Abstract: The MRI apparatus includes a main magnet forming a static magnetic field in a bore, and a gradient coil assembly which forms a magnetic field gradient in the static magnetic field and includes a plurality of shim trays arranged therein at a predefined interval and at least one first shim token provided between the shim trays.

Abstract: A magnetic resonance imaging (MRI) method and apparatus in which conductors are installed in the space between a static coil unit and a gradient coil unit to eliminate asymmetry of eddy current induced in the static coil unit. The structure permits a symmetrical distribution of eddy current when the concentric arrangement of the static coil unit and gradient coil unit has deviated. The MRI apparatus includes: a static coil unit configured to form a static field in a subject; a gradient coil unit configured to form a gradient field in the static field; and one or more conductors installed in the space between the static coil unit and the gradient coil unit, and configured to symmetrically distribute eddy current induced in the static coil unit.

Abstract: The present invention provides a current limiting module and a hybrid current limiter using different kinds of superconducting wires. The current limiting module includes a first superconducting wire that is wound in a predetermined direction, and a second superconducting wire that has quench characteristic different from the first superconducting wire and is wound to generate magnetic flux in a direction opposite to magnetic flux induced by the first superconducting wire. According to the present invention, inductance is generated due to unequal supply of fault current. Therefore, it is possible to prevent current from being suddenly increased, and to reduce the number of superconducting wires required to manufacture the current limiting module. Further, the hybrid current limiter does not need to include a separate coil for operating a fast switch.

Abstract: A fault current limiter comprises a pancake type current limiting module, comprising at least two pancake type bifilar winding modules stacked and connected to each other in series, each of the bifilar winding modules having a bobbin, a first superconducting wire wound around the bobbin in a bifilar manner, and at least one pair of first metal blocks installed and fixed to the bobbin and attached to the first superconducting wire; and a superconducting bypass reactor that has the current limiting module disposed therein, and is connected in parallel with the current limiting module.

Abstract: The present invention provides a current limiting module and a hybrid current limiter using different kinds of superconducting wires. The current limiting module includes a first superconducting wire that is wound in a predetermined direction, and a second superconducting wire that has quench characteristic different from the first superconducting wire and is wound to generate magnetic flux in a direction opposite to magnetic flux induced by the first superconducting wire. According to the present invention, inductance is generated due to unequal supply of fault current. Therefore, it is possible to prevent current from being suddenly increased, and to reduce the number of superconducting wires required to manufacture the current limiting module. Further, the hybrid current limiter does not need to include a separate coil for operating a fast switch.

Abstract: A fault current limiter is disclosed. The fault current limiter of the present invention includes a current limiting module and a superconducting bypass reactor. The current limiting module includes at least two pancake type bifilar winding modules, which are stacked and connected to each other in series. Each bifilar winding module has a bobbin, a first superconducting wire wound around the bobbin in a bifilar manner, and at least one pair of first metal blocks, which are installed and fixed to the bobbin and attached to the first superconducting wire. The superconducting bypass reactor is formed into a hollow shape so that the current limiting module can be disposed therein. A second superconducting wire is wound around the bypass reactor such that the superconducting bypass reactor is connected in parallel with the current limiting module.

Abstract: Disclosed herein is a non-inductive winding wire-type solenoid bobbin. The bobbin includes a cylindrical bobbin body, winding grooves formed on an outer circumferential surface of the bobbin body at regular intervals, and a connection channel provided on one side of each of the winding grooves. According to the present invention, an inner wire is in direct contact with liquid nitrogen through the connection channel, thus increasing the cooling effect when an electrical power system experiences trouble, and a superconducting fault current limiter including the bobbin limits a current, therefore minimizing damage to the inner wire, and makes a fast recovery after the fault current is limited to allow the current to resume flowing in the system.