Patent classifications
H01F6/006
HYBRID WOUND-ROTOR MOTOR AND GENERATOR WITH INDUCTION FEED AND PERSISTENT CURRENT
A system for operation in a motor mode comprises a cryocooler to cool a superconducting coil of a rotor. The system further comprises a flux pump to provide flux to the superconducting coil to produce-a persistent current. Also, the system comprises a main stator coil. An alternating current within the main stator coil generates a rotating magnetic field, which interacts with the persistent current to generate an electromagnetic torque to rotate the rotor. The system also comprises a control stator coil to generate a current at a non-superconducting coil of the rotor. In one or more embodiments, a magnitude, phase, and/or frequency of the rotating magnetic field of the main stator coil and a magnetic field of the non-superconducting coil is varied in comparison a magnitude, phase, and/or frequency of the rotating magnetic field produced by the main stator coil alone to control a speed of the rotor.
Hybrid superconducting magnetic device
A hybrid superconductive device for stabilizing an electric grid comprises (a) a magnetic core arrangement at least partially carrying an AC winding the AC winding connectable to an AC circuit for a current to be limited in the event of a fault; (b) at least one superconductive coil configured for storing electromagnetic energy; the superconductive coil magnetically coupled with the core arrangement and saturating the magnetic core arrangement during use. The hybrid superconductive device further comprises a switch unit preprogrammed for switching electric current patterns corresponding to the following modes: at least partially charging the superconductive coil; a standby mode when the superconductive coil is looped back; and at least partially discharging the superconductive coil into the circuit. Optionally, hybrid superconductive device comprises at least one passage located within said magnetic flux. The passage conducts a material flow comprising components magnetically separable by said magnetic flux.
SYSTEMS AND METHODS FOR RAMPING DOWN MAGNETIC RESONANCE MAGNET
A magnetic resonance system may include a magnetic resonance magnet and a storage container configured to accommodate the magnetic resonance magnet. The storage container may also contain an endothermic liquid. The magnetic resonance system may further include a ramping-down device configured to trigger releasing electric energy by the magnetic resonance magnet. The first ramping-down device may include an electric energy consumption device configured to consume at least a portion of the released electric energy by the magnetic resonance magnet.
Flexibile superconducting lead assembly
There is set forth herein a superconducting lead assembly comprising: a positive superconducting wire; a negative superconducting wire, wherein the positive superconducting wire is configured to conduct inflow current to a cryogenic apparatus and wherein the negative superconducting wire is configured to conduct outflow current away from the cryogenic apparatus; and an electrically insulating separator, wherein the positive superconducting wire and the negative superconducting wire are arranged proximately one another and on opposite sides of the electrically insulating separator for cancellation of electromagnetic forces attributable to current flowing simultaneously in opposite directions within the positive superconducting wire and the negative superconducting wire, and wherein a length of the superconducting lead assembly is flexible. In one embodiment the positive superconducting wire and the negative superconducting wire can include high temperature superconducting (HTS) material.
Power management for cryogen compressors
In a superconducting magnet arrangement, such as used in a magnetic resonance system, and a power management method therefor, an enhanced economic power mode (EPM) is implemented wherein the compressor operation is controlled by magnet pressure, temperature and time, so as to ensure the readiness of the magnet system for a scanning operation upon exiting the enhanced EPM. A processor implementing the enhanced EPM looks for a signal that indicates that the magnet system is operational and, in the absence of that signal for a predetermined period of time, enters into EPM. Exit from EPM occurs if certain conditions are violated, but then re-entry into EPM is attempted (re-starting EPM), thereby making the magnet system ready for operation again, if and when a patient scan is to be implemented.
Cryogenic field sensing for compensating magnetic field variations in magnetic resonance imaging magnets
A superconducting magnet includes superconducting magnet coils (C.sub.1, C.sub.2, C.sub.3, C.sub.4, C.sub.5, C.sub.6, S.sub.1, S.sub.2) disposed inside a magnet cryostat (12). The superconducting magnet coils generate a static (B.sub.0) magnetic field when an electric current flows in the superconducting magnet coils. A superconducting B.sub.0 compensation circuit (30, 60, 70) is also disposed inside the magnet cryostat, and is coupled with the superconducting magnet coils to passively reduce temporal variations in the B.sub.0 magnetic field generated by the superconducting magnet coils. An electric current sensor (40) is also disposed inside the magnet cryostat and is connected to measure electric current flowing in the superconducting B.sub.0 compensation circuit. An active B.sub.0 compensation component (50) is operatively connected with the electric current sensor to receive the measurement of electric current flowing in the superconducting B.sub.0 compensation circuit and to provide active B.sub.0 magnetic field compensation based on the measured electric current.
SUPERCONDUCTING MAGNET ASSEMBLY
A superconducting magnet arrangement comprises a field coil assembly with coil windings that when in operation are electrically superconducting. The field coil assembly is circuited between connection ports for a voltage supply. A switching module switches a sub-section of the field coil assembly's coil windings between its electrical superconducting and electrical resistive states, said sub-section forming a switching coil circuited between the connection ports. In the operational state where both the switching coil and the field coil(s) are superconducting and carry a permanent electrical current, the field coil(s) and the switching coil together generate a stationary magnetic field. According to the invention the switch windings give a significant contribution to the magnetic field. The field coil assembly's coil windings that may be switched between it electrically superconducting and resistive states form the switching coil. That is, the switching coil forms part of the field coil assembly and contributes significantly to the magnetic field generated by the field coil assembly.
Systems and methods for ramping down magnetic resonance magnet
A magnetic resonance system may include a magnetic resonance magnet and a storage container configured to accommodate the magnetic resonance magnet. The storage container may also contain an endothermic liquid. The magnetic resonance system may further include a ramping-down device configured to trigger releasing electric energy by the magnetic resonance magnet. The first ramping-down device may include an electric energy consumption device configured to consume at least a portion of the released electric energy by the magnetic resonance magnet.
Methods for adjusting a magnetic field of a magnetic resonance tomography device, magnetic power supplies, and magnetic resonance tomography devices
A method for adjusting a magnetic field of a magnetic resonance tomography (MRT)-device having a magnet includes: transferring the magnet from an operating state to a non-operating state in a ramp-down mode; subsequently transferring the magnet from the non-operating state to the operating state in a ramp-up mode; observing a reference parameter different from the magnetic field; setting a target value for the reference parameter; comparing the observed reference parameter to the target value; and finishing the ramp-up mode when the reference parameter reaches the target value.
Magnetic resonance apparatus with a cooling device, and method for producing such a magnetic resonance apparatus
A magnetic resonance (MR) apparatus has an MR scanner with a basic field magnet formed by a superconducting coil so as to generate a basic magnetic field, a ramp device for ramping down and/or ramping up the basic field magnet, with a ramp component arranged on the MR scanner emitting heat in the ramp-up process and/or a ramp-down process, and a cooling device and at least one electronic unit to be cooled. The cooling device has a cooling plate that, with respect to the MR scanner, is in outward heat-conducting contact with the ramp component. Outwardly adjoining the cooling plate in heat-conducting contact is a carrier plate, which carries at least one electronic unit in heat-conducting contact.