WO2022160796A1 - 一种基于分布式加热器网络的超导磁体系统失超保护电路 - Google Patents

一种基于分布式加热器网络的超导磁体系统失超保护电路 Download PDF

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WO2022160796A1
WO2022160796A1 PCT/CN2021/125452 CN2021125452W WO2022160796A1 WO 2022160796 A1 WO2022160796 A1 WO 2022160796A1 CN 2021125452 W CN2021125452 W CN 2021125452W WO 2022160796 A1 WO2022160796 A1 WO 2022160796A1
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heater
superconducting
coil
coils
protection circuit
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PCT/CN2021/125452
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English (en)
French (fr)
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宋运兴
李亮
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华中科技大学
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Priority to US17/799,928 priority Critical patent/US20230065221A1/en
Publication of WO2022160796A1 publication Critical patent/WO2022160796A1/zh

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F6/00—Superconducting magnets; Superconducting coils
    • H01F6/02—Quenching; Protection arrangements during quenching
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F6/00—Superconducting magnets; Superconducting coils
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F6/00—Superconducting magnets; Superconducting coils
    • H01F6/005—Methods and means for increasing the stored energy in superconductive coils by increments (flux pumps)
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
    • Y02E40/60—Superconducting electric elements or equipment; Power systems integrating superconducting elements or equipment

Definitions

  • the invention belongs to the field of quench protection of a superconducting magnet system, and more particularly, relates to a quench protection circuit of a superconducting magnet system based on a distributed heater network.
  • superconducting magnets As we all know, compared with resistive magnets, superconducting magnets have small size, high current density, low energy consumption, and high magnetic field strength. They are widely used in basic scientific research, medical and health, transportation, defense industry, electrical engineering and other fields. In particular, superconducting magnet systems are widely used in the fields of NMR and MRI. However, there are conditions for a superconducting magnet to maintain a superconducting state, which is constrained by temperature, current, magnetic field, and even strain. Any one or several variables beyond the critical interval of the superconducting wire will cause the superconducting magnet in normal operation to return from the superconducting state to the resistive state, thereby losing the superconducting characteristic (ie quenching).
  • the superconducting magnet is in a superconducting state, that is, a non-resistance state.
  • a superconducting state that is, a non-resistance state.
  • tiny normal regions will appear inside the superconducting magnet. If this normal region is not controllable, it will continue to expand until the entire magnet quenches.
  • the superconducting wire where the normal zone first appears would be very hot enough to melt the wire and destroy the superconducting magnet.
  • superconducting magnet terminal voltage or interlayer voltage may appear extremely high voltage, resulting in flashover between conductors and eventually destroying the superconducting magnet.
  • a certain protection circuit is used to deliberately quench all superconducting coils at the same time when a small normal area appears in the magnet, so that the energy can be released to all volumes of each superconducting coil as uniformly as possible, it will greatly reduce the temperature of the magnet and the terminal voltage, thereby protecting the superconducting magnet.
  • a circuit that implements this function is called a quench protection circuit. Typically, this is achieved by a network of distributed heaters attached to predetermined locations of the magnet coils.
  • Figure 1 shows a typical prior art superconducting magnet quench protection circuit (10) comprising eight superconducting coils L1-L8 (101) connected in series.
  • the superconducting coil subsets L1 and L8 are active shielding coils, and the current directions thereof are opposite to the current directions of the superconducting coil subsets L2-L7.
  • a heater is attached to the surface of each superconducting coil in thermal contact with it. These heaters are connected in series to form a heater network 105 .
  • the heater network 105 and the second diode assembly 106 are connected in series, and this series arrangement is connected in parallel with the superconducting coil subset L3-L6.
  • a pair of current leads 104 are connected to both ends of the superconducting coil 101 for connection with the excitation power supply.
  • the low temperature superconducting switch 103 and the current lead 104 are connected in parallel.
  • the first diode integrated assembly 102 and the low temperature superconducting switch 103 are connected in parallel.
  • the threshold voltage of the first diode integrated assembly 102 is higher than the maximum excitation voltage at both ends of the magnet for protecting the low temperature superconducting switch 103 .
  • the second diode integrated assembly 106 prevents the heater network 105 from conducting electricity, preventing the quench protection circuit from malfunctioning and causing the magnet to quench.
  • the threshold voltage of the second diode assembly 106 is selected to be greater than the maximum voltage across L3-L6 during magnetization or demagnetization.
  • Each of the diode-integrated assemblies 102 and 106 typically consists of two sets of two or more diodes connected in series and then anti-parallel. There are at least two defects in this circuit: 1) All heaters are connected in series, once an open circuit occurs somewhere in the circuit, the superconducting coil 101 will lose its protection completely. 2) All heaters are connected in series, resulting in a very high voltage across the coil subsets L3-L6, forcing heaters with smaller resistance values to be designed, but in this way, during the quench process, The heating power of the heater is low, resulting in a slow response of the quench protection.
  • the superconducting coil subsets L1 and L8 are active shielding coils, and the current directions thereof are opposite to the current directions of the superconducting coil subsets L2-L7.
  • the heater network 105 is composed of M heater modules H1-H8, each heater module includes a plurality of heaters, and each heater module is respectively connected in parallel with one of the coils.
  • each heater module in the N (N ⁇ M) heater modules includes at least M heaters, and each superconducting coil is thermally coupled with at least one heater in the heater modules; each of the M-N heater modules
  • the heater modules include at least one heater, each of the N superconducting coils in parallel with the N heater modules being thermally coupled to at least one heater of each heater unit of the M-N heater modules.
  • a pair of current leads 104 are connected to both ends of the superconducting coil 101 for connection with the excitation power supply.
  • the low temperature superconducting switch 103 and the current lead 104 are connected in parallel.
  • the first diode integrated assembly 102 and the low temperature superconducting switch 103 are connected in parallel.
  • the threshold voltage of the first diode integrated assembly 102 is higher than the maximum excitation voltage at both ends of the magnet for protecting the low temperature superconducting switch 103 .
  • This quench protection circuit has at least five disadvantages: 1) Each heater module is connected in parallel with one of the superconducting coils. During the quenching process, the current flowing through each superconducting coil is different, which leads to the appearance of the internal magnet system. Extremely large unbalanced force, which may cause structural damage to the superconducting magnet system; 2) Because the aforementioned currents flowing through each superconducting coil are not the same, the stray field contour lines will also be in space.
  • Each heater module does not have a diode integrated component in series, which cannot prevent the heater network from conducting electricity during the ramp-up or ramp-down process. It may trigger the malfunction of the quench protection circuit and cause the superconducting magnet to quench; 4) When N ⁇ M, the quench protection circuit cannot make all the superconducting coils quench at the same time, and some coils have a quench delay; 5) Since each The heater modules are respectively connected in parallel with one of the superconducting coils, resulting in complicated connection of the quench protection circuit, requiring a large number of heaters, and high cost.
  • the invention provides a quench protection circuit for a superconducting magnet system based on a distributed heater network, which is used to solve the problems of low protection reliability, slow circuit response, and current flowing through symmetrical coils in the existing superconducting magnet system quench protection circuit. Unbalanced forces and stray field expansion caused by inequalities lead to technical problems that limit the application.
  • Each heater in the heater network is thermally coupled to one of the M superconducting coils, and each superconducting coil is thermally coupled to at least one heater in each heater module.
  • the beneficial effect of the present invention is that the coil subsets from which the heater network is taken are distributed symmetrically in space.
  • the current difference flowing through the symmetrical coil can be controlled at a very low level, so that the magnitude of the unbalanced force can be controlled at an acceptable value, and the range of the stray field spatial expansion can also be controlled. at an acceptable value.
  • the heater network is a regular, compact series-parallel network with greatly improved reliability and quench response. Therefore, the solution of the present application can effectively solve the technical problems of the existing quench protection circuit, such as low protection reliability, slow circuit response, unbalanced force and stray field expansion caused by unequal currents flowing through the symmetrical coils.
  • the present invention can also be improved as follows.
  • the heater module is connected in series with a diode component to prevent the quenching of the superconducting coil caused by the malfunction of the quench protection circuit.
  • the superconducting coil subset is composed of one superconducting coil, a plurality of superconducting coils, a superconducting sub-coil, or a superconducting sub-coil and a superconducting coil;
  • the conductor coil is part of the superconducting coil.
  • a further beneficial effect of the present invention is that the subset of superconducting coils can be a collection of any part of the coils, and the circuit connection mode can be flexibly designed according to actual needs.
  • N 1, m>1, and m*n ⁇ M.
  • a further beneficial effect of the present invention is that the subsets of coils from which the heater network is taken are spatially symmetrical, and the heater network contains only one heater module.
  • the currents flowing through the symmetrical coils are always the same, that is, the currents flowing through L1 and L8, L2 and L7, L3 and L6, and L4 and L5 are always equal. Therefore, there is no problem of unbalanced force and no problem of the stray field expanding outward in space.
  • the heater network is a regular, compact series-parallel network. The reliability and quench response are greatly improved compared to the prior art. For example, as long as there is still one branch conducting, all superconducting coils will not lose quench protection.
  • the coil subsets taken from the heater network are distributed symmetrically in space, and the structures of the two heater modules of the heater network are completely identical.
  • the currents flowing through L3 and L4, L5 and L6, L1 and L2, L7 and L8 are always equal, and the difference between the currents flowing through L1 and L8, L2 and L7 can be controlled at a reasonable level, so that the unbalanced force
  • the size can be controlled to an acceptable value, and the range of the stray field spatially outward expansion can also be controlled to an acceptable value.
  • the heater network is a regular, compact series-parallel network with greatly improved reliability and quench response. The two heater modules in the heater network 105 back up each other, and even if one module is completely disconnected, the other module can protect all the superconducting coils 101 . It can be seen that the circuit reliability is further improved.
  • the coil subsets taken from the heater network are distributed symmetrically in space, and the structures of the two heater modules located at the spatially symmetrical positions are identical.
  • the currents flowing through L3 and L4, L5 and L6, L1 and L2, L7 and L8 are always equal, and the difference between the currents flowing through L1 and L8, L2 and L7 can be controlled at a reasonable level, so that the unbalanced force
  • the size can be controlled to an acceptable value, and the range of the stray field spatially outward expansion can also be controlled to an acceptable value.
  • the heater network is a regular, compact series-parallel network with greatly improved reliability and quench response.
  • the three heater modules in the heater network 105 are mutually backed up, and even if two of the modules are completely disconnected, the remaining one module can protect all the superconducting coils 101 . It can be seen that the circuit reliability is further improved.
  • 1 is a schematic diagram of a prior art quench protection circuit
  • FIG. 2 is a schematic diagram of another prior art quench protection circuit
  • FIG. 3 is a schematic diagram of a quench protection circuit of a superconducting magnet system provided by an embodiment of the present invention
  • FIG. 4 is a schematic diagram of another quench protection circuit of a superconducting magnet system provided by an embodiment of the present invention.
  • FIG. 5 is a schematic diagram of another quench protection circuit of a superconducting magnet system provided by an embodiment of the present invention.
  • FIG. 6 is a schematic diagram of another quench protection circuit of a superconducting magnet system provided by an embodiment of the present invention.
  • FIG. 7 is a schematic diagram of another quench protection circuit of a superconducting magnet system provided by an embodiment of the present invention.
  • FIG. 8 is a schematic diagram of another quench protection circuit of a superconducting magnet system provided by an embodiment of the present invention.
  • FIG. 9 is a schematic diagram of another quench protection circuit of a superconducting magnet system according to an embodiment of the present invention.
  • 10 is a quench protection circuit
  • 101 is a superconducting coil
  • 102 is a first diode integrated component
  • 103 is a low temperature superconducting switch
  • 104 is a current lead
  • 105 is a heater network
  • 106 is a second diode integrated component
  • 1051, 1052, 1053 are heater modules.
  • the quench protection circuit of Figure 1 has the following advantages: it can ensure that the currents through the symmetrical coils are always equal, that is, the currents flowing through L1 and L8, L2 and L7, L3 and L6, and L4 and L5 are always equal. However, there are at least two defects in this circuit.
  • the analysis is as follows: 1) All heaters are connected in series to form a single loop. Once an open circuit occurs somewhere in the line, the heater network will not be able to obtain thermal power, so that the superconducting coil cannot be triggered. As a result, the superconducting coil 101 loses its protection completely.
  • the quench protection circuit in Figure 2 has at least five shortcomings, which are analyzed as follows: 1) Each heater module is connected in parallel with one of the superconducting coils. During the quenching process, due to the normal diffusion speed of each superconducting coil Different from the volume, the terminal voltage of each superconducting coil is different, so the current flowing through each superconducting coil is different, resulting in a great unbalanced force inside the magnet system, which may affect the superconducting coil. The magnetic conductor system will cause structural damage; 2) Due to the different currents flowing through each superconducting coil analyzed above, the stray field contour lines will expand outward in space, bringing safety hazards; 3) Each The heater module does not have a series diode integrated component.
  • the heater network cannot be prevented from conducting electricity, which may trigger the malfunction of the quench protection circuit and cause the magnet to quench.
  • the quench protection circuit cannot make all the superconducting coils quench at the same time, and some coils have a quench delay.
  • the present invention provides the following embodiments to solve the technical problems existing in the existing quench protection circuit.
  • the superconducting coil subsets L1 and L8 are active shielding coils, and the current directions thereof are opposite to the current directions of the superconducting coil subsets L2-L7.
  • a pair of current leads 104 are connected to both ends of the superconducting coil 101 for connection with an excitation power source (not shown).
  • the low temperature superconducting switch 103 and the current lead 104 are connected in parallel.
  • the first diode integrated assembly 102 and the low temperature superconducting switch 103 are connected in parallel.
  • the threshold voltage of the first diode integrated assembly 102 is higher than the maximum excitation voltage at both ends of the magnet for protecting the low temperature superconducting switch 103 .
  • Each heater in heater network 105 is thermally coupled to one of the superconducting coils, and each superconducting coil is thermally coupled to at least one heater.
  • the heater network 105 and the second diode assembly 106 are connected in series, and this series arrangement is connected in parallel with the superconducting coil subset L3-L6.
  • the second diode integrated assembly 106 prevents the heater network 105 from conducting electricity, preventing the quench protection circuit from malfunctioning and causing the magnet to quench.
  • the threshold voltage of the second diode assembly 106 is selected to be greater than the maximum voltage across L3-L6 during magnetization or demagnetization.
  • the low temperature superconducting switch 103 is heated by a heater (not shown), the low temperature superconducting switch 103 behaves as a large resistance, and most of the current (from the excitation power) passes through the superconducting Coil 101, the excitation power supply magnetizes the superconducting coil 101.
  • the power supply for heating the heater of the low-temperature superconducting switch 103 is turned off, and the low-temperature superconducting The switch 103 returns to the superconducting state while the voltage of the field power supply is adjusted to 0, and the current lead 104 is removed to limit heat loss into the superconducting magnet system, which enters the Persistent mode.
  • the low temperature superconducting switch 103 is heated by a heater (not shown), the low temperature superconducting switch 103 behaves as a large resistance, and most of the current passes through the superconducting coil 101 and the current lead 104 and excitation power.
  • the excitation power supply outputs a reverse voltage to demagnetize.
  • a DC load or diode is connected in series with the excitation power circuit to create a larger voltage drop. When the current on the power dial shows 0, the excitation power supply can be turned off and the current lead 104 can be removed.
  • the heater network includes m (m>1) branches, and each branch is connected with n (n ⁇ 1) heaters in series.
  • n n ⁇ 1 heaters in series.
  • the heater networks H1-H8 are connected in parallel, and each superconducting coil is thermally coupled to one of the heaters.
  • FIG. 4 the principle of the quench protection circuit is described. If the superconducting coil L4 quenches, a voltage will rapidly build up across the coil subset L3-L6. This voltage provides thermal power to each heater in heater network 105 to generate heat. These heaters, due to their thermal coupling with the superconducting coil, will accelerate the L4 quench and quench all other coils that are not quenched, converting the magnetic energy stored in the superconducting coil into thermal energy and quenching all volumes of all coils as much as possible These energies are absorbed, thereby realizing the protection of the superconducting coil 101 . In Figure 4, all 8 heaters in the heater network are connected in parallel, and the reliability is greatly improved. Unless the entire heater network is open, the quench of the superconducting coil attached to the unopened heater can always be triggered, so as not to be as shown in Figure 1, once the circuit is open, the coil loses its quench protection completely.
  • m can choose any value > 1
  • n can choose any value ⁇ 1, but the product of m and n must be ⁇ M, and ensure that each coil has at least one heater thermally coupled to it.
  • the voltage of the heater network is taken from the coil subset L3-L6, this is just an example.
  • the voltage of the heater network can be taken from the voltage between any symmetrical coils (that is, the subset of coils connected in parallel with the heater network can expand or shrink along the spatially symmetrical position of the entire set of coils), or even a Or a plurality of coils in symmetrical positions are divided into several symmetrical sub-coils, and the voltage of the heater network can be taken from the voltage between any symmetrical coils including the sub-coils, as shown in FIG. 5 as an example. But the voltage of the heater network cannot take the voltage between the low temperature superconducting switches 103 . If the coil is divided into several sub-coils, the physical location of the heater is not limited to the surface of the coil, but may be attached to the surface of the sub-coils.
  • the advantages of the quench protection circuit shown in Figure 3 are: 1) The subset of coils from which the heater network is taken are spatially symmetrically distributed. During the quench process, the currents flowing through the symmetrical coils are always the same, that is, the currents flowing through L1 and L8, L2 and L7, L3 and L6, and L4 and L5 are always equal. Therefore, there is no problem of unbalanced force and no problem of the stray field expanding outward in space. 2) The heater network is a regular, compact series-parallel network. The reliability and quench response are greatly improved compared to the prior art. For example, as long as there is still one branch conducting, all superconducting coils will not lose quench protection.
  • FIG. 6 is a schematic diagram of a quench protection circuit according to another embodiment of the present invention.
  • the heater network 105 includes two structurally identical heater modules, and the second diode assembly 106 includes two structurally identical diode assembly modules.
  • One heater module in the heater network 105 and one diode module in the second diode assembly 106 are connected in series, and this series arrangement is connected in parallel with the superconducting coil subsets L1-L2 or L7-L8.
  • the second diode integrated assembly 106 prevents the heater network 105 from conducting electricity, preventing the quench protection circuit from malfunctioning and causing the superconducting magnet to quench.
  • the threshold voltage of any module in the second diode assembly 106 is selected to be greater than the maximum voltage across L1-L2 and L7-L8 during magnetization or demagnetization.
  • Each heater of each heater module in heater network 105 is thermally coupled to one of the superconducting coils, and each superconducting coil is thermally coupled to at least one heater of each heater module.
  • Any heater module in the heater network includes m (m ⁇ 1) branches, and each branch is connected with n (n ⁇ 1) heaters in series.
  • m and n can choose any value ⁇ 1, but the product of m and n must be ⁇ M, while ensuring that each coil is thermally coupled to at least one heater in each heater module.
  • the heater network contains two identical heater modules, each heater module contains only one branch, and each branch is 8 heaters are connected in series. Two heaters are attached to each superconducting coil, and they come from two different heater modules.
  • the heater network contains two identical heater modules, each heater module contains 8 parallel branches, and each branch only contains a heater. Attached to each superconducting coil are two heaters from two different heater modules.
  • the voltage of the heater network is taken from coil subsets L1-L2 and L7-L8, this is just an example.
  • the voltage of the heater network can be taken from any symmetrical coil or voltage between symmetrical sub-coils, but not from L1-L4 and L5-L8 (the only special cases). Because in this case, if there is a symmetrical quench (such as a normal region of the same size at the symmetrical position of L1 and L8), the superconducting magnet cannot be protected.
  • the advantages of the quench protection circuit shown in Figure 6 are: 1) The subset of coils from which the heater network is taken are spatially symmetrically distributed. During the quenching process, the currents flowing through L3 and L4, L5 and L6, L1 and L2, L7 and L8 are always equal, and the difference between the currents flowing through L1 and L8, L2 and L7 can be controlled at a reasonable level, so that the unbalanced force The size can be controlled to an acceptable value, and the range of the stray field spatially outward expansion can also be controlled to an acceptable value. 2) The heater network is a regular, compact series-parallel network, and the reliability and quench response are greatly improved.
  • the two heater modules in the heater network 105 back up each other, and even if one module is completely disconnected, the other module can protect all the superconducting coils 101 . It can be seen that the reliability of the circuit shown in FIG. 6 is further improved than that of the circuit shown in FIG. 3 .
  • FIG. 9 is a diagram of a quench protection circuit according to another embodiment of the present invention.
  • the superconducting coil subsets L1 and L8 are active shielding coils, and the current directions thereof are opposite to the current directions of the superconducting coil subsets L2-L7.
  • a pair of current leads 104 are connected to the superconducting coil 101 for connection with the excitation power supply.
  • the low temperature superconducting switch 103 and the current lead 104 are connected in parallel.
  • the first diode integrated assembly 102 and the low temperature superconducting switch 103 are connected in parallel.
  • the threshold voltage of the first diode integrated assembly 102 is higher than the maximum excitation voltage at both ends of the superconducting magnet for protecting the low temperature superconducting switch 103 .
  • Each heater of each heater module in heater network 105 is thermally coupled to one of the superconducting coils, and each superconducting coil is thermally coupled to at least one heater in each heater module.
  • the heater network 105 includes 3 heater modules, each heater module has m (m ⁇ 1) parallel branches, each parallel branch has n (n ⁇ 1) heaters in series, and the heater module 1051 Structurally identical to 1053, m*n ⁇ M.
  • the second diode integrated assembly 106 includes three diode assembly modules that are identical in structure. One heater module in heater network 105 and one diode module in second diode assembly 106 are connected in series with corresponding subsets of superconducting coils (L1-L2, L3-L6, L7-L8, respectively) in parallel. The threshold voltage of any module in the second diode assembly 106 is selected to be greater than the maximum voltage across L1-L2, L3-L6, and L7-L8 during magnetization or demagnetization.
  • the voltage of the heater network is taken from coil subsets L1-L2, L3-L6 and L7-L8, which is just one example.
  • the voltage of the heater network can be taken from any symmetrical coil or voltage between symmetrical sub-coils.
  • the advantages of the quench protection circuit shown in Figure 9 are: 1) The subset of coils from which the heater network is taken are spatially symmetrically distributed. During the quenching process, the currents flowing through L3 and L4, L5 and L6, L1 and L2, L7 and L8 are always equal, and the difference between the currents flowing through L1 and L8, L2 and L7 can be controlled at a reasonable level, so that the unbalanced force The size can be controlled to an acceptable value, and the range of the stray field spatially outward expansion can also be controlled to an acceptable value. 2) The heater network is a regular, compact series-parallel network, and the reliability and quench response are greatly improved.
  • the three heater modules in the heater network 105 are mutually backed up, and even if two of the modules are completely disconnected, the remaining one module can protect all the superconducting coils 101 . It can be seen that the reliability of the circuit shown in FIG. 9 is further improved than that of the circuit shown in FIG. 6 .
  • the heater network in Figure 9 includes three heater modules. It is easy to think: if the heater module is extended to M modules, the reliability of the quench protection circuit will be greatly increased. However, if the number of heater modules continues to increase, the disadvantage is that the inconsistency of the current will greatly increase, causing the unbalanced force and the stray field to expand spatially and become uncontrollable. Therefore, the present invention limits the number of heater modules to N ⁇ 3.

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Abstract

本发明属于超导磁体系统失超保护领域，具体涉及一种基于分布式加热器网络的超导磁体系统失超保护电路，包括：串联的M个超导线圈，以及由N个加热器模块构成的加热器网络；其中，M>N，N≤3，不同的加热器模块与不同的超导线圈子集并联，且所有超导线圈子集之间在空间上具有对称性；每个加热器模块有m个并联支路，每个并联支路有n个加热器串联，m≥1，n≥1；且当N＝1时，m>1；加热器网络中的每一个加热器跟M个超导线圈中的一个超导线圈热耦合，且每个超导线圈与每一个加热器模块中的至少一个加热器热耦合。本发明能有效解决现有保护电路所存在的保护可靠性低、电路响应慢、流过对称线圈的电流不相等引起的不平衡力和杂散场扩张等的技术问题。

Description

一种基于分布式加热器网络的超导磁体系统失超保护电路 【技术领域】
本发明属于超导磁体系统失超保护领域，更具体地，涉及一种基于分布式加热器网络的超导磁体系统失超保护电路。
【背景技术】
众所周知，跟阻性磁体相比，超导磁体体积小、电流密度高、能耗低、磁场强度高，在基础科学研究、医疗卫生、交通运输、国防工业、电工等领域被广泛应用。特别地，超导磁体系统在NMR和MRI领域中得到广泛应用。然而，超导磁体维持超导态是有条件的，它受温度、电流、磁场、甚至应变的约束。任何一个或几个变量超出超导线的临界区间，都将使得正常运行中的超导磁体由超导态回到电阻态，从而失去超导特性(即失超)。
在正常升磁、降磁或稳态运行时，超导磁体处于超导态即无电阻状态。然而一旦由于局部的扰动(这种扰动可以是机械、温度、气压或者电磁)，超导磁体内部将出现微小的正常区。如果该正常区不可控，它将不断扩大直至整个磁体失超。而最开始出现正常区的超导线的温度会非常高，足以熔化导线，从而破坏超导磁体。另外，在失超过程中，超导磁体端电压或层间电压可能出现极高压，导致导体之间发生闪络，最终破坏超导磁体。如果在磁体出现微小正常区的时候，采用某种保护电路故意让所有超导线圈同时失超，让能量尽可能均匀地释放到每一个超导线圈的所有体积上，将极大地降低磁体温度和端电压，从而保护超导磁体。实现该功能的电路被称为失超保护电路。典型地，可通过附接到磁体线圈预定位置的分布式加热器网络来实现。
图1示出了一种典型现有技术超导磁体失超保护电路(10)，包括8个 串联连接的超导线圈L1-L8(101)。其中，超导线圈子集L1和L8为主动屏蔽线圈，其电流方向和超导线圈子集L2-L7的电流方向相反。每个超导线圈的表面贴有一个与其热接触的加热器。这些加热器串联连接构成了加热器网络105。加热器网络105和第二二极管集成组件106串联连接，且这个串联装置与超导线圈子集L3-L6并联连接。超导线圈101两端接了一对电流引线104用于和励磁电源连接。低温超导开关103和电流引线104并联。第一二极管集成组件102和低温超导开关103并联连接。第一二极管集成组件102的门限电压高于磁体两端最大的励磁电压，用于保护低温超导开关103。当磁体处于升磁(Ramp-up)或降磁(Ramp-down)时，第二二极管集成组件106阻止加热器网络105导电，防止失超保护电路误动作导致磁体失超。第二二极管集成组件106的门限电压被选择为大于升磁或降磁过程中L3-L6两端的最大电压。二极管集成组件102和106中的每一个，通常由两组两个二极管或多个二极管串联连接再被反并联组成。该电路至少存在两个缺陷：1)所有加热器串联连接，一旦线路某处出现开路，超导线圈101将彻底失去保护。2)所有加热器串联连接，导致线圈子集L3-L6两端的电压非常高，迫使在加热器设计时，只能设计阻值较小的加热器，但这样一来，在失超过程中，加热器的加热功率较低，导致失超保护响应较慢。
图2示出了另一种现有技术超导磁体失超保护电路(10)，包括M(M＝8)个串联连接的超导线圈L1-L8(101)。其中，超导线圈子集L1和L8为主动屏蔽线圈，其电流方向和超导线圈子集L2-L7的电流方向相反。加热器网络105由M个加热器模块H1-H8组成，每个加热器模块包括多个加热器，且每个加热器模块分别和其中一个线圈并联。其中，N(N≤M)个加热器模块中每个加热器模块包括至少M个加热器，每个超导线圈与加热器模块中的至少一个加热器热耦合；M-N个加热器模块中每个加热器模块包括至少一个加热器，与N个加热器模块并联的N个超导线圈中的每个超 导线圈与M-N个加热器模块中每个加热器单元的至少一个加热器热耦合。超导线圈101两端接了一对电流引线104用于和励磁电源连接。低温超导开关103和电流引线104并联连接。第一二极管集成组件102和低温超导开关103并联连接。第一二极管集成组件102的门限电压高于磁体两端最大的励磁电压，用于保护低温超导开关103。这种失超保护电路至少存在5个缺点：1)每个加热器模块分别和其中一个超导线圈并联，失超过程中，流过每个超导线圈的电流不一样，导致磁体系统内部出现极大的不平衡力，该不平衡力有可能对超导磁体系统产生结构破坏；2)由于前述的流过每个超导线圈的电流不一样，也会导致杂散场等高线会在空间上朝外扩张，带来安全隐患；3)每个加热器模块没有串联二极管集成组件，在升磁(Ramp-up)或降磁(Ramp-down)过程中，无法阻止加热器网络导电，有可能触发失超保护电路误动作导致超导磁体失超；4)当N<M时，失超保护电路不能让所有超导线圈同时失超，部分线圈出现失超延时；5)由于每个加热器模块分别和其中一个超导线圈并联，导致该失超保护电路连接复杂，且需要大量的加热器，成本过高。
综上，需要提供一种新的失超保护电路来解决上述问题。
【发明内容】
本发明提供一种基于分布式加热器网络的超导磁体系统失超保护电路，用以解决现有超导磁体系统失超保护电路因保护可靠性低、电路响应慢、流过对称线圈的电流不相等引起的不平衡力和杂散场扩张等而导致应用受限的技术问题。
本发明解决上述技术问题的技术方案如下：一种基于分布式加热器网络的超导磁体系统失超保护电路，包括：串联的M个超导线圈，以及由N个加热器模块构成的加热器网络；其中，M>N，N≤3，不同的加热器模块 与不同的超导线圈子集并联，且所有超导线圈子集之间在空间上具有对称性；每个加热器模块有m个并联支路，每个并联支路有n个加热器串联，m≥1，n≥1；且当N＝1时，m>1；
所述加热器网络中的每一个加热器跟所述M个超导线圈中的一个超导线圈热耦合，且每个超导线圈与每一个加热器模块中的至少一个加热器热耦合。
本发明的有益效果是：加热器网络取自的线圈子集在空间上对称分布。失超过程中，流过对称线圈的电流差可以控制在一个很低的水平，从而不平衡力的大小可以被控制在一个可以接受的数值，杂散场空间上朝外扩张的范围也可以被控制在一个可以接受的数值。特别地，当N＝1时，电流差为0，不平衡力为0，杂散场空间上不朝外扩张。另外，加热器网络是一个规则的、紧凑的串并联网络，可靠性和失超响应都有大幅提高。因而，本申请方案能够有效解决现有失超保护电路所存在的保护可靠性低、电路响应慢、流过对称线圈的电流不相等引起的不平衡力和杂散场扩张等的技术问题。
上述技术方案的基础上，本发明还可以做如下改进。
进一步，当某一加热器模块的发热功率足以使超导线圈失超时，则将该加热器模块串联二极管组件，以防止失超保护电路误动作导致超导线圈失超。
进一步，所述超导线圈子集为：由一个超导线圈构成，由多个超导线圈构成，由一个超导子线圈构成，或者，由超导子线圈和超导线圈构成；其中，超导子线圈为超导线圈的一部分。
本发明的进一步有益效果是：超导线圈子集可以是任一一部分线圈的集合，可根据实际需要灵活设计电路连接方式。
进一步，所述N＝1，m>1，且m*n≥M。
本发明的进一步有益效果是：加热器网络取自的线圈子集在空间上是 对称分布，且加热器网络只含一个加热器模块。失超过程中，流过对称线圈的电流始终保持一致，即：流过L1和L8，L2和L7，L3和L6以及L4和L5的电流都始终相等。所以，不存在不平衡力的问题，也不存在杂散场空间上朝外扩张的问题。另外，加热器网络是一个规则的、紧凑的串并联网络。跟现有技术相比，可靠性和失超响应都有大幅提高。例如：只要还有一条支路导通，就不至于所有超导线圈失去失超保护。
进一步，所述N＝2，且m*n≥M。
本发明的进一步有益效果是：首先，加热器网络取自的线圈子集在空间上对称分布，且加热器网络的两个加热器模块结构完全一致。失超过程中，流过L3和L4，L5和L6，L1和L2，L7和L8的电流始终相等，流过L1和L8，L2和L7的电流差别可以控制在合理水平，从而不平衡力的大小可以被控制在一个可以接受的数值，杂散场空间上朝外扩张的范围也可以被控制在一个可以接受的数值。另外，加热器网络是一个规则的、紧凑的串并联网络，可靠性和失超响应都有大幅提高。加热器网络105中的两个加热器模块相互备份，哪怕其中一个模块彻底断路，另一个模块可以保护所有超导线圈101。可知：电路可靠性进一步提高了。
进一步，所述N＝3，且m*n≥M。
本发明的进一步有益效果是：首先加热器网络取自的线圈子集在空间上对称分布，且位于空间对称位置的两个加热器模块结构完全相同。失超过程中，流过L3和L4，L5和L6，L1和L2，L7和L8的电流始终相等，流过L1和L8，L2和L7的电流差别可以控制在合理水平，从而不平衡力的大小可以被控制在一个可以接受的数值，杂散场空间上朝外扩张的范围也可以被控制在一个可以接受的数值。另外，加热器网络是一个规则的、紧凑的串并联网络，可靠性和失超响应都有大幅提高。加热器网络105中的三个加热器模块相互备份，哪怕其中两个模块彻底断路，剩下的一个模块可以保护所有超导线圈101。可知：电路可靠性又进一步提高了。
【附图说明】
图1为现有技术失超保护电路示意图；
图2为另一现有技术失超保护电路示意图；
图3为本发明实施例提供的一种超导磁体系统失超保护电路示意图；
图4为本发明实施例提供的另一种超导磁体系统失超保护电路示意图；
图5为本发明实施例提供的另一种超导磁体系统失超保护电路示意图；
图6为本发明实施例提供的另一种超导磁体系统失超保护电路示意图；
图7为本发明实施例提供的另一种超导磁体系统失超保护电路示意图；
图8为本发明实施例提供的另一种超导磁体系统失超保护电路示意图；
图9为本发明实施例提供的另一种超导磁体系统失超保护电路示意图。
在所有附图中，相同的附图标记用来表示相同的元件或者结构，其中：
10为失超保护电路，101为超导线圈，102为第一二极管集成组件，103为低温超导开关，104为电流引线，105为加热器网络，106为第二二极管集成组件，1051、1052、1053均为加热器模块。
【具体实施方式】
为了使本发明的目的、技术方案及优点更加清楚明白，以下结合附图及实施例，对本发明进行进一步详细说明。应当理解，此处所描述的具体实施例仅仅用以解释本发明，并不用于限定本发明。此外，下面所描述的本发明各个实施方式中所涉及到的技术特征只要彼此之间未构成冲突就可以相互组合。
图1的失超保护电路存在以下优点：能保证通过对称线圈的电流始终相等，即：流过L1和L8，L2和L7，L3和L6以及L4和L5的电流都始终相等。但该电路至少存在两个缺陷，分析如下：1)所有加热器串联连接构成单一回路，一旦线路某处出现开路，加热器网络将无法获得热功率，从而无法触发超导线圈失超，最终将导致超导线圈101彻底失去保护。2)所 有加热器串联连接构成单一回路，加热器的设计将会变得非常困难，甚至找不到满足要求的设计，因为一方面，由于加热器网络串联连接，加热器网络两端的电阻非常大，哪怕通过加热器网络105的电流很小，都将导致线圈子集L3-L6两端的电压非常高，超导线圈存在高压击穿的风险；另一方面，为了限制L3-L6两端的电压，加热器电阻需要选择一个较小值，加热器的加热功率降低，失超保护响应较慢，最终导致线圈的热点温度较高，超导线存在高温熔化的风险。
而另外图2的失超保护电路至少存在五个缺点，分析如下：1)每个加热器模块分别和其中一个超导线圈并联，失超过程中，由于每个超导线圈的正常区扩散速度和体积不一样，导致每个超导线圈的端电压不一样，从而流过每个超导线圈的电流不一样，导致磁体系统内部出现极大的不平衡力，该不平衡力有可能对超导磁体系统产生结构破坏；2)由于前述分析的流过每个超导线圈的电流不一样，也会导致杂散场等高线会在空间上朝外扩张，带来安全隐患；3)每个加热器模块没有串联二极管集成组件，在升磁(Ramp-up)或降磁(Ramp-down)过程中，无法阻止加热器网络导电，有可能触发失超保护电路误动作导致磁体失超。4)当N<M时，失超保护电路不能让所有超导线圈同时失超，部分线圈出现失超延时，例如：N＝1，L1两端的加热器模块并联了8个加热器，其他线圈两端各并联了一个加热器。假设L2先失超，L2两端的加热器先建立起电压，该加热器粘贴在L1表面，触发L1失超。L1两端后建立起电压，然后触发L3～L8失超。由此可见：L3～L8的失超比L1慢。5)由于每个加热器模块分别和其中一个超导线圈并联，导致该失超保护电路连接复杂，且需要大量的加热器，成本过高，例如：N＝M＝8，所需最少的加热器数量为＝M*N+M-N＝64个。
本发明基于以上分析而给出如下实施例以解决现有失超保护电路存在的技术问题。
实施例一
请参考图3，失超保护电路10包括M(M＝8)个串联连接的超导线圈L1-L8(101)。其中，超导线圈子集L1和L8为主动屏蔽线圈，其电流方向和超导线圈子集L2-L7的电流方向相反。超导线圈101两端接了一对电流引线104用于和励磁电源(未示出)连接。低温超导开关103和电流引线104并联。第一二极管集成组件102和低温超导开关103并联连接。第一二极管集成组件102的门限电压高于磁体两端最大的励磁电压，用于保护低温超导开关103。加热器网络105中的每一个加热器跟其中一个超导线圈热耦合，且每个超导线圈和至少一个加热器热耦合。加热器网络105和第二二极管集成组件106串联连接，且这个串联装置与超导线圈子集L3-L6并联连接。当磁体处于升磁(Ramp-up)或降磁(Ramp-down)时，第二二极管集成组件106阻止加热器网络105导电，防止失超保护电路误动作导致磁体失超。第二二极管集成组件106的门限电压被选择为大于升磁或降磁过程中L3-L6两端的最大电压。
在升磁(Ramp-up)过程中，低温超导开关103被一个加热器(未示出)加热，低温超导开关103表现为一个大电阻，大部分电流(励磁电源来的)经过超导线圈101，励磁电源给超导线圈101充磁，当超导磁体系统的视场(Field of View)区域磁场达到目标磁场时，关掉给低温超导开关103加热器加热的电源，低温超导开关103回到超导态，同时把励磁电源的电压调至0，移除电流引线104，以限制到超导磁体系统中的热损失，超导磁体系统进入持久模式(Persistent mode)。
在降磁(Ramp-down)过程中，低温超导开关103被一个加热器(未示出)加热，低温超导开关103表现为一个大电阻，大部分电流经过超导线圈101、电流引线104和励磁电源。励磁电源输出一个反向电压实现降磁。有时为了加速降磁，在励磁电源回路串联一个直流负载或二极管以建立更大的压降。当电源表盘上电流显示为0时，即可关掉励磁电源以及移除电流引线104。
加热器网络包括m(m>1)条支路，每条支路串联了n(n≥1)个加热器。特别地，当m＝8，n＝1时，图3变为图4，加热器网络H1-H8并联连接，每个超导线圈和其中一个加热器热耦合。
以图4为例，阐述该失超保护电路原理。假如超导线圈L4失超，线圈子集L3-L6两端将快速建立一个电压。该电压给加热器网络105中的每个加热器提供热功率使之发热。这些加热器由于和超导线圈热耦合，将加速L4失超以及使得未失超的其他所有线圈失超，让储存在超导线圈中的磁能转化为热能并尽可能地让所有线圈的所有体积吸收这些能量，从而实现对超导线圈101的保护。图4中，加热器网络中的所有8个加热器并联，可靠性大大提高。除非整个加热器网络开路，否则总能触发贴有未开路的加热器的超导线圈失超，不至于如图1所示那样，一旦线路开路，线圈彻底失去失超保护。
根据设计的需要，m可以选择任意>1的值，以及n可以选择任意≥1的值，但是m和n的乘积必须≥M，并且确保每一个线圈都至少有一个加热器与之热耦合。
图3中，加热器网络的电压取自线圈子集L3-L6，这只是一个示例。根据设计的需要，加热器网络的电压可以取自任意对称线圈之间的电压(就是与加热器网络并联的线圈子集可以沿着整个线圈集合空间对称的位置扩大或缩小)，甚至可以把一个或者多个对称位置的线圈分成若干个对称子线圈，加热器网络的电压可以取自包括子线圈在内的任一对称线圈之间的电压，如图5所示为其中一个示例。但加热器网络的电压不能取低温超导开关103之间的电压。若线圈被分为好几个子线圈，则加热器的物理位置不局限于线圈的表面，也可以贴在子线圈的表面。
图3所示的失超保护电路的优点在于：1)加热器网络取自的线圈子集在空间上是对称分布。失超过程中，流过对称线圈的电流始终保持一致，即：流过L1和L8，L2和L7，L3和L6以及L4和L5的电流都始终相等。 所以，不存在不平衡力的问题，也不存在杂散场空间上朝外扩张的问题。2)加热器网络是一个规则的、紧凑的串并联网络。跟现有技术相比，可靠性和失超响应都有大幅提高。例如：只要还有一条支路导通，就不至于所有超导线圈失去失超保护。
实施例二
请参考图6，为本发明的另一实施方式的失超保护电路示意图。加热器网络105包含两个结构上完全一样的加热器模块，第二二极管集成组件106包含两个结构上完全一样的二极管组件模块。加热器网络105中的一个加热器模块和第二二极管集成组件106中的一个二极管模块串联连接，且这个串联装置与超导线圈子集L1-L2或L7-L8并联连接。当磁体处于升磁(Ramp-up)或降磁(Ramp-down)时，第二二极管集成组件106阻止加热器网络105导电，防止失超保护电路误动作导致超导磁体失超。第二二极管集成组件106中的任一模块的门限电压被选择为大于升磁或降磁过程中L1-L2和L7-L8两端的最大电压。加热器网络105中的每一个加热器模块的每一个加热器跟其中一个超导线圈热耦合，每个超导线圈和每一个加热器模块中的至少一个加热器热耦合。
加热器网络中的任一加热器模块包括m(m≥1)条支路，每条支路串联了n(n≥1)个加热器。根据设计的需要，m和n可以选择任意≥1的值，但是m和n的乘积必须≥M，同时确保每一个线圈与每一个加热器模块中的至少一个加热器热耦合。
特别地，1)当m＝1，n＝8时，图6变为图7，加热器网络含两个完全一样的加热器模块，每个加热器模块只含一条支路，每条支路由8个加热器串联组成。每个超导线圈上贴有两个加热器，他们分别来自两个不同的加热器模块。2)当m＝8，n＝1时，图6变为图8，加热器网络含两个完全一样的加热器模块，每个加热器模块含8条并联支路，每条支路只含一个加热器。每个超导线圈上贴有两个加热器，它们分别来自两个不同的加热 器模块。
图6中，两个加热器模块相互备份，哪怕其中一个模块彻底断路，另一个模块可以保护所有超导线圈101。可知：图6所示的电路的可靠性比图3的电路可靠性又提高了。
图6中，加热器网络的电压取自线圈子集L1-L2和L7-L8，这只是一个示例。根据设计的需要，加热器网络的电压可以取自任意对称线圈或者对称子线圈之间的电压，但不能取自L1-L4和L5-L8(是唯一的特例)。因为这种情况下，假如出现对称失超(如L1和L8的对称位置上同时出现一个大小相同的正常区)，超导磁体不能被保护。
图6所示的失超保护电路的优点在于：1)加热器网络取自的线圈子集在空间上对称分布。失超过程中，流过L3和L4，L5和L6，L1和L2，L7和L8的电流始终相等，流过L1和L8，L2和L7的电流差别可以控制在合理水平，从而不平衡力的大小可以被控制在一个可以接受的数值，杂散场空间上朝外扩张的范围也可以被控制在一个可以接受的数值。2)加热器网络是一个规则的、紧凑的串并联网络，可靠性和失超响应都有大幅提高。加热器网络105中的两个加热器模块相互备份，哪怕其中一个模块彻底断路，另一个模块可以保护所有超导线圈101。可知：图6所示的电路的可靠性比图3的电路可靠性又提高了。
实施例三
请参考图9，为本发明的另一实施方式的失超保护电路图。失超保护电路10包括M(M＝8)个串联连接的超导线圈L1-L8(101)。其中，超导线圈子集L1和L8为主动屏蔽线圈，其电流方向和超导线圈子集L2-L7的电流方向相反。超导线圈101接了一对电流引线104用于和励磁电源连接。低温超导开关103和电流引线104并联。第一二极管集成组件102和低温超导开关103并联连接。第一二极管集成组件102的门限电压高于超导磁体两端最大的励磁电压，用于保护低温超导开关103。加热器网络105中的 每一个加热器模块的每一个加热器跟其中一个超导线圈热耦合，每个超导线圈与每一个加热器模块中的至少一个加热器热耦合。
加热器网络105包含3个加热器模块，每个加热器模块有m(m≥1)个并联支路，每个并联支路有n(n≥1)个加热器串联，且加热器模块1051和1053结构上完全相同，m*n≥M。第二二极管集成组件106包含3个结构上完全一样的二极管组件模块。加热器网络105中的一个加热器模块和第二二极管集成组件106中的一个二极管模块串联连接后与相应的超导线圈子集(分别为L1-L2、L3-L6、L7-L8)并联。第二二极管集成组件106中的任一模块的门限电压被选择为大于升磁或降磁过程中L1-L2、L3-L6和L7-L8两端的最大电压。
图9中，加热器网络的电压取自线圈子集L1-L2、L3-L6和L7-L8，这只是其中一个例子。根据设计的需要，加热器网络的电压可以取自任意对称线圈或者对称子线圈之间的电压。
图9所示的失超保护电路的优点在于：1)加热器网络取自的线圈子集在空间上对称分布。失超过程中，流过L3和L4，L5和L6，L1和L2，L7和L8的电流始终相等，流过L1和L8，L2和L7的电流差别可以控制在合理水平，从而不平衡力的大小可以被控制在一个可以接受的数值，杂散场空间上朝外扩张的范围也可以被控制在一个可以接受的数值。2)加热器网络是一个规则的、紧凑的串并联网络，可靠性和失超响应都有大幅提高。加热器网络105中的三个加热器模块相互备份，哪怕其中两个模块彻底断路，剩下的一个模块可以保护所有超导线圈101。可知：图9所示的电路的可靠性比图6的电路可靠性又提高了。
图9中的加热器网络包括三个加热器模块。很容易想到：如果把加热器模块继续扩展到M个模块，失超保护电路的可靠性将大大增加。然而，如果加热器模块数继续增加，带来的弊端是电流的不一致性将大大增加，从而导致不平衡力和杂散场空间上朝外扩展变得不可控制。因此，本发明 限制加热器模块数N≤3。
本领域的技术人员容易理解，以上所述仅为本发明的较佳实施例而已，并不用以限制本发明，凡在本发明的精神和原则之内所作的任何修改、等同替换和改进等，均应包含在本发明的保护范围之内。

Claims (7)

  1. 一种基于分布式加热器网络的超导磁体系统失超保护电路，其特征在于，包括：串联的M个超导线圈，以及由N个加热器模块构成的加热器网络；其中，M>N，N≤3，不同的加热器模块与不同的超导线圈子集并联，且所有超导线圈子集之间在空间上具有对称性；每个加热器模块有m个并联支路，每个并联支路有n个加热器串联，m≥1，n≥1；且当N＝1时，m>1；
    所述加热器网络中的每一个加热器跟所述M个超导线圈中的一个超导线圈热耦合，且每个超导线圈与每一个加热器模块中的至少一个加热器热耦合。
  2. 根据权利要求1所述的一种基于分布式加热器网络的超导磁体系统失超保护电路，其特征在于，在一个加热器模块的发热功率足以使超导线圈失超时，则将该加热器模块串联二极管组件。
  3. 根据权利要求1所述的一种基于分布式加热器网络的超导磁体系统失超保护电路，其特征在于，所述超导线圈子集为：由一个超导线圈构成，由多个超导线圈构成，由一个超导子线圈构成，或者，由超导子线圈和超导线圈构成；其中，超导子线圈为超导线圈中的一部分。
  4. 根据权利要求1所述的一种基于分布式加热器网络的超导磁体系统失超保护电路，其特征在于，分别与相互处于对称位置的线圈子集并联的两个加热器模块的电路结构相同。
  5. 根据权利要求1至3任一项所述的一种基于分布式加热器网络的超导磁体系统失超保护电路，其特征在于，所述N＝1，m>1，且m*n≥M。
  6. 根据权利要求1至4任一项所述的一种基于分布式加热器网络的超导磁体系统失超保护电路，其特征在于，所述N＝2，m*n≥M。
  7. 根据权利要求1至4任一项所述的一种基于分布式加热器网络的超导磁体系统失超保护电路，其特征在于，所述N＝3，m*n≥M。
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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6147844A (en) * 1998-12-30 2000-11-14 General Electric Company Quench protection for persistant superconducting magnets for magnetic resonance imaging
CN106558869A (zh) * 2016-12-20 2017-04-05 上海联影医疗科技有限公司 一种用于超导磁体系统的失超保护电路及失超保护方法
CN107221401A (zh) * 2016-03-22 2017-09-29 上海联影医疗科技有限公司 一种超导磁体系统及其失超保护方法
CN112908608A (zh) * 2021-01-27 2021-06-04 华中科技大学 一种基于分布式加热器网络的超导磁体系统失超保护电路

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2422958B (en) * 2005-02-04 2008-07-09 Siemens Magnet Technology Ltd Quench protection circuit for a superconducting magnet
US8482369B2 (en) * 2011-10-31 2013-07-09 General Electric Company Single switch dump resistor ladder network for magnet quench protection
CN102751699B (zh) * 2012-06-15 2015-05-13 中国科学院电工研究所 一种核磁共振超导磁体失超保护装置
JP2015097222A (ja) * 2013-11-15 2015-05-21 株式会社日立製作所 超伝導磁石
CN103916060B (zh) * 2014-04-16 2016-05-25 华中科技大学 一种多级电位补偿装置及失超检测装置
CN105513743B (zh) * 2014-10-17 2019-01-01 通用电气公司 超导磁体系统及其失超保护装置
JP2017045866A (ja) * 2015-08-27 2017-03-02 株式会社日立製作所 超電導磁石装置
JP6580501B2 (ja) * 2016-03-08 2019-09-25 住友重機械工業株式会社 超伝導サイクロトロン及び超伝導電磁石
US10515749B2 (en) * 2017-10-20 2019-12-24 The Florida State University Research Foundation, Inc. Frequency loss induced quench protection system for high temperature superconductors and associated method of use
CN109273187A (zh) * 2018-09-14 2019-01-25 上海东软医疗科技有限公司 一种超导磁体的开关保护电路

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6147844A (en) * 1998-12-30 2000-11-14 General Electric Company Quench protection for persistant superconducting magnets for magnetic resonance imaging
CN107221401A (zh) * 2016-03-22 2017-09-29 上海联影医疗科技有限公司 一种超导磁体系统及其失超保护方法
CN106558869A (zh) * 2016-12-20 2017-04-05 上海联影医疗科技有限公司 一种用于超导磁体系统的失超保护电路及失超保护方法
CN112908608A (zh) * 2021-01-27 2021-06-04 华中科技大学 一种基于分布式加热器网络的超导磁体系统失超保护电路

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