110 results about "Superconducting fault current limiters" patented technology

The present invention relates to a complex superconducting fault current limiter which adds a current limiting reactor to a superconductor to protect the power line from a fault current, and more particularly, to a complex superconducting fault current limiter using a minimum number of superconducting fault current limiters, while avoiding series and parallel connections of a plurality of superconductors and coils, in order to economically manufacture the fault current limiter in a small size. A superconductor, a high speed switch, and a circuit breaker are connected in series to each other, and a first reactor with a low impedance and a second reactor with a high impedance are connected in parallel to the power line so as to provide a branch circuit for the current to the series circuit. A semiconductor switch is connected in parallel to the second reactor with a high impedance in accordance with the opening high speed switch. A circuit is breaker trip drive controller is configured so as to be connected to the superconductor and the branch circuit, and when a fault current occurs, the fault current is branched into the branch circuit, so that the second reactor limits the fault current. When a fault current occurs, the circuit breaker trip drive controller provides a trip drive signal to the circuit breaker for tripping in accordance with the voltage of the superconductor or the current of the branch circuit.

A resistive superconducting fault current limiter comprises: a superconducting limiter element which is in a superconductive state in the event of a normal current occurrence, and which is in a normal conductive state having a predetermined resistance when a fault current larger than a predetermined threshold current value flows; a superconducting serial coil serially connected to the superconducting limiter element so as to face each other so that a current loss can be minimized accordingly as currents flow in opposite directions thus to cancel magnetic fields, and having a threshold current value greater than the threshold current value of the superconducting limiter element by a predetermined ratio; and a normal conductor parallel coil connected to the superconducting limiter element in parallel and having a predetermined resistance smaller than the resistance of the superconducting limiter element when a fault current occurs, for preventing the superconducting limiter element from being overheated by dividing a current flowing through the superconducting limiter element and for uniformly quenching the superconducting limiter element by generating a magnetic field when a fault current occurs

A superconducting current limiting device (30) comprising: an interconnected high magnetic permeability structure including a central core (50) interconnected to at least a first and second arm (31, 32) branching off therefrom; a superconductive coil (33, 34) surrounding the central core for biasing the central core; a first alternating current coil (36, 37) surrounding the first arm and interconnected to an alternating current source; a second alternating current coil (38, 39) surrounding a second arm and interconnected to an alternating current load; the first and second alternating current coils being magnetically coupled to the central core wherein the device operates so as to limit the current passing through the device upon the occurrence of a fault condition in the load.

The invention discloses a method of optimal configuration of a plurality of superconducting fault current limiter based on a sensitivity technology, which comprises the steps of: calculating the three-phase short-circuit current of all nodes in a whole system, and finding b nodes with the short-circuit current exceeding the standard value; determining braches for installation and reliable startup of the SFCLs (superconducting fault current limiter) according to startup conditions of the SFCLs; calculating the sensitivity of self-impedance of each station with the short-circuit current exceeding the standard value, sequencing the stations in a sensitivity descending order, and taking the top a branches as candidate braches for installation of the SFCLs; and taking c candidate braches as optimal branches for a multi-objective optimization algorithm NSGA-II (non-dominated sorting genetic algorithm-II) in next step, determining a scheme with the optimal installation positions of the SFCLs, the number of SFCLs to be installed and the impedance, thereby realizing global optimum configuration. By adopting the method, the search space to be understood is reduced greatly, the speed of calculation is increased, and optimization results are more suitable for actual applications. Meanwhile, the problem of weight selection resulting from conversion of multi-objective optimization to single-objective optimization can be avoided, and a decision-maker can make final decisions according to actual engineering needs.

The present invention provides a fault detection system and a detection method for a quench-type superconducting fault current limiter. The present invention is characterized in that the present invention consists of a full wave rectification module, a logic circuit module, an analog-digital conversion module, a superconducting control switch module and a current rate detecting module. The working method of the present invention is as follows: (1) signal collection, (2) signal treatment and transmission, (3) analog-digital conversion and output, (4) current limiter operation determination. The present invention has the advantages that as follows: 1. a hardware apparatus is combined with a computer software programming; the hardware apparatus is of simple design and the software programming is easy to be understood; 2. a di/dt fault current rate is adopted to control the operation of the superconducting fault current limiter, which avoids the incorrect operation under the traditional control method; 3. the analog-digital conversion module is cooperated with the logic circuit, so the operation of the superconducting fault current limiter is more accurate and reliable; 4. the data calculation and data processing ability with high speed of the computer is used, so the reliability of the control system is greatly improved.

The invention relates to a resistive-type superconducting fault current limiter digital modeling and simulation method based on a YBCO superconducting tape. On the basis of establishing a YBCO superconducting tape equivalent structure model, a YBCO superconducting tape equivalent circuit model, a YBCO superconducting tape thermal conduction model and a resistive-type superconducting fault current limiter circuit model, the line current and the superconducting tape current are calculated according to given circuit parameters of the current limiter, and structure parameters and initial operation conditions of the superconducting tape; the temperature of the superconducting tape is calculated according to the YBCO superconducting tape thermal conduction model; the resistance of the superconducting tape is calculated according to the YBCO superconducting tape equivalent circuit model, the temperature of the superconducting tape, and the superconducting tape current; and the line current and the superconducting tape current are calculated according to the resistive-type superconducting fault current limiter circuit model, and simulating calculation of the resistive-type superconducting fault current limiter is achieved. The resistive-type superconducting fault current limiter digital modeling and simulation method based on the YBCO superconducting tape can be used for superconducting fault current limiters with multiple units and complex structures.

The invention supplies a DC superconduction fault current limiter, whose structure is: two superconduction coupling coil w1 and w2, has the same inductance wrapped on ring shaped core and one superconduction coil w1 is current limiting inductor whose two ends are connected to load loop, and another superconduction coil w2 as bias winding is connected to DC power source E2 and resistor R2 in series, w1 and w2 cooled by cooling device current limiting effect. The invention has advantages is: notable current limiting effect and low loss; short response time and high reliability, when the system operates normally, superconduction coil has very small stored energy and won't create overvoltage after accident protection; detecting, triggering and current limiting are integrated without need of adding control circuit, simple structure and small volume. The invention can satisfy DC fault protective device of individual system such as ship, plane, oil platform, mobile communication station and electric automobile.

The invention relates to a saturated iron core type superconducting fault current limiter with a direct current control system, which comprises a superconducting magnet, a reactance system, namely an iron core and an alternating current winding, a refrigeration system and a monitoring system and also comprises a direct current control system which is connected with two ends of the superconducting magnet and connected with the monitoring system by a data wire; the direct current control system comprises a direct current power module, a magnetic energy absorption module and a control module. The invention also provides a method for controlling the current limiter; when an electric net has normal operation, the control module of the direct current control system automatically adjusts the size of the direct current excitation current in the superconducting magnet according to the size of load in the electric net; when the electric net has short-circuit fault, the control module actively cuts off a direct current loop, simultaneously releases the magnetic energy of the superconducting magnet and clamps the overvoltage; the total iron core of the current limiter participates in the current limiting; and after the fault of the electric net is removed or cut, the control module improves the output voltage of the power supply and forces the superconducting magnet to rapidly magnetize through a power electronic switch so that the current limiter can be rapidly restored to a low resistance state.

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.

The invention relates to power systems and automation, in particular to a system and a method for improving FRT (fault ride-though) capability of a DFIG-WT (doubly fed induction generator based wind turbine) on the basis of an SFCL (superconducting fault current limiter) and an SMES (superconducting magnetic energy storage). The system is characterized in the on the basis of the typical DFIG-WT, aresistor type SFCL is mounted on the stator side of the DFIG-WT, and the SMES is mounted on a direct current link of the DFIG-WT through a bidirectional DC/DC converter; the resistor type SFCL is used for limiting stator fault current of the DFIG-WT, improving generator terminal voltage sag of the DFIG-WT and absorbing partial surplus active power in the DFIG-WT; the SMES is used for stabilizingunbalanced power and electromagnetic torque oscillation. According to an FRT method for the DFIG-WT on the basis of the SFCL and the SMES, fault current can be limited under symmetrical faults and asymmetrical faults, voltage change is inhibited, and unbalanced power and electromagnetic torque oscillation are stabilized. Efficient FRT support can be provided for the DFIG-WT during FRT, and transient performance of the DFIG-WT is improved.

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.

The present invention relates to a reclosing control system and method using a superconducting fault current limiter. The reclosing control system includes a superconducting fault current limiting device in which two circuits, each having a switch and a superconducting fault current limiter connected in series with each other, are connected in parallel with each other. A recloser is disposed between the superconducting fault current limiting device and a distribution line and is configured to control reclosing. The distribution line is connected to the recloser and is configured to transfer power to a load.

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.

The invention relates to a compact iron core structure, which comprises two to six mouth-shaped iron cores, wherein, each mouth-shaped iron core comprises an intermediate iron core column, a side column, an upper yoke iron and a lower yoke iron. Each side column is sleeved with an alternating current winding, the cross-section shape of the intermediate iron core column is different from that of the side column, two to six of the intermediate iron core columns are compactly combined and assembled into a combined intermediate column which has an angle of 360 DEG around the center, an assembled insulating partition is arranged between each two intermediate iron core columns, the outline of a cross-section rim of the combined intermediate column is of a circle, and one direct current winding is sleeved outside the combined intermediate column. The iron core structure effectively utilizes space to ensure that the iron core structure is more reasonable, reduces the whole volume of a saturable core superconducting fault current limiter and a saturable reactor and so on, strengthens the excitation degree of the direct current winding to the iron cores, decreases the magnetic leakage, reduces manufacturing cost, and contributes to industrialized application.

The invention discloses an impedance composite superconducting fault current limiter based on a novel superconducting material. The superconducting fault current limiter comprises a square iron core (18), wherein an MgB2 superconducting winding (11) is arranged on the upper side of the iron core (18) and connected with a reactor (10) in parallel; a high temperature superconducting winding (17) isarranged on the lower side of the iron core (18) and connected with a direct current voltage source (13) in series; and a magnetic switch (16) and a value adjustable first resister (12) are connectedin series between the high temperature superconducting winding (17) and the direct current voltage source (13) to form a first circuit. Under the condition of satisfying the line current-carrying capacity, the superconducting fault current limiter uses the fewest superconductors, can improve the inductive impedance level in case of fault, and also can reduce voltage loss in normal operation and ensure the reliability of operation.

The present invention discloses a half-wave expulsion type superconducting fault-current limiter having an integral high speed switch module. The fault-current limiter has minimum superconducting elements and a circuit of which is formed in a hybrid type with an integral high speed switch module. The fault-current limiter supplies an electric power supplied from a power feeder to a system without loss thereof according to unique characteristics of the superconducting element when a normal current flows, and restricts an over current through a high speed switching contact point integrally inter-working with a driving coil and an arc changeover switch past a half period in a case that the over-current is generated by accidents such as thunder-stroke, earth fault and short circuit, such that electric power appliances such as circuit breakers in an electric power system can be normally operated.

The invention discloses a parallel superconducting fault current limiter, which comprises a reactance system, a direct current control system and a low-temperature system, wherein each phase of the reactance system consists of an iron core, two alternating current windings and a direct current exciting winding; and the two alternating windings are connected to a grid in parallel, and the two alternating current windings are the same. The ratio of the cross section of a direct current iron core column of the direct current exciting winding and the cross section of the alternating current iron core columns of the alternating windings is 1.01:10. Compared with serial superconducting fault current limiter, the novel superconducting fault current limiter has advantages in many aspects and thus represents a substantial progress in the industrialization process of the superconducting fault current limiter. The superconducting fault current limiter is expected to provide a breach to the further industrialization of the superconducting fault current limiter.

The invention relates to a superconducting fault current limiter-based flexible direct-current transmission system current-limiting electric reactor selection method, and belongs to the technical field of direct-current transmission. According to the method, when a direct-current side line fault occurs in a modularized multi-level flexible direct-current power transmission system, the current-limiting electric reactance of the direct-current line is calculated to be matched with the superconducting fault current limiter to inhibit the fault current so as to ensure that the fault removal can becompleted under the condition that a multi-level converter is not locked. According to the method disclosed by the invention, a calculation method for selecting the fixed impedance in a substituted mode is improved, and the resistance value of the superconducting fault current limiter is subjected to piecewise linearization fitting based on a least square method so as to optimize and solve. According to the method disclosed by the invention, the reasonable value-taking margin of the current-limiting electric reactor can be calculated under the influence of the dynamic resistance value of thesuperconducting fault current limiter, the system stability and the dynamic response capability can be effectively improved, and the method has guiding and reference meaning to the practical engineering in the future. According to the method disclosed by the invention, the cooperation between various primary equipment parameters is comprehensively considered, the primary equipment is more reasonably selected, the utilization efficiency of primary equipment is improved, the system investment cost is lowered, and the economical efficiency is improved.

The invention proposes an optimal configuration method of a superconduction fault current limiter in an active power distribution network. The optimal configuration method comprises the steps of acquiring a parameter of a power distribution network system and an access position and capacity of a distributed power supply, calculating steady-state power flow to obtain a voltage and a phase angle ofeach node in a steady state, and calculating a current of each branch in the steady state; considering a short-circuit current calculation method after access of the distributed power supply, calculating a short-circuit current of each node, finding out a node of which the short-circuit current exceeds standard, and calculating the current of each branch under a short-circuit state; selecting a branch capable of normally starting according to a starting condition of the superconduction fault current limiter, and sieving a candidate branch according to a branch sensitivity sequencing method; considering cost and current limitation effect of the fault current limiter, and performing multi-target optimal calculation on an installation position and installation impedance of the superconductionfault current limiter by improved multi-target particle swarm optimization; and obtaining a Pareto solution under different installation numbers for site selection and sizing in the power distribution network. By the optimal configuration method, the probability that local optimum of the algorithm is sunken is reduced, and the result accuracy is improved.