JP2014229753A - Quench detector and quench detection method of superconducting coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a quench detector and a quench detection method of a superconducting coil which allows for high sensitivity and high speed quench detection, and thereby enhancement of reliability of a superconducting coil, without being affected by noise from a power supply.SOLUTION: A superconducting coil is formed by winding four tape-like superconducting wire rods 11a, 11b, 11c, 11d, where a superconducting layer is formed of a rare earth oxide superconductor on a substrate, spirally while superposing. A plurality of current detection elements 18a, 18b, 18c, 18d for measuring the strand current are provided at one side edge of each superconducting wire rod 11a-11d, and a bridge circuit is configured by detection signals detected by these current detection elements 18a-18d. A determination is made that quench has occurred, when balance cannot be maintained in the bridge circuit.

Description

  The present invention relates to a quench detection device and a quench detection method for a superconducting coil that can quickly detect a quench in which a superconducting coil shifts from a superconducting state to a normal conducting state and avoid an abnormal situation.

  Various devices have been proposed for detecting a quench in which a superconducting coil cannot maintain a superconducting state and shifts to a normal conducting state. As such a quench detection device, for example, a device that detects a voltage (potential difference) between both electrodes of a superconducting coil and determines that a quench has occurred when a voltage higher than a certain level is detected is known.

  As a quench detection device for this type of superconducting coil, for example, a quench detection device described in Patent Document 1 is known. That is, in this quench detection device, two intermediate taps are derived from the superconducting coil, and the fixed terminal of the three-terminal variable resistor is connected between the two intermediate taps, and is connected in series between both coil ends of the superconducting coil. These two bridge resistors are connected.

  A bridge circuit is configured by the superconducting coil and the bridge resistor, and the movable terminal of the three-terminal variable resistor and the common connection point of both bridge resistors serve as the detection output terminal. According to this quench detection device, it is possible to detect quenching of a superconducting coil generated in an arbitrary coil portion that is separated.

JP 7-174803 A

  In the quench detection device of the conventional configuration described in Patent Document 1 described above, when a quench occurs in a part of the superconducting coil, a normal conduction resistance component is generated in the coil part, and thus the bridge circuit is unbalanced. Quench is detected. However, in the rare-earth oxide superconductor, since the rate of occurrence of electrical resistance due to quenching is slow, the coil may locally rise in temperature, and the superconducting wire may be melted. Furthermore, it is difficult to reduce the voltage value for determining the quench due to noise generated from the power source, and therefore there is a problem that the delay of the quench detection is likely to occur and the detection accuracy is lowered.

  Accordingly, an object of the present invention is to quench a superconducting coil that can perform quench detection with high sensitivity and high speed without being affected by noise from the power source, and can improve the reliability of the superconducting coil. The object is to provide a detection device and a quench detection method.

  In order to achieve the above object, a superconducting coil quench detection device according to the invention of claim 1 is formed by winding a tape-shaped superconducting wire having a superconducting layer formed of a rare earth oxide superconductor on a substrate. A superconducting coil quench detection device that forms a superconducting coil by winding a plurality of superconducting wires, and measures and detects a strand current on at least one side edge of each superconducting wire. A current detection element that emits a signal is provided, a bridge circuit is configured by a plurality of detection signals from the current detection elements, and it is possible to determine that quenching has occurred when equilibrium is not maintained in the bridge circuit. .

  The quench detection device for a superconducting coil according to a second aspect of the present invention is the invention according to the first aspect, wherein the current detection elements of the respective superconducting wires are arranged on a line extending in the radial direction from the center of the superconducting coil. It is characterized by.

  A quench detection device for a superconducting coil according to a third aspect of the present invention is the invention according to the first or second aspect, wherein the superconducting coil is formed by winding four superconducting wires. A current detection element is provided on one side edge of each superconducting wire.

  According to a fourth aspect of the present invention, there is provided the superconducting coil quench detection device according to any one of the first to third aspects, wherein the current detection element is a Hall element and the detection signal is a Hall voltage. It is characterized by that.

  The superconducting coil quench detection device according to claim 5 is the invention according to any one of claims 1 to 4, wherein the plurality of superconducting wires are sequentially switched between an inner peripheral side and an outer peripheral side. It is characterized by being wound.

  The superconducting coil quench detection device according to a sixth aspect of the invention is the invention according to any one of the first to fifth aspects, wherein the current detection element is located at a position where both side edges of each superconducting wire face each other. One pair is provided.

  A quench detection method for a superconducting coil according to a seventh aspect of the invention is a quench detection method using the quench detection device for a superconducting coil according to any one of the first to sixth aspects, wherein each of the superconducting coils A wire current is measured by a current detection element provided on the wire, a detection signal is generated, a bridge circuit is configured by the plurality of detection signals, and it is detected whether or not the balance of the bridge circuit is maintained. And

According to the present invention, the following effects can be exhibited.
In the superconducting coil quench detection device of the present invention, a superconducting coil is formed by wrapping a plurality of superconducting wires in a superposed state, and at the same time, at least one side edge of the superconducting wire is measured to detect a detection signal. A current sensing element is provided. And the bridge circuit is comprised by the some detection signal by those electric current detection elements.

  As described above, when the superconducting coil is wound in a state where a plurality of superconducting wires are overlapped, and each superconducting wire is provided with a current detection element, the wire current flowing through one of the superconducting wires is reduced. In this case, commutation occurs to compensate for the decreased strand current, and the strand current flowing through the other superconducting wire increases. The increase or decrease in the strand current is detected by the current detection element, and the balance is not maintained in the bridge circuit based on those detection signals. Therefore, in that case, it can be determined that quenching has occurred in the superconducting coil.

  In this case, since the bridge circuit determines the balance based on the relative value such as the ratio of multiple detection signals, even if the absolute value of the detection signal fluctuates due to noise from the power supply of the superconducting coil, the influence is avoided. can do.

  Therefore, according to the quench detection apparatus for a superconducting coil of the present invention, quench detection can be performed with high sensitivity and high speed without being affected by noise from the power source, and the reliability of the superconducting coil can be improved. There is an effect.

It is a figure which shows a part of superconducting coil of embodiment which actualized this invention, Comprising: The perspective view which shows the state which provided the current detection element in the one side edge of four superconducting wires. Sectional drawing which shows a tape-shaped superconducting wire. A superconducting coil is shown, (a) is a top view which shows the state which expanded the superconducting coil and its part, (b) is sectional drawing which shows a superconducting coil. The electric circuit diagram which shows a bridge circuit. The partial perspective view which shows the state which replaces a tape-shaped superconducting wire from an inner peripheral side to an outer peripheral side in the double pancake coil as a superconducting coil. In a double pancake coil, explanatory drawing which shows typically the replacement state of the inner peripheral side and outer peripheral side of four superconducting wires. The graph which shows the time when a heater is attached to one superconducting wire among four superconducting wires, and when the same state as quenching is caused, and the change in the strand current flowing in each superconducting wire. The graph which shows the time when a heater is attached to two superconducting wires among four superconducting wires, and the state similar to quenching is caused, and the change of the strand current flowing through each superconducting wire. The graph which shows the time when a heater is attached to three superconducting wires among four superconducting wires, and when the same state as quenching is caused, and the change in the wire current flowing through each superconducting wire. The perspective view which shows another example of this invention and shows the state which provided the current detection element in the position corresponding to the both-sides edge of four superconducting wires.

Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS.
As shown in FIG. 2, the superconducting wire 11 in the form of a tape has a superconducting layer 14 formed on a substrate 12 via an intermediate layer 13, a first stabilizing layer 15 is formed on the superconducting layer 14, and A second stabilizing layer 16 is coated on the outer peripheral portion of these, and an insulating coating layer 17 is formed so as to cover the second stabilizing layer 16. By providing the insulating coating layer 17 as the outermost layer, electrical insulation between the superconducting wires 11 can be achieved when the superconducting wires 11 are wound in a spiral shape.

The substrate 12 is made of a metal such as nickel alloy (Hastelloy), silver, or silver alloy, for example, to a thickness of 100 μm and a width of 10 mm. The intermediate layer 13 includes gadolinium / zirconium oxide (Gd / Zr oxide), magnesium oxide (MgO), yttrium-stabilized zirconium (YSZ), barium / zirconium oxide (Ba / Zr oxide), cerium oxide (CeO ₂ ). ) And the like, for example, a thickness of 500 nm and a width of 10 mm.

  The superconducting layer 14 is formed, for example, to a thickness of about 1 μm and a width of 10 mm by a rare earth oxide superconductor CVD method (chemical vapor deposition method). As rare earth elements, lanthanum (La), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), dysprosium (Dy), holmium (Ho), erbium (Er), yttrium (Y), And ytterbium (Yb). Examples of rare earth oxides include RE, Ba, Cu, and O. However, RE represents a rare earth element. Specific examples of the superconducting layer 14 include yttrium / barium / copper oxide and lanthanum / barium / copper oxide (La / Ba / Cu oxide).

  The first stabilization layer 15 is formed to have a thickness of about 15 μm and a width of 10 mm, for example, by sputtering metal such as silver. The second stabilization layer 16 is formed to have a thickness of about 50 μm, for example, by plating with a metal such as copper. The insulating coating layer 17 is formed of a synthetic resin such as an epoxy resin.

  As shown in FIGS. 3A and 3B, the superconducting coil 10 is formed by winding the tape-shaped superconducting wire 11 into a coil shape (spiral shape). The superconducting coil 10 may be either a single pancake coil or a double pancake coil. The double pancake coil is formed by stacking a coil formed by winding a tape-shaped superconducting wire 11 in two upper and lower stages through an intermediate frame (not shown).

  When the tape-shaped superconducting wire 11 is wound in a coil shape, the superconducting wire 11 is arranged such that the superconducting layer 14 is located on the inner peripheral side and the substrate 12 is located on the outer peripheral side. By disposing the superconducting layer 14 on the inner peripheral side, the arc of the superconducting layer 14 becomes smaller than the arc on the outer peripheral side of the substrate 12, so that the compressive strain increases and the superconducting coil 10 receives a hoop stress. This is preferable because the tensile strain exerted on the material is relaxed and the resistance to the hoop stress is increased.

  As shown in FIGS. 1 and 3A, in the present embodiment, the superconducting coil 10 is formed by winding four superconducting wires 11a, 11b, 11c, and 11d in a superposed state. On one side edge of each of the superconducting wires 11a to 11d, a first current detecting element 18a, a second current detecting element 18b, a third current detecting element 18c, and a fourth current for measuring a wire current and generating a detection signal. Each of the detection elements 18d is attached. These first to fourth current detection elements 18 a to 18 d are arranged on a line extending in the radial direction from the center of the superconducting coil 10.

  As shown in FIG. 4, the quench detection device for the superconducting coil 10 has a bridge circuit (Wheatstone) based on detection signals generated by the current detection elements 18 a to 18 d provided on the respective side edges of the four superconducting wires 11 a to 11 d. Bridge circuit) 20 is configured, and the quench of the superconducting coil 10 is detected by the bridge circuit 20. The bridge circuit 20 is connected in a rhombus shape by connection lines having the respective current sensing portions 21a, 21b, 21c, and 21d, and a battery 23 is connected between the first connection point 22a and the second connection point 22b facing each other. In addition, a galvanometer 25 is connected between the first intermediate point 24a and the second intermediate point 24b.

  The galvanometer 21 includes a first galvanometer 21a, a second galvanometer 21b, a third galvanometer 21c, and a fourth galvanometer 21d, and a first current attached to each of the superconducting wires 11a to 11d. The detection element 18a, the second current detection element 18b, the third current detection element 18c, and the fourth current detection element 18d are connected by connection lines (not shown). The detection signals detected by the first to fourth current detection elements 18a to 18d are transmitted to the first to fourth galvanometers 21a to 21d, respectively, between the first intermediate point 24a and the second intermediate point 24b. When a minute current flows through the galvanometer 25 and the galvanometer 25 detects the minute current, it is determined that quenching has occurred in the superconducting coil 10. In other words, when the balance of the bridge circuit 20 is not maintained, it is determined that quenching has occurred in the superconducting coil 10.

  On the other hand, when there is no change in the current flowing through each of the superconducting wires 11a to 11d and the current detected by the first to fourth current detection elements 18a to 18d does not vary, the first to fourth current detection portions 21a to 21d. Since there is no change in the detection signal at, current does not flow through the galvanometer 25, and it is determined that quenching has not occurred in the superconducting coil 10. That is, when the bridge circuit 20 is maintained in balance, it is determined that quenching has not occurred in the superconducting coil 10.

  The current detection element 18 is, for example, a Hall element, and its detection signal is a Hall voltage. The Hall element is an application of the Hall effect that shows a magnetic action against current. When a magnetic field is applied to the current flowing in the superconducting wire 11, electrons in the superconducting wire 11 are biased by Lorentz force and a potential difference (Hall as an output voltage) is applied. Voltage).

  As shown in FIG. 5, the four superconducting wires 11a to 11d are wound with the inner peripheral side and the outer peripheral side interchanged. This state will be described in the case of two superconducting wires 11a and 11b. The superconducting wire 11a having one tape shape runs on the superconducting wire 11b having the other tape shape at a predetermined position, so that the inner peripheral side The position and the outer peripheral side position are interchanged. Accordingly, in the case of the four superconducting wires 11a to 11d, the inner and outer positions of the four superconducting wires 11a to 11d are made equal every turn by sequentially switching the inner peripheral side and the outer peripheral side every 90 degrees in the circumferential direction. Can be arranged.

  As shown in FIG. 6, the replacement state of the four superconducting wires 11a to 11d will be schematically described. When the four superconducting wires 11a to 11d are represented by 1, 2, 3, and 4, they are wound in the order of 1, 2, 3, and 4 from the inner peripheral side (left side in FIG. 6) in the upper stage of the double pancake coil. In the lower stage, winding is performed in the order of 4, 3, 2, and 1 from the inner peripheral side. Thus, the strand current which flows into each superconducting wire 11a-11d by replacing the position of the four superconducting wires 11a-11d in the superconducting coil 10 in order from the inner peripheral side to the outer peripheral side by the method shown in FIG. Can be made uniform.

  The quench detection apparatus for the superconducting coil 10 of the present embodiment includes first to fourth current detection elements 18a to 18d attached to the superconducting wires 11a to 11d, and first to fourth current detection elements 18a to 18d. It is comprised by the bridge circuit 20 grade | etc., Formed by the connected 1st-4th current detection part 21a-21d.

  As shown in FIG. 3A, a pair of electrodes 26a and 26b are provided on the outer peripheral portion of the superconducting coil 10 with a metal having good conductivity such as copper. One electrode 26a is connected to the inner peripheral ends of the four superconducting wires 11a to 11d through a lead wire, and the other electrode 26b is bundled to the outer peripheral ends of the four superconducting wires 11a to 11d. Connected with.

Next, a quench detection method using the quench detection device for the superconducting coil 10 configured as described above will be described together with its action.
Now, the superconducting coil 10 of this embodiment is cooled according to a conventional method to be in a superconducting state, and a predetermined current is passed between the electrodes 26a and 26b of the superconducting coil 10 in the superconducting state, thereby energizing in a state without electrical resistance. It can continue and a predetermined magnetic field can be generated.

  In this superconducting state, a part of the superconducting wire 11 constituting the superconducting coil 10 deviates from the superconducting state and shifts to the normal conducting state for some reason, and quenching may occur. The superconducting coil 10 is always monitored by the bridge circuit 20 in order to detect the occurrence of such a quench.

  As shown in FIGS. 1 and 3A, in this embodiment, the superconducting coil 10 is formed by winding four superconducting wires 11a to 11d in a superposed manner, and each superconducting wire 11a to 11d. The first to fourth current detection elements 18a to 18d are attached to one side edge, respectively.

  Therefore, as shown in FIG. 4, the detection signals detected by the first to fourth current detection elements 18 a to 18 d are input to the first to fourth galvanometers 21 a to 21 d of the bridge circuit 20. In this bridge circuit 20, the ratio of the current flowing through the first galvanometer 21a and the current flowing through the second galvanometer 21b is such that the current flowing through the third galvanometer 21c and the current flowing through the fourth galvanometer 21d. In this case, no current flows between the first intermediate point 24a and the second intermediate point 24b, and the value of the galvanometer 25 indicates zero. At this time, it is determined that there is no abnormality in the superconducting coil 10 and the superconducting state is maintained.

  However, when the detection signals from the first to fourth current detection elements 18a to 18d fluctuate, the ratio of the current of the first galvanometer 21a and the current of the second galvanometer 21b is the same as that of the third galvanometer 21c. Unlike the ratio between the current and the current in the fourth galvanometer 21d, a minute current flows between the first intermediate point 24a and the second intermediate point 24b, and the value of the galvanometer 25 shows a constant value. This can be detected. At this time, it is determined that the deviation from the superconducting state starts in a part of the superconducting coil 10 and reaches the quench.

In order to confirm whether or not quench detection of such a superconducting coil 10 is possible, the following test was performed.
That is, as shown in FIG. 7, a heater is attached to one superconducting wire (tape 1) 11a among the four superconducting wires 11a to 11d (heater power is 0.6 W), and the normal conducting state The current flowing through each of the superconducting wires (tapes 1 to 4) 11a to 11d at that time was measured and shown as the relationship between time and current.

  As shown in FIG. 7, in tape 1, the electrical resistance increased in the normal conduction state and the current value decreased greatly, while in tapes 2 to 4, the current value increased due to current commutation. Current commutation means a phenomenon in which when a quench occurs in a certain tape, the current rapidly moves to an adjacent tape. This commutation occurred in a short time of about 1.4 seconds immediately after the normal conducting region was generated. Accordingly, the first to fourth current detection elements 18a to 18d are provided on the tapes 1 to 4 to measure a minute current, and the quench of the superconducting coil 10 can be detected by the bridge circuit 20 based on the detection signals. There was found.

  In this case, the potential difference (voltage) between the electrodes 26a and 26b provided at both ends of the superconducting wire 11 could not be detected. Therefore, it has been found that it is difficult to detect the quench of the superconducting coil 10 by measuring the voltage between the electrodes 26a and 26b.

  Also, as shown in FIG. 8, among the four superconducting wires 11a to 11d, two superconducting wires (tapes 1 and 4) 11a and 11d are attached and heated (the heater power is 0.6 W). The normal conduction state was forcibly caused, and the current flowing through each superconducting wire (tape 1 to 4) 11 at that time was measured and shown as the relationship between time and current.

  As shown in FIG. 8, in tapes 1 and 4, the electrical resistance increased in the normal conducting state and the current value decreased greatly, while in tapes 2 and 3, the current value increased due to current commutation. Therefore, it has been clarified that the first to fourth current detection elements 18a to 18d are provided on the tapes 1 to 4, and the quenching of the superconducting coil 10 can be detected by the bridge circuit 20 based on the detection signals.

  Also in this case, the voltage between the electrodes 26a and 26b at both ends of the superconducting wire 11 could not be detected. Therefore, it has been found that it is difficult to detect the quench of the superconducting coil 10 by measuring the voltage between the electrodes 26a and 26b.

  Further, as shown in FIG. 9, among the four superconducting wires 11a to 11d, three superconducting wires (tapes 1, 2 and 4) 11a, 11b, and 11d are attached with heaters (the heater power is 0.6W), the normal conduction state was forcibly caused, and the current flowing through each superconducting wire (tape 1 to 4) 11 at that time was measured and shown as the relationship between time and current.

  As shown in FIG. 9, in Tapes 1, 2, and 4, the electrical resistance increased and the current value decreased in the normal conduction state, while in Tape 3, the current value increased due to current commutation. Therefore, it has become clear that the first to fourth current detecting elements 18a to 18d are provided on the tapes 1 to 4, and the quenching of the superconducting coil 10 can be detected by the bridge circuit 20 based on the detection signals.

  Also in this case, the voltage between the electrodes 26a and 26b at both ends of the superconducting wire 11 could not be detected. Therefore, it has been found that it is difficult to detect the quench of the superconducting coil 10 by measuring the voltage between the electrodes 26a and 26b.

The effects obtained by the embodiment described in detail above are collectively described below.
(1) In the quench detection device for the superconducting coil 10 of the present embodiment, the superconducting coil 10 is formed by winding the superconducting wire 11 in a state where four superconducting wires 11 are overlapped, and current detection elements 18a to 18a are formed on one side edge of the superconducting wire 11. 18d is provided. And the bridge circuit 20 is comprised by the some detection signal detected by those electric current detection elements 18a-18d.

  For this reason, when the strand current flowing through any one of the superconducting wires 11 decreases due to normal conduction, commutation occurs rapidly to compensate for the decreased strand current, and the strand current flowing through the other superconducting wires 11 increases. To do. Therefore, when the slight increase / decrease in the strand current is detected by the current detection elements 18a to 18d and the balance is not maintained in the bridge circuit 20 based on the detection signals, it is determined that quenching has occurred in the superconducting coil 10. be able to.

  In this case, since the bridge circuit determines the balance based on the relative value such as the ratio of the plurality of detection signals, even if the absolute value of the detection signal fluctuates due to noise from the power source of the superconducting coil 10, the influence is affected. It can be avoided.

Therefore, according to the quench detection device for superconducting coil 10 of the present embodiment, quench detection can be performed with high sensitivity and high speed without being affected by noise from the power source, and the reliability of superconducting coil 10 is improved. There is an effect that can be.
(2) The current detection elements 18 a to 18 d of the superconducting wires 11 a to 11 d are arranged on a line extending in the radial direction from the center of the superconducting coil 10. For this reason, when the superconducting coil 10 is energized, the current detection elements 18a to 18d are provided side by side in the direction of the magnetic field received by the tape-shaped superconducting wire 11, and it is easy to detect the quench without requiring correction due to displacement. It can be performed with high accuracy.
(3) The superconducting coil 10 is formed by winding four superconducting wires 11 so as to overlap each other, and current detection elements 18a to 18d are provided on one side edges of the superconducting wires 11a to 11d. Therefore, the bridge circuit 20 can be easily configured based on the four detection signals obtained by the first to fourth current detection elements 18a to 18d, and quench detection of the superconducting coil 10 can be performed efficiently.
(4) The current detection element 18 is a Hall element, and the detection signal is a Hall voltage. Therefore, the Hall element can accurately detect the Hall voltage of each of the superconducting wires 11a to 11d, and the bridge circuit 20 can accurately detect the quench of the superconducting coil 10.
(5) The plurality of superconducting wires 11a to 11d are wound so that the inner peripheral side and the outer peripheral side are sequentially switched. For this reason, it can arrange | position so that an inner peripheral side position and an outer peripheral side position may become equal about several superconducting wire 11a-11d, About the detection signal by the electric current detection element 18a-18d of each superconducting wire 11a-11d, The fluctuation | variation by the inside / outside position of superconducting wire 11a-11d can be suppressed.
(6) In the quench detection method using the above-described quench detection apparatus, the wire current is measured by the current detection elements 18a to 18d provided in the superconducting wires 11a to 11d, and a detection signal is emitted, and the plurality of detection signals Thus, the bridge circuit 20 is configured. Therefore, by detecting whether or not the balance of the bridge circuit 20 is maintained, quench detection of the superconducting coil 10 can be performed easily and with high sensitivity.

It should be noted that the embodiments described above can be modified and embodied as follows.
-As shown in FIG. 10, you may provide the said current detection element 18a, 18b, 18c, 18d in the position which the both-sides edge of each superconducting wire 11a-11d opposes. In this case, the shielding current received by the current detection element 18 can be canceled by the pair of current detection elements 18a, 18b, 18c, and 18d, and the detection accuracy by the current detection element 18 can be improved.

  The superconducting coil 10 may be configured by winding two superconducting wires 11 and two current detecting elements 18 may be attached to each superconducting wire 11. Further, since there are four galvanometers 21 of the bridge circuit 20, it is preferable to set the number of superconducting wires 11 to which the current detection element 18 is attached to a multiple of two.

As the current detection element 18, a detection element using a pickup coil, a Rogowski coil or the like may be used.
A current signal detected by the current detection element 18 or the like may be used as the detection signal.

  DESCRIPTION OF SYMBOLS 10 ... Superconducting coil, 11, 11a, 11b, 11c, 11d ... Superconducting wire, 12 ... Board | substrate, 14 ... Superconducting layer, 18, 18a, 18b, 18c, 18d ... Current detection element, 20 ... Bridge circuit.

Claims (7)

A quench detection device for a superconducting coil configured by winding a tape-shaped superconducting wire having a superconducting layer formed of a rare earth oxide superconductor on a substrate,
The superconducting wire is wound in a state where a plurality of superconducting wires are overlapped to form a superconducting coil, and at least one side edge of each superconducting wire is provided with a current detecting element for measuring a wire current and generating a detection signal. A superconducting coil quench detection device, wherein a bridge circuit is configured by a plurality of detection signals from a detection element, and it is possible to determine that quenching has occurred when equilibrium is not maintained in the bridge circuit. 2. The superconducting coil quench detection device according to claim 1, wherein the current detecting element of each superconducting wire is disposed on a line extending in a radial direction from the center of the superconducting coil. The superconducting coil is formed by winding four superconducting wires in a superposed state, and a current detection element is provided on one side edge of each superconducting wire. The superconducting coil quench detection device according to claim 1. The superconducting coil quench detection device according to any one of claims 1 to 3, wherein the current detection element is a Hall element, and the detection signal is a Hall voltage. The quench detection device for a superconducting coil according to any one of claims 1 to 4, wherein the plurality of superconducting wires are wound with the inner peripheral side and the outer peripheral side being sequentially switched. The quench detection device for a superconducting coil according to any one of claims 1 to 5, wherein a pair of the current detection elements are provided at opposing positions on both side edges of each superconducting wire. A quench detection method using the superconducting coil quench detection device according to any one of claims 1 to 6,
A strand current is measured by a current detection element provided in each superconducting wire, a detection signal is generated, a bridge circuit is configured by the plurality of detection signals, and it is detected whether the bridge circuit is maintained in balance. A quench detection method for a superconducting coil.