KR100821378B1 - Superconductive magnet apparatus - Google Patents

Abstract

Provided is a superconducting magnet device that can continue to generate a magnetic field for a predetermined time even if a power failure occurs.

The UPS device 15 which has a built-in battery and backs up the control power of the components in the excitation power supply section 10 at the time of power failure, and the output of the excitation power supply section is short circuited. A switch circuit 18 for opening and an output short circuit / release circuit 16 for receiving a power supply from a UPS device, which are in a short circuit state when a power failure occurs and in an open state when a power failure occurs. Equipped.

Battery, magnetic field, superconducting, magnet

Description

Superconductive magnet apparatus

BRIEF DESCRIPTION OF THE DRAWINGS It is a block diagram which shows embodiment of an excitation power supply part in the superconducting magnet apparatus by this invention.

2 is a view showing the configuration of a cooling device of the superconducting coil of the superconducting magnet device according to the present invention.

3 is a circuit diagram illustrating an example of the current control unit illustrated in FIG. 1.

4 is a diagram illustrating a configuration of an excitation power supply unit in a conventional superconducting magnet device.

Explanation of symbols on the main parts of the drawings

18: switch circuit

20: cooling device

21: vacuum insulation container

22: heat radiation shielding container

23: GM Refrigerator

24: electric plate

25: room temperature space

26: cold storage container (保 冷 容器)                 

27 supply pipe

28: safety valve

30: superconducting coil

The present invention relates to a superconducting magnet device.

The conventional superconducting magnet device includes a superconducting coil, an excitation power supply unit for supplying electric power to the superconducting coil, and a cooling device for cooling the superconducting coil. 4 shows an example of an excitation power supply unit in a conventional superconducting magnet device of a conventional power supply type. The superconducting coil 30 receives electric power from the excitation power supply unit 40 to generate a magnetic field. The excitation power supply section 40 includes a transformer section 41 for stepping down a voltage from a commercial power supply to a predetermined voltage value, and a rectifier for rectifying the voltage from the transformer section 41. The rectifier 42 and the current control unit 40 for controlling the current to the superconducting coil 30.

In such an excitation power supply unit 40, when a power failure occurs, the power supply to the superconducting coil 30 as well as the cooling device is stopped, and the coil conduction current decreases rapidly. For this reason, heat is generated by the AC loss in the superconducting coil 30, and quench phenomenon (superconductor or superconducting device when the superconductor or superconducting device is transferred from the superconducting state to the superconducting state is impossible and irreversible). Phenomenon) occurs. For this reason, even if the coil temperature rises rapidly and the power failure is restored, the time until the coil temperature is lowered to the energizable temperature by the cooling device (typically one day) becomes impossible to conduct electricity to the superconducting coil 30. .

As a countermeasure against power failure, if an uninterruptible power system (hereinafter abbreviated as UPS) is provided to supply all the power of the excitation power supply unit 40 and the cooling device, a UPS device having a large power capacity is required. There is a drawback that the apparatus becomes large and expensive.

Then, the subject of this invention is providing the superconducting magnet apparatus which can continue generating a magnetic field for a predetermined time even if a power failure occurs.

A superconducting magnet device according to an embodiment of the present invention is a superconducting magnet device that cools a superconducting coil supplied with power from an excitation power supply unit in a refrigerator, and includes a battery to control components in the excitation power supply unit when a power failure occurs. A UPS device for backing up the power supply, a short circuit for opening and shorting the output of the excitation power supply unit, and receiving the electric power supply from the UPS device to turn the switch circuit into a short circuit state when a power failure occurs. On the other hand, it is comprised so that the output short circuit and release circuit which will be in an open state at the time of power recovery may be provided.

According to another embodiment of the present superconducting magnet device, when the superconducting coil is housed in a vacuum insulated container and cooled by being thermally coupled to the freezing stage of the refrigerator, the inside of the vacuum insulated container may further include a latent heat of evaporation ( A cold storage container containing a cooling medium for cooling by latent heat may be arranged to be thermally coupled with the superconducting coil so as to perform cooling when a power failure occurs.

In still another embodiment of the present superconducting magnet device, the excitation power supply section includes a current control section, and in this case, the detection is provided on a power supply line between the switch circuit and the superconducting coil to detect a current flowing through the superconducting coil. And a current control circuit at the time of receiving power from the UPS device, receiving a current value detected by the detection means, and matching the current value in the current control unit with the current value detected at the time of restoration. do.

According to still another embodiment of the present superconducting magnet device, a combination of the other embodiment and another embodiment, that is, the superconducting coil is cooled by being housed in a vacuum insulation container and thermally coupled to the freezing stage of the refrigerator, In the vacuum insulated container, a cold storage container containing a cooling medium for cooling by latent heat of evaporation is arranged to thermally couple with the superconducting coil to perform cooling in the event of a power failure. A detection means for detecting a current flowing through the superconducting coil by being provided in a power line between the switch circuit and the superconducting coil, receiving a power supply from the UPS device, Receives the detected current value and detects the current value in the current control unit at the time of restoration The superconducting magnet apparatus comprising the clothing exhibits the current-controlling circuit for matching a current value is provided.

In any of the above embodiments, it is preferable to use one of a sterling refrigerator, a pulse refrigerator and a GM refrigerator for the refrigerator, and helium for the cooling medium.

With reference to FIG. 1, FIG. 2, embodiment of this invention is described. First, with reference to FIG. 2, the superconducting coil 30 and its cooling apparatus 20 in the superconducting magnet device of the always-on power supply type to which the present invention is applied will be described.

The cooling device 20 has a vacuum insulation container 21 and a heat radiation shielding container 22 disposed therein, and a superconducting coil 30 is disposed in the heat radiation shielding container 22. Cooling in the vacuum insulated container 21 is performed by a cryogenic refrigerator, for example, a GM refrigerator 23 (also in the case of a sterling refrigerator and a pulse refrigerator). That is, the first stage freezing stage of the GM refrigerator 23 is thermally coupled to a part of the heat radiation shielding container 22, and the second stage freezing stage is thermally coupled to the heat transfer plate 24. The superconducting coil 30 has its bobbin 31 thermally coupled to the heat transfer plate 24. Here, the illustration of the supporting structure of the superconducting coil 30 and the heat radiation shielding container 22 is omitted.

In the vacuum insulated container 21, a room temperature space 25 communicating with the outside of the vacuum insulated container 21 is formed in the central axis portion of the vacuum insulated container 21 through the heat radiation shielding container 22, and the superconducting coil in the room temperature space 25. Use the strong magnetic field generated by (30).

In the vacuum insulation container 21, a cold storage container 26 for storing liquid helium is arranged on the heat transfer plate 24. The cold storage container 26 is connected to a supply pipe 27 for supplying liquid helium or gas helium from the outside of the vacuum insulation container 21 and a pipe for the safety valve 28. When gas helium is supplied, it cools together at the time of initial cooling of the superconducting coil 30, and gas helium is liquefied.

It is possible to suppress the temperature rise of the superconducting coil 30 by absorbing the amount of heat infiltration into the vacuum insulation container 21 after the cooling device is stopped by the electrostatic generation by the latent heat of evaporation of liquid helium in the cold storage container 26. .

In general, the heat input into the superconducting coil 30 after the cooling device is stopped is several W or less. Assuming that there is no heat generation due to the AC loss of the superconducting coil 30, the amount of liquid helium necessary to absorb the power interruption within tens of minutes and the intrusion heat accompanying the stop of the cooling apparatus is sufficient as a repairman. Since the liquid helium contained in the cold storage container 26 does not evaporate while the cooling device is in operation, regular replenishment during operation is not necessary, and sufficient replenishment after the power failure is completed and restored.

Next, with reference to FIG. 1, the excitation power supply part 10 which concerns on embodiment of this invention is demonstrated. The excitation power supply unit 10 includes a transformer unit 11 for stepping down the voltage from the commercial power source to a predetermined voltage value, a rectifier unit 12 for rectifying the voltage from the transformer unit 11, In addition to the current control unit 13 for controlling the current to the superconducting coil 30, it has the following components.

In other words, the excitation power supply unit 10 includes an ammeter 14 for detecting a current flowing through the superconducting coil 30, a UPS device 15 built in a battery and connected to the transformer unit 11, and a UPS device 15. The output side of the current control unit 13 is connected between the connected output short / release circuit 16, the current control circuit 17 at the time of recovery, and the output line of the current control unit 13, and is output by the output short / release circuit 16. It has a switch circuit 18 for shorting.

Since the UPS device 15 is for operating each element inside the excitation power supply unit 10 in the event of a power failure, the battery capacity is preferably sufficiently small as compared with the power capacity of the UPS device of the prior art described above. The output short circuit / release circuit 16 turns on the switch circuit 18 at the time of power failure, short-circuits the output of the current control unit 13, in other words, the input side of the superconducting coil 30, and switches the circuit 18 at the time of power recovery. OFF to release the short circuit on the output side of the current control unit 13. The current control circuit 17 at the time of restoration receives the current value flowing through the superconducting coil 30 during the power failure from the ammeter 14, and receives the output current from the current control unit 13 at the time of restoration. Match the current flowing in

The operation of the liquid helium and the excitation power supply unit 10 of the cold storage container 26 will be described below.

The operation in the normal state (non-power failure) is as follows.

⑴ Cold storage container 26 is in the state containing liquid helium.

UPS device 15 is in a normal power supply state.

(B) The output short / release circuit 16 keeps the switch circuit 18 open.

On the other hand, operations during power failure and power failure are as follows.

When the voltage of the transformer 11 falls below a predetermined value, the UPS device 15 enters a backup state by the built-in battery.

(B) The output short circuit / release circuit 16 is operated by the backup power supplied from the UPS device 15. When the output of the transformer section 11 disappears, the output circuit 11 is short-circuited.

During the blackout, the increase in the coil temperature is suppressed by the latent heat of evaporation of the liquid helium in the cold storage container 26.

The current control circuit 17 at the time of restoration operates to set the output current value of the current control unit 13 in the excitation power supply unit 10 to the current value obtained from the ammeter 14.

The operation at the time of restoration is as follows.

When the power failure is restored, the current control circuit 17 at the time of restoration sets the output current value of the current control section 13 in the excitation power supply section 10 to the current value from the ammeter 14 obtained at the time of restoration.

⑼ The output short circuit / release circuit 16 turns the switch circuit 18 to an open state when the voltage of the transformer section 11 is restored. As a result, the current control unit 13 flows the current having the same value as that flowing in the superconducting coil 30 at the time of restoration to the superconducting coil 30, and returns to the normal state.

When the voltage of the transformer 11 is restored, the UPS device 15 returns to the power supply state of the above-mentioned V.

3 shows an example of the basic configuration of the negative feedback type current control unit 13. The collector of the transistor Tr1 is connected to the rectifier 12, and one end of the current detection resistor R1 is connected to the emitter. The output of the operational amplifier OP1 is connected to the base of the transistor Tr1. One end of the resistor R1 is connected to the inverting input terminal of the operational amplifier OP1. The other end of the resistor R1 reaches the switch circuit 18 and is connected to the non-inverting input terminal of the operational amplifier OP1 via the resistor R2. The signal voltage V from the current control circuit 17 at the time of restoration is connected to both ends of the resistor R2. However, this circuit only shows the minimum structure necessary for explaining an example of the connection relationship of the current control circuit 17 and the current control part 13 at the time of restoration.

As described above, according to the superconducting magnet device of this embodiment, the magnetic field generation by the superconducting coil 30 can be continued even if the battery is allowed within the UPS device 15 even while the power failure is continued.

Although the present invention has been described with reference to preferred embodiments, the present invention is not limited to the above embodiments. That is, in the above embodiment, the cold storage container in which the ammeter 14, the UPS device 15, the output short circuit / release circuit 16, the current control circuit 17 at the time of recovery, the switch circuit 18, and the liquid helium ( The case of 26) is provided. This is applicable even if the duration of the power failure is about ten minutes, and it is also necessary to stabilize the current supply to the superconducting coil 30 at the time of restoration. However, in the case where the required specification needs to be able to cope only with a short time outage such as a few seconds, the UPS device 15, the output short / release circuit 16 and the switch circuit 18 may be provided only. That is, in the case of power failure for several seconds, the current may be circulated by the switch circuit 18 using the current path of the superconducting coil 30 as a closed loop.

Alternatively, if the stabilization of the current supply to the superconducting coil 30 at the time of restoration can be ignored, the cold storage container containing the UPS device 15, the output short / release circuit 16, the switch circuit 18, and liquid helium The structure provided with only (26) may be sufficient.

The superconducting magnet device according to the present invention can continue to generate a magnetic field by the superconducting coil within a predetermined time even when the power supply to the exciting power supply unit is lost due to a power failure and the cooling device is stopped.

Claims (5)

In a superconducting magnet device that cools a superconducting coil supplied with power from an exciting power supply unit in a refrigerator, A UPS device incorporating a battery for backing up the control power of the components in the excitation power supply unit when a power failure occurs; A switch circuit for shorting and opening the output of the excitation power supply unit; An output short circuit and a release circuit for receiving the power supply from the UPS device to turn the switch circuit into a short state when a power failure occurs, and to open it when a power failure occurs; The excitation power supply unit includes a current control unit, In addition, detection means for detecting a current flowing through the superconducting coil provided on a power line between the switch circuit and the superconducting coil; And a power-up current control circuit for receiving power from the UPS device and receiving a current value detected by the detection means and matching the current value in the current control unit with the current value detected at the time of power-up. Superconducting magnet device. The method according to claim 1, The superconducting coil is accommodated in a vacuum insulation container and cooled by being thermally coupled to the freezing stage of the refrigerator, In the vacuum insulated container, a cold storage container containing a cooling medium to be cooled by latent heat of evaporation is arranged to thermally couple the superconducting coil so that the power failure occurs. A superconducting magnet device, characterized in that for cooling. delete delete The method according to claim 1 or 2, The refrigerator is one of a sterling refrigerator, a pulse refrigerator, a GM refrigerator, and the cooling medium is helium.

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