JP-7854810-B2 - Control systems and related technologies for charging uninsulated/partially insulated superconducting magnets

JP7854810B2JP 7854810 B2JP7854810 B2JP 7854810B2JP-7854810-B2

Inventors

ブルンナー，ダニエル
マムガード，ロバート

Assignees

マサチューセッツインスティテュートオブテクノロジー

Dates

Publication Date: 20260507
Application Date: 20200617
Priority Date: 20190618

Claims (20)

A method for controlling a superconducting magnet having no or partial electrical insulation between each winding of the superconducting magnet, The physical characteristics of the superconducting magnet are perceived using a sensor, wherein the physical characteristics include temperature, voltage, current, magnetic field, and/or magnetic flux density. The method involves using a control circuit to determine electrical parameters, including current and/or voltage, for supplying power to the superconducting magnet, based on the sensed physical characteristics and a model of the superconducting magnet stored in a computer-readable storage medium, wherein the model associates the sensed physical characteristics with the critical current of the superconductor of the superconducting magnet, the critical current being the current at which the superconductor loses its superconducting properties, and the determination of the electrical parameters is made by using the model to charge the superconducting magnet with an allowable current increased to maintain the superconducting state or the maximum allowable current, thereby reducing or minimizing the charging time while avoiding overheating of the superconducting magnet to a temperature at which the superconductor loses its superconducting properties. A method comprising providing the determined electrical parameters to the superconducting magnet.
The method according to claim 1, The physical characteristics are re-perceived after a time interval has elapsed since the perception of the physical characteristics. Using the control circuit, the electrical parameters for supplying power to the superconducting magnet are re-determined based on the re-sensed physical characteristics and the model. A method further comprising providing the re-determined electrical parameters to the superconducting magnet.
A method according to claim 2, wherein determining includes calculating the critical current of the superconductor of the superconducting magnet, calculating the difference between the calculated current passing through the superconductor and the critical current, and comparing the difference with a set value to set the electrical parameters based on the difference.
A method according to claim 2, wherein determining includes calculating the critical current of the superconductor of the superconducting magnet, dividing the calculated current passing through the superconductor by the critical current to create a ratio, comparing the ratio with a set value, and setting the electrical parameter based on the result of the comparison.
A method according to any one of claims 1 to 4, wherein the determination comprises calculating future parameters of the superconducting magnet based on the perceived physical characteristics and the model, and setting the electrical parameters based on the calculated future parameters, wherein the calculated future parameters are temperature, current, and critical current.
A method according to claim 5, wherein the model includes a thermal model of the superconducting magnet.
A method according to any one of claims 1 to 6, further comprising determining a degree of cooling based on the model and the sensed physical characteristics, and controlling a cooling system for the superconducting magnet based on the determined degree of cooling.
A device for controlling a superconducting magnet having no or partial electrical insulation between each winding of the superconducting magnet, Including a control circuit, the control circuit is Receiving the sensed physical characteristics of the superconducting magnet from the sensor, wherein the physical characteristics include temperature, voltage, current, magnetic field, and/or magnetic flux density. The method involves determining electrical parameters, including current and/or voltage, for supplying power to the superconducting magnet, based on the perceived physical characteristics and a model of the superconducting magnet stored in a computer-readable storage medium, wherein the model associates the perceived physical characteristics with the critical current of the superconductor of the superconducting magnet, the critical current being the current at which the superconductor loses its superconducting properties, and the determination of the electrical parameters is made by using the model to charge the superconducting magnet with an allowable current increased to maintain the superconducting state or the maximum allowable current, thereby reducing or minimizing the charging time while avoiding overheating of the superconducting magnet to a temperature exceeding the temperature at which the superconductor loses its superconducting properties. A device configured to provide the determined electrical parameters to the superconducting magnet.
The apparatus according to claim 8, wherein the control circuit further comprises After a time interval has elapsed since the initial sensing of the aforementioned physical features, the resensing physical features are received. Based on the re-perceived physical characteristics and the model, the electrical parameters for supplying the superconducting magnet are re-determined. A device configured to provide the re-determined electrical parameters to the superconducting magnet.
The apparatus according to claim 9, wherein the control circuit is configured to calculate the critical current of the superconductor of the superconducting magnet, calculate the difference between the calculated current passing through the superconductor and the critical current, compare the difference with a set value, and determine the electrical parameters by setting the electrical parameters based on the difference.
The apparatus according to claim 9, wherein the control circuit is configured to calculate the critical current of the superconductor of the superconducting magnet, divide the calculated current passing through the superconductor by the critical current to create a ratio, compare the ratio with a set value, and determine the electrical parameters by setting the electrical parameters based on the result of the comparison.
An apparatus according to any one of claims 8 to 11, wherein the control circuit is configured to determine the electrical parameters by calculating the future parameters of the superconducting magnet based on the sensed physical characteristics and setting the electrical parameters based on the calculated future parameters, wherein the calculated future parameters are temperature, current, and critical current.
The apparatus according to claim 12, wherein the model includes a thermal model of the superconducting magnet.
An apparatus according to any one of claims 8 to 13, wherein the control circuit is configured to determine a degree of cooling based on the model and the sensed physical characteristics, and to control a cooling system for the superconducting magnet based on the determined degree of cooling.
It is a system, A superconducting magnet having no or partial electrical insulation between each winding of the superconducting magnet, A system comprising the apparatus according to any one of claims 8 to 14.
It is a system, A superconducting magnet comprising a coil of superconducting material including two electrical terminals, wherein the windings of the coil are separated by a metal conductor, An apparatus according to any one of claims 8 to 14, wherein the control circuit in the apparatus is coupled to the two terminals to drive a current through a coil for charging the superconducting magnet, and is configured to provide through the coil a current that is small enough to avoid the quench effect of the superconducting magnet and large enough to charge the magnet within a predetermined period of time, A system including a cooling structure that is thermally coupled to a coil to remove heat generated by the charging of the superconducting magnet by the current, and that allows the current to be large enough to charge the magnet within the predetermined period without causing the quench effect.
A system according to claim 16, wherein the cooling structure is configured to maintain the temperature of the coil at 4K or higher.
The system according to claim 16, wherein the control circuit further includes one or more feedback loops.
The system according to claim 18, wherein the one or more feedback loops provide feedback on the temperature of the coil.
The system according to claim 18, wherein the one or more feedback loops feed back the current passing through the coil.

Description

[0001] This disclosure relates to superconducting magnets, and more specifically to superconducting magnets using partial insulation and no insulation, and to control systems, apparatus, and methods for controlling superconducting magnets. [0002] Superconducting magnets with partial- and/or no-insulation (PI/NI) between superconducting turns may be used because they can be designed to be passively safe during quenching. Quenching is the transition from a superconductor to a normal (i.e., non-superconducting) conductor caused by a superconductor current exceeding the operating magnetic field, temperature, and/or current density thresholds. Quenching can cause a large amount of energy stored in the magnetic field to accumulate as thermal energy in a small volume of magnet, which can damage some or all of the superconducting magnet. This can be avoided by PI/NI magnets by allowing current to flow from around the quench zone to adjacent superconducting turns and/or by electrically coupling the quench to adjacent turns. [0003] In this embodiment, the system includes a superconducting magnet, the superconducting magnet itself including a coil of superconducting material. The coil includes two electrical terminals. The windings of the coil are separated by a metal conductor. A control circuit is coupled to the two terminals to supply or drive current through the coil for charging the superconducting magnet. Furthermore, the control circuit is configured to supply a current through the coil that is small enough to avoid the quench effect of the superconducting magnet, but large enough to charge the magnet within a predetermined period. A cooling structure is thermally coupled to the coil to remove the heat generated by the charging of the superconducting magnet by the current, and enables the current to be large enough to charge the magnet within a predetermined period without causing a quench effect. [0004] One or more of the following characteristics may be included individually or in combination. [0005] The cooling structure can be configured to maintain the coil temperature at 4K or higher. [0006] The control circuit may include one or more feedback loops. [0007] One or more feedback loops can provide feedback on the coil temperature. [0008] One or more feedback loops can feed back the current passing through the coil. [0009] One or more feedback loops can feed back the magnetic field of the coil. [0010] The control circuit may include a coil model. [0011] The model may include temperature limits for the coil, current limits for the coil, and magnetic field limits for the coil. [0012] Temperature limits, current limits, and magnetic field limits can define the range in which the coil acts as a superconductor. [0013] In another embodiment, a method for controlling a superconducting magnetic coil includes: driving a current through the superconducting magnetic coil with a variable current source; monitoring the current through the superconducting magnetic coil, the temperature of the superconducting magnetic coil, and the magnetic field around the superconducting magnetic coil with a control circuit; determining the current operating point of the superconducting magnetic coil by comparing the temperature, current, and magnetic field with a model of the superconducting magnetic coil stored in the control circuit; determining the maximum current available for charging the coil based on the operating point and the operating range of the superconducting magnetic coil; and adjusting the current to match the maximum current in order to supply energy to the superconducting magnetic coil. The model defines the operating range in which the coil acts as a superconductor with respect to the superconducting magnetic coil. [0014] One or more of the following characteristics may be included. [0015] The control circuit can control the cooling system to cool the superconducting magnetic coil when the maximum current is applied, so that the superconducting magnetic coil remains within its operating range. [0016] The cooling structure can be configured to maintain the coil temperature at 4K or higher. [0017] The control circuit may include one or more feedback loops. [0018] One or more feedback loops can provide feedback on the coil temperature. [0019] One or more feedback loops can feed back the current passing through the coil. [0020] One or more feedback loops can feed back the magnetic field of the coil. [0021] The model may include temperature limits for the coil, current limits for the coil, and magnetic field limits for the coil. [0022] Temperature limits, current limits, and magnetic field limits can define the range in which the coil acts as a superconductor. [0023] The windings of the superconducting magnetic coil can be separated by a metal conductor. [0024] Some embodiments relate to a method for controlling a superconducting magnet having no or partial electrical insulation between each winding of the superconducting