線間の一水平ダクト内の冷
却媒体の上流側で上下に冷却媒体の流路を有し、後流側
で前記冷却媒体を合流させるようにすると共に、折流区
内に二重の折流区を形成するように入り口側垂直ダクト
に巻線端からはみ出させた絶縁性の分流板を設け、冷却
媒体の流れを前記二重の折流区で同方向に流すようにし
たことを特徴とする変圧器巻線。
2. The transformer winding according to claim 1, wherein a cooling medium flow path is vertically provided on the upstream side of the cooling medium in one horizontal duct between the windings in the vicinity of the center in the height direction of each of the folded regions. In addition, the cooling medium is merged on the downstream side, and an insulating shunt is made to extend from the winding end to the inlet side vertical duct so as to form a double folded area inside the folded area. A transformer winding, characterized in that a plate is provided so that the flow of the cooling medium is made to flow in the same direction in the double bent region.
【請求項3】前記請求項1の変圧器巻線において、絶縁
冷却媒体の入り口側垂直ダクトに巻線端からはみ出させ
ると共に、半径方向の幅を巻線の半径方向の幅より狭く
した絶縁性の分流板を、一折流区内に高さ方向の位置を
変えて複数個挿入したことを特徴とする変圧器巻線。
3. The transformer winding according to claim 1, wherein the insulating cooling medium is made to protrude from the winding end into a vertical duct on the inlet side, and the radial width is made narrower than the radial width of the winding. A transformer winding, characterized in that a plurality of the current distribution plates of (1) are inserted in one bent region at different positions in the height direction.
【請求項4】前記請求項1の変圧器巻線において、前記
各折流区高さ方向の中央付近の巻線間に、絶縁冷却媒体
の入り口側垂直ダクトに巻線端からはみ出させると共
に、半径方向の幅を巻線の半径方向の幅より狭くし、内
径側垂直ダクトを構成させる垂直スペーサを囲うように
切り欠きを入れた絶縁性の分流板を挿入したことを特徴
とする変圧器巻線。
4. The transformer winding according to claim 1, wherein between the windings in the vicinity of the center in the height direction of each of the flow folds, a vertical duct on the inlet side of the insulating cooling medium protrudes from the winding end. A transformer winding characterized in that the width in the radial direction is made narrower than the width in the radial direction of the winding, and an insulating shunt plate is inserted so as to surround the vertical spacer forming the inner diameter side vertical duct. line.
【請求項5】前記請求項1の変圧器巻線において、前記
各折流区高さ方向の中央付近の巻線間に、絶縁冷却媒体
の入り口側垂直ダクトに巻線端からはみ出させると共
に、半径方向の幅を巻線の半径方向の幅より狭くし、そ
の周方向長さを複数の水平スペーサ分とした絶縁性の分
流板を、水平スペーサに張り合わせた状態で挿入したこ
とを特徴とする変圧器巻線。
5. The transformer winding according to claim 1, wherein between the windings in the vicinity of the center in the height direction of each of the flow folds, a vertical duct on the inlet side of the insulating cooling medium protrudes from the winding end, The width of the winding in the radial direction is made narrower than the width of the winding in the radial direction, and an insulating diversion plate whose circumferential length is divided into a plurality of horizontal spacers is inserted in a state of being bonded to the horizontal spacers. Transformer winding.
JP16770694A 1994-07-20 1994-07-20 Transformer winding Expired - Fee Related JP3254914B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP16770694A JP3254914B2 (en) 1994-07-20 1994-07-20 Transformer winding

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP16770694A JP3254914B2 (en) 1994-07-20 1994-07-20 Transformer winding

Publications (2)

Publication Number Publication Date
JPH0831663A true JPH0831663A (en) 1996-02-02
JP3254914B2 JP3254914B2 (en) 2002-02-12

Family

ID=15854709

Family Applications (1)

Application Number Title Priority Date Filing Date
JP16770694A Expired - Fee Related JP3254914B2 (en) 1994-07-20 1994-07-20 Transformer winding

Country Status (1)

Country Link
JP (1) JP3254914B2 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09243651A (en) * 1996-03-04 1997-09-19 Koichi Nakamura Measuring method for flow velocity of fluid and measuring method for flow velocity of cooling gas in electric-apparatus winding
CN112071583A (en) * 2020-07-23 2020-12-11 中国科学院电工研究所 High-isolation voltage-resistant planar transformer and high-voltage insulation method thereof

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09243651A (en) * 1996-03-04 1997-09-19 Koichi Nakamura Measuring method for flow velocity of fluid and measuring method for flow velocity of cooling gas in electric-apparatus winding
CN112071583A (en) * 2020-07-23 2020-12-11 中国科学院电工研究所 High-isolation voltage-resistant planar transformer and high-voltage insulation method thereof
CN112071583B (en) * 2020-07-23 2021-11-05 中国科学院电工研究所 High-voltage isolation voltage-resistant planar transformer and high-voltage insulation method thereof
US11328857B2 (en) 2020-07-23 2022-05-10 Institute Of Electrical Engineering, Chinese Academy Of Sciences High-voltage isolation withstand planar transformer and high-voltage insulation method thereof

Also Published As

Publication number Publication date
JP3254914B2 (en) 2002-02-12

Similar Documents

Publication Publication Date Title
JPH08503577A (en) Core-type transformer with cooling liquid diversion band
JP3254998B2 (en) Transformer winding
JPH0831663A (en) Transformer winding
JPH07161541A (en) Transformer winding
JP2001148314A (en) Transformer
JP3535562B2 (en) Gas-cooled power equipment
JPS58151009A (en) Winding of stationary induction electric apparatus
JPH09162040A (en) Winding of transformer
JPS61136209A (en) Self-cooled, oil-filled winding of electric equipment
JPH11168014A (en) Transformer
JPH0822918A (en) Transformer winding
JPH05234776A (en) Gas-insulated transformer
JP2000260629A (en) Winding of stationary induction electric apparatus
JP3465373B2 (en) Winding cooling structure of gas insulation equipment
JPS60944B2 (en) transformer
JPS596492B2 (en) Stationary induction electric winding
JP2508994B2 (en) Induction electric disk winding
JPH11121250A (en) Winding of induction electrical apparatus
JP2000077236A (en) Stationary induction device
JPS607457Y2 (en) electrical equipment winding
JPS6113365B2 (en)
JPH05326292A (en) Gas insulated transformer
JPS6023486B2 (en) Forced circulation liquid-cooled electrical equipment
JPS61150308A (en) Winding of electric equipment
JPH0831656A (en) Winding wire of transformer

Legal Events

Date Code Title Description
LAPS Cancellation because of no payment of annual fees