JPH08138927A - Superconductive coil quench detecting device - Google Patents

Abstract

PURPOSE: To obtain a superconductive coil quench detecting device which is less affected by magnetic noises so as to accurately detect a very low voltage induced with quench of a superconductive coil. CONSTITUTION: When a quench occurs in a superconductive coil 2 inside a vacuum thermally insulated vessel 3, a voltage is generated in the superconductive coil 2, but no voltage is generated in pickup coils 4a and 4b provided adjacent to the superconductive coil 2, a quench detector 5 judges that a quench occurs in the superconductive coil 2 basing on a voltage generated in the coil 2, a power supply 1 is shut off by a circuit breaker 9, and a protective resistor introducing switch 10 is turned on so as to make a discharge take place through a protective resistor 11. If magnetic noises are introduced from outside, a voltage generated in the superconductive coil 2 is canceled out with a voltage generated by the pickup coils 4a and 4b, so that a quench detector 5 is not actuated and protected against the effect of magnetic noises.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coil protection for a superconducting coil, that is, a superconducting coil quench detecting device.

[0002]

15 and 16 show, for example, Japanese Patent Publication No. 5-5.
It is a conventional superconducting coil quench detection device disclosed in Japanese Patent No. 8246. FIG. 15 is a circuit block diagram, and FIG.
6 is a sectional view of the device. In the figure, 1 is a power source, 2 is a superconducting coil, 3 is a vacuum heat insulating container that houses the superconducting coil 2, 4 is a pickup coil, and 5 is a quench detector. The superconducting coil 2 is wound around a coil bobbin 6 and housed inside a cryogenic container 7, and a coolant 8 such as liquid helium is provided.
It is cooled by and maintains the superconducting state.

Reference numeral 9 is a circuit breaker, 10 is a switch for turning on a protective resistance, and 11 is a protective resistance. Reference numeral 12 is a current lead for supplying a current from the power source 1 to the superconducting coil 2 in the cryogenic container 7. There are two positive and negative current leads, but only one is shown. 6 to 12 are Japanese Patent Publication No. 5-582.
Although not shown in Japanese Patent Publication No. 46, it was added to clarify the contents of the patent for the purpose of detecting the quench of the superconducting coil and protecting the superconducting coil.

Next, the operation will be described. The superconducting coil has zero electric resistance, carries a large current, and is used as a magnetic field generator or an energy storage device. When a current I to the superconducting coils of the inductor box L, and the superconducting coil energy LI ^2/2 is accumulated. On the other hand, in the superconducting coil, the superconducting state may be destroyed due to external disturbance, and the superconducting coil may transit to the normal conducting state. When a normal conduction state is locally generated in the superconducting coil, the temperature rises due to Joule heat generation in that portion, and the conduction heat destroys the superconducting state in the vicinity, and the superconducting state is destroyed at an accelerated rate. This phenomenon is called quench.

Since a large current is flowing through the superconducting coil and a large amount of energy is accumulated, when the quench occurs, the accumulated energy is rapidly released into the coil, which may result in burnout or damage to the superconducting coil. Therefore, when normal conduction occurs, it detects the occurrence of normal conduction at an early stage, interrupts the current flowing in the superconducting coil by opening the circuit breaker, and quickly uses the external protective resistance to consume the stored energy. There is a need to.

As a means for detecting a quench, the means shown in the preceding example has been conventionally used. That is, the pickup coil 4 is attached to the outside of the vacuum shutoff container 3,
The pickup coil 4 and the superconducting coil 2 are magnetically coupled via the magnetic field H generated by the superconducting coil 2. When the current I of the superconducting coil 2 is increased (excited) by the power source 1, the superconducting coil 2 has an inductance and a voltage E1 is generated between the terminals of the superconducting coil 2. The pickup coil 4 which is magnetically coupled,
An induced voltage E2 proportional to the current change speed of the superconducting coil is generated.

When the current in the superconducting coil 2 is reduced (demagnetized), a voltage is similarly generated between the terminals of the superconducting coil 2 and an induced voltage is generated in the pickup coil 4.
When the current value of the superconducting coil 2 is kept constant, the change in current is zero, so that the induction voltage between the terminals of the superconducting coil 2 and the pickup coil induction voltage is also zero. Inside the quench detector 5, the connection method is such that the superconducting coil terminal voltage E1 and the pickup coil induced voltage E2 cancel each other, and the quench detector 5 has an external output of zero. Since the pickup coil 4 generates only a voltage and does not flow a current, a thin normal conducting wire may be wound.

When the normal conduction state (not shown) of the resistance r occurs in the superconducting coil 2 due to external disturbance, the superconducting coil 2
, A resistance voltage E3 of current I × resistance r is generated and superposed on the superconducting coil terminal voltage E1. Since the voltage accompanying the generation of the normal conducting resistance does not affect the induced voltage E2 of the pickup coil 4, an unbalanced voltage is output to the output of the quench detector 5 which was balanced when E3 was not generated. It

When this unbalanced voltage exceeds the reference value, it is judged as a quench, and the switch 1 for turning on the protective resistance.
0 is closed and circuit breaker 9 is opened. The electric current I flowing in the superconducting coil 2 is applied to the superconducting coil 2 and the external protection resistor 11
The energy that is commutated to the circuit configured by and is attenuated with the decay time constant L / R and accumulated in the superconducting coil is consumed by the external protection resistor 11.

[0010]

Since the conventional superconducting coil quench detection circuit is constructed as described above and utilizes the magnetic coupling between the superconducting coil and the pickup coil, it is easily affected by magnetic noise. It had a drawback. That is, when the superconducting coil is installed alone in a place where there is nothing that generates a fluctuating magnetic field in the periphery,
It was possible to accurately detect the resistive voltage generated in the superconducting coil.

However, in recent years, the field of application of the superconducting coil has expanded, and it may be installed near a magnetic noise source such as a motor, or the superconducting coil that is the object of quench detection may be affected by a leakage magnetic field. There are cases where other superconducting coils or normal conducting coils are installed side by side in such an arrangement and operated. In such a case, a voltage is generated in the pickup coil under the influence of a fluctuating magnetic field other than the magnetic field generated by the superconducting coil which is going to detect the quench, which causes malfunction of the quench detector.

The present invention has been made to solve the above problems, and it is an object of the present invention to provide a superconducting coil quench detection device which has little influence of magnetic noise and can detect quench of a superconducting coil with high accuracy. To aim.

[0013]

[Means for Solving the Problems]

(1) The superconducting coil quench detection device according to the present invention is provided with a pickup coil in the vicinity of the superconducting coil, and according to the comparison between the voltage applied to the superconducting coil and the voltage induced in the pickup coil, In a quench detection device for detecting a voltage due to a normal conducting resistance generated in a superconducting coil, two pickup coils having the same number of turns are arranged on both sides in the axial direction of the superconducting coil, and each pickup coil has a different polarity with respect to an induced voltage generated. They are connected in series, and the induction voltage of the pickup coil and the voltage generated between the superconducting coil terminals in series are canceled.

(2) Further, the two pickup coils having the same number of turns are arranged on both sides of the superconducting coil winding frame flange.

(3) Further, the two pickup coils having the same number of turns are arranged on both sides of the outer surface of the flange of the superconducting coil frame, and are wound over the entire radial surface where the superconducting coil exists. It is a thing.

(4) Further, a pickup coil is provided in the vicinity of the superconducting coil, and in accordance with the comparison between the voltage applied to the superconducting coil and the voltage induced in the pickup coil, the normal coil generated in the superconducting coil is detected. In a quench detection device for detecting a voltage due to a conductive resistance, two pickup coils having the same number of turns are arranged on an outer peripheral side and an inner peripheral side in a radial direction of a superconducting coil, and each pickup coil has a different polarity with respect to an induced voltage generated. They are connected in series, and the induction voltage of the pickup coil and the voltage generated between the superconducting coil terminals in series are canceled.

(5) The two pickup coils having the same number of turns are arranged on the outer circumferential side of the superconducting coil in the radial direction and on the inner circumferential side of the winding frame in the radial direction of the superconducting coil.

(6) Further, the two pickup coils having the same number of turns are arranged such that the outer circumference side of the superconducting coil in the radial direction and the inner circumference side of the superconducting coil in the radial direction are between the superconducting coil and the bobbin. It is arranged in.

(7) Further, the two pickup coils having the same number of turns are wound over the entire length of the superconducting coil axial direction on the outer circumferential side of the superconducting coil radial direction and on the inner circumferential side of the superconducting coil radial direction winding frame. It is a lined coil.

(8) Further, a pickup coil is provided in the vicinity of the superconducting coil, and in accordance with the comparison between the voltage applied to the superconducting coil and the voltage induced in the pickup coil, the normal coil generated in the superconducting coil is detected. In a quench detection device that detects the voltage due to conductive resistance, four or more pickup coils with the same number of turns are placed around the cross section of the superconducting coil, and each pickup coil is connected in series with different polarities with respect to the induced voltage generated. The induction voltage of the pickup coil in series and the voltage generated between the superconducting coil terminals are canceled.

(9) Further, the pickup coil is composed of four pickup coils having the same number of turns, and is arranged at four locations near the inner diameter side and the outer diameter side on both outer sides of the superconducting coil frame flange. is there.

(10) Further, a pickup coil is provided in the vicinity of the superconducting coil, and in accordance with the comparison between the voltage applied to the superconducting coil and the voltage induced in the pickup coil, the normal coil generated in the superconducting coil is detected. In a quench detection device that detects a voltage due to a conductive resistance, a plurality of pickup coils are arranged around a superconducting coil, and each pickup coil is connected in series with different polarities with respect to an induced voltage generated, and is connected in series. The induction voltage of the pickup coil and the voltage generated between the superconducting coil terminals are canceled.

(11) Further, regarding the number of turns of each of the plurality of pickup coils, the sum of the total magnetic fluxes surrounded by the respective turns of the plurality of pickup coils is surrounded by each turn of the superconducting coil with respect to the external magnetic field. The number of turns is equal to the total magnetic flux.

(12) In the plurality of pickup coils, the sum of the magnetic fluxes enclosed by the turns of the plurality of pickup coils with respect to the external magnetic field is the sum of the magnetic fluxes enclosed by the turns of the superconducting coil. The number of turns of the coil is smaller than that of the superconducting coil, and at least one of the attenuating means and the amplifying means is provided. The attenuating means is an attenuating means for attenuating the terminal voltage of the superconducting coil. Of the output voltage of the attenuating means or the voltage between the terminals of the superconducting coil, and the voltage from the amplifying means or the voltage of the plurality of pickup coils. Is configured to cancel.

(13) When using the amplification means,
The pickup coils are not connected in series, but the output voltage of each pickup coil is amplified by the amplifying means and the amplified outputs are added.

(14) In the plurality of pickup coils, the sum of the magnetic fluxes enclosed by the turns of the plurality of pickup coils with respect to the external magnetic field is the sum of the magnetic fluxes enclosed by the turns of the superconducting coil. The number of turns is larger than that of the superconducting coil, and at least one of the amplifying means and the attenuating means is provided. The amplifying means is an amplifying means for amplifying the terminal voltage of the superconducting coil, and the attenuating means is each pickup coil. Of the superconducting coil and the voltage from the attenuating means or the attenuating means for attenuating the output voltage of the When the attenuating means is not used, the output voltage of the plurality of pickup coils is canceled.

(15) When a damping means is used,
The pickup coils are not connected in series, but the output voltage of each pickup coil is attenuated by the attenuating means and the attenuated outputs are added.

(16) Further, a pickup coil is provided in the vicinity of the superconducting coil, and in accordance with a comparison between the voltage applied to the superconducting coil and the voltage induced in the pickup coil, the normal coil generated in the superconducting coil is detected. In a quench detection device for detecting a voltage due to a conductive resistance, when a plurality of superconducting coils are provided, a plurality of pickup coils are arranged around each of these superconducting coils, and each pickup coil corresponding to each of the superconducting coils is The total sum of the magnetic fluxes surrounded by the turns of the plurality of pickup coils corresponding to the superconducting coils is connected to the external magnetic field in such a manner that different polarities are connected in series with each other with respect to the generated induced voltage. A picker with a number of turns equal to the total magnetic flux enclosed by each turn of each corresponding superconducting coil. With the Pukoiru, which is constituted so that the voltage from each of the superconducting coils, and a voltage from the plurality of pickup coils corresponding to the respective superconducting coils cancel each.

(17) Further, a pickup coil is provided in the vicinity of the superconducting coil, and in accordance with the comparison between the voltage applied to the superconducting coil and the voltage induced in the pickup coil, the normal coil generated in the superconducting coil is detected. In a quench detection device for detecting a voltage due to a conductive resistance, when a plurality of superconducting coils are provided, a plurality of pickup coils are arranged around each of these superconducting coils, and each pickup coil corresponding to each of the superconducting coils is The total sum of the magnetic fluxes surrounded by the turns of the plurality of pickup coils corresponding to the superconducting coils is connected to the external magnetic field in such a manner that different polarities are connected in series with each other with respect to the generated induced voltage. The number of turns must be smaller than the sum of the magnetic flux enclosed by each turn of the corresponding superconducting coil. In addition to being an up coil, at least one of an attenuating means and an amplifying means is provided, the attenuating means is an attenuating means for attenuating the voltage of each of the superconducting coils, and the amplifying means changes the output voltage of each of the pickup coils. Amplifying means for amplifying the respective outputs, and adding the amplified outputs to the corresponding superconducting coils respectively. Each voltage from the attenuating means or each voltage for each superconducting coil if each attenuating means is not used, Each voltage from the amplifying means corresponding to the superconducting coil or each voltage of the plurality of pickup coils corresponding to each superconducting coil is canceled when the amplifying means is not used.

(18) When using the amplification means,
The pickup coils are not connected in series, but the output voltage of each pickup coil is amplified by the amplifying means and the amplified outputs are added to the corresponding superconducting coils.

(19) When using the amplifying means, the pickup coil between the superconducting coils adjacent to each other is
Adjacent superconducting coils are pickup coils shared by each other, and the outputs of the pickup coils are respectively amplified by amplifying means to obtain two outputs, and these two outputs correspond to the adjacent superconducting coils. It is intended to be output.

(20) Further, a pickup coil is provided in the vicinity of the superconducting coil, and in accordance with the comparison between the voltage applied to the superconducting coil and the voltage induced in the pickup coil, the normal coil generated in the superconducting coil is detected. In a quench detection device for detecting a voltage due to a conductive resistance, when a plurality of superconducting coils are provided, a plurality of pickup coils are arranged around each of these superconducting coils, and each pickup coil corresponding to each of the superconducting coils is The total sum of the magnetic fluxes surrounded by the turns of the plurality of pickup coils corresponding to the superconducting coils is connected to the external magnetic field in such a manner that different polarities are connected in series with each other with respect to the generated induced voltage. The number of turns is such that each turn of the corresponding superconducting coil is larger than the total of the surrounding magnetic flux. In addition to being an up coil, at least one of an amplifying means and an attenuating means is provided, and the amplifying means is an amplifying means for amplifying the voltage of each superconducting coil, and the attenuating means attenuates each of the pickup coil voltages. Attenuating means for adding the respective attenuated outputs to the corresponding superconducting coils, respectively, and each voltage from the amplifying means or each voltage for each superconducting coil and each superconducting coil if this amplifying means is not used. The respective voltages from the attenuating means corresponding to the above or the respective voltages of the plurality of pickup coils corresponding to the respective superconducting coils are canceled when the attenuating means is not used.

(21) When a damping means is used,
The pickup coils are not connected in series, but the output voltage of each pickup coil is attenuated by the attenuating means and the attenuated outputs are added to each corresponding superconducting coil.

(22) When the attenuating means is used, the pickup coils between the adjacent superconducting coils are pickup coils shared by the adjacent superconducting coils, and the outputs of the pickup coils are attenuated by the attenuating means. Two outputs are obtained, and these two outputs are made to correspond to the superconducting coils adjacent to each other.

[0035]

[Action]

(1) In the superconducting coil quench detection device according to the present invention, two pickup coils having the same number of turns are arranged on both sides in the axial direction of the superconducting coil, and each pickup coil is arranged in series with different polarities with respect to the induced voltage generated. The induction voltage of the pickup coil connected in series and the generated voltage between the superconducting coil terminals are canceled.

(2) Two pickup coils having the same number of turns are arranged on both sides of the superconducting coil winding frame flange.

(3) Further, the two pickup coils having the same number of turns are arranged on both sides of the outer surface of the flange of the superconducting coil frame, and are wound on the entire radial surface where the superconducting coil exists. .

(4) Further, two pickup coils having the same number of turns are arranged on the outer circumferential side and the inner circumferential side in the radial direction of the superconducting coil, and each pickup coil is in series with different polarities with respect to the induced voltage generated. In this way, the induction voltage of the pickup coil and the voltage generated between the terminals of the superconducting coil are canceled in series.

(5) The two pickup coils having the same number of turns are arranged on the outer circumferential side of the superconducting coil in the radial direction and on the inner circumferential side of the winding frame in the radial direction of the superconducting coil.

(6) Further, two pickup coils having the same number of turns are arranged between the superconducting coil and the bobbin on the radially outer side of the superconducting coil and on the radially inner side of the superconducting coil. To be installed.

(7) Further, two pickup coils having the same number of turns are wound over the entire length of the superconducting coil axial direction on the outer circumferential side of the superconducting coil radial direction and on the inner circumferential side of the superconducting coil radial direction winding frame. Make the coil a wire.

(8) Further, the pickup coils having the same number of turns are arranged at four or more places around the cross section of the superconducting coil, and the pickup coils are connected so as to have different polarities in series with each other with respect to the induced voltage. The induced voltage of the pickup coil and the generated voltage between the superconducting coil terminals cancel each other.

(9) Further, the pickup coil is composed of four pickup coils having the same number of turns, and the pickup coils are arranged at four locations near the inner diameter side and the outer diameter side on both outer sides of the superconducting coil frame flange.

(10) In addition, a plurality of pickup coils are arranged around the superconducting coil, and the pickup coils are connected so as to have different polarities in series with respect to the induced voltage generated. The voltage and the voltage generated between the superconducting coil terminals cancel each other.

(11) Further, regarding the number of turns of each of the plurality of pickup coils, the sum of the magnetic fluxes surrounded by the respective turns of the plurality of pickup coils is surrounded by each turn of the superconducting coil with respect to the external magnetic field. The number of turns is equal to the total of the magnetic flux.

(12) In the plurality of pickup coils, the sum of the magnetic fluxes enclosed by the turns of the plurality of pickup coils with respect to the external magnetic field is the sum of the magnetic fluxes enclosed by the turns of the superconducting coil. The number of turns of the coil is smaller than that of the superconducting coil, and at least one of the attenuating means and the amplifying means is provided, the attenuating means attenuates the voltage across the terminals of the superconducting coil, and the amplifying means uses the output voltage of each pickup coil. Is amplified and the respective outputs thus amplified are added, and the voltage from the attenuating means or the inter-terminal voltage of the superconducting coil and the voltage from the amplifying means or the voltages of the plurality of pickup coils are canceled.

(13) When using the amplifying means,
The pickup coils are not connected in series, but the output voltage of each pickup coil is amplified by the amplifying means and the amplified outputs are added.

(14) In the plurality of pickup coils, the sum of the magnetic fluxes enclosed by the turns of the plurality of pickup coils with respect to the external magnetic field is the sum of the magnetic fluxes enclosed by the turns of the superconducting coil. The number of turns of the coil is larger than that of the superconducting coil, and at least one of the amplifying means and the attenuating means is provided. And adding each of the attenuated outputs, the voltage from the amplifying means or the voltage between the terminals of the superconducting coil when the amplifying means is not used and the voltage from the attenuating means or when the attenuating means is not used. Is canceled by the output voltages of the plurality of pickup coils.

(15) When using a damping means,
The pickup coils are not connected in series, but the output voltage of each pickup coil is attenuated by the attenuating means and the attenuated outputs are added.

(16) When a plurality of superconducting coils are provided, a plurality of pickup coils are arranged around each of these superconducting coils, and each pickup coil corresponding to each superconducting coil generates an induced voltage. With respect to the external magnetic field, the total sum of the magnetic fluxes surrounded by the turns of the plurality of pickup coils corresponding to the respective superconducting coils is the corresponding superconducting The pickup coil has a number of turns such that each turn of the coil is equal to the total of the magnetic fluxes enclosed, and the voltage from each superconducting coil and the voltage from the plurality of pickup coils corresponding to each superconducting coil are respectively Cancel.

(17) When a plurality of superconducting coils are provided, a plurality of pickup coils are arranged around each of these superconducting coils, and each pickup coil corresponding to each superconducting coil generates an induced voltage. With respect to the external magnetic field, the total sum of the magnetic fluxes surrounded by the turns of the plurality of pickup coils corresponding to the respective superconducting coils is the corresponding superconducting The pickup coil has a number of turns that is smaller than the total of the magnetic flux surrounded by each turn of the coil, and at least one means of an attenuating means and an amplifying means is provided, and the attenuating means applies a voltage to each of the superconducting coils. Attenuating, the amplifying means amplifies the output voltage of each of the pickup coils, and outputs each amplified output as described above. The respective superconducting coils corresponding to each other, each voltage from the attenuating means or each voltage for each superconducting coil if this attenuating means is not used, and each voltage from the amplifying means corresponding to each superconducting coil or this When the amplifying means is not used, the respective voltages of the plurality of pickup coils corresponding to the respective superconducting coils cancel each other.

(18) When using the amplification means,
The pickup coils are not connected in series, but the output voltage of each pickup coil is amplified by the amplifying means and the amplified outputs are added to the corresponding superconducting coils.

(19) When the amplifying means is used, the pickup coil between the superconducting coils adjacent to each other is
Adjacent superconducting coils are pickup coils shared by each other, and the outputs of the pickup coils are respectively amplified by amplifying means to obtain two outputs, and these two outputs correspond to the adjacent superconducting coils. Output.

(20) When a plurality of superconducting coils are provided, a plurality of pickup coils are arranged around each of these superconducting coils, and each pickup coil corresponding to each superconducting coil generates an induced voltage. With respect to the external magnetic field, the total sum of the magnetic fluxes surrounded by the turns of the plurality of pickup coils corresponding to the respective superconducting coils is the corresponding superconducting The pickup coil has a number of turns such that each turn of the coil is larger than the total of the magnetic fluxes surrounding it, and at least one of an amplifying means and an attenuating means is provided, and the amplifying means amplifies the voltage of each superconducting coil. Then, the attenuating means attenuates the pickup coil voltages, and the attenuated outputs correspond to the corresponding outputs. Each superconducting coil is summed up, and each voltage from the amplifying means or each voltage for each superconducting coil and each voltage from the attenuating means corresponding to each superconducting coil or this attenuating means when the amplifying means is not used If is not used, the respective voltages of the plurality of pickup coils corresponding to the respective superconducting coils are canceled.

(21) When using the damping means,
The pickup coils are not connected in series, but the output voltage of each pickup coil is attenuated by the attenuating means, and the attenuated outputs are added to each corresponding superconducting coil.

(22) When the attenuating means is used, the pickup coils between the adjacent superconducting coils are pickup coils shared by the adjacent superconducting coils, and the outputs of the pickup coils are attenuated by the attenuating means. Two outputs are obtained, and these two outputs are outputs corresponding to the superconducting coils adjacent to each other.

[0057]

【Example】

Example 1. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a circuit block diagram, and FIG. 2 is a device sectional view. In the figure, 1 to 3, 5 to 7 and 9 to 11 are shown in FIG.
5, the same as FIG. 4a and 4b are superconducting coils 2
The pickup coil is arranged close to the winding frame 6. The number of turns of the pickup coil of 4a is the same as that of the number of turns of the pickup coil, and the number of turns is determined so that the total magnetic flux surrounded by each turn of the pickup coil is 1/2 of the total magnetic flux surrounded by each turn of the superconducting coil. Since no current flows in the pickup coil, it is possible to use a thin wire, and the cross section is smaller than the cross section of the superconducting coil.

Next, the operation will be described. The two pickup coils 4a and 4b in FIG. 1 are connected so that the induced voltages are added as shown in the figure. By arranging the pickup coils as shown in FIG. 2, the average value of the external magnetic noise experienced by the two pickup coils and the external magnetic noise experienced by the superconducting coil 2 become substantially equal, and the number of turns of the pickup coil is picked up. By determining that the total magnetic flux enclosed by each turn of the coil is 1/2 of the total magnetic flux enclosed by each turn of the superconducting coil, even when the superconducting coil is excited, degaussed, and even when there is external magnetic noise. The sum of the voltage induced between the superconducting coils and the voltage induced in the pickup coils 4a and 4b becomes equal to each other and cancels each other out, and the input to the quench detector becomes zero.

When a part of the superconducting coil is transferred to normal conduction and a resistive voltage is generated, it becomes an unbalanced voltage, and the quench detector output voltage changes. When the quench detector voltage becomes equal to or higher than the set value, it is judged as quench and the superconducting coil protection operation is started, as in the case of the conventional technique.

Example 2. In the above-described first embodiment, the case where two pickup coils are arranged on both side surfaces of the superconducting coil winding frame is shown. This arrangement corresponds to the case where the cross section of the superconducting coil is long in the axial direction and thin in the radial direction. However, various values are selected for the ratio of the axial length and the radial thickness of the cross section of the superconducting coil depending on the purpose of the superconducting coil, and there are cases where the axial length is short and the radial direction is thick.

In this case, the two pickup coils are arranged on the inner diameter side 4a and the outer diameter side 4b in the radial direction as shown in FIG. It becomes easy to cancel the induced voltage due to external magnetic noise. As in the case of FIG. 1, the number of turns of the pickup coil is determined so that the total magnetic flux surrounded by each turn of the pickup coil is 1/2 of the total magnetic flux surrounded by each turn of the superconducting coil.

Example 3. In the second embodiment, 4a is arranged outside the winding frame 6, but if it is installed in the winding frame in the vicinity of the superconducting coil as shown in FIG. 4, the symmetry with respect to external magnetic noise is improved, The detection accuracy is improved.

Example 4. Normally, various measuring wires, measuring wire fixing jigs, tightening bolts and nuts, etc. are attached to the superconducting coil winding frame 6, and the pickup coil mounting space is limited. Therefore, the pickup coil is shown in FIG. It will be arranged like this. Further, since the tightening support member for fixing the winding or for instructing the expansion electromagnetic force in the radial direction is wound around the outer peripheral portion of the superconducting coil, the pickup coil arrangement is as shown in FIG.

When there is a space in the winding frame flange or the outer peripheral portion of the superconducting coil, the pickup coil winding portion as shown in FIGS. 5 and 6 is made equal to the axial length of the superconducting coil or equal to the radial length. As a result, the symmetry with respect to the external magnetic noise is improved, and the detection accuracy is further improved. FIG. 5 shows an example of a superconducting coil that is long in the axial direction, and FIG. 6 shows an example of a superconducting coil that is short in the axial direction.

Example 5. As shown in the fourth embodiment, when there is not enough space in the winding frame flange or the outer peripheral portion of the superconducting coil, the pickup coils 4a and 4b may be divided into a plurality of parts as shown in FIG. . FIG. 7 shows an example in which the pickup coil attached to the winding frame flange is divided into two, and if the pickup coil is further divided and arranged around the coil cross section, the symmetry is improved and the detection accuracy is improved. If this Example 5 (case of four pickup coils) is applied to Example 8 (case of two pickup coils) described later, there is also a merit that the effect is higher.

Example 6. In the above-described first to fifth embodiments, the magnetic noise source is relatively far away or the position is uncertain, and the pickup coils 4a and 4b have the same number of turns. However, when the magnetic noise source position is near, the contribution of the varying magnetic field of the magnetic noise differs between the superconducting coil 6 and the pickup coils 4a and 4b, and it is difficult to cancel the induced voltage.

In such a case, the induced voltage can be canceled by changing the number of turns of the pickup coils 4a and 4b as shown in FIG. For example, in the case of an electromagnet or the like having a magnetic noise source installed in the vicinity as shown in the figure, it is possible to calculate the magnetic flux surrounded by the superconducting coil 2 and the pickup coils 4a and 4b by magnetic field calculation. The appropriate number of turns of can be calculated. Although the present embodiment describes the case where the number of pickup coils is two, the cancel accuracy is further improved when the number of pickup coils is two or more.

Example 7. The above Examples 1 to 6 have been described for the case where the current changing speed of the superconducting coil is small, that is, the case of the superconducting coil for generating a DC magnetic field. In this case, the voltage induced in the superconducting coil or the pickup coil is about 10V at most. On the other hand, in the case of a superconducting pulse coil, the superconducting coil current change rate is several hundred to several thousand A /
In some cases, the induced voltage, which is proportional to the inductance of the superconducting coil multiplied by the current change speed, may reach several thousand V.

In such a case, even if the influence of magnetic noise is canceled in the initial design, the induced voltage is applied to the quench detector 5 without being canceled and the quench detector is damaged due to changes in the magnetic noise position or the like. It may reach. The method shown in FIGS. 9 and 10 solves this problem. FIG. 9 is a circuit block diagram, and FIG. 10 is a device sectional view.

In FIGS. 9 and 10, 1, 2, 4a, 4
b and 9 to 11 are the same as those in FIGS. 1 and 2 or have the same functions. Reference numeral 13 is an attenuator (insulation amplifier) for attenuating the voltage between the superconducting coil terminals. The number of turns of the pickup coil in each of Examples 1 to 6 is determined so that the sum of the magnetic fluxes surrounded by the respective turns of the respective pickup coils becomes equal to the total of the magnetic fluxes enclosed by the respective turns of the superconducting coil.

In this embodiment, the pickup coil 4a,
The number of turns of 4b is the same, which is smaller than the number of turns of the pickup coil of the first embodiment by the ratio of the attenuation rate of the attenuator 13. That is, the attenuator attenuation factor is 1/20. As described above, by using the attenuator 13 to attenuate the voltage between the terminals of the superconducting coil and balance it with the induced voltage of the pickup coil, it becomes possible to detect the resistive voltage generated in the superconducting coil.

Further, even if an inductive imbalance voltage is generated, the voltage is small, and the quench detector is not damaged. Further, in the small current region where the superconducting coil does not reach the quench, the damping ratio of the attenuator 13 is adjusted while exciting the superconducting coil at a slow and constant current changing speed, so that the voltage between the superconducting coil terminals and the pickup coil induction. There is also an effect that the accuracy of canceling the voltage can be increased.

In this embodiment, the case where the pickup coils 4a and 4b are attached to the winding frame flange and the number of turns is the same has been described. However, the same is true even if the pickup coil position and the number of turns are changed as in the second to sixth embodiments. effective.

Example 8. In Examples 1 to 7, the quench can be accurately detected when the magnetic noise position is fixed, but an imbalance voltage is generated when the magnetic noise source changes from the initially set position. have.

As means for solving this problem, there is one shown in FIG. In FIG. 11, 14a and 14b are amplifiers. Others are the same as in FIG. With the configuration of FIG. 11, the unbalanced voltage can be canceled by adjusting the amplification factors of the amplifiers 14a and 14b even when the magnetic noise source changes from the initially set position to an arbitrary position. As in the case of Example 7, the attenuator, the attenuation factor of each amplifier, and the amplification factor are adjusted while the superconducting coil is excited at a slow and constant current change rate in a small current region where quenching does not occur. There is also an effect that it is possible to further improve the cancellation accuracy of the voltage between the superconducting coil terminals and the pickup coil induced voltage.

In this embodiment, the case of using two pickup coils has been described. However, if a plurality of pickup coils are provided and an amplifier is connected to each of them as shown in the fifth embodiment, the canceling accuracy is further improved. It is clear to do. Further, this embodiment can be applied to the arrangement of the pickup coils of the first to fourth embodiments.
In some cases, the attenuator may not be used and only the amplifier may be used.

An amplifier may be used on the superconducting coil side and an attenuator may be used on the pickup coil side. In this case, the number of turns of the plurality of pickup coils is such that the sum of the magnetic fluxes surrounded by the respective turns of the plurality of pickup coils with respect to the external magnetic field is larger than the total of the magnetic fluxes surrounded by the respective turns of the superconducting coil. The number of turns is
Then, the gains of the amplifier and the attenuator may be adjusted according to the ratio of the total magnetic flux of both. Note that only one of the amplifier and the attenuator may be used.

Example 9. Examples 1 to 8 describe the case of one superconducting coil. FIG. 12 is a schematic diagram in which a pickup coil is attached when a plurality of superconducting coils are arranged, and FIG. 13 is a block diagram of the quench detection device. In FIG. 12, 2a, 2b, 2c ... Are superconducting coils, and 4a-4b ,. 14a, 14b1, 14b2, 14c1, 1
4c2, 14d1, ... Are amplifiers.

In FIG. 13, superconducting coils 2a, 2b, ...
Corresponding to the power supplies 1a, 1b, ..., Quench detector 5
a, 5b, ..., Circuit breakers 9a, 9b, ..., Protective resistance input switches 10a, 10b ,.
11b, ..., Attenuators 13a, 13b ,.

Pickup coils 4a and 4b and amplifier 1
A quench detector for the superconducting coil 2a is constituted by 4a, 14b1, an attenuator 13a and a quench detector 5a. Pickup coils 4b and 4c and amplifiers 14b2 and 14c1
The superconducting coil 2 with the attenuator 13b and the quench detector 5b.
Configure the quench detector of b. Similarly, a quench detection device is constructed for each superconducting coil.

That is, this configuration is similar to the circuit configuration in which one superconducting coil is provided for each of the superconducting coils in Examples 1 to 8, except that the pickup coil between the superconducting coils is different. The point is that two outputs are shared by the shared pickup coils via amplifiers. Of course, a pickup coil may be provided for each superconducting coil, but sharing the pickup coil is economical because it requires less space.

Here, for simplification, the superconducting coil 2a,
In 2b, 2c, ..., the currents are all changed. In the superconducting coil system arranged as shown in the figure, the magnetic field change rate experienced by the pickup coil 4a at the end is different from the magnetic field change rate experienced by the pickup coil 4b, and the induced voltages are not the same. In such a case, the applied voltage of the superconducting coil 2a and the pickup coil 4a are adjusted by adjusting the amplification factors of the amplifiers 14a and 14b in accordance with the ratios of the magnetic field changing speeds that each experiences.
It is possible to accurately cancel the induced voltage of 4b.

In this embodiment, the superconducting coils 2a, 2b,
2c, ... are the same, but generally 2
Amplifiers 14a, 14b1, 14b2, 14c, even if the dimensions of a, 2b, 2c, ...
By adjusting the amplification factors of 1, 14c2, 14d1, ..., Quench detection of all coils becomes possible. 1
It is obvious that more general cases can be dealt with by increasing the number of pickup coils and the number of amplifiers for one superconducting coil.

Although the case where the superconducting coils are arranged on a straight line has been described in the present embodiment, it may not be on a straight line such as an arc. It may also be on the circumference. All pickup coils have two amplifiers on the circumference.

Further, in FIG. 13, each superconducting coil 2a, 2
b, ... Corresponding to the quench detectors 5a, 5b ,.
However, the quench detector may be shared by one unit so that when any of the superconducting coils is quenched, the currents of all the superconducting coils are attenuated. In addition, FIG.
Then, the power supplies 1a, 1b, ... Are provided corresponding to the respective superconducting coils 2a, 2b, ..
You may make it supply to each superconducting coil 2a, 2b, ....

As shown in FIG. 14, pickup coils 4b1 and 4b2, 4c1 and 4c are provided between the superconducting coils.
Even in the case of providing two or more such as 2, 4d1 and 4d2, it can be applied by obtaining two amplified outputs from the respective pickup coils.

Example 10. In the ninth embodiment, the pickup coils 4b, 4c and the like are shared between the superconducting coils, but they may be provided separately. That is, the configurations of Examples 1 to 8 may be provided for each superconducting coil.

Example 11. In the above-mentioned Embodiments 7 to 9, it is assumed that the number of pickup coil windings is smaller than the number of main coil windings, but it is also possible to make it larger than the number of main coil windings. An attenuator is connected instead of the amplifier, and an amplifier is connected to the superconducting coil instead of the attenuator. Further, either the attenuator or the amplifier may be used instead of using both the attenuator and the amplifier.

The circuit of FIG. 1 of the first embodiment, the circuit of FIG. 9 of the seventh embodiment, the circuit of FIG. 11 of the eighth embodiment, and the circuit of FIG. 1 of the ninth embodiment.
In the circuit of 3 and the like, the outputs on the superconducting coil side and the pickup coil side are directly connected to cancel each other's outputs, but the outputs on the superconducting coil side and the pickup coil side are respectively detected by the quench detector. Lead to 5,
It may be possible to compare the outputs of the both and determine whether or not the outputs can be canceled.

In the eighth embodiment, as shown in FIG. 11, the pickup coils 4a and 4b are separated and the amplifiers 14a and 1b are separated.
Input to 4b, but pickup coil 4
a, 4b are connected in series, and the pickup coils 4a, 4a,
Both ends of each coil of 4b may be input to amplifiers 14a and 14b, such as an isolation amplifier, respectively.
The case in which the pickup coils are connected in series is not limited to the eighth embodiment, and the pickup coils may be connected in series when the amplifier or the attenuator is used as the pickup coil as described in the eleventh embodiment.

[0091]

As described above, according to the present invention, since the induced voltage of the pickup coil and the generated voltage of the superconducting coil are canceled with respect to the external magnetic field, it is affected by external magnetic noise. Without this, there is an effect that the quench of the superconducting coil can be accurately detected.

[Brief description of drawings]

FIG. 1 is a block diagram of a superconducting coil quench detection device according to a first embodiment of the present invention.

FIG. 2 is a sectional view of a main part near a pickup coil according to the first embodiment of the present invention.

FIG. 3 is a cross-sectional view of a main part near a pickup coil according to a second embodiment of the present invention.

FIG. 4 is a sectional view of an essential part near a pickup coil according to a third embodiment of the present invention.

FIG. 5 is a sectional view of an essential part near a pickup coil according to a fourth embodiment of the present invention.

FIG. 6 is a sectional view of an essential part near a pickup coil according to a fourth embodiment of the present invention.

FIG. 7 is a cross-sectional view of a main part near a pickup coil according to a fifth embodiment of the present invention.

FIG. 8 is a cross-sectional view of a main part near a pickup coil according to a sixth embodiment of the present invention.

FIG. 9 is a block diagram of a superconducting coil quench detector according to a seventh embodiment of the present invention.

FIG. 10 is a sectional view of an essential part near a pickup coil according to a seventh embodiment of the present invention.

FIG. 11 is a block diagram of a superconducting coil quench detector according to an eighth embodiment of the present invention.

FIG. 12 is a cross-sectional view of a main part near a pickup coil according to a ninth embodiment of the present invention.

FIG. 13 is a block diagram of a superconducting coil quench detector according to Example 9 of the present invention.

FIG. 14 is a sectional view of an essential part near a pickup coil according to a ninth embodiment of the present invention.

FIG. 15 is a block diagram of a conventional superconducting coil quench detection device.

FIG. 16 is a cross-sectional view of a main part near a conventional pickup coil.

[Explanation of symbols]

1 power supply, 2, 2a, 2b, 2c superconducting coil,
3 vacuum heat insulator, 4, 4a, 4b, 4c, 4d pickup coil, 5 quench detector, 6 reel, 7
Cryogenic container, 8 refrigerant, 9 circuit breaker, 10 protective resistance input switch, 11 protective resistance, 12 current lead, 13 attenuator, 14a, 14b, 14b1, 1
4b2, 14c1, 14c2, 14d1 amplifier.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Takuya Kishida 3-3-22 Nakanoshima, Kita-ku, Osaka Kansai Electric Power Co., Inc. (72) Inventor Katsuyoshi Toyota 1-2-1, Wadasaki-cho, Hyogo-ku, Kobe No. Sanryo Electric Co., Ltd. Kobe Works (72) Inventor Tsuneaki Minato 1-2-2 Wadazaki-cho, Hyogo-ku, Kobe Sanryo Electric Co., Ltd. Kobe Works (72) Naoyuki Harada Wadazaki, Hyogo-ku, Kobe 1-2-1 Machi Sanryo Electric Co., Ltd. Kobe Works (72) Inventor Nao Ichihara 1-2 1-2 Wadazaki-cho, Hyogo-ku Kobe City Sanryo Electric Co., Ltd. Kobe Works

Claims (22)

[Claims] 1. A pickup coil is provided in the vicinity of the superconducting coil, and a normal conducting resistance is generated in the superconducting coil according to a comparison between a voltage applied to the superconducting coil and a voltage induced in the pickup coil. In a superconducting coil quench detection device that detects voltage, two pickup coils with the same number of turns are arranged on both sides in the axial direction of the superconducting coil, and each pickup coil is connected in series with different polarities with respect to the induced voltage generated. A superconducting coil quench detection device, characterized in that the induction voltage of the pickup coil in series and the voltage generated between the superconducting coil terminals are canceled. 2. The superconducting coil quench detection device according to claim 1, wherein the two pickup coils having the same number of turns are arranged on both sides of the superconducting coil frame flange. 3. The coil according to claim 1, wherein the two pickup coils having the same number of turns are arranged on both sides of the outer surface of the flange of the superconducting coil frame, and are wound over the entire radial surface where the superconducting coil exists. A superconducting coil quench detection device characterized in that 4. A pickup coil is provided in the vicinity of the superconducting coil, and the normal conducting resistance generated in the superconducting coil is used in accordance with the comparison between the voltage applied to the superconducting coil and the voltage induced in the pickup coil. In a superconducting coil quench detection device that detects voltage, two pickup coils with the same number of turns are arranged on the outer and inner circumference sides of the superconducting coil in the radial direction, and each pickup coil has different polarities with respect to the induced voltage generated. A superconducting coil quench detection device, wherein the superconducting coil quench detection device is configured to be connected in series so as to cancel the induction voltage of the pickup coil and the generated voltage between the superconducting coil terminals in series. 5. The arrangement according to claim 4, wherein the two pickup coils having the same number of turns are arranged on the outer circumferential side of the superconducting coil in the radial direction and on the inner circumferential side of the winding frame in the radial direction of the superconducting coil. Superconducting coil quench detector. 6. The pick-up coil having the same number of turns according to claim 4, wherein the superconducting coil and the bobbin are arranged on the radially outer side of the superconducting coil and on the radially inner side of the superconducting coil. A superconducting coil quench detector characterized by being arranged between them. 7. The pickup coil according to claim 4, wherein the two pickup coils having the same number of turns are provided on an outer peripheral side in a radial direction of the superconducting coil and an inner peripheral side of the radial winding frame of the superconducting coil on a whole surface in a length direction in the superconducting coil axial direction. A superconducting coil quench detection device characterized in that a coil is wound across. 8. A pickup coil is provided in the vicinity of the superconducting coil, and a normal conducting resistance generated in the superconducting coil is provided in accordance with a comparison between a voltage applied to the superconducting coil and a voltage induced in the pickup coil. In a superconducting coil quench detector that detects voltage, four or more pickup coils with the same number of turns are placed around the cross section of the superconducting coil, and each pickup coil is connected in series with different polarities with respect to the generated induced voltage. A superconducting coil quench detection device, characterized in that the induction voltage of the pickup coil in series and the voltage generated between the superconducting coil terminals are canceled. 9. The pick-up coil according to claim 8, wherein the pick-up coil is composed of four pick-up coils having the same number of turns, and the pick-up coils are arranged at four locations near the inner diameter side and the outer diameter side of both outer sides of the superconducting coil frame flange. A superconducting coil quench detection device characterized by the above. 10. A pickup coil is provided in the vicinity of the superconducting coil, and the normal conducting resistance generated in the superconducting coil is provided in accordance with the comparison between the voltage applied to the superconducting coil and the voltage induced in the pickup coil. In a quench detection device that detects a voltage, a plurality of pickup coils are arranged around the superconducting coil, and each pickup coil is connected in series with different polarities with respect to the induced voltage generated. A superconducting coil quench detection device, characterized in that the induced voltage and the voltage generated between the terminals of the superconducting coil are canceled. 11. The number of turns of each of the plurality of pickup coils according to claim 1,
The superconducting coil quench is characterized in that the number of turns is such that the sum of the magnetic fluxes surrounded by the turns of the plurality of pickup coils is equal to the total of the magnetic fluxes surrounded by the turns of the superconducting coil with respect to the external magnetic field. Detection device. 12. The superconducting device according to claim 1, wherein a plurality of pickup coils have a sum of magnetic fluxes surrounded by respective turns of the plurality of pickup coils with respect to an external magnetic field. The number of turns of the coil is smaller than the total of the surrounding magnetic flux, and at least one of attenuating means and amplifying means is provided, and the attenuating means attenuates the terminal voltage of the superconducting coil. The amplifying means is an amplifying means for amplifying the output voltage of each pickup coil and adding the amplified outputs, and the voltage from the attenuating means or the terminal voltage of the superconducting coil and the voltage from the amplifying means or A superconducting coil quench detection device characterized in that it is configured to cancel the voltages of the plurality of pickup coils. 13. The amplifier according to claim 12, wherein when the amplifying means is used, the pickup coils are not connected in series and the output voltage of each pickup coil is amplified by the amplifying means and the amplified outputs are added. A superconducting coil quench detector characterized in that 14. The superconducting device according to claim 1, wherein a plurality of pickup coils have a sum of magnetic fluxes surrounded by respective turns of the plurality of pickup coils with respect to an external magnetic field. A coil having a number of turns such that each turn of the coil is larger than the total of the magnetic fluxes surrounding it, and at least one of an amplifying means and an attenuating means is provided, and the amplifying means is an amplifier for amplifying the terminal voltage of the superconducting coil The attenuating means is an attenuating means for attenuating the output voltage of each pickup coil and adding the attenuated outputs, and the voltage from the amplifying means or the voltage between the terminals of the superconducting coil when the amplifying means is not used. , The voltage from the attenuating means or the output voltage of the plurality of pickup coils will be canceled if the attenuating means is not used. A superconducting coil quench detection device characterized by being configured as described above. 15. When the attenuation means is used in claim 14, the pickup coils are not connected in series, but the output voltage of each pickup coil is attenuated by the attenuation means and the attenuated outputs are added. A superconducting coil quench detector characterized in that 16. A pickup coil is provided in the vicinity of the superconducting coil, and a normal conducting resistance is generated in the superconducting coil according to a comparison between a voltage applied to the superconducting coil and a voltage induced in the pickup coil. In the case of a superconducting coil quench detection device that detects voltage, if it has a plurality of superconducting coils, a plurality of pickup coils are arranged around each of these superconducting coils, and each pickup coil corresponding to each of the above superconducting coils is generated. Connected in series with different polarities with respect to the induced voltage, and to the external magnetic field, the sum of the magnetic fluxes surrounded by the turns of the plurality of pickup coils corresponding to the superconducting coils is the above-mentioned correspondence. The number of turns of each superconducting coil is equal to the total of the surrounding magnetic flux. A superconducting coil quench detecting device, wherein the superconducting coil quench detecting device is configured to cancel each of the voltages from the respective superconducting coils and the voltages from a plurality of pickup coils corresponding to the respective superconducting coils. 17. A pickup coil is provided in the vicinity of the superconducting coil, and the normal conducting resistance is generated in the superconducting coil according to the comparison between the voltage applied to the superconducting coil and the voltage induced in the pickup coil. In the case of a superconducting coil quench detection device that detects voltage, if it has a plurality of superconducting coils, a plurality of pickup coils are arranged around each of these superconducting coils, and each pickup coil corresponding to each of the above superconducting coils is generated. Connected in series with different polarities with respect to the induced voltage, and to the external magnetic field, the sum of the magnetic fluxes surrounded by the turns of the plurality of pickup coils corresponding to the superconducting coils is the above-mentioned correspondence. The number of turns is smaller than the total of the magnetic flux surrounded by each turn of each superconducting coil. In addition to the up coil, at least one of an attenuating means and an amplifying means is provided, the attenuating means is an attenuating means for attenuating the voltage of each of the superconducting coils, and the amplifying means changes the output voltage of each of the pickup coils. Amplifying means for amplifying the respective outputs, and adding the amplified outputs to the corresponding superconducting coils respectively. Each voltage from the attenuating means or each voltage for each superconducting coil if each attenuating means is not used, It is characterized in that each voltage from the amplifying means corresponding to the superconducting coil or each voltage of the plurality of pickup coils corresponding to each superconducting coil is canceled when the amplifying means is not used. Superconducting coil quench detector. 18. When the amplifying means is used in claim 17, the pickup coils are not connected in series, the output voltage of each pickup coil is amplified by the amplifying means, and each amplified output is associated with a corresponding superconducting coil. A superconducting coil quench detection device characterized in that addition is made for each coil. 19. The pick-up coil between adjacent superconducting coils according to claim 17 or 18, wherein the superconducting coils adjacent to each other are pick-up coils shared by the superconducting coils adjacent to each other. Is amplified by amplifying means to obtain two outputs, and the two outputs are made to correspond to the superconducting coils adjacent to each other, respectively, a superconducting coil quench detection device. 20. A pickup coil is provided in the vicinity of the superconducting coil, and a normal conducting resistance generated in the superconducting coil is provided according to a comparison between a voltage applied to the superconducting coil and a voltage induced in the pickup coil. In the case of a superconducting coil quench detection device that detects voltage, if it has a plurality of superconducting coils, a plurality of pickup coils are arranged around each of these superconducting coils, and each pickup coil corresponding to each of the above superconducting coils is generated. Connected in series with different polarities with respect to the induced voltage, and to the external magnetic field, the sum of the magnetic fluxes surrounded by the turns of the plurality of pickup coils corresponding to the superconducting coils is the above-mentioned correspondence. The number of turns is such that each turn of each superconducting coil is larger than the total of the surrounding magnetic flux. In addition to the up coil, at least one of an amplifying means and an attenuating means is provided, and the amplifying means is an amplifying means for amplifying the voltage of each superconducting coil, and the attenuating means attenuates each of the pickup coil voltages. Attenuating means for adding the respective attenuated outputs to the corresponding superconducting coils, respectively, and each voltage from the amplifying means or each voltage for each superconducting coil and each superconducting coil if this amplifying means is not used. The superconducting coil is configured to cancel each voltage from the attenuating means corresponding to the above or each voltage of the plurality of pickup coils corresponding to each superconducting coil when the attenuating means is not used. Quench detector. 21. When the attenuating means is used in claim 20, the pickup coils are not connected in series and the output voltage of each pickup coil is attenuated by the attenuating means, and the attenuated outputs correspond to the corresponding superconductors. A superconducting coil quench detection device characterized in that addition is made for each coil. 22. When the damping means is used according to claim 20 or 21, the pickup coil between the superconducting coils adjacent to each other is a pickup coil shared by the superconducting coils adjacent to each other, and the output of the pickup coil. Is attenuated by an attenuator to obtain two outputs, and the two outputs are respectively made outputs corresponding to the superconducting coils adjacent to each other.