Control system for charging of non/partially insulated superconducting magnets and related techniques

Abstract

A system comprises a superconducting magnet comprising a coil of superconducting material. The coil includes two electrical terminals. The windings of the coil are separated by a metallic conductor. A control circuit is coupled to the two terminals to drive a current through the coil to charge the superconducting magnet and configured to provide a current through the coil that is sufficiently small to avoid a quenching effect of the superconducting magnet but also large enough to charge the magnet within a predetermined time period. A cooling structure is thermally coupled to the coil to remove heat caused by charging the superconducting magnet with the current to allow for the current to be sufficiently large to charge the magnet within the predetermined time period without causing the quenching effect.

1 . A system comprising:
 a superconducting magnet comprising a coil of superconducting material, the coil comprising two electrical terminals, wherein the windings of the coil are separated by a metallic conductor;   a control circuit coupled to the two terminals to drive a current through the coil to charge the superconducting magnet, and configured to provide a current through the coil that is sufficiently small to avoid a quenching effect of the superconducting magnet but also large enough to charge the magnet within a predetermined time period;   a cooling structure thermally coupled to the coil to remove heat caused by charging the superconducting magnet with the current to allow for the current to be sufficiently large to charge the magnet within the predetermined time period without causing the quenching effect.   
     
     
         2 . The system of  claim 1  wherein the cooling structure is configured to maintain a temperature of the coil at 4 deg K or higher. 
     
     
         3 . The system of  claim 1  wherein the control circuit further comprises one or more feedback loops. 
     
     
         4 . The system of  claim 3  wherein the one or more feedback loops feeds back a temperature of the coil. 
     
     
         5 . The system of  claim 3  wherein the one or more feedback loops feeds back a current through the coil. 
     
     
         6 . The system of  claim 3  wherein the one or more feedback loops feeds back a magnetic field of the coil. 
     
     
         7 . The system of  claim 1  wherein the control circuit comprises a model of the coil. 
     
     
         8 . The system of  claim 7  wherein the model comprises a temperature limit of the coil, a current limit of the coil, and a magnetic field limit of the coil. 
     
     
         9 . The system of  claim 8  wherein the temperature limit, the current limit, and the magnetic field limit define a region within which the coil acts as a superconductor. 
     
     
         10 . A method of controlling a superconducting magnetic coil comprising:
 driving, by a variable current supply, a current through the superconducting magnetic coil;   monitoring, by a control circuit, the current through the superconducting magnetic coil, a temperature of the superconducting magnetic coil, and a magnetic field about the superconducting magnetic coil;   comparing, by the control circuit, the temperature, current, and magnetic field to model of the superconducting magnetic coil stored in the control circuit to determine a current operating point of the superconducting magnetic coil, wherein the model defines an operating range for the superconducting magnetic coil within which the coil acts as a superconductor;   determining a maximum current that can be used to charge the coil based on the operating point of the superconducting magnetic coil and the operating range of the superconducting magnetic coil; and   adjusting the current to match the maximum current to energize the superconducting magnetic coil.   
     
     
         11 . The method of  claim 10  further comprising controlling, by the control circuit, a cooling system to cool the superconducting magnetic coil while applying the maximum current so that the superconducting magnetic coil remains in the operating range. 
     
     
         12 . The method of  claim 11  wherein the cooling structure is configured to maintain a temperature of the coil at 4 deg K or higher. 
     
     
         13 . The method of  claim 10  wherein the control circuit further comprises one or more feedback loops. 
     
     
         14 . The method of  claim 13  wherein the one or more feedback loops feeds back a temperature of the coil. 
     
     
         15 . The method of  claim 13  wherein the one or more feedback loops feeds back a current through the coil. 
     
     
         16 . The system of  claim 13  wherein the one or more feedback loops feeds back a magnetic field of the coil. 
     
     
         17 . The method of  claim 10  wherein the model comprises a temperature limit of the coil, a current limit of the coil, and a magnetic field limit of the coil. 
     
     
         18 . The method of  claim 17  wherein the temperature limit, the current limit, and the magnetic field limit define a region within which the coil acts as a superconductor. 
     
     
         19 . The method of  claim 1  wherein windings of the superconducting magnetic coil are separated by a metallic conductor.