JP2007274754A - Superconducting current limiter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a superconducting current limiter that reduces the size of a cryostat for housing the superconducting current limiter as much as possible and facilitates maintenance. <P>SOLUTION: The superconducting current limiter is so constructed that a superconducting current limiting element is placed in each of electric circuits of multiple phases. The superconducting current limiting elements are each constructed of a noninductive winding coil, and are coaxial concentrically or coaxially disposed. Therefore, it is possible to reduce the size of a cryostat for housing the superconducting current limiter as much as possible, to ensure a space in a cubicle to facilitate maintenance, and to reduce pressure rise in the cryostat. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a superconducting current limiting device that suppresses a short-circuit current flowing in a power system when a power system fault occurs.

  When an accident occurs in the power system, a current limiting device is used as a device that suppresses a short-circuit current flowing in the power system to a predetermined value or less. The current limiting device has an impedance close to zero when the system is stationary, but has a function of suppressing a short-circuit current to a predetermined value or less by generating a high impedance when a system fault occurs. One installation location where such a current limiting device is expected to be applied is, for example, grid connection. In the grid connection, a switching method is used in which two systems are connected by a current limiting device, the power of the two systems is always interchanged, an accident current is suppressed in the event of an accident, and then the two systems are disconnected.

  Up to now, the current limiting device has been technically verified for its usefulness, but the cost merit cannot be sufficiently exhibited, and it has not necessarily been widely introduced into the power system. However, in recent years, it has become clear that yttrium-based high-temperature superconducting wire has improved characteristics, lengthened, and reduced costs, and it has been found that there are also cost advantages, so development for practical use is rapidly progressing. .

Generally, since the current limiting device is housed in a standard board (cubicle), it is required to reduce the size as much as possible and to facilitate maintenance after the current limiting device is introduced. As a general superconducting current limiting device, a configuration described in FIG.
JP-A-4-359626 Japanese Patent No. 2774672

  By the way, normally, the cryostat that houses the current limiting device is arranged in a limited space called a standard board (cubicle), and thus downsizing of the cryostat is an important issue. The cryostat that houses the current limiting elements for three phases is preferably cylindrical in consideration of the pressure increase during current limiting.

Conventionally, the current limiting elements for three phases are symmetrically arranged at intervals of 120 ° as described in FIG. When the current limiting element is arranged in such a shape, it is necessary to arrange a cryostat having an inner diameter that is at least twice as large as the outer diameter of the current limiting element, which is an obstacle to miniaturization of the cryostat. Further, the conventional cryostat has a problem that the amount of radiant heat is large and the pressure inside the cryostat increases.
The present invention has been made to cope with the above situation, and an object thereof is to provide a superconducting current limiting device including a superconducting current limiting element capable of reducing the size of a cryostat.

  In order to solve the above-described problem, the superconducting current limiting device of the present invention includes a superconducting current limiting element interposed in each of the plurality of phases, and each superconducting current limiting element is configured by a non-inductive winding coil. And it is arrange | positioned coaxially concentrically or coaxially.

  According to the present invention, the cryostat accommodating the superconducting current limiting device can be miniaturized as much as possible to secure the space in the cubicle, thereby facilitating maintenance and reducing the pressure increase inside the cryostat.

Hereinafter, the best embodiment of a superconducting current limiting device according to the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a configuration diagram of a superconducting current limiting device according to a first embodiment of the present invention. FIG. 1 (a) is a plan view, and FIGS. 1 (b), (c), and (d) are the same. It is a perspective view of a U-phase non-inductive current limiting element, a V-phase non-inductive current limiting element, and a W-phase non-inductive current limiting element of (a).

  As shown in FIG. 1, the superconducting current limiting device of this embodiment has a U-phase non-inductive current limiting element 11, a V-phase non-inductive current limiting element 12, and a W-phase non-inductive current limiting element 13 arranged concentrically. Configured. Each non-inductive current limiting element includes at least one superconducting wire 21, one or more winding frames 22, and two or more electrodes 23a and 23b. The inductance between the electrode 23a and the electrode 23b is as follows. The winding configuration is as close to zero as possible. A configuration example of the non-inductive current limiting element is described in, for example, Patent Document 2, but may be a current limiting element configured by a bifilar winding.

  In this embodiment, the U-phase non-inductive current limiting element 11 has the largest coil outer diameter, then the V-phase non-inductive current limiting element 12 has the largest coil outer diameter, and the W-phase non-inductive current limiting element 13 has a coil outer diameter. However, there is no correlation between the coil diameter and the phase, and any of six combinations of the phase and the coil diameter may be used. However, it is necessary to adjust the coil diameter so that the non-inductive current limiting coils for three phases are concentrically accommodated. That is, when defined as large-diameter non-inductive current limiting element, medium-diameter non-inductive current-limiting element, and small-diameter non-inductive current-limiting element in the order of the coil diameter, the medium diameter is smaller than the coil outer diameter of the small-diameter non-inductive current limiting element. The coil inner diameter of the non-inductive current limiting element needs to be large, and the coil inner diameter of the non-inductive current limiting element having a larger diameter needs to be larger than the outer diameter of the coil of the medium non-inductive current limiting element.

  As shown in FIG. 1, by arranging the three-phase current limiting elements concentrically, the required inner diameter of the cryostat is almost equal to the U-phase non-inductive current limiting element 11 which is a large-diameter non-inductive current limiting element. Compared with, for example, the conventional current limiting device disclosed in Patent Document 1, a cryostat having a diameter at least twice as large as the coil diameter of the current limiting element is required. Can be realized.

  Although the present embodiment shows an example in which the superconducting current limiting device is applied to a three-phase circuit, the present invention can also be applied to a two-phase circuit or a multiphase circuit having four or more phases. In a two-phase electric circuit, two non-inductive current limiting elements having different diameters are arranged concentrically to constitute a superconducting current limiting device. In a four-phase circuit, four non-inductive current limiting elements having different diameters are arranged concentrically to constitute a superconducting current limiting device. Hereinafter, the superconducting current limiting device is configured in the same manner to a multiphase electric circuit. In addition, a two-phase circuit is a circuit having a phase difference of 180 degrees, a four-phase circuit is a circuit having a phase difference of 90 degrees, and a five-phase circuit is a circuit having a phase difference of 72 degrees. Can do.

(Second Embodiment)
FIG. 2 is a perspective view of a superconducting current limiting device according to the second embodiment of the present invention.
As shown in FIG. 2, the superconducting current limiting device of this embodiment has a configuration in which a U-phase non-inductive current limiting element 11, a V-phase non-inductive current limiting element 12, and a W-phase non-inductive current limiting element 13 are arranged on the same axis. It has become. Compared to the first embodiment of FIG. 1, the configuration is longer in the axial direction. For example, when it is necessary to preferentially reduce the radial length over the axial length, the present embodiment is more effective than the first embodiment of FIG. 21 is a superconducting wire, 22 is a winding frame, and 23a and 23b are electrodes.

  In the case of the present embodiment, the U-phase non-inductive current limiting element 11, the V-phase non-inductive current limiting element 12, and the W-phase non-inductive current limiting element 13 can be made equal in size. Compared with a current limiting device, a significant reduction in size can be realized.

  Although the present embodiment shows an example in which the superconducting current limiting device is applied to a three-phase circuit, the present invention can be easily applied to a two-phase circuit or a multiphase circuit having four or more phases. In a two-phase electric circuit, two non-inductive current limiting elements are arranged coaxially to constitute a superconducting current limiting device. In a four-phase circuit, four non-inductive current limiting elements are arranged coaxially to constitute a superconducting current limiting device. Hereinafter, the superconducting current limiting device is configured in the same manner to a multiphase electric circuit. In addition, a two-phase circuit is a circuit having a phase difference of 180 degrees, a four-phase circuit is a circuit having a phase difference of 90 degrees, and a five-phase circuit is a circuit having a phase difference of 72 degrees. Can do.

(Third embodiment)
3A and 3B are configuration diagrams of a third embodiment of the present invention, in which FIG. 3A is a plan view of a superconducting current limiting device, and FIG. 3B is a configuration of the superconducting current limiting device of FIG. It is a perspective view of the element coil to do.

  As shown in FIG. 3, the superconducting current limiting device of this embodiment divides the non-inductive current limiting elements of the U phase, the V phase, and the W phase into a plurality of element coils, and the non-inductive current limiting of each phase. The element is configured by connecting a plurality of element coils in series or in parallel. In FIG. 3, the U-phase non-inductive current limiting element has two element coils 31a and 31b, the V-phase non-inductive current limiting element has two element coils 31c and 31d, and the W-phase non-inductive current limiting element has two elements. The coils 31e and 31f are included. Then, the non-inductive element coils 31a and 31b, the non-inductive element coils 31c and 31d, and the non-inductive element coil 31e are arranged in a uniform configuration around the coil axis of one non-inductive element coil 31f. Here, three sets of the same number of non-inductive element coil groups are configured by any combination of non-inductive element coils, but in the figure, one set of element coils 31a and 31b, one set of element coils 31c and 31d, one element coil 31e, 31f constitutes one set, and non-inductive element coils in each set are electrically connected in series, and non-inductive element coil groups connected in series in each set are respectively connected to each phase of the three-phase circuit. It is connected.

  By dividing the non-inductive current limiting element into a plurality of element coils in this way, the ineffective space when arranging the coils can be further reduced. As a result, it is possible to reduce the size of the cryostat.

  Here, the non-inductive coils in each group are electrically connected in series, but instead of this configuration, the non-inductive coils in each group are electrically connected in parallel. Also good. Furthermore, it is good also as a series-parallel structure which connected the some noninductive coil electrically in series and in parallel by each group structure. Even with such an arrangement, the same effect as described above can be obtained.

  4A and 4B show a superconducting current limiting device according to the present invention, which is a modification of the third embodiment of FIG. 3. FIG. 4A is a plan view of the superconducting current limiting device, and FIG. 2) is a perspective view of an element coil constituting the superconducting current limiting device of FIG.

  As shown in FIG. 4, in this embodiment, the U-phase non-inductive current limiting element (which may be replaced with a V-phase or a W-phase) arranged at the center is composed of one element coil 33. . On the other hand, a plurality of V-phase and W-phase element coils surrounding the periphery are formed. That is, an even number of element coils are arranged in a uniform configuration with one element coil 33 as the center, and the even number of element coils constitute two sets of the same number of element coil groups. Two sets of element coil groups are connected to the two-phase electric circuit among the three-phase electric circuits, respectively, and one element coil 33 arranged at the center is connected to the remaining one-phase electric circuit. FIG. 4 shows a case in which three V-phase element coils are formed of 32a, 32b, and 32c, and three W-phase element coils are respectively formed of 32d, 32e, and 32f. This is an example showing that the U phase, the V phase, and the W phase only need to be configured in a non-inductive manner and do not necessarily have the same shape.

  As described above, the non-inductive current limiting element is divided into a plurality of element coils, so that the ineffective space when the coils are arranged is further reduced. As a result, the cryostat can be miniaturized.

(Fourth embodiment)
FIG. 5 is a perspective view of a superconducting current limiting device according to a fourth embodiment of the present invention.
As shown in FIG. 5, the superconducting current limiting device of the present embodiment has a U-phase non-inductive current limiting element 11, a V-phase non-inductive current limiting element 12, and a W-phase non-inductive current limiting element 13 arranged in a straight line. It has a configuration. In addition, 21 is a superconducting wire, 22 is a winding frame, and 23a and 23b are electrodes.

  In the configuration of the superconducting current limiting device according to the present embodiment, a coil that constitutes the superconducting current limiting element is provided with multiple non-inductive element coils that constitute a superconducting current limiting element excluding one superconducting current limiting element. A non-inductive element coil of multiples of 3 is arranged in a uniform configuration with the coil axis of the same as the center, and two sets of non-inductive element coil groups of the same number are configured by any combination of non-inductive element coils. Non-inductive element coils in which each non-inductive element coil in each group is electrically connected in series, parallel, or series-parallel, and each group is connected in series, parallel, or series-parallel. Are connected to the two-phase circuit among the three-phase circuits, and the superconducting current limiting element is connected to the remaining one-phase circuit. When the cryostat is cylindrical, the configuration is not necessarily optimal. However, for example, when the cryostat has a rectangular parallelepiped shape, it is particularly effective for realizing miniaturization.

(Fifth embodiment)
6A and 6B are configuration diagrams of a superconducting current limiting device according to a fifth embodiment of the present invention. FIG. 6A is a plan view of the superconducting current limiting device, and FIG. FIG. 4C is a perspective view of the V-phase current limiting coil of FIG. 1A, and FIG. 1D is a perspective view of the W-phase current limiting coil of FIG. is there.

  As shown in FIG. 6, the superconducting current limiting device of this embodiment differs from the first embodiment of FIG. 1 in that a U-phase current limiting coil 41, a V-phase current limiting coil 42, and a W-phase current limiting coil 43. Each element is not a non-inductive configuration but an induction coil.

  In this embodiment, considering that the current phases of the U phase, the V phase, and the W phase are shifted by 120 °, the U phase, the V phase, and the W phase so that the coil center magnetic field at each moment becomes almost zero. The shape and the number of turns of the phase coil are set, and it is configured to be apparently non-inductive when the three-phase current is applied. 21 is an induction coil, 22 is a winding frame, and 23a and 23b are electrodes.

  According to the present embodiment, for example, when an accident current flows in the U phase and the U phase coil is quenched, the non-inductivity described above is lost, and inductance occurs in the V phase and the W phase. There is also an effect that the current limiting effect automatically appears in the phase.

(Sixth embodiment)
FIG. 7: is a block diagram of the superconducting current limiting device of the 6th Embodiment of this invention, The figure (a) is a perspective view of the conductor structure of a superconducting current limiting device, The figure (b) is the figure (a) (C) is a partial side view of a conductor different from FIG. (A), FIG. (D) is a conductor different from FIG. (B) and (c). It is a partial side view.

  As shown in FIG. 7A and FIG. 7B, the superconducting current limiting element (superconducting collective conductor) 51 of the superconducting current limiting device of this embodiment is composed of three superconducting wires (52a, 52b, 52c). It is composed of an aggregate conductor, and each superconducting wire is electrically insulated by an insulator 53. The three superconducting wires are connected to the U phase, V phase, and W phase of the system, respectively. 21 is an induction coil, 22 is a winding frame, and 23a and 23b are electrodes.

  According to this embodiment, similarly to the fifth embodiment, when a three-phase current is applied, the magnetic field generated by the coil is canceled, and the inductance of the coil can be ideally zero. In addition, for example, when an accident current flows in the U phase and the U phase coil is quenched, the non-inductivity described above is lost, and inductance occurs in the V phase and the W phase. There is an effect that the effect appears automatically.

  Further, the superconducting current limiting element (superconducting collective conductor) 51A of the first modification of the superconducting current limiting device of the present embodiment has a U phase composed of superconducting wires of 54a and 54b as shown in FIG. 7C. The V phase is composed of superconducting wires 54c and 54d, and the W phase is composed of superconducting wires 54e and 54f. The phases are electrically insulated by an insulator 53.

  Furthermore, the superconducting current limiting element (superconducting collective conductor) 51B of the second modification of the superconducting current limiting device of the present embodiment is composed of superconducting wires of 54a and 54b as shown in FIG. 7 (d). The V phase is composed of superconducting wires 54c and 54d, and the W phase is composed of superconducting wires 54e and 54f. The superconducting wires are electrically insulated by an insulator 53.

  By configuring the superconducting current limiting element of the superconducting current limiting device as in the first and second modified examples, the coil can be used when a three-phase current is applied as in the sixth embodiment. The magnetic field generated by is canceled and the inductance of the coil can ideally be zero. In addition, for example, when an accident current flows in the U phase and the U phase coil is quenched, the non-inductivity is lost, and inductance is generated in the V phase and the W phase. There is an effect that the effect appears automatically.

BRIEF DESCRIPTION OF THE DRAWINGS It is a block diagram of the 1st Embodiment of this invention, the figure (a) is a top view of a superconducting current limiting device, the figure (b), the figure (c), and the figure (d) are the figures (a) ) Are perspective views of U-phase, V-phase, and W-phase non-inductive current limiting elements. The block diagram of the 2nd Embodiment of this invention. It is the block diagram of the 3rd Embodiment of this invention, The figure (a) is a top view of a superconducting current limiting device, The figure (b) is the element coil which comprises the superconducting current limiting device of the same figure (a). Perspective view. FIG. 3A is a modification of the third embodiment of FIG. 3, in which FIG. 3A is a plan view of the superconducting current limiting device, and FIG. 3B is an element coil constituting the superconducting current limiting device of FIG. Perspective view. The perspective view of the 4th Embodiment of this invention. It is a block diagram of the 5th Embodiment of this invention, The figure (a) is a top view of a superconducting current limiting device, The figure (b), the figure (c), and the figure (d) are the figures (a) ) Is a perspective view of each element coil constituting the U-phase, V-phase, and W-phase superconducting current limiting elements. It is a block diagram of the superconducting current limiting device of the 6th Embodiment of this invention, The figure (a) is a perspective view of the conductor structure of a superconducting current limiting device, The figure (b) is the conductor of the figure (a). FIG. 3C is a partial side view of a conductor different from FIG. 1A, and FIG. 4D is a partial side view of a conductor different from FIG. 2B and FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... U-phase non-inductive current limiting element, 12 ... V-phase non-inductive current limiting element, 13 ... W-phase non-inductive current limiting element, 21 ... Superconducting wire, 22 ... Winding frame, 23a, 23b ... Electrode, 31a, 31b ... Element coil of U-phase non-inductive current limiting element, 31c, 31d... Element coil of V-phase non-inductive current limiting element, 31e, 31f... Element coil of W-phase non-inductive current limiting element, 32a, 32b, 32c. Element coil of induction current limiting element, 32d, 32e, 32f ... Element coil of V phase non-inductive current limiting element, 33 ... Element coil of W phase non-inductive current limiting element, 41 ... U phase current limiting coil, 42 ... V phase Current limiting coil, 43 ... W phase current limiting coil, 51, 51A, 51B ... Superconducting current limiting element, 52a ... U phase superconducting wire, 52b ... V phase superconducting wire, 52c ... W phase superconducting wire, 53 ... insulation Body, 54a, 54b ... superconducting wire for U phase, 54c, 54d ... for V phase Conductive lines, 54e, 54f ... W-phase superconducting wire.

Claims (8)

  A superconducting current limiting element characterized in that a superconducting current limiting element is inserted in each of the electric paths of the plurality of phases, and each of the superconducting current limiting elements is composed of a non-inductive winding coil and is coaxially arranged. apparatus.   A superconducting current limiting element is inserted in each of the electric paths of the plurality of phases, each superconducting current limiting element is composed of a non-inductive winding coil, and the coil axes of all superconducting current limiting elements arranged coaxially are the same. A superconducting current limiting device characterized by being arranged in a straight line.   The superconducting current limiting device according to claim 1 or 2, wherein the multi-phase electric circuit is a three-phase electric circuit.   In a three-phase current limiting superconducting current limiting device in which a superconducting current limiting element is inserted in each phase constituting a three-phase circuit, the number of non-inductive element coils constituting the superconducting current limiting element is a multiple of three. In the non-inductive element coil, the non-inductive element coils other than the non-inductive element coil are arranged in a uniform configuration around the coil axis of one non-inductive element coil, and any non-inductive The same number of non-inductive element coil groups is composed of a combination of element coils, and non-inductive element coils in each group are electrically connected in series or in parallel, and each group is connected in series or in parallel. A nonconducting element coil group is connected to each phase of a three-phase circuit, respectively.   In a three-phase current limiting superconducting current limiting device in which a superconducting current limiting element is inserted in each phase constituting a three-phase circuit, the number of non-inductive element coils constituting the superconducting current limiting element is a multiple of three. In the non-inductive element coil, the non-inductive element coils excluding the non-inductive element coil are arranged in a uniform configuration around the coil axis of one non-inductive element coil, and any non-inductive element coil is provided. Three sets of non-inductive element coil groups of the same number are formed by the combination of inductive element coils, and non-inductive element coils in each set are electrically connected in series and in parallel in each set, and in each set A superconducting current limiting device, wherein non-inductive element coil groups connected in series and parallel are connected to each phase of a three-phase circuit.   In a superconducting current limiting device having a three-phase current limit, in which a superconducting current limiting element is inserted in each phase constituting a three-phase circuit, one superconducting current limiting element and the one superconducting current limiting element Including an even number of non-inductive element coils constituting the superconducting current limiting element except for the coil, and the even number of non-inductive element coils arranged in a uniform configuration around the coil axis of the coil constituting the superconducting current limiting element. In addition, two sets of non-inductive element coil groups of the same number are formed by a combination of arbitrary non-inductive element coils arranged in this equal configuration, and the non-inductive element coils in each group are electrically connected in series or in parallel. Or a non-inductive element coil group connected in series, parallel, or series-parallel in each group is connected to a two-phase circuit among the three-phase circuits, and The superconducting current limiting element is for the remaining one phase Superconducting current limiting device, characterized in that connected to the road.   In a three-phase current limiting superconducting current limiting device in which a superconducting current limiting element is inserted in each phase constituting a three-phase circuit, each of the superconducting current limiting elements is composed of an induction winding coil and coaxially concentric The superconducting current limiting device is characterized in that the value of the central magnetic field generated per unit energization current value generated by each induction winding coil is substantially the same value. In a superconducting current limiting device having a three-phase current limiting element in which a superconducting current limiting element is inserted in each phase constituting a three-phase electric circuit, the coil constituting the superconducting current limiting element is a multiple of three superconducting currents. The conductor is wound with an assembly conductor composed of an insulator inserted at a position where the superconducting wire group is divided into three equal parts, and each divided conductor of the aggregate conductor divided into three equal parts is connected to a three-phase electric circuit. A superconducting current limiting device.

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