JPH0554244B2 - - Google Patents
Info
- Publication number
- JPH0554244B2 JPH0554244B2 JP58092391A JP9239183A JPH0554244B2 JP H0554244 B2 JPH0554244 B2 JP H0554244B2 JP 58092391 A JP58092391 A JP 58092391A JP 9239183 A JP9239183 A JP 9239183A JP H0554244 B2 JPH0554244 B2 JP H0554244B2
- Authority
- JP
- Japan
- Prior art keywords
- discharge resistor
- superconducting coil
- resistance value
- resistor
- coil
- 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 - Lifetime
Links
- 239000000463 material Substances 0.000 claims description 8
- 230000007704 transition Effects 0.000 claims description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 16
- 239000007788 liquid Substances 0.000 description 9
- 229910052757 nitrogen Inorganic materials 0.000 description 8
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 7
- 229910052802 copper Inorganic materials 0.000 description 6
- 239000010949 copper Substances 0.000 description 6
- 239000003507 refrigerant Substances 0.000 description 5
- 230000001965 increasing effect Effects 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 229910052782 aluminium Inorganic materials 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 230000015556 catabolic process Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 230000017525 heat dissipation Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000001307 helium Substances 0.000 description 1
- 229910052734 helium Inorganic materials 0.000 description 1
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 1
- 230000001939 inductive effect Effects 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 230000001052 transient effect Effects 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F6/00—Superconducting magnets; Superconducting coils
- H01F6/003—Methods and means for discharging superconductive storage
Description
【発明の詳細な説明】
［発明の目的］
（産業上の利用分野）
本発明は、超電導コイルが常電導へ転移したと
きに、コイル電流を減少させるための超電導コイ
ルの保護回路に関する。DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a protection circuit for a superconducting coil for reducing coil current when the superconducting coil transitions to normal conductivity.
（従来の技術）
従来の超電導コイルの保護回路においては、放
電抵抗器として通常の抵抗器を用いるので、その
抵抗値はほとんど変化しない。このため、超電導
コイルのエネルギーを速やかに放出しようとする
ときには、放電抵抗器の抵抗値を大きくすること
が必要である。しかし、放電抵抗器の抵抗値を大
きくすると、コイル電流を放電抵抗器へ移すとき
の発生電圧が高くなるため、コイル電流を遮断す
る開閉器に高電圧の直流電流遮断能力が必要とな
るほか、電流遮断時の過渡電圧により超電導コイ
ルが絶縁破壊するおそれがある。(Prior Art) In a conventional superconducting coil protection circuit, a normal resistor is used as a discharge resistor, so its resistance value hardly changes. Therefore, when attempting to quickly release the energy of the superconducting coil, it is necessary to increase the resistance value of the discharge resistor. However, if the resistance value of the discharge resistor is increased, the voltage generated when transferring the coil current to the discharge resistor increases, so the switch that interrupts the coil current must have high-voltage DC current interrupting ability. There is a risk of dielectric breakdown of the superconducting coil due to transient voltage when the current is interrupted.
（発明が解決しようとする課題）
本発明は、コイル電流遮断時における放電抵抗
器の抵抗値を小さくすることにより、コイル電流
遮断時の発生電圧を低く抑えるとともに、放電抵
抗器自信の発熱にともなう温度上昇で、その抵抗
値が増加することにより、速やかなエネルギー放
出を可能ならしめる。超電導コイルの保護回路を
提供することにある。(Problems to be Solved by the Invention) The present invention reduces the resistance value of the discharge resistor when the coil current is cut off, thereby suppressing the voltage generated when the coil current is cut off and reducing the heat generated by the discharge resistor itself. As the temperature rises, its resistance value increases, allowing rapid energy release. The purpose of the present invention is to provide a protection circuit for superconducting coils.
［発明の構成］
（課題を解決するための手段）
上記課題を解決するために、本発明では、超電
導コイルが常電導へ転移する際に前記超電導コイ
ルのコイル電流を減少させるための放電抵抗器を
有する超電流コイルの保護回路において、前記放
電抵抗器は、温度上昇にともない抵抗値が増大す
る材料で構成され、予め極低温状態に冷却されて
いることを特徴とする超電導コイルの保護回路、
及び前記放電抵抗器に並列に接続される抵抗器を
有することを特徴とする前記超電導コイルの保護
回路を提供する。[Structure of the Invention] (Means for Solving the Problems) In order to solve the above problems, the present invention provides a discharge resistor for reducing the coil current of the superconducting coil when the superconducting coil transitions to normal conductivity. A protection circuit for a superconducting coil, characterized in that the discharge resistor is made of a material whose resistance value increases as the temperature rises, and is cooled in advance to an extremely low temperature.
and a protection circuit for the superconducting coil, comprising a resistor connected in parallel to the discharge resistor.
（作用）
上記した構成を有する本発明によれば、以下の
ような作用が得られる。(Function) According to the present invention having the above-described configuration, the following effects can be obtained.
放電抵抗器を、温度上昇にともない抵抗値が増
大する材料（例えば、銅、アルミニウム等の純金
属）で構成し、コイル電流の通電前は、この放電
抵抗器を極低温状態に冷却しておくことにより、
その抵抗値を小さくして、コイル電流遮断時の発
生電圧を低く抑えるとともに、通電後は、放電抵
抗器自体の発熱により、極低温から常温付近まで
の温度上昇を実現することにより、比較的容易
に、放電抵抗器の抵抗値を大幅に変化させること
が可能となる。 The discharge resistor is made of a material whose resistance value increases as the temperature rises (e.g., pure metal such as copper or aluminum), and the discharge resistor is cooled to an extremely low temperature before the coil current is applied. By this,
By reducing the resistance value, the voltage generated when the coil current is cut off is kept low, and after energization, the temperature rises from extremely low temperatures to around room temperature due to the heat generated by the discharge resistor itself, making it relatively easy to use. In addition, it becomes possible to significantly change the resistance value of the discharge resistor.
一方、通常の抵抗器を極低温状態に冷却した放
電抵抗器と並列に接続することにより、冷却され
ている放電抵抗器への熱入力を少なくすることが
可能となる。 On the other hand, by connecting an ordinary resistor in parallel with a discharge resistor that has been cooled to an extremely low temperature, it is possible to reduce the heat input to the cooled discharge resistor.
（実施例）
本発明の実施例について、図面を参照しつつ詳
細に説明する。(Example) Examples of the present invention will be described in detail with reference to the drawings.
第１図は、本発明による超電導コイルの保護回
路の第１実施例を示したものである。図におい
て、１は超電導コイル、２はクライオスタツト、
３は放電抵抗器、４は液体窒素容器、５はコイル
電流を放電抵抗器３へ移すためにコイル電流を遮
断する開閉器、６は超電導コイル１を励磁する電
源である。図に示すように、放電抵抗器３は、開
閉器５によりコイル電流を遮断すると、超電導コ
イル１と直列に接続されて閉回路を構成する。こ
こで、放電抵抗器３は、無酸素銅で構成され、コ
イル電流の通電前は液体窒素により極低温状態に
冷却されている。なお、放電抵抗器３を構成する
材料は、無酸素銅に限定されず、温度上昇にとも
ない抵抗値が増大する材料であれば、どのような
ものでも良いが、特に抵抗値の増加量が大きい材
料（例えば、銅、アルミニウム等の純金属）が好
ましい。また、放熱抵抗器３を冷却する冷媒も液
体窒素には限定されず、液体ヘリウム等の極低温
冷媒であれば、どのようなものでも良い。 FIG. 1 shows a first embodiment of a protection circuit for a superconducting coil according to the present invention. In the figure, 1 is a superconducting coil, 2 is a cryostat,
3 is a discharge resistor, 4 is a liquid nitrogen container, 5 is a switch that interrupts the coil current in order to transfer the coil current to the discharge resistor 3, and 6 is a power source that excites the superconducting coil 1. As shown in the figure, when the coil current is cut off by the switch 5, the discharge resistor 3 is connected in series with the superconducting coil 1 to form a closed circuit. Here, the discharge resistor 3 is made of oxygen-free copper, and is cooled to an extremely low temperature with liquid nitrogen before the coil current is applied. Note that the material constituting the discharge resistor 3 is not limited to oxygen-free copper, and may be any material as long as the resistance value increases as the temperature rises, but in particular, the material that increases the resistance value is large. Materials (eg, pure metals such as copper, aluminum, etc.) are preferred. Further, the refrigerant for cooling the heat dissipation resistor 3 is not limited to liquid nitrogen, but any cryogenic refrigerant such as liquid helium may be used.
第２図は、放電抵抗器３を構成する無酸素銅の
温度と電気抵抗率の関係を表したものである。図
から読み取れるように、液体窒素温度（77K）と
常温（300K）とでは、電気抵抗率がおよそ１桁
変化する。このように、極低温状態からであれ
ば、比較が小さいため急激な温度上昇を実現する
ことができ、比較的容易に、抵抗値を大幅に変化
させることが可能となる。 FIG. 2 shows the relationship between the temperature and electrical resistivity of oxygen-free copper constituting the discharge resistor 3. FIG. As can be seen from the figure, the electrical resistivity changes by approximately one order of magnitude between liquid nitrogen temperature (77K) and room temperature (300K). In this way, from an extremely low temperature state, a rapid temperature rise can be achieved since the comparison is small, and the resistance value can be changed significantly with relative ease.
これにより、常温の抵抗値に対して、初期抵抗
値は約１割であるから、コイル電流遮断時の発生
電圧も、最終発生電圧に対して約１割となる。す
なわち、コイル電流遮断時の発生電圧を低く抑え
ることができるため、直流の遮断電圧が250V程
度のノーヒユーズ遮断器を用いて、抵抗により発
生する電圧が1000から2000Vとなる超電導コイル
の保護回路を構成することが可能になる。また、
コイル電流遮断後は、放電抵抗器自体の発熱によ
り冷媒を蒸散させて、極低温から常温付近までの
温度上昇を実現することにより、コイル電流の減
衰にともなつて放電抵抗器３の抵抗値を急激に増
加させることができるため、速やかなエネルギー
放出が可能になる。 As a result, since the initial resistance value is about 10% of the resistance value at room temperature, the voltage generated when the coil current is cut off is also about 10% of the final generated voltage. In other words, since the voltage generated when the coil current is cut off can be kept low, a no-fuse circuit breaker with a DC cutoff voltage of about 250V is used to configure a protection circuit for a superconducting coil whose voltage generated by the resistance is 1000 to 2000V. It becomes possible to do so. Also,
After the coil current is cut off, the refrigerant is evaporated by the heat generated by the discharge resistor itself, and the temperature rises from an extremely low temperature to around room temperature, and the resistance value of the discharge resistor 3 decreases as the coil current attenuates. Since it can be increased rapidly, it is possible to quickly release energy.
第３図は、本発明による超電導コイルの保護回
路の第２実施例を示したものである。図におい
て、７は通常の抵抗器で、極低温状態に冷却した
放電抵抗器３と並列に接続される。このような構
成によれば、両抵抗器の合成抵抗値の変化幅は放
電抵抗器３のみの場合に比べて小さくなるが、極
低温状態に冷却されている放電抵抗器３への熱入
力を少なくすることが可能となる。これにより、
コイル電流遮断時における放電抵抗器３への急激
な熱入力を防止することができるため、極低温冷
媒である液体窒素の突沸を防止することが可能と
なり、全体として放電抵抗器の構成を簡易化する
ことができる。 FIG. 3 shows a second embodiment of a protection circuit for a superconducting coil according to the present invention. In the figure, 7 is an ordinary resistor, which is connected in parallel with the discharge resistor 3 cooled to an extremely low temperature. According to such a configuration, the width of change in the combined resistance value of both resistors is smaller than that in the case of only the discharge resistor 3, but the heat input to the discharge resistor 3 which is cooled to an extremely low temperature is reduced. It becomes possible to reduce the amount. This results in
Since it is possible to prevent sudden heat input to the discharge resistor 3 when the coil current is cut off, it is possible to prevent bumping of liquid nitrogen, which is a cryogenic refrigerant, and the overall configuration of the discharge resistor is simplified. can do.
本実施例における実際の数値例を示すと、以下
のようになる。通電電流1000A、蓄積エネルギー
1MJの超電導コイルのエネルギーを最大発生電圧
1000Vで放出させるとき、合成抵抗は１Ωであ
る。抵抗器７の抵抗値を1.5Ω、液体窒素で冷却
された放電抵抗器３の抵抗値を0.3Ωから３Ωま
で変化させるようにすると、初期の合成抵抗値は
0.25Ωで、1000Aの通電による発熱電圧は、250V
となるので、例えば、ノーヒユーズ遮断器を用い
て遮断することが可能である。この時、液体窒素
で冷却された放電抵抗器３への熱負荷は全体の1/
３の333KJとなる。放電抵抗器３は、銅で作るも
のとして、液体窒素温度から、100℃まで温度変
化させる場合の熱容量は90J／ｇ、したがつて、
3.7Kgの材料が必要となる。常温における抵抗率
を1.8×10-8Ωｍとして、３Ωとなるようにする
には、断面積1.66mm2、長さ250ｍとなる。これ
は、直径1.45mmの銅線を直径200mmのコイル状に
１往復無誘導巻きに巻くと長さ300mmとなる大き
さである。 An actual numerical example in this embodiment is as follows. Carrying current 1000A, stored energy
Maximum generated voltage of 1MJ superconducting coil energy
When discharging at 1000V, the combined resistance is 1Ω. If the resistance value of resistor 7 is changed to 1.5Ω, and the resistance value of discharge resistor 3 cooled with liquid nitrogen is varied from 0.3Ω to 3Ω, the initial combined resistance value is
The heating voltage when 1000A is applied at 0.25Ω is 250V.
Therefore, for example, it is possible to shut off using a no-fuse circuit breaker. At this time, the heat load on the discharge resistor 3 cooled with liquid nitrogen is 1/1/2 of the total.
It becomes 333KJ of 3. The discharge resistor 3 is made of copper and has a heat capacity of 90 J/g when the temperature is changed from liquid nitrogen temperature to 100°C.
3.7Kg of material is required. Assuming that the resistivity at room temperature is 1.8×10 -8 Ωm, in order to achieve a resistivity of 3Ω, the cross-sectional area will be 1.66mm 2 and the length will be 250m. This means that if a copper wire with a diameter of 1.45 mm is wound into a coil with a diameter of 200 mm in one reciprocating non-inductive winding, the length will be 300 mm.
［発明の効果］
以上説明したように、本発明によれば、放熱抵
抗器を予め極低温状態に冷却しておくことによ
り、コイル電流遮断時における放電抵抗器の抵抗
値を小さくして、コイル電流遮断時の発生電圧を
低く抑えるとともに、極低温から常温付近までの
温度上昇を実現することにより、比較的容易に、
その抵抗値を大幅に変化させることができる。ま
た、コイル電流遮断後は、コイル電流の減衰にと
もなつて放電抵抗器の抵抗値を急速に増加させる
ことができるため、速やかなエネルギー放出が可
能になる。[Effects of the Invention] As explained above, according to the present invention, by cooling the heat radiation resistor to an extremely low temperature state in advance, the resistance value of the discharge resistor at the time of cutting off the coil current is reduced, and the coil By keeping the voltage generated during current interruption low and increasing the temperature from extremely low temperatures to around room temperature, it is relatively easy to
Its resistance value can be changed significantly. Further, after the coil current is cut off, the resistance value of the discharge resistor can be rapidly increased as the coil current attenuates, so that energy can be released quickly.
一方、通常の抵抗器を極低温状態に冷却した放
電抵抗器と並列に接続することにより、冷却され
ている放電抵抗器への熱入力を少なくすることが
可能となり、コイル電流遮断時における放電抵抗
器への急激な熱入力を防止することができるた
め、極低温冷媒の突沸を防止することができ、全
体として放電抵抗器の構成を簡易化することがで
きる。 On the other hand, by connecting a normal resistor in parallel with a discharge resistor that has been cooled to an extremely low temperature, it is possible to reduce the heat input to the cooled discharge resistor, and the discharge resistance when the coil current is cut off can be reduced. Since sudden heat input to the device can be prevented, bumping of the cryogenic refrigerant can be prevented, and the overall configuration of the discharge resistor can be simplified.
第１図は、本発明の第１実施例を示す超電導コ
イルの保護回路図、第２図は、温度変化にともな
う抵抗率変化の例を示す特性図、第３図は、本発
明の第２実施例を示す超電導コイルの保護回路図
である。
１……超導電コイル、２……クライオスタツ
ト、３……放電抵抗器、７……抵抗器。
FIG. 1 is a protection circuit diagram of a superconducting coil showing the first embodiment of the present invention, FIG. 2 is a characteristic diagram showing an example of resistivity change due to temperature change, and FIG. It is a protection circuit diagram of a superconducting coil showing an example. 1... superconducting coil, 2... cryostat, 3... discharge resistor, 7... resistor.
Claims (1)
電導コイルのコイル電流を減少させるための放電
抵抗器を有する超電導コイルの保護回路におい
て、前記放電抵抗器は、温度上昇にともない抵抗
値が増大する材料で構成され、予め極低温状態に
冷却されていることを特徴とする超電導コイルの
保護回路。 ２ 前記放電抵抗器に並列に接続される抵抗器を
有することを特徴とする特許請求の範囲第１項記
載の超電導コイルの保護回路。[Claims] 1. A protection circuit for a superconducting coil having a discharge resistor for reducing the coil current of the superconducting coil when the superconducting coil transitions to normal conductivity, wherein the discharge resistor A protection circuit for a superconducting coil, which is made of a material whose resistance value increases and is cooled to an extremely low temperature in advance. 2. The superconducting coil protection circuit according to claim 1, further comprising a resistor connected in parallel to the discharge resistor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9239183A JPS59218712A (en) | 1983-05-27 | 1983-05-27 | Protective circuit for superconductive coil |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9239183A JPS59218712A (en) | 1983-05-27 | 1983-05-27 | Protective circuit for superconductive coil |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS59218712A JPS59218712A (en) | 1984-12-10 |
| JPH0554244B2 true JPH0554244B2 (en) | 1993-08-12 |
Family
ID=14053115
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP9239183A Granted JPS59218712A (en) | 1983-05-27 | 1983-05-27 | Protective circuit for superconductive coil |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS59218712A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0812232B2 (en) * | 1990-09-28 | 1996-02-07 | 通商産業省工業技術院長 | SQUID element |
| JPH0485706U (en) * | 1990-11-30 | 1992-07-24 | ||
| CN114038640B (en) * | 2021-09-18 | 2023-05-23 | 盛雷城精密电阻（江西）有限公司 | Ultrahigh frequency radio frequency resistor and production method thereof |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS52104749A (en) * | 1976-02-28 | 1977-09-02 | Furukawa Electric Co Ltd | Holding device for superconductive electromagnet coil |
| JPS5483390A (en) * | 1977-12-16 | 1979-07-03 | Toshiba Corp | Protective device for superconductive coil |
| JPS54137658A (en) * | 1978-04-19 | 1979-10-25 | Hitachi Ltd | Energy remover for superconductive coil |
-
1983
- 1983-05-27 JP JP9239183A patent/JPS59218712A/en active Granted
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS52104749A (en) * | 1976-02-28 | 1977-09-02 | Furukawa Electric Co Ltd | Holding device for superconductive electromagnet coil |
| JPS5483390A (en) * | 1977-12-16 | 1979-07-03 | Toshiba Corp | Protective device for superconductive coil |
| JPS54137658A (en) * | 1978-04-19 | 1979-10-25 | Hitachi Ltd | Energy remover for superconductive coil |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS59218712A (en) | 1984-12-10 |
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