JP2010010631A - Superconducting coil device and inspection method of superconducting coil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect abnormality of superconducting coil simply with safety by measuring both end voltages of the superconducting coil. <P>SOLUTION: The superconducting coil device 1 includes a superconducting coil 2, a voltage measurement unit 6, a current control unit 7, and a heater 8. When abnormality of the superconducting coil 2 is detected, the superconducting coil 2 is heated by the heater 8, current is applied to the superconducting coil 2 from the current control unit 7. If both end voltages of the superconducting coil 2 exceeds a predetermined threshold, the voltage measurement unit 6 determines that the superconducting coil 2 is abnormal. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a superconducting coil device and a superconducting coil inspection method that can detect abnormalities in a superconducting coil by measuring the voltage across the superconducting coil.

  The superconducting coil undergoes a normal conducting transition (quenching) when an abnormality occurs and the temperature rises. The superconducting coil may burn out when quenching occurs.

  Therefore, in order to protect the superconducting coil, the superconducting coil device is provided with an abnormality detector. The abnormality detector measures the voltage of the superconducting coil and determines that it is abnormal when the coil voltage exceeds a predetermined threshold. In addition, the superconducting coil device includes a protection unit that releases electromagnetic energy accumulated in the superconducting coil in accordance with a signal from the abnormality detector.

  On the other hand, in the high-temperature superconducting coil, the quench propagation speed is generally less than one hundredth of that of the metal-based superconducting coil. That is, in the high-temperature superconducting coil, the quench propagation speed is slow, and even if an abnormality occurs in the coil, a large coil voltage is not generated immediately. That is, it is difficult to measure the coil voltage of the high-temperature superconducting coil to detect the coil abnormality. Therefore, there is a risk that the superconducting coil may burn out before the protection unit operates.

  Therefore, a technique for detecting an abnormality in the superconducting coil before quenching is required.

  The superconducting coil device described in Patent Document 1 always detects a combination of the heat generation amount and temperature of the superconducting coil, and provides a monitoring reference and a detection value that are a combination of the heat generation amount and temperature at which the superconducting coil does not quench. In comparison, the superconducting coil has a configuration for detecting an abnormality before quenching occurs.

In addition, the superconducting coil device described in Patent Document 2 accumulates various data such as the coil temperature and coil voltage that cause quenching, and the degree of vacuum in the vacuum vessel in which the superconducting coil is housed, It has a configuration in which it is transmitted to a service center to check for signs of abnormality.
JP 2007-266244 A JP 2002-252380 A

  In general, in a superconducting coil device, it is difficult to provide a voltage tap for measuring a voltage of a part of a coil and a thermometer for measuring temperatures at a plurality of positions of the coil from the viewpoint of manufacturing complexity and manufacturing cost. , Measurable locations are limited.

  Therefore, in the superconducting coil devices of Patent Document 1 and Patent Document 2, the number of points where voltage taps and thermometers are provided is limited, so that the number of measurement points such as coil voltage and coil temperature cannot be obtained sufficiently. If it does so, it will become a problem by the point which cannot detect abnormality depending on the location in a superconducting coil.

  Further, if the superconducting coil is abnormal, it is necessary to quickly cut off the supply of current.

  It is an object of the present invention to provide a superconducting coil device and a superconducting coil inspection method that can easily and safely detect abnormalities in a superconducting coil by measuring the voltage across the superconducting coil.

  In order to solve the above problems, a superconducting coil device according to the present invention includes a vacuum container, a heat shield container accommodated in the vacuum container, a superconducting coil accommodated in the heat shield container, and an abnormality of the superconducting coil. A heating unit that raises the temperature of the superconducting coil at the time of detection; a current control unit that supplies current to the superconducting coil; and a heating unit that is heated by the heating unit and energized from the current control unit. A voltage measuring unit that measures a voltage and determines that the superconducting coil is abnormal when the voltage exceeds a predetermined threshold value is provided.

  Further, the superconducting coil device according to the present invention includes a vacuum container, a heat shield container accommodated in the vacuum container, a superconducting coil accommodated in the heat shield container, and an abnormality in the superconducting coil. A magnetic field generating coil that applies a magnetic field to the superconducting coil, a current control unit that supplies a current to the superconducting coil, a magnetic field that is applied to the magnetic field generating coil and that is supplied from the current control unit, at both ends of the superconducting coil A voltage measuring unit that measures a voltage and determines that the superconducting coil is abnormal when the voltage exceeds a predetermined threshold value is provided.

  Furthermore, in the method for inspecting a superconducting coil according to the present invention, when the heating unit heats the superconducting coil and the current control unit energizes the superconducting coil, the voltage measuring unit measures the voltage across the superconducting coil, When the voltage exceeds a predetermined threshold, the superconducting coil is determined to be abnormal.

  INDUSTRIAL APPLICABILITY The present invention can provide a superconducting coil device and a superconducting coil inspection method that can easily and safely detect abnormalities in a superconducting coil by measuring the voltage across the superconducting coil.

  Embodiments of a superconducting coil device and a superconducting coil inspection method according to the present invention will be described with reference to the accompanying drawings.

[First Embodiment]
A first embodiment of a superconducting coil device and a superconducting coil inspection method according to the present invention will be described with reference to FIGS.

  FIG. 1 is a schematic configuration diagram showing a superconducting coil device according to a first embodiment of the present invention.

  As shown in FIG. 1, a superconducting coil device 1 includes a superconducting coil 2, a vacuum vessel 3, a refrigerator 4, a power source 5, a voltage measuring unit 6, a current control unit 7, a heater 8, and heater control. Part 9.

  Superconducting coil 2 is formed by winding superconducting tape wire 11. The superconducting tape wire 11 is, for example, a metallic superconducting wire. An oxide-based high-temperature superconducting wire may also be used. As the high-temperature superconducting wire, for example, bismuth (for example, Bi2223 phase, Bi2212 phase), yttrium (for example, YBCO), thallium (Tl), or mercury (Hg) is used.

  The superconducting coil 2 is accommodated in the vacuum vessel 3, and the atmosphere of the superconducting coil 2 is maintained in a vacuum state by the vacuum vessel 3.

  The refrigerator 4 includes a first stage 13 and a second stage 14 and has a multistage cooling structure. The first stage 13 and the second stage 14 are insulated by the heat shield container 15 accommodated in the vacuum container 3. The two-stage stage 14 is thermally connected to the superconducting coil 2 via the cooling plate 16. Further, the superconducting coil 2 is accommodated in the heat shield container 15.

  The power source 5 excites the superconducting coil 2. The power source 5 is electrically connected to the superconducting coil 2 via current leads 17 connected to electrode portions at both ends of the superconducting coil 2. The current lead 17 and the vacuum vessel 3 are electrically insulated. The power source 5 may be any device as long as it can excite the superconducting coil 2.

  The voltage measuring unit 6 measures the voltage across the superconducting coil 2.

  The voltage measuring unit 6 is an abnormality detector that determines whether or not the voltage across the superconducting coil 2 exceeds a predetermined threshold. The voltage measuring unit 6 determines that the superconducting coil 2 is abnormal when the voltage across the superconducting coil 2 exceeds a predetermined threshold. The predetermined threshold is determined by the shape and size of the superconducting coil 2, the temperature, the current supplied to the superconducting coil 2, the magnetic field applied to the superconducting coil 2, and the material of the superconducting tape wire 11.

  Further, the voltage measuring unit 6 acquires the current value supplied from the current control unit 7 to the superconducting coil 2 and acquires the temperature of the superconducting coil 2 from the heater control unit 9. The voltage measuring unit 6 periodically records the voltage across the superconducting coil 2, the current value supplied to the superconducting coil 2, and the temperature of the superconducting coil 2. The voltage measuring unit 6 determines that the superconducting coil 2 is abnormal when the relationship between the recorded voltage, current, and temperature exceeds a predetermined range. The predetermined range includes various error factors such as tolerance of the shape and size of the superconducting coil 2, temperature measurement error, measurement error of the current supplied to the superconducting coil 2, and error of the magnetic field applied to the superconducting coil 2. It is decided by. It can also be determined by a statistical method from the records of the voltage across the superconducting coil 2, the current value supplied to the superconducting coil 2, and the temperature of the superconducting coil 2.

  The current control unit 7 acquires the determination result of the presence or absence of abnormality of the superconducting coil 2 from the voltage measurement unit 6. The current control unit 7 controls the current flowing through the superconducting coil 2 based on the determination result. For example, when the voltage measuring unit 6 detects an abnormality in the superconducting coil 2, the current control unit 7 rapidly decreases the output current of the power supply 5 or cuts off the supply. That is, the current control unit 7 is also a protection unit for the superconducting coil 2.

  The heater 8 is provided on the second stage 14 of the refrigerator 4. The heater 8 raises the temperature of the superconducting coil 2 via the two-stage stage 14 and the cooling plate 16. The heater 8 is an electric heater that is heated by electric power supplied from the heater control unit 9.

  The heater control unit 9 controls the heater 8. The heater 8 and the heater control unit 9 are heating units for the superconducting coil 2.

  The superconducting coil device 1 controls the temperature of the superconducting coil 2 by the refrigerator 4 in the normal operation. Specifically, if the superconducting coil 2 is a high-temperature superconducting coil, the temperature of the superconducting coil 2 is controlled to approximately 20K.

  On the other hand, the superconducting coil device 1 raises the temperature of the superconducting coil 2 by the heater 8 when inspecting the presence or absence of abnormality such as deterioration of the superconducting coil 2. Specifically, if the superconducting coil 2 is a high-temperature superconducting coil, the temperature of the superconducting coil 2 is changed from approximately 20K to approximately 70K. The superconducting coil device 1 raises the temperature of the superconducting coil 2, energizes the superconducting coil 2, and measures the voltage across the superconducting coil 2.

  FIG. 2 is a schematic configuration diagram showing the superconducting coil of the superconducting coil device according to the first embodiment of the present invention.

  As shown in FIG. 2, the superconducting coil 2 includes a superconducting tape wire 11 and a winding frame 21.

  The superconducting tape wire 11 is formed to have a width of 4.4 mm and a thickness of 0.2 mm, for example.

  The winding frame 21 is formed with an inner diameter of 50 mm, for example, and the superconducting tape wire 11 is wound 86 turns.

  FIG. 3 is a diagram showing an example of the temperature dependence of the critical current of the superconducting tape wire used in the superconducting coil device according to the first embodiment of the present invention.

  FIG. 3 shows the critical current values Ic when the magnetic field application angle with respect to the wide surface of the superconducting tape wire 11 is 90 degrees and the magnetic fields are 0.5T, 1.0T, 2.0T, and 3.0T, respectively. The temperature dependence of the value Ic / Ic (77K, 0T) divided by the critical current value Ic (77K, 0T) in a self magnetic field at a temperature of 77K is shown.

  Here, the critical current value is a current value when an electric field of 1 μV / cm is generated in the superconducting tape wire 11.

  As shown in FIG. 3, the superconducting tape wire 11 has a smaller critical current value as the temperature is higher, unless the strength of the magnetic field is changed. That is, the superconducting tape wire 11 has a characteristic that the critical current value decreases as the temperature rises.

  FIG. 4 is a diagram showing an example of the relationship between the critical current value and the temperature for the superconducting coil of the superconducting coil device according to the first embodiment of the present invention.

  As shown in FIG. 4, the superconducting coil 2 has a smaller critical current value as the temperature is higher. That is, the superconducting coil 2 has a characteristic that the critical current value decreases as the temperature rises. Specifically, if the superconducting coil 2 is a high-temperature superconducting coil, the superconducting coil 2 has a critical current value of about 386 A when the temperature is about 20 K, and the critical current value when the temperature is about 70 K. It is approximately 87A.

  The superconducting coil device 1 supplies a current to the superconducting coil 2 to the vicinity of the critical current in order to detect whether there is an abnormality such as deterioration of the superconducting coil 2, and compares the coil voltage with a predetermined threshold value. The superconducting coil device 1 determines that the superconducting coil 2 has an abnormality such as deterioration if the coil voltage is higher than a predetermined threshold.

  Further, the superconducting coil device 1 detects the voltage at both ends of the superconducting coil 2, the current value supplied to the superconducting coil 2, and the temperature of the superconducting coil 2 in order to detect the presence or absence of abnormality such as deterioration of the superconducting coil 2. Record regularly. Superconducting coil device 1 determines that superconducting coil 2 is abnormal when the relationship among voltage, current, and temperature exceeds a predetermined range.

  Here, when the superconducting coil device 1 inspects the superconducting coil 2, the superconducting coil 2 is heated by the heater 8. When the temperature of the superconducting coil 2 rises to, for example, about 70K, the critical current value of the superconducting coil 2 can be reduced.

  Therefore, according to the superconducting coil device 1, the electromagnetic force applied to the superconducting tape wire 11 is reduced by reducing the current value necessary for detecting the abnormality of the superconducting coil 2, and the current is supplied when an abnormal voltage occurs. The time to shut off can be shortened. If the time for interrupting the supply of current is shortened, the risk of the coil burning out during inspection of the superconducting coil 2 is reduced.

  Therefore, according to the superconducting coil device 1 of the present embodiment, the voltage across the superconducting coil 2 can be measured, and the abnormality of the superconducting coil 2 can be detected simply and safely.

[Second Embodiment]
A second embodiment of a superconducting coil device and a superconducting coil inspection method according to the present invention will be described with reference to FIGS.

  FIG. 5 is a schematic configuration diagram showing a superconducting coil device according to a second embodiment of the present invention.

  In the superconducting coil device 1A according to the present embodiment, the same components as those of the superconducting coil device 1 of the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

  As shown in FIG. 5, the superconducting coil device 1A includes a superconducting coil 2, a vacuum vessel 3, a refrigerator 4, a power source 5, a voltage measuring unit 6, a current control unit 7, a heater 8A, and heater control. Part 9A.

  The heater 8A is provided in the superconducting coil 2. The heater 8 </ b> A changes the temperature of the superconducting coil 2.

  The heater control unit 9A controls the heater 8A. The heater 8 </ b> A and the heater control unit 9 </ b> A are heating units for the superconducting coil 2.

  FIG. 6 is a schematic configuration diagram showing a superconducting coil and a heater of the superconducting coil device according to the second embodiment of the present invention.

  As shown in FIG. 6, the superconducting coil 2 of the superconducting coil device 1A is provided with a plurality of heaters 8A. The plurality of heaters 8A are arranged substantially concentrically on the bottom surface 22 of the superconducting coil 2 formed in a cylindrical shape.

  The superconducting coil device 1 </ b> A heats any of the heaters 8 </ b> A when inspecting whether there is an abnormality such as deterioration of the superconducting coil 2. As a result, the temperature of the superconducting coil 2 partially rises. That is, a temperature gradient is generated in the circumferential direction of the superconducting coil 2. Of the superconducting coil 2, the critical current value decreases in the portion where the temperature has increased, and therefore the current value necessary for detecting an abnormality decreases compared to other portions where the temperature has not increased. Then, the superconducting coil device 1A can weight the portion of the superconducting coil 2 where it is desired to check whether there is an abnormality. At this time, when the voltage between both ends of the superconducting coil 2 is measured, the voltage generated at the portion where the temperature has risen becomes dominant.

  The superconducting tape wire 11 has a characteristic that the critical current decreases as the temperature rises. For this reason, when the temperature of the superconducting coil 2 changes, the position of the superconducting tape wire 11 where the maximum voltage is generated changes.

  That is, the superconducting coil device 1 </ b> A can change the distribution of the voltage generated in the superconducting coil 2 by generating a temperature gradient in the circumferential direction inside the superconducting coil 2 and energizing the superconducting coil 2 with current. Become.

  Further, the ratio of the voltage generated at a part of the superconducting tape wire 11 to the voltage at both ends of the superconducting coil 2 by measuring the voltage at both ends of the superconducting coil 2 by generating a temperature gradient in the circumferential direction inside the superconducting coil 2. Can be changed. If it does so, an abnormal location can be specified easily by changing the heating position of superconducting coil 2 one by one.

  Therefore, according to 1 A of the superconducting coil apparatus of this embodiment, the abnormality of the superconducting coil 2 can be detected simply and safely by measuring the voltage across the superconducting coil 2.

[Third Embodiment]
A superconducting coil device and a superconducting coil inspection method according to a third embodiment of the present invention will be described with reference to FIGS.

  FIG. 7 is a schematic configuration diagram illustrating a superconducting coil device according to a third embodiment of the present invention.

  In the superconducting coil device 1B according to the present embodiment, the same components as those of the superconducting coil device 1 according to the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

  As shown in FIG. 7, the superconducting coil device 1B includes a superconducting coil 2A, a vacuum vessel 3, a refrigerator 4, a power source 5, a voltage measuring unit 6, a current control unit 7, a heater 8, and heater control. Part 9.

  Superconducting coil 2A is formed by winding superconducting tape wire 11A. The superconducting tape wire 11A is, for example, an oxide-based high-temperature superconducting wire. As the high-temperature superconducting wire, for example, yttrium (for example, YBCO) is used.

  FIG. 8 is a schematic configuration diagram showing a superconducting coil of the superconducting coil device according to the third embodiment of the present invention.

  As shown in FIG. 8, the superconducting coil 2 </ b> A includes a superconducting tape wire 11 </ b> A and a winding frame 21.

  The superconducting tape wire 11A is formed to have a width of 4.4 mm and a thickness of 0.2 mm, for example.

  The winding frame 21 is formed with an inner diameter of 50 mm, for example, and the superconducting tape wire 11A is wound 86 turns.

  FIG. 9 is a diagram showing an example of the magnetic field dependence of the critical current of the superconducting tape wire used in the superconducting coil device according to the third embodiment of the present invention.

  FIG. 9 shows the critical current value Ic when the temperature of the superconducting tape wire 11A is 40K, 60K, and 70K, and the magnetic field application angle with respect to the wide surface of the superconducting tape wire 11A is 0 degree or 90 degrees. Shows the magnetic field dependence of the value Ic / Ic (77K, 0T) divided by the critical current value Ic (77K, 0T) in the self-magnetic field.

  As shown in FIG. 9, the superconducting tape wire 11A is less dependent on the magnetic field application angle as the temperature is higher. That is, the superconducting tape wire 11A has a characteristic that the dependence of the critical current on the magnetic field angle decreases as the temperature increases.

  10 to 12 are diagrams showing the relationship between the voltage generated at each turn and the temperature of the superconducting coil in the superconducting coil of the superconducting coil device according to the third embodiment of the present invention. FIG. 10 is a diagram showing a case where the temperature of the superconducting coil is 20K. FIG. 11 is a diagram showing a case where the temperature of the superconducting coil is 60K. Further, FIG. 12 is a diagram showing a case where the temperature of the superconducting coil is 70K.

  The voltage generated at each turn of the superconducting coil 2A is a value normalized with the voltage of the turn at which the maximum voltage is generated as a representative value. Further, the superconducting tape wire 11A in the innermost layer of the superconducting coil 2A is defined as the first turn.

  As shown in FIG. 10, when the temperature of the superconducting coil 2A was 20K, the maximum voltage was generated at the 37th turn of the superconducting tape wire 11A.

  Further, as shown in FIG. 11, when the temperature of the superconducting coil 2A was 60K, the maximum voltage was generated at the 23rd turn of the superconducting tape wire 11A.

  Furthermore, as shown in FIG. 12, when the temperature of the superconducting coil 2A was 70K, the maximum voltage was generated at the first turn of the superconducting tape wire 11A.

  When a current is passed through the superconducting coil 2A, a magnetic field is applied to each turn of the superconducting tape wire 11A, and a voltage is generated in the superconducting coil 2A. At this time, the magnitude and angle of the magnetic field received by each turn of the superconducting tape wire 11A differ due to the influence of the gradient of the magnetic field generated in the superconducting coil 2A. Therefore, the voltage generated by each turn of the superconducting tape wire 11A is different. When the voltage across the superconducting coil 2A is measured, the voltage near the turn where the maximum voltage is generated in the superconducting tape wire 11A becomes dominant.

  The superconducting tape wire 11A has a characteristic that the dependence of the critical current on the magnetic field angle decreases as the temperature increases. For this reason, when the temperature of the superconducting coil 2A changes, the turn position of the superconducting tape wire 11A where the maximum voltage is generated is different.

  That is, the superconducting coil device 1B can change the distribution of the voltage generated in the superconducting coil 2A by changing the temperature of the superconducting coil 2A and passing a current through the superconducting coil 2A.

  Further, by changing the temperature of the superconducting coil 2A and measuring the voltage across the superconducting coil 2A, the ratio of the voltage generated at each turn of the superconducting tape wire 11A to the voltage across the superconducting coil 2A can be changed. It becomes possible.

  Therefore, according to the superconducting coil device 1B of the present embodiment, the voltage across the superconducting coil 2A can be measured, and the abnormality of the superconducting coil 2A can be detected simply and safely.

[Fourth Embodiment]
A superconducting coil device and a superconducting coil inspection method according to a fourth embodiment of the present invention will be described with reference to FIGS.

  FIG. 13 is a schematic configuration diagram illustrating a superconducting coil device according to a fourth embodiment of the present invention.

  In the superconducting coil device 1C according to the present embodiment, the same components as those of the superconducting coil device 1 according to the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

  As shown in FIG. 13, the superconducting coil device 1C includes a superconducting coil 2, a vacuum vessel 3, a refrigerator 4, a power source 5, a voltage measuring unit 6, a current control unit 7, a heater 8B, and heater control. Part 9B.

  The heater 8B is provided in the superconducting coil 2. The heater 8B changes the temperature of the superconducting coil 2.

  The heater control unit 9B controls the heater 8B. The heater 8B and the heater control unit 9B are heating units for the superconducting coil 2.

  FIG. 14 is a schematic configuration diagram showing a superconducting coil and a heater of a superconducting coil device according to the fourth embodiment of the present invention.

  As shown in FIG. 14, the heater 8 </ b> B of the superconducting coil device 1 </ b> C includes an inner peripheral heater 24 and an outer peripheral heater 25. The inner peripheral heater 24 is a bottom surface 22 of the superconducting coil 2 formed in a cylindrical shape, and is provided biased to the inner peripheral edge. The outer peripheral side heater 25 is a bottom surface 22 of the superconducting coil 2 formed in a cylindrical shape, and is provided biased to the outer peripheral edge.

  The inner peripheral heater 24 and the outer peripheral heater 25 are connected to the heater control unit 9B.

  The superconducting coil device 1C changes the temperature of the superconducting coil 2 by the heater 8B when inspecting the presence or absence of abnormality such as deterioration of the superconducting coil 2. Specifically, the heater 8B generates a temperature gradient between the inner peripheral side and the outer peripheral side in the superconducting coil 2 due to the temperature difference between the inner peripheral heater 24 and the outer peripheral heater 25, that is, in the radial direction. The superconducting coil device 1 </ b> C generates a temperature gradient in the radial direction inside the superconducting coil 2, energizes the superconducting coil 2, and measures the voltage across the superconducting coil 2.

  When a current is passed through the superconducting coil 2, a magnetic field is applied to each turn of the superconducting tape wire 11 and a voltage is generated in the superconducting coil 2. At this time, the magnitude and angle of the magnetic field received by each turn of the superconducting tape wire 11 differ depending on the influence of the gradient of the magnetic field generated in the superconducting coil 2. Therefore, the voltage generated by each turn of the superconducting tape wire 11 is different. When the voltage at both ends of the superconducting coil 2 is measured, the voltage near the turn where the maximum voltage is generated in the superconducting tape wire 11 becomes dominant.

  Here, the superconducting tape wire 11 has a characteristic that the critical current decreases as the temperature rises regardless of the magnetic field angle dependency. For this reason, when a temperature gradient is appropriately applied in the radial direction inside the superconducting coil 2, the difference in voltage generated at each turn of the superconducting tape wire 11 can be reduced or increased.

  That is, the superconducting coil device 1C applies a temperature gradient in the radial direction inside the superconducting coil 2 and energizes the superconducting coil 2 so that the voltage generated at each turn of the superconducting tape wire 11 is applied to both ends of the superconducting coil 2. It becomes possible to make the proportion of the voltage approximately equal.

  Also, the superconducting coil device 1C applies a temperature gradient in the radial direction inside the superconducting coil 2 and energizes the superconducting coil 2 to generate a voltage generated at any turn of the superconducting tape wire 11. It becomes possible to make it the maximum ratio which occupies for the voltage of both ends of 2.

  Therefore, according to the superconducting coil device 1C of this embodiment, the voltage across the superconducting coil 2 can be measured, and the abnormality of the superconducting coil 2 can be detected simply and safely.

[Fifth Embodiment]
A fifth embodiment of a superconducting coil device and a superconducting coil inspection method according to the present invention will be described with reference to FIG.

  FIG. 15 is a schematic configuration diagram illustrating a superconducting coil device according to a fifth embodiment of the present invention.

  In the superconducting coil device 1D according to the present embodiment, the same components as those of the superconducting coil device 1 of the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

  As shown in FIG. 15, the superconducting coil device 1D includes a superconducting coil 2, a vacuum container 3, a refrigerator 4, a power source 5, a voltage measuring unit 6, a current control unit 7, a magnetic field generating coil 27, And a magnetic field generating coil controller 28.

  The magnetic field generating coil 27 is accommodated in the vacuum vessel 3. A plurality of magnetic field generating coils 27 are provided around the superconducting coil 2, for example, two sandwiching the superconducting coil 2. The magnetic field generating coil 27 applies a magnetic field around the superconducting coil 2. The magnetic field generating coil 27 generates a magnetic field having a uniform strength or a magnetic field with appropriate strength distribution. A superconducting coil can be used as the magnetic field generating coil 27.

  The magnetic field generation coil control unit 28 controls the magnetic field generation coil 27.

  On the other hand, the superconducting coil device 1D applies a magnetic field to the superconducting coil 2 by the magnetic field generating coil 27 when inspecting the presence / absence of abnormality such as deterioration of the superconducting coil 2.

  In order to detect the presence or absence of abnormality such as deterioration of the superconducting coil 2, a current is passed through the superconducting coil 2 to near the critical current, and the coil voltage is compared with a predetermined threshold value. If the coil voltage is higher than a predetermined threshold, it is determined that there is an abnormality such as deterioration of the superconducting coil 2.

  Here, the superconducting coil device 1 </ b> D applies a magnetic field to the superconducting coil 2 by the magnetic field generating coil 27 when inspecting the superconducting coil 2. When a magnetic field is applied to the superconducting coil 2, the critical current value of the superconducting coil 2 can be reduced.

  Therefore, according to the superconducting coil device 1D, by reducing the current value necessary for detecting an abnormality such as deterioration of the superconducting coil 2, it is possible to shorten the time for interrupting the supply of current when an abnormal voltage occurs. If the time for interrupting the supply of current is shortened, the risk of the coil burning out during inspection of the superconducting coil 2 is reduced.

  In addition, the superconducting coil device 1D applies a magnetic field whose intensity is appropriately distributed to the superconducting coil 2 by the magnetic field generating coil 27. Then, the critical current value of the superconducting coil 2 is also distributed in the superconducting coil 2 according to the strength of the applied magnetic field.

  That is, the superconducting coil device 1D applies a magnetic field having an appropriately distributed intensity to the superconducting coil 2 and energizes the superconducting coil 2 so that the voltage generated at each turn of the superconducting tape wire 11 is superconducting coil. It is possible to make the ratio of the voltage at both ends of 2 substantially equal.

  In addition, the superconducting coil device 1D applies a magnetic field with appropriately distributed strength to the superconducting coil 2 and energizes the superconducting coil 2 to generate a voltage generated at any location of the superconducting tape wire 11. It is possible to make the maximum ratio of the voltage across the superconducting coil 2.

  Therefore, according to the superconducting coil device 1D of this embodiment, the voltage across the superconducting coil 2 can be measured, and the abnormality of the superconducting coil 2 can be detected simply and safely.

[Sixth Embodiment]
A sixth embodiment of the superconducting coil device and superconducting coil inspection method according to the present invention will be described with reference to FIG.

  FIG. 16 is a schematic configuration diagram illustrating a superconducting coil device according to a sixth embodiment of the present invention.

  In the superconducting coil device 1E according to the present embodiment, the same components as those in the superconducting coil device 1 according to the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

  As shown in FIG. 16, the superconducting coil device 1 </ b> E includes a superconducting coil group 30, a vacuum vessel 3, a refrigerator 4, a power source 5, a voltage measuring unit 6, and a current control unit 7.

  The superconducting coil group 30 includes a plurality of superconducting coils 2. The plurality of superconducting coils 2 are arranged in a toroidal shape, for example. Further, it may be arranged in a multipole shape.

  In order to detect the presence or absence of abnormality such as deterioration of the superconducting coil 2, a current is passed through the superconducting coil 2 to near the critical current, and the coil voltage is compared with a predetermined threshold value. If the coil voltage is higher than a predetermined threshold, it is determined that there is an abnormality such as deterioration of the superconducting coil 2.

  Here, when the superconducting coil device 1 </ b> E inspects the superconducting coil 2, the superconducting coil group 30 selects one or more superconducting coils 2 to be inspected from the superconducting coil group 30. It is assumed that the superconducting coil group 30 includes N superconducting coils 2 and selects M superconducting coils 2 to be inspected. There are N> M relationships.

  When inspecting the superconducting coils 2, the current control unit 7 supplies current to the (N−M) superconducting coils 2 (superconducting coils 2 for generating a magnetic field), and M superconducting coils 2 ( A magnetic field is applied to the superconducting coil 2) to be inspected. When the magnetic field is applied to the M superconducting coils 2, the critical current value decreases.

  Therefore, according to the superconducting coil device 1E, by reducing the current value necessary for detecting an abnormality such as deterioration of the superconducting coil 2, it is possible to shorten the time for interrupting the supply of current when an abnormal voltage occurs. If the time for interrupting the supply of current is shortened, the risk of the coil burning out during inspection of the superconducting coil 2 is reduced.

  Further, in the superconducting coil device 1E, the strength is appropriately distributed to M superconducting coils 2 (superconducting coils 2 to be inspected) by (N−M) superconducting coils 2 (superconducting coils 2 for generating a magnetic field). Apply a magnetic field. Then, the critical current value of the M superconducting coils 2 (superconducting coils 2 to be inspected) is distributed in each superconducting coil 2 according to the strength of the applied magnetic field.

  That is, the superconducting coil device 1E applies a magnetic field with appropriately distributed strength to the superconducting coil 2 and energizes the superconducting coil 2 so that the voltage generated at each turn of the superconducting tape wire 11 is superconducting coil. It is possible to make the ratio of the voltage at both ends of 2 substantially equal.

  In addition, the superconducting coil device 1E applies a magnetic field with appropriately distributed strength to the superconducting coil 2 and applies a current to the superconducting coil 2, thereby generating a voltage generated at any location of the superconducting tape wire 11. It is possible to make the maximum ratio of the voltage across the superconducting coil 2.

  Therefore, according to the superconducting coil device 1E of this embodiment, the voltage across the superconducting coil 2 can be measured, and the abnormality of the superconducting coil 2 can be detected simply and safely.

The schematic block diagram which showed the superconducting coil apparatus which concerns on 1st Embodiment of this invention. The schematic block diagram which showed the superconducting coil of the superconducting coil apparatus which concerns on 1st Embodiment of this invention. The figure which showed an example of the temperature dependence of the critical current of the superconducting tape wire used for the superconducting coil apparatus which concerns on 1st Embodiment of this invention. The figure which showed an example of the relationship between a critical current value and temperature about the superconducting coil of the superconducting coil apparatus which concerns on 1st Embodiment of this invention. The schematic block diagram which showed the superconducting coil apparatus which concerns on 2nd Embodiment of this invention. The schematic block diagram which showed the superconducting coil and heater of the superconducting coil apparatus which concern on 2nd Embodiment of this invention. The schematic block diagram which showed the superconducting coil apparatus which concerns on 3rd Embodiment of this invention. The schematic block diagram which showed the superconducting coil of the superconducting coil apparatus which concerns on 3rd Embodiment of this invention. The figure which showed an example of the magnetic field dependence of the critical current of the superconducting tape wire used for the superconducting coil apparatus which concerns on 3rd Embodiment of this invention. The figure which showed the relationship between the voltage which generate | occur | produces in each turn, and the temperature of a superconducting coil about the superconducting coil of the superconducting coil apparatus which concerns on 3rd Embodiment of this invention. The figure which showed the relationship between the voltage which generate | occur | produces in each turn, and the temperature of a superconducting coil about the superconducting coil of the superconducting coil apparatus which concerns on 3rd Embodiment of this invention. The figure which showed the relationship between the voltage which generate | occur | produces in each turn, and the temperature of a superconducting coil about the superconducting coil of the superconducting coil apparatus which concerns on 3rd Embodiment of this invention. The schematic block diagram which showed the superconducting coil apparatus which concerns on 4th Embodiment of this invention. The schematic block diagram which showed the superconducting coil and heater of the superconducting coil apparatus which concern on 4th Embodiment of this invention. The schematic block diagram which showed the superconducting coil apparatus which concerns on 5th Embodiment of this invention. The schematic block diagram which showed the superconducting coil apparatus which concerns on 6th Embodiment of this invention.

Explanation of symbols

1, 1A, 1B, 1C, 1D, 1E Superconducting coil device 2, 2A Superconducting coil 3 Vacuum container 4 Refrigerator 5 Power supply 6 Voltage measuring unit 7 Current control unit 8, 8A, 8B Heater 9, 9A, 9B Heater control unit 11 11A Superconducting tape wire 13 First stage 14 Second stage 15 Heat shield container 16 Cooling plate 17 Current lead 21 Winding frame 22 Bottom surface 24 Inner side heater 25 Outer side heater 27 Magnetic field generating coil 28 Magnetic field generating coil control unit 30 Superconducting coil group

Claims (11)

A vacuum vessel;
A heat shield container housed in the vacuum container;
A superconducting coil housed in the heat shield container;
A heating unit that increases the temperature of the superconducting coil when detecting an abnormality in the superconducting coil;
A current control unit for energizing the superconducting coil;
A voltage measuring unit that measures the voltage across the superconducting coil heated by the heating unit and energized from the current control unit, and determines that the superconducting coil is abnormal when the voltage exceeds a predetermined threshold; A superconducting coil device comprising: The heating unit is
The superconducting coil device according to claim 1, wherein a temperature gradient is generated in a circumferential direction inside the superconducting coil when an abnormality of the superconducting coil is detected. 2. The superconducting coil device according to claim 1, wherein the superconducting coil includes a superconducting tape wire having a characteristic that the dependence of the critical current on the magnetic field angle decreases as the temperature rises. The heating unit is
The superconducting coil device according to claim 1 or 3, wherein a temperature gradient is generated in a radial direction inside the superconducting coil when an abnormality of the superconducting coil is detected. The heating unit is
An electric heater for heating the superconducting coil;
The superconducting coil device according to any one of claims 1 to 4, further comprising a control unit for the electric heater. The voltage measuring unit records the voltage at both ends of the superconducting coil, the current value passed through the superconducting coil, and the temperature of the superconducting coil, and the relationship between the voltage, the current, and the temperature is predetermined. The superconducting coil device according to any one of claims 1 to 5, wherein the superconducting coil is determined to be abnormal when exceeding the range. A vacuum vessel;
A heat shield container housed in the vacuum container;
A superconducting coil housed in the heat shield container;
A magnetic field generating coil that applies a magnetic field to the superconducting coil when detecting an abnormality in the superconducting coil;
A current control unit for energizing the superconducting coil;
Voltage measurement is performed by measuring a voltage across the superconducting coil that is applied with a magnetic field to the magnetic field generating coil and energized from the current control unit, and when the voltage exceeds a predetermined threshold, And a superconducting coil device. The superconducting coil device according to claim 7, wherein the magnetic field generating coil is a superconducting coil. A superconducting coil group having a plurality of the superconducting coils;
The current control unit selects at least one superconducting coil to be inspected from the superconducting coil group and less than the total number, selects the remainder of the superconducting coil group as a superconducting coil for magnetic field generation, and applies a magnetic field to the superconducting coil for magnetic field generation, And a voltage measuring unit that measures the voltage at both ends of the inspection target superconducting coil energized from the current control unit, and determines that the inspection target superconducting coil is abnormal when the voltage exceeds a predetermined threshold. The superconducting coil device according to claim 7. The superconducting coil device according to claim 9, wherein the superconducting coil group is arranged in a toroidal shape or a multipole shape. The heating unit heats the superconducting coil,
When the current control unit supplies current to the superconducting coil,
A method for inspecting a superconducting coil, wherein a voltage measuring unit measures a voltage at both ends of the superconducting coil, and determines that the superconducting coil is abnormal when the voltage exceeds a predetermined threshold.

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