Abstract: A quench detection system for a fault current limiter (1), in particular, a high temperature superconductor fault current limiter, making use of a differential protection relay wherein in fault event the differential protection relay operates a triggering mechanism of a circuit breaker (2), thereby opening the electrical circuit and interrupting power supply to downstream components, and a method for quench detection wherein the magnitude of voltage drop during quench is converted to a current signal being proportional to the voltage and which is monitored by the differential protection relay.

Abstract: The superconducting current-limiting device contains at least one coil (61), the conductive track of which is formed from at least one band-shaped superconductor (17), where a holding element (2, 41, 10, 51, 62) is located between adjacent coil windings. The holding element (2, 41, 51, 62) is constructed wider than the superconductor (17) in the axial direction of the coil (61). The holding element (2, 41, 51, 62) further includes a flat strip (11) and an undulating strip (12, 42, 52). The flat strip (11) extends essentially parallel to the band-shaped superconductor (17) at an essentially constant distance (22) therefrom. The undulating strip (12, 42, 52) extends essentially parallel to the flat strip (11), and in the longitudinal direction periodically has regions (15, 43, 53) distant from and regions (13) close to the flat strip (11). The regions (13) of the undulating strip (12, 42, 52) near to the flat strip have a mechanical connection (21) to the flat strip (11).

Abstract: A system and method for generating a magnetic field in a rotating machine. In one embodiment, a primary winding assembly is configured to generate a rotatable magnetic field. The assembly is connected to receive multiple signals of different phases to effect field rotation. A set of secondary windings is positioned for generation of current based on magnetic coupling during the field rotation. The secondary windings include conductor capable of supporting superconducting current flow. A rotatable machine includes a stator and a rotor winding coupled for rotation with respect to the stator. The secondary windings are formed in a circuit for providing superconducting current through the rotor winding.

Abstract: A fault current limiter that maximizes transient stability by minimizing the power swing experienced by the generator during a fault condition is disclosed. A superconducting fault current limiter (SCFCL) is used, whereby the impedance of the SCFCL changes in the presence of a fault. In parallel with the SCFCL is a shunt impedance, which is the impedance seen by the generator during the fault. By decreasing the ratio of the reactance of the shunt impedance to its resistance, the stability of the power system may be enhanced.

Abstract: The present disclosure is related to a peak current limiting apparatus of the present disclosure comprising a trigger element serially connected between a power supply source and the load, diverting a fault current to other paths connected in parallel when the fault current exceeding a threshold is generated, a main contact switch serially connected between the trigger element and a load, a driving coil connected in parallel with the trigger element, and generating a repulsive force in response to the fault current to detach a contact point of the main contact switch, and a peak limiting impedance element serially connected between a connection node between the trigger element and the main contact switch and the driving coil, and limiting a first peak level of the fault current flowing through the driving coil to a predetermined level.

Abstract: The present invention concerns a superconducting fault current limiter (1) comprising a rectifier bridge (2) made of active devices (3a, 3b, 3c, 3d) connected to a circuit that is to be protected, said rectifier bridge (2) comprising four branches connected by means of four nodes (4, 5, 6, 7), wherein a first node (4) and a second node(5), not adjacent to said first node (4), are connected to said circuit that is to be protected (12, 13), characterized in that it comprises a central branch (8) connected from the third node (6) to the fourth node (7) of said rectifier bridge (2), comprising or consisting of at least one circuit element comprising an inductive component, whose aim is to reduce the amplitude of the ripple of the current through said central branch (8), and a nonlinear superconducting resistive component, having: a first operating condition, wherein the current through said central branch (8) does not exceed a given threshold value, so that said at least one circuit element, comprising a nonli

Abstract: A fault current limiter comprising: an input node; an output node; a variable impedance element coupled between the input node and the output node; a closed loop cryocooler circuit, comprising a first cryocooler for cooling the variable impedance element and a second cryocooler, thermally coupled to the first cryocooler, for cooling the first coolant, wherein the variable impedance element comprises Magnesium Diboride.

Abstract: Disclosed is the structure of a persistent current switch and a control method for the same. In the switch structure, a portion of a superconducting wire to be used as a switch is formed with slits such that the flow of current is controlled by the switch, to facilitate a transition between the superconducting state and the normal state of the superconducting wire. The structure of the persistent current switch includes a first slit longitudinally extending from a first point on one end of a superconducting wire to a second point and from a third point to a fourth point, the second, third, and fourth points being arranged sequentially in a longitudinal line, and second and third slits provided at opposite sides of a region between the second point and the third point where no first slit exists.

Abstract: A system for ramping-down a superconducting magnet includes an electrically conductive lead connectable to a superconducting magnet and a plurality of diode assemblies arranged in series and coupled to the electrically conductive lead. Switches are arranged in parallel with the plurality of diode assemblies, with each switch having a first position and a second position and wherein each switch, when in the first position, forms an electrical short between first and second nodes of a corresponding diode assembly. A controller receives a magnet parameter value indicative of a present state of the superconducting magnet, determines a number of diode assemblies through which current from the electrically conductive lead is desired to pass based on the magnet parameter value, and selectively actuates the switches coupled to the determined number of diode assemblies to the second position to pass current from the superconducting magnet through the determined number of diode assemblies.

Abstract: There is provided an apparatus for decreasing an inrush current which comprises a power system including a transformer, and a superconducting fault current limiter electrically connected to the transformer. A resistance value of the superconducting fault current limiter is calculated by using a variation of the inrush current and a variation of the voltage drop of the power system according to a value of insertion resistance. In the apparatus for decreasing the inrush current, the optimal resistance value considering both the decrease rate of the inrush current and the voltage drop by the insertion of the superconducting fault current limiter is decided as the resistance value of the superconducting fault current limiter. Accordingly, the power system is efficiently operated depending on the characteristics of the power system in which the superconducting fault current limiter is installed.

Abstract: The present invention relates to a quench controlled high temperature superconductor component wherein at least one depression is provided in a surface of the component resulting in a reduced wall thickness, and, wherein an electrical shunt is applied into the depression.

Abstract: Electric fault current limiter has superconducting elements inside a cryogenic vessel and bushings for connecting an external circuit. The electric fault current limiter (1) includes a cryogenic vessel (2) and superconducting assemblies (5) including high temperature type superconducting elements (HTSC) immersed in a liquid coolant (6) such as liquefied nitrogen. Bushings (25, 28) with conductors (17, 18) are associated with a main body (3) of the vessel (2) such that the conductors (17, 18) extend horizontally from a surrounding space into an ullage space (8) situated between a level (7) of the liquid coolant (6) inside the vessel (2) and a cover (4). The arrangement of the bushings (25, 28) according to the invention allows for removing the cover (4) without dismantling electrical connections between the current limiter (1) and a circuit to be protected as is necessary with prior art limiters.

Abstract: A localized area is at least partially contained within a perimeter of a shield ring formed by a closed superconducting current path of a material that is superconductive below a critical temperature. The shield ring is at least partially within a perimeter of a compensation coil that is coupled to a current source. One or more measurement devices are responsive to magnetic fields in the vicinity of the localized area, allowing compensation by controlling current to the compensation coil. A heater can raise temperature of the shield ring out of a superconducting condition.

Abstract: The active shield superconducting electromagnet apparatus includes: a main switching circuit in which first and second main coils, first and second shield coils, and a first superconducting persistent current switch are connected in series; a sub switching circuit in which a bypass circuit, in which a superconducting fault current limiter and a second superconducting persistent current switch are connected in series, are connected to a series circuit of the first main coil and the second main coil in parallel; a first closed circuit in which at least one of the first main coil and the first shield coil, and a first quench protection circuit are connected in series; and a second closed circuit in which one of the second main coil and the second shield coil, and a second quench protection circuit are connected in series.

Abstract: A superconducting fault current-limiter is provided, including a superconducting element configured to resistively or inductively limit a fault current, and one or more variable-impedance shunts electrically coupled in parallel with the superconducting element. The variable-impedance shunt(s) is configured to present a first impedance during a superconducting state of the superconducting element and a second impedance during a normal resistive state of the superconducting element. The superconducting element transitions from the superconducting state to the normal resistive state responsive to the fault current, and responsive thereto, the variable-impedance shunt(s) transitions from the first to the second impedance.

Abstract: A superconductive magnetic coil arrangement has a superconducting magnetic coil and a circuit for quench protection. The quench protection circuit includes at least one diode connected in parallel with a portion of the superconductive magnetic coil. The at least one diode is in thermal contact with the superconductive magnetic coil A magnetic resonance tomography apparatus embodies such a magnetic coil arrangement.

Abstract: An apparatus, system and method for measuring electrical dissipation in a coil wound with superconducting wire or tape are disclosed. The superconducting coil may include one or more superconducting wires wound together with a witness winding. The one or more superconducting wires may be electrically connected to the witness winding. The one or more superconducting wires may be shaped as a tape. The witness winding may be a tape. The superconducting coil may be wound into a flat pancake structure. The witness winding may be configured to detect a quench in the one or more superconducting wires, which may otherwise interfere with the superconductivity of the one or more superconducting wires.

Abstract: A superconducting magnet apparatus that in one embodiment includes at least one superconducting coil and a passive quench protection circuit electrically coupled to the coil in parallel. The circuit includes a heater and a current limiter connected in series. The heater is thermally coupled to the coil and the current limiter blocks current through the circuit at a current lower than the current rating of the heater.

Abstract: A superconducting coil quench detection method and device capable of detecting a quench detection voltage even in a superconducting coil where a plurality of element coils are connected with a plurality of current sources and operated with repetitive pulses or AC and a voltage of several kV is applied continuously as an induction voltage. A super conducting power storage unit is also provided.

Abstract: A terminal apparatus for a superconducting cable system connects an overhead transmission cable or power appliance such as a breaker in an ambient temperature state to a superconducting cable through which power is transmitted at a cryogenic temperature. The terminal apparatus has: a refrigerant tub which is connected to the end of a superconducting cable and is filled with a refrigerant; a vacuum heat insulating container that surrounds the exterior of the refrigerant tub; a current lead having one end connected to the end portion of the superconducting cable and the other end connected to the overhead transmission cable or power appliance through the refrigerant tub and the vacuum heat insulating container; and a superconducting fault current limiter installed at a center portion of the current lead in the interior of the refrigerant tub to limit fault current.

Abstract: A superconductor for mitigating the effects of local current disruptions in a superconducting filament. The superconductor comprises superconducting filaments covered by a medium in electrical communication with the filaments. The covering medium has anisotropic conductivity, the conductivity in a direction substantially aligned with the filaments being selected to stabilize the superconductor near the critical temperature, and the conductivity of the covering in a direction substantially perpendicular to the filaments being selected to permit controlled current sharing between the filaments, especially when a filament is compromised, while simultaneously limiting alternating current (ac) losses. In various embodiments, the covering comprises a wire mesh having longitudinal wires made of a first material having a first conductivity, and transverse wires made of a second material having a second conductivity, different from the first conductivity.

Abstract: A superconductive current limiter component with magnetic field triggering has a tubular superconductor element (1) which is connected in electrical parallel with a trigger coil (3), wherein the trigger coil runs from a first end of the tubular superconductor element (1) on one side of the lateral face of the tubular superconductor element (1) in the direction of the second end of the tubular superconductor element (1), is deflected at that point to the other side of the lateral face and runs back in the direction of the first end, and so on.

Abstract: A superconducting fault current limiter comprises a superconducting element having a plurality of superconducting portions and at least connector. Each superconducting portion has end regions and each connector is connected to the end regions of adjacent superconducting portions to electrically and thermally connect adjacent superconducting portions of the superconducting fault current limiter together. Each connector provides a local reduction in the critical current and quench current of the end regions of the superconducting portions in contact with the at least one connector. This provides a phased transition of the superconducting fault current limiter in relation to the severity of a fault current.

Abstract: A superconducting device comprises a vacuum chamber and means to evacuate the vacuum chamber. A base plate is provided within the vacuum chamber and first, second and third cylindrical walls extend from the base plate. The second and third cylindrical walls are arranged coaxial with the first cylindrical wall. A first chamber is defined between the first cylindrical wall and the second cylindrical wall, a second chamber is defined between the second cylindrical wall and the third cylindrical wall and a third chamber is defined within the third cylindrical wall. A superconducting wire is arranged within the second chamber and a cryogenic insulating material is arranged within the second chamber to encapsulate the superconducting wire. A material having a high specific heat capacity is arranged within the first chamber and there are means to cool the base plate.

Abstract: A fault current limiter designed for connection into a medium voltage, high voltage, or extra-high voltage substation or other high voltage source such as a generator station, the limiter including: a ferromagnetic circuit formed from a ferromagnetic material and including at least a first limb, a second limb and a third limb; a first input phase coil wound around the first limb, a second output phase coil wound around the third limb; a saturation mechanism surrounding a limb for magnetically saturating the ferromagnetic material; a containment vessel providing a substantially uniform, low electrical conductivity medium surrounding the ferromagnetic circuit, the phase coils and the saturation mechanism.

Abstract: A core-saturated superconductive fault current limiter and a control method of the fault current limiter. The fault current limiter includes a superconductive magnet (2), a core (4), an AC winding (5), a cryostat system, a monitor system (7) and a DC control system (6). The output of the DC control system (6) is connected to the two terminals of the superconductive magnet (2). The DC control system (6) is also connected to the monitor system (7). The core (4) has an unequal section core structure. The control method includes: controlling the current which is flowing through the superconductive magnet (2) for limiting the fault current in the power net (1) in the case of a short circuit fault event.

Abstract: A fault current limiter including: a ferromagnetic circuit formed from a ferromagnetic material and including at least a first limb, and a second limb; a saturation mechanism surrounding a limb for magnetically saturating the ferromagnetic material; a phase coil wound around a second limb; a dielectric fluid surrounding the phase coil; a gaseous atmosphere surrounding the saturation mechanism.

Abstract: A superconducting article is provided which incorporates an early quench detection facility. The superconducting article includes a first superconductive segment and a second superconductive segment, along with a magnetic field sensor(s). The magnetic field sensor(s) is disposed to monitor relative change in strength of a net magnetic field generated by a first current passing through the first superconductive segment and a second current passing through the second superconductive segment. A relative change in strength of the net magnetic field indicates degradation of a critical quench current of the first superconductive segment or the second superconductive segment, caused for example, by formation of one or more hot-spots or quench regions in the first or second superconductive segment. The indication of degradation is thus obtained prior to complete superconductive segment quenching.

Abstract: The present invention relates to a resistive type high temperature superconductor based fault current limiter with improved heat exchange capability composed of a thermally conductive matrix material 8 with a plurality of superconductor components 5 embedded in the thermally conductive matrix material 8 wherein the plurality of superconductor components 5 is connected electrically in parallel.

Abstract: A method is for suppressing induced steady state and transient currents and voltages in the DC circuit and coil of a magnetically saturated core fault current limiter. The method includes the steps of: (a) providing a first current coil connected to a DC power source surrounding the core for magnetically saturating the core; and (b) providing a second resistive current coil surrounding the core and either short circuited or interconnected to the DC power source in parallel to the first current coil and wound around the core in a forward or reverse sense to the first current coil.

Abstract: According to a first aspect the present invention relates to a fault current limiter formed by a conductor tape (11, 41, 51, 61, 71) coated with a high temperature superconductor and having at least one mounting element (12, 42, 52, 62, 72) which is essentially holding the conductor tape solely on one or more edge regions in such a way that the principal surfaces of the tape cannot get in touch with the mounting element. According to a second aspect the present invention relates to a fault current limiter formed by a conductor tape coated with a high temperature superconductor and comprising at least one mounting element (23, 24) which is contacting the conductor tape on one or on both major surfaces in an electrically conducting manner such that the conductor tape (21) in its normal conducting state is electrically shunted by the mounting element (23) in the contact region.

Abstract: The invention provides an electric grid stabilization metadevice including a plurality of interactive grid devices each forming part of a respective electrical path of an electric grid and each including, a variable impedance device that inserts a current limiting impedance in the respective path when a fault occurs, a state detection transducer connected to the variable impedance device to change a detection state when the fault occurs and an integral communications system having transmission and reception capabilities and being connected to the state detection transducer and variable impedance device, wherein a fault detected by each of the interactive grid devices automatically causes transmission of a signal to another integrated grid device, reception of the signal by the other integrated grid device and an insertion of a current limiting impedance by the other integrated grid device.

Abstract: Provided is a superconducting cable having a structure such that cable cores, each having a superconducting layer, are housed in a thermal insulation pipe and the superconducting layer of each cable core has portions having different critical current values. When an excessive current flows in the superconducting layer in case of a short-circuit failure, the current exceeds the critical current value of the portion having a smaller critical current value first, which results in damage to the portion, suppressing the occurrence of damage to the other normal portion. A superconducting cable line using this superconducting cable and a splitter for accommodating the cable cores therein is also provided.

Abstract: Disclosed is provided a hybrid-type superconducting fault current limiter for rapidly limiting a fault current, the fault current limiter having a first circuit and a second circuit which are connected in parallel with each other, wherein the first circuit includes a superconductor and a circuit breaker which are connected in series with each other, and wherein the second circuit includes a driver having a driving coil and an electromagnetic repeller, a short contact connected in parallel with the driver, and a current limiting unit connected in series with a third circuit including the driver and the short contact. The hybrid-type superconducting fault current limiter comprises a power semiconductor element switch connected in series with the first circuit, the power semiconductor element switch normally maintaining an ON state and being activated and changed into an OFF state by a fault sensing signal generated according to an inflow of the fault current.

Abstract: A superconducting transformer system is configured to be included within a utility power grid having a known fault current level. The superconducting transformer system includes a non-superconducting transformer interconnected between a first node and a second node of the utility power grid. A superconducting transformer is interconnected between the first node and the second node of the utility power grid. The superconducting transformer and the non-superconducting transformer are electrically connected in parallel. The superconducting transformer has a lower series impedance than the non-superconducting transformer when the superconducting transformer is operated below a critical current level and a critical temperature. The superconducting transformer is configured to have a series impedance that is at least N times the series impedance of the non-superconducting transformer when the superconducting transformer is operated at or above one or more of the critical current level and the critical temperature.

Abstract: A system for protecting superconducting generator field coils including a controller configured to monitor for a quenching of a superconducting field coil of a generator and control a dissipation of a current flow in the superconducting field coil in an event of the quenching, and an armature coil of the generator configured to cause the dissipation of the current flow in the superconducting field coil responsive to the controller in the event of the quenching of the superconducting field coil. A method for protecting superconducting generator field coils including monitoring for a quenching of a superconducting field coil of a generator, and dissipating a current flow in the superconducting field coil via an armature coil of the generator in response to a detection of the quenching.

Abstract: The present invention is directed to a superconductor component 1 suitable as fault current limiter comprising a superconductor body 2 provided with a shunt coil 3 and an electrical contact 4 on at least one end of the superconductor body 2 wherein the superconductor component 2 is provided with means for reducing currents 6 induced within the electrical contacts 4.

Abstract: The present invention is directed to a superconducting current limiting component, particularly to a ceramic high temperature superconducting current limiting component which is self triggering, comprising a coil (1) made of ceramic high temperature superconductor material, wherein around the outer surface of the coil (1) made of ceramic high temperature superconductor material a second coil (3) is applied as a shunt and, preferably, wherein the coil (1) made of ceramic high temperature superconductor material is applied onto a hollow cylindrical body (2) made of a ceramic high temperature superconductor material.

Abstract: A coil system for inductively heating a superconducting magnet in order to provide an internal energy dump by uniformly quenching a high performance superconducting magnet. The quench-inducing system uses AC magnetic fields that require negligible reactive power. The system is especially suited for inducing a relatively uniform quench in dry superconducting magnets.

Abstract: In devices for producing strong current high power impulses, the electronic components, which include passive components including capacitors and/or switch elements, including semi-conductor switches, diodes or similar elements, need to be protected against overcurrents in the event of an error function. Generally, serial resistance and serial inductance are used. The serial resistance and the serial inductance are combined together in such a manner that a coil having necessary resistance and inductance values is produced.

Abstract: A superconducting magnet assembly comprising a superconducting magnet (1) which, under working conditions, generates a magnetic field in a working volume, the superconducting magnet being connected in parallel with a series combination of a superconducting fault current limiter (7) and a resistor (5). The magnet is further connected in parallel to a DC power source (4) whereby under working conditions, the magnet can be energised by the power source to generate a desired magnetic field in the working volume.

Abstract: A device for converting an electric current includes at least one phase module having an AC terminal and at least one DC terminal. Phase module branches, each of which is equipped with serially connected submodules, are respectively provided between each DC terminal and each AC terminal. Each submodule is provided with at least one power semiconductor. Semiconductor protecting means are connected in parallel or in series to at least one of the power semiconductors to enable the device to withstand even high short-circuit currents for a sufficient period of time. A method for protecting the power semiconductors of the device, is also provided.

Abstract: A magnetic flux coupling-type superconducting current limiter is capable of protecting lines more effectively by winding reactors of a primary coil and a secondary coil in series in the structure where the primary coil and the secondary coils are wound in parallel in the conventional magnetic flux-lock type current limiter to increase a linked flux generated from an iron core. An electric conducting current which rapidly increases when a fault occurs is divided into the secondary coil and a superconducting coil to decrease a load on the superconducting element and it is opened more rapidly than the existing superconducting current limiter during a quench time such that it better limits a fault current.

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: An alternating current system 10 has a primary circuit 11 which forms a primary winding 18 on a core 16. A secondary winding 24 is connected with a current source 26 or, alternatively, with an impedance 60. The core 16 is threaded by a superconducting coil 20 having a current source 22. In normal use, current in the coil 20 provides a DC bias level of flux in the core 16, and the source 26 is varied to maintain substantially constant flux, thereby minimising losses in the primary circuit 11. In fault conditions, current in the coil 20 is reduced or removed to increase voltage losses across the coil 18, thereby limiting fault current. The impedance 60 can also be switched into circuit, creating further current limiting by virtue of the transformer effect of the windings 18, 24.

Abstract: An improved persistent current switch design and method of operation are disclosed. By way of example, a persistent current switch circuit comprises a heating element and a switch element located proximate to the heating element, the switch element being substantially formed from a material (by way of example only, titanium) which exhibits a superconducting temperature value below a superconducting temperature value exhibited by a material (by way of example only, aluminum) used to provide a connection to the switch element. The switch element is responsive to the heating element such that the heating element is used to control whether or not the switch element is in a superconducting state. The switch element may also have a folded geometry. Such persistent current switches exhibit low power and low inductance.

Abstract: An alternating current system 10 has a primary circuit 11 which forms a primary winding 18 on a core 16. A secondary winding 24 is connected with a current source 26 or, alternatively, with an impedance 60. The core 16 is threaded by a superconducting coil 20 having a current source 22. In normal use, current in the coil 20 provides a DC bias level of flux in the core 16, and the source 26 is varied to maintain substantially constant flux, thereby minimizing losses in the primary circuit 11. In fault conditions, current in the coil 20 is reduced or removed to increase voltage losses across the coil 18, thereby limiting fault current. The impedance 60 can also be switched into circuit, creating further current limiting by virtue of the transformer effect of the windings 18, 24.

Abstract: A method of constructing a superconducting coil. The method includes embedding a plurality of heater elements throughout a superconducting coil. The heater elements are positioned according to a predetermined distribution and substantially in thermal contact with the coil for heating the coil in response to a quench condition. Other aspects of the invention involve an active protection circuit and a high temperature superconductor magnet that includes such an active protection circuit for internally dissipating stored magnetic energy in the event of a quench.

Abstract: An assembly comprising a number of superconductive coils, at least one quench heater arranged to heat the superconductive coil(s) in the event that at least part of at least one of the coils enters a quenched state; means for transferring energy from the coil(s) to the heater(s) in the event that at least part of at least one of the coils enters a quenched state; wherein the means for transferring energy from the coil(s) to the heater(s) includes a series capacitance, through which the energy transferred must pass.

Abstract: A superconducting coil system includes a superconducting coil and a protective link of superconducting material coupled to the superconducting coil. A rotating machine includes first and second coils and a protective link of superconducting material. The second coil is operable to rotate with respect to the first coil. One of the first and second coils is a superconducting coil. The protective link is coupled to the superconducting coil.