JPS63924B2 - - Google Patents
Info
- Publication number
- JPS63924B2 JPS63924B2 JP17274079A JP17274079A JPS63924B2 JP S63924 B2 JPS63924 B2 JP S63924B2 JP 17274079 A JP17274079 A JP 17274079A JP 17274079 A JP17274079 A JP 17274079A JP S63924 B2 JPS63924 B2 JP S63924B2
- Authority
- JP
- Japan
- Prior art keywords
- transformer
- metal container
- tap
- limiting resistor
- cooling
- 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.)
- Expired
Links
- 238000001816 cooling Methods 0.000 claims description 19
- 239000002184 metal Substances 0.000 claims description 18
- 239000003507 refrigerant Substances 0.000 claims description 17
- 239000007788 liquid Substances 0.000 claims description 6
- 238000005507 spraying Methods 0.000 claims description 3
- NBVXSUQYWXRMNV-UHFFFAOYSA-N fluoromethane Chemical compound FC NBVXSUQYWXRMNV-UHFFFAOYSA-N 0.000 description 10
- 230000007935 neutral effect Effects 0.000 description 6
- 230000000694 effects Effects 0.000 description 3
- 230000005684 electric field Effects 0.000 description 3
- 238000009413 insulation Methods 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 229910018503 SF6 Inorganic materials 0.000 description 2
- 239000002826 coolant Substances 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000011810 insulating material Substances 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 238000005086 pumping Methods 0.000 description 2
- SFZCNBIFKDRMGX-UHFFFAOYSA-N sulfur hexafluoride Chemical compound FS(F)(F)(F)(F)F SFZCNBIFKDRMGX-UHFFFAOYSA-N 0.000 description 2
- 229960000909 sulfur hexafluoride Drugs 0.000 description 2
- 238000004804 winding Methods 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 238000010292 electrical insulation Methods 0.000 description 1
- 239000002360 explosive Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 239000002480 mineral oil Substances 0.000 description 1
- 235000010446 mineral oil Nutrition 0.000 description 1
- 230000000116 mitigating effect Effects 0.000 description 1
- 239000003921 oil Substances 0.000 description 1
- 230000002040 relaxant effect Effects 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- TXEYQDLBPFQVAA-UHFFFAOYSA-N tetrafluoromethane Chemical compound FC(F)(F)F TXEYQDLBPFQVAA-UHFFFAOYSA-N 0.000 description 1
- 238000005979 thermal decomposition reaction Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H9/00—Details of switching devices, not covered by groups H01H1/00 - H01H7/00
- H01H9/0005—Tap change devices
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H1/00—Contacts
- H01H1/62—Heating or cooling of contacts
Landscapes
- Transformer Cooling (AREA)
Description
【発明の詳細な説明】
この発明は、変圧器のタツプをタツプ選択器に
よつて無電流状態で順次選択し、変圧器の負荷電
流を変圧器の第1のタツプから第2のタツプへ限
流抵抗器を介して切換開閉器で転流させる負荷時
タツプ切換装置に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention involves sequentially selecting the taps of a transformer in a currentless state by a tap selector to limit the load current of the transformer from the first tap to the second tap of the transformer. This invention relates to an on-load tap switching device that commutates current with a switching switch via a current resistor.
従来の電力用変圧器においては、そのタンク内
に鉱油を封入し、絶縁と巻線および鉄心の冷却を
兼ね備えさせる方法が取られてきた。近年、人口
の密集するビルデイングの受電設備や市街地に設
備される配電設備用変圧器には、特に安全面から
不燃化・非爆発性化・小形軽量化等が強く要求さ
れるようになつてきた。このような要求に対応す
べく各種変圧器が提案されているが、その一つと
して特に高電圧大容量変圧器に適した方式とし
て、電気絶縁を六弗化硫黄(SF6)でおこない、
冷却を弗化炭素(フロン)でおこなうガス絶縁蒸
発冷却変圧器が提案されている(例えば、電気書
院刊「電気計算」昭和35年7月号第60頁〜第64
頁)。この種の蒸発冷却変圧器においても、従来
の油入変圧器と同様に負荷タツプ切換器を取り付
け、変圧器に電圧調整機能を持たせれば有用であ
る。この用途の負荷時タツプ切換器においても、
従来の油入変圧器の場合と同様に、タツプ切換器
の小形化を図るためには、いわゆる抵抗式負荷時
タツプ切換器を使用することが得策である。ま
た、この負荷時タツプ切換器は切換開閉器とタツ
プ選択器から構成され、切換開閉器は点検の便を
考慮して変圧器本体とは別室に配置されること、
およびタツプ選択器は変圧器本体と同じ室内に配
置され同じ絶縁媒体、つまり中に浸漬されること
は、従来の油入変圧器用負荷時タツプ切換器と類
似である。 In conventional power transformers, mineral oil is sealed in the tank to provide both insulation and cooling of the windings and core. In recent years, there has been a strong demand for transformers for power receiving equipment in densely populated buildings and power distribution equipment installed in urban areas to be non-combustible, non-explosive, smaller and lighter, especially from a safety perspective. . Various types of transformers have been proposed to meet these demands, and one method that is especially suitable for high-voltage, large-capacity transformers is one that uses sulfur hexafluoride (SF6) for electrical insulation.
A gas-insulated evaporative cooling transformer that uses carbon fluoride (fluorocarbons) for cooling has been proposed (for example, Denki Shoin, "Denki Kakaku", July 1960 issue, pp. 60-64).
page). This type of evaporative cooling transformer is also useful if it is equipped with a load tap changer in the same way as conventional oil-immersed transformers, and the transformer is provided with a voltage adjustment function. In the on-load tap changer for this purpose,
As in the case of conventional oil-immersed transformers, in order to reduce the size of the tap changer, it is expedient to use a so-called resistive on-load tap changer. In addition, this on-load tap changer consists of a changeover switch and a tap selector, and the changeover switch must be placed in a separate room from the transformer body for ease of inspection.
The tap selector and tap selector are located in the same room as the transformer body and are immersed in the same insulating medium, similar to conventional on-load tap changers for oil-immersed transformers.
この場合の問題点の1つとして、SF6ガスは油
に較べ冷却特性の面で劣るため特に切換開閉器の
限流抵抗器および連続通電用接点が必然的に大形
化せざるを得ないこと、およびSF6ガスは構造物
として使用される鉄鋼などを触媒として比較的低
温(150℃〜200℃)で熱分解を起し腐蝕性ガスを
発生するので、あまり高い温度にできないという
難点がある。この難点を解決するためには、変圧
器の巻線および鉄心を冷却するための冷媒(フロ
ン)を利用して、主として切換開閉器部の発熱部
を直接冷却してやれば効果的である。しかしなが
ら、切換開閉器内部には、タツプ切換時に生ずる
アークによる接点の消耗粉あるいは機構部の機械
的摩耗粉等が発生するので、変圧器本体の冷媒と
同一の循還系で取りあつかうには問題がある。従
つて、切換開閉器の冷却はその外部から間接的に
おこなうことが望しい。 One of the problems in this case is that SF 6 gas has inferior cooling properties compared to oil, so the current limiting resistor of the switching switch and the contact for continuous energization, in particular, have to be larger. Also, SF 6 gas causes thermal decomposition at relatively low temperatures (150°C to 200°C) using the steel used in structures as a catalyst and generates corrosive gas, so it has the disadvantage that it cannot be heated to very high temperatures. be. In order to solve this difficulty, it is effective to directly cool mainly the heat generating part of the switching switch section using a refrigerant (fluorocarbon) for cooling the windings and core of the transformer. However, inside the changeover switch, there is a problem in dealing with it in the same circulation system as the refrigerant of the transformer, because powder from the contacts due to the arc that occurs during tap switching or powder from mechanical wear from the mechanical parts is generated. There is. Therefore, it is desirable that the switching switch be cooled indirectly from the outside.
第1図に上記のような従来の油入変圧器用負荷
時タツプ切換器と同一の構成によるガス絶縁蒸発
冷却変圧器用負荷時タツプ切換器の切換開閉器部
を間接的に冷却する方法を示す。第1図におい
て、1は負荷時タツプ切換器の頭部ケース、2は
絶縁媒体のSF6ガスが封入された変圧器タンク、
3は切換開閉器、4はタツプ選択器、5はタツプ
選択器の駆動機構ケース、6は絶縁媒体のSF6ガ
スが封入された切換開閉器収納用の絶縁容器、7
は切換開閉器の限流抵抗器、8は絶縁容器6とタ
ツプ選択器駆動機構5の上蓋を連結するフラン
ジ、9は切換開閉器3の大地電位部と充電部の間
の電界を緩和するために設けられた大地シール
ド、10は大地シールド9と同じ働きをする充電
部シールド、11は切換開閉器3とタツプ選択器
4とを電気的に接続するための接続コンタクト、
12は切換開閉器3の中に構成された変圧器の中
性点となる中性点電位部と変圧器の中性点ブツシ
ングを接続するための中性点接続コンタクト、1
3はフランジ8を中性点電位に保つための接続リ
ード、14は変圧器の冷媒(フロン)を噴霧する
ためのノズル、15は頭部カバー、16はノズル
14から噴霧された水滴状のフロンである。切換
開閉器3は負荷時タツプ切換器頭部ケース1、絶
縁容器6、フランジ8、タツプ選択器駆動機構5
の上蓋および頭部ケースカバー15によつて密封
されSF6ガスが封入されている。切換開閉器収納
ケース6は対地絶縁を維持するために絶縁物で作
られている。また、対地絶縁部のシールドリング
9,10は油入式の場合でも高電圧の場合には必
要であるが、ガス絶縁方式においては絶縁耐力が
ほぼ一意的に最高電位傾度で決るので、部分的電
界集中を緩和するため必要不可欠な要素となる。 FIG. 1 shows a method for indirectly cooling the switch section of an on-load tap changer for a gas-insulated evaporatively cooled transformer, which has the same structure as the conventional on-load tap changer for an oil-immersed transformer as described above. In Figure 1, 1 is the head case of the on-load tap changer, 2 is the transformer tank filled with SF 6 gas as an insulating medium,
3 is a switching switch, 4 is a tap selector, 5 is a drive mechanism case for the tap selector, 6 is an insulating container for storing the switching switch filled with SF 6 gas as an insulating medium, 7
is a current limiting resistor of the switching switch; 8 is a flange connecting the insulating container 6 and the top cover of the tap selector drive mechanism 5; and 9 is for relaxing the electric field between the ground potential part and the live part of the switching switch 3. 10 is a live part shield that has the same function as the earth shield 9; 11 is a connection contact for electrically connecting the switching switch 3 and the tap selector 4;
Reference numeral 12 denotes a neutral point connection contact for connecting a neutral point potential section, which is a neutral point of the transformer, configured in the switching switch 3 and a neutral point bushing of the transformer;
3 is a connection lead for keeping the flange 8 at neutral point potential, 14 is a nozzle for spraying refrigerant (fluorocarbon) for the transformer, 15 is a head cover, and 16 is a water droplet of fluorocarbon sprayed from the nozzle 14. It is. The switching switch 3 includes a load tap switching device head case 1, an insulating container 6, a flange 8, and a tap selector drive mechanism 5.
It is sealed by the top lid and the head case cover 15 and filled with SF 6 gas. The switching switch storage case 6 is made of an insulating material to maintain ground insulation. In addition, the shield rings 9 and 10 of the ground insulation part are necessary in the case of high voltage even in the oil-immersed type, but in the case of the gas-insulated type, the dielectric strength is almost uniquely determined by the highest potential gradient, so it is partially necessary. This is an essential element to alleviate electric field concentration.
上記のような構成においては次のような難点が
ある。 The above configuration has the following drawbacks.
(イ) 切換開閉器収納ケース6が絶縁物で構成され
ているため冷却特性が悪い。(a) Since the switching switch storage case 6 is made of an insulating material, its cooling characteristics are poor.
(ロ) ノズル14が1個では、絶縁容器6の全面を
均等に冷却することはむずかしく、また多数つ
けるのは配管が複雑になり不経済である。(b) With one nozzle 14, it is difficult to uniformly cool the entire surface of the insulating container 6, and with multiple nozzles 14, piping becomes complicated and uneconomical.
(ハ) 充電部シールドリング10は、フランジ8に
固定されているが、その取り付け足が長くなる
ため不安定である。(c) Although the live part shield ring 10 is fixed to the flange 8, it is unstable because its attachment leg becomes long.
この発明は上記欠点を解消するためになされた
もので、少なくとも限流抵抗器は金属容器の壁面
と対向させ、冷却手段で冷却媒体を噴霧して金属
容器の外周を冷却することによつて、冷却性能の
向上を図つた負荷時タツプ切換装置を提供する。 This invention was made in order to eliminate the above-mentioned drawbacks, and by arranging at least the current limiting resistor to face the wall surface of the metal container, and cooling the outer periphery of the metal container by spraying a cooling medium with the cooling means, Provided is a load tap switching device that improves cooling performance.
以下、図について説明する。第2図において、
1〜7,10,11,15,16は従来と同様で
ある。17は駆動機構5と絶縁容器6とを連結し
た金属容器で、内部の壁面が限流抵抗器7と対向
するようにされている。18は変圧器タンク2と
同電位とされ金属容器17と対向した複数個のノ
ズル穴18aを有する円環状体で、ポンプ等の圧
送手段(図示せず)によつてフロン等の冷却媒体
が供給される。なお、円環状体18は電界緩和用
の大地シールドを兼ねている。なお、円環状体1
8と図示しない圧送手段とで冷却手段19を構成
している。20は切換開閉器側の中性点接続コン
タクトで、金属容器17と摺動自在に接触してい
る。 The figures will be explained below. In Figure 2,
1 to 7, 10, 11, 15, and 16 are the same as the conventional one. A metal container 17 connects the drive mechanism 5 and the insulating container 6, and has an inner wall facing the current limiting resistor 7. Reference numeral 18 denotes an annular body having a plurality of nozzle holes 18a that is at the same potential as the transformer tank 2 and faces the metal container 17, and is supplied with a cooling medium such as fluorocarbon by a pressure feeding means (not shown) such as a pump. be done. Note that the annular body 18 also serves as a ground shield for mitigating the electric field. In addition, the toric body 1
8 and a pressure feeding means (not shown) constitute a cooling means 19. Reference numeral 20 denotes a neutral point connection contact on the switching switch side, which is in slidable contact with the metal container 17.
上記の構成において、図示しない変圧器の冷媒
(フロン)の溜りから図示しない圧送手段によつ
て円環状体18の内部に冷媒が圧送され、ノズル
穴18aから金属容器17の円周方向に沿つて噴
霧される。従つて、その下方に配置された接続コ
ンタクト11および限流抵抗器7を囲むように配
置され、タツプ切換毎にジユール熱により温度が
上昇する限流抵抗器7により加熱された金属容器
17が冷却される。加熱により蒸気となつた冷媒
(フロン)は前記文献等で公知の現象により図示
しない変圧器のラジエーターで冷却され、液体に
戻り、元の前記の冷媒溜りに戻る。蒸発せず温度
が多少上昇しただけの冷媒はそのまま冷媒溜りに
落下し、ラジエータで冷却されて液体となつた低
温の冷媒と混合して冷やされる。冷媒溜りの冷媒
は再度前記圧送手段で円環状体18に圧送される
という循環を繰り返す。 In the above configuration, the refrigerant is pumped into the annular body 18 from the refrigerant (fluorocarbon) pool of the transformer (not shown) by a pumping means (not shown), and is fed from the nozzle hole 18a along the circumferential direction of the metal container 17. Sprayed. Therefore, the metal container 17, which is heated by the current limiting resistor 7, which is arranged so as to surround the connection contact 11 and the current limiting resistor 7 arranged below it, and whose temperature increases due to Joule heat every time the tap is switched, is cooled down. be done. The refrigerant (fluorocarbon), which has become a vapor due to heating, is cooled by a radiator of a transformer (not shown) according to a phenomenon known in the above-mentioned literature, returns to a liquid, and returns to the original refrigerant reservoir. The refrigerant, which has not evaporated and whose temperature has only increased slightly, falls directly into the refrigerant reservoir, where it is cooled by being mixed with the low-temperature refrigerant that has been cooled by the radiator and turned into a liquid. The refrigerant in the refrigerant reservoir is again pumped to the annular body 18 by the pumping means, and the circulation is repeated.
上記実施例において、金属容器17は鍔付の単
なる円筒状容器としたが、この円筒部分に突起を
出し公知の冷却フインの役割をさせることもまた
効果的である。 In the above embodiment, the metal container 17 is a simple cylindrical container with a flange, but it is also effective to have a protrusion on the cylindrical portion to serve as a known cooling fin.
また、金属容器17にフロン液体を少なくとも
限流抵抗器7が浸積される程度に満せば、限流抵
抗器7はフロンにより直接冷却され、このフロン
液体に伝えられた熱は対流等により金属容器17
に伝達されるので、SF6ガスのみの場合より冷却
特性は良好となる。 Furthermore, if the metal container 17 is filled with fluorocarbon liquid at least to the extent that the current limiting resistor 7 is immersed, the current limiting resistor 7 is directly cooled by the fluorocarbon, and the heat transferred to the fluorocarbon liquid is transferred by convection or the like. metal container 17
The cooling characteristics are better than in the case of only SF 6 gas.
上記のような公知の技術の組み合せによる改良
は当業者の容易に推察し得るところであり、本発
明の趣旨を変更することなくその能率改善をおこ
なうことが出来るのはいうまでもない。 Those skilled in the art can easily infer improvements by combining the known techniques as described above, and it goes without saying that the efficiency can be improved without changing the spirit of the present invention.
以上の構成を取ることにより、次の効果が生ず
る。 By adopting the above configuration, the following effects occur.
(イ) 冷媒を収容した金属容器を採用することによ
り最も発熱量が大きい限流抵抗器からの発熱が
有効に冷媒(フロン)に伝達され得るので、限
流抵抗器の温度上昇を低くおさえることが出来
る。(b) By using a metal container containing the refrigerant, the heat generated from the current limiting resistor, which generates the largest amount of heat, can be effectively transferred to the refrigerant (fluorocarbon), so the temperature rise of the current limiting resistor can be kept low. I can do it.
(ロ) 切換開閉器の円周囲りに均等に冷媒を噴霧す
るので、冷却効果を増大するとともに、特にノ
ズルを多数取りつける必要がなく経済的であ
る。(b) Since the refrigerant is evenly sprayed around the circumference of the switching switch, the cooling effect is increased and there is no need to install a large number of nozzles, making it economical.
(ハ) また、接続コンタクトの冷却も容易となり、
この接続コンタクトに連なる切換開閉器内部の
連続通電接点に対する冷却効果も期待すること
が出来る。(c) It also makes it easier to cool the connection contacts.
A cooling effect can also be expected for the continuously energized contacts inside the switching switch connected to this connection contact.
第1図は従来の負荷時タツプ切換装置の構成
図、第2図はこの発明の一実施例を示す構成図で
ある。図において、2は変圧器タンク、3は切換
開閉器、4はタツプ選択器、6は絶縁容器、7は
限流抵抗器、17は金属容器、19は冷却手段で
ある。なお各図中同一符号は同一又は相当部分を
示す。
FIG. 1 is a block diagram of a conventional on-load tap switching device, and FIG. 2 is a block diagram showing an embodiment of the present invention. In the figure, 2 is a transformer tank, 3 is a switching switch, 4 is a tap selector, 6 is an insulating container, 7 is a current limiting resistor, 17 is a metal container, and 19 is a cooling means. Note that the same reference numerals in each figure indicate the same or equivalent parts.
Claims (1)
で順次選択し、上記変圧器の負荷電流を上記変圧
器の第1のタツプから第2のタツプへ限流抵抗器
を介して切換開閉器で転流させるものにおいて、 上記変圧器を収納する変圧器タンク内に懸架さ
れた筒状の絶縁容器と、この絶縁容器の下部に連
結された金属容器と、 上記絶縁容器および上記金属容器の内部に収納
された上記切換開閉器および上記金属容器壁面に
接近して配置された上記限流抵抗器と、 上記限流抵抗器が浸漬される程度に上記金属容
器に収容された液冷媒と、 上記変圧器タンクと同電位に保持され上記金属
容器と対向した複数個のノズル穴を有する円環状
体と、この円環状体に液冷媒を圧送する圧送手段
とでなり、上記液冷媒を噴霧して上記金属容器の
外周を冷却する冷却手段と、 を備えてなることを特徴とする負荷時タツプ切換
装置。[Claims] 1 Taps of the transformer are sequentially selected in a no-current state by a selector, and the load current of the transformer is transferred from the first tap to the second tap of the transformer through a current limiting resistor. A cylindrical insulating container suspended in a transformer tank housing the transformer, a metal container connected to the lower part of the insulating container, and the insulating container and the switching switch housed inside the metal container and the current limiting resistor placed close to the wall surface of the metal container, and the current limiting resistor being housed in the metal container to such an extent that it is immersed. an annular body having a plurality of nozzle holes that is held at the same potential as the transformer tank and facing the metal container; and a pressure-feeding means for force-feeding the liquid refrigerant to the annular body; An on-load tap switching device comprising: cooling means for cooling the outer periphery of the metal container by spraying a liquid refrigerant.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP17274079A JPS5696819A (en) | 1979-12-29 | 1979-12-29 | On-load tap changer |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP17274079A JPS5696819A (en) | 1979-12-29 | 1979-12-29 | On-load tap changer |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS5696819A JPS5696819A (en) | 1981-08-05 |
JPS63924B2 true JPS63924B2 (en) | 1988-01-09 |
Family
ID=15947429
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP17274079A Granted JPS5696819A (en) | 1979-12-29 | 1979-12-29 | On-load tap changer |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS5696819A (en) |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102009035699A1 (en) * | 2009-07-30 | 2011-02-10 | Maschinenfabrik Reinhausen Gmbh | Arrangement of a tap changer on a control transformer |
JP2011035162A (en) * | 2009-07-31 | 2011-02-17 | Toshiba Corp | On-load tap changer |
JP6505496B2 (en) * | 2015-04-28 | 2019-04-24 | 株式会社東芝 | Gas-insulated on-load tap changer |
-
1979
- 1979-12-29 JP JP17274079A patent/JPS5696819A/en active Granted
Also Published As
Publication number | Publication date |
---|---|
JPS5696819A (en) | 1981-08-05 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CA1089944A (en) | Vapor-cooled terminal-bushings for oil-type circuit- interrupters | |
US10910138B2 (en) | Gas-insulated electrical apparatus, in particular gas-insulated transformer or reactor | |
US10714256B2 (en) | Electrical device comprising a gas-insulated apparatus, in particular a gas-insulated transformer or reactor | |
US2924635A (en) | Electrical apparatus | |
JPS63924B2 (en) | ||
US2858355A (en) | Electrical apparatus | |
US4006332A (en) | Convection heating apparatus for multi-phase gas-type circuit interrupters | |
JP2553157B2 (en) | Stationary induction equipment | |
US2759987A (en) | Cooling electrical apparatus | |
US4205289A (en) | Vaporization cooled electrical inductive apparatus | |
US1746977A (en) | Electrical apparatus | |
JP2000224722A (en) | Gas insulating electrical apparatus | |
JPH01147816A (en) | Stationary induction apparatus | |
JPH01111310A (en) | Static induction device | |
JP3077958B2 (en) | Stationary induction device | |
JPS63923B2 (en) | ||
US3271711A (en) | Insulated electrical apparatus | |
US1224150A (en) | Arc-suppressing device. | |
JPS596506A (en) | Stationary induction apparatus | |
JP3028853B2 (en) | Stationary induction device | |
JPH076922A (en) | Stationary induction electric apparatus | |
JPS63164306A (en) | Gas-insulated stationary induction electric apparatus | |
KR19980702794A (en) | Stop Induction Electrical Equipment | |
JPS632308A (en) | On-load tap changer | |
JPH02144905A (en) | Static induction instrument |