JP5108539B2 - Intermediate connection structure of superconducting cable - Google Patents

Description

  The present invention relates to an intermediate connection structure for a superconducting cable for supporting a connecting portion between cable cores of a superconducting cable in a refrigerant container. The connecting portion between the cable cores has a different core structure and becomes a so-called inflection point, but a cylindrical protective cover for storing and supporting the connecting portion between the cable cores in a stable state is disposed in the refrigerant container. The present invention relates to an intermediate connection structure of a superconducting cable.

  In the case of an OF cable, the connection structure between conductors in a power transmission line is shown in FIG. 4 (see, for example, Patent Document 1). In this example, the cable conductors 32 and 32 exposed from the insulating paper 31 and 31 stripped of the OF cable in the junction box main body case 36 are opposed to the epoxy unit 33 whose side surfaces are tapered. They are connected via an integrated central conductor 34. A reinforcing insulating paper 35 is wound around the connection portion and the outer periphery of the epoxy unit 33, and a ring-shaped flange portion 33 a formed at the center portion of the epoxy unit 33 is attached to the mounting flange 36 a facing the connection box body case 36. , 36a, the connection portions of the cable conductors 32, 32 are supported in a fixed state in the junction box main body case 36. The inner space 37 of the junction box body case 36 is filled with insulating oil, and the connection portions of the cable conductors 32 and 32 are kept in an oil-immersed state.

Such a basic structure of the connection part structure of conductors in which an epoxy unit is provided in the junction box main body case is also adopted for a superconducting cable (see, for example, FIG. 3 of Patent Document 2). In the case of a superconducting cable, the internal space of the junction box main body case is filled with a refrigerant such as liquid nitrogen, and the superconducting conductors facing each other via a connection sleeve are formed at both ends of the central conductor integrated with the epoxy unit. Connected together. A hollow portion for inserting the former and the superconducting conductor is formed on one end side of the connection sleeve, and a hollow portion for inserting the center conductor is formed on the other end side, and the former is compressed and connected in the hollow portion. The superconducting conductor is conductively connected to the connection sleeve, for example, by solder connection. The connection sleeve and the central conductor are conductively connected via a multiband made of, for example, a conductive elastic member.
JP 7-245863 A JP 2007-28710 A

  In the conductor connection structure using the conventional epoxy unit as described above, there is a problem that the structural dimension of the entire connection portion is increased. Further, there is a problem that the conductor resistance of the connection portion is high. That is, first, the solder connection portion that electrically connects the superconducting conductor and the connection sleeve has a higher resistance than the superconducting conductor. Next, the connection sleeve itself made of copper had a high resistance. Also, the central conductor formed of aluminum alloy or the like has a high resistance. Further, since the connection sleeve and the central conductor are conductively connected in a multi-faceted elastic contact state via a multiband, the connection portion has a high resistance.

  In particular, in the conductor connection structure of a three-core collective superconducting cable, it is necessary to combine the structures of the connection portions, and there is a difficulty in that the structure of the entire connection portion becomes too large. For example, when an intermediate connection part for a superconducting cable is configured to increase the capacity of an existing power transmission line system, there is a concern that the size becomes enormous and cannot be stored in a manhole.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an intermediate connection structure for a superconducting cable that is compact and can cope with an increase in capacity.

The intermediate connection structure of the superconducting cable of the present invention is an intermediate connection structure of a superconducting cable for supporting the connection part between the cable cores of the superconducting cable in the refrigerant container,
A cylindrical protective cover that stores and supports the connection portion between the cable cores is disposed in the refrigerant container.

  According to such a configuration, since the connection portion between the cable cores that are mechanically inflection points is housed and supported by the cylindrical protective cover, the load is applied in a state in which the connection portion is constrained so as not to bend. It can be dispersed evenly and supported in a stable state. Thereby, the bulky epoxy unit for supporting the connection part of cable cores like the conventional one becomes unnecessary, and the connection part structure can be made compact. In addition, since the support state of the connection portion between the cable cores is stabilized, for example, if the formers are compression-connected with a connection sleeve, a connection structure in which the superconducting conductors are directly connected to each other via the superconducting wire becomes possible. . Thereby, the conductor resistance in a connection part can be reduced significantly and energization of a large current is attained.

  The protective cover may be supported in a fixed state in the refrigerant container. If it does in this way, propagation of the scale bug phenomenon (longitudinal buckling) which generate | occur | produces in a cable resulting from the shrinkage | contraction etc. accompanying cooling with a refrigerant | coolant can be blocked | prevented by the connection part of cable cores.

  The protective cover may be removably supported in the refrigerant container by bolt fastening. In this way, the protective cover can be easily assembled and disassembled, and non-defective products can be collected.

  The protective cover may be removably supported in the refrigerant container by concave and convex fitting. In this way, the protective cover can be easily assembled and disassembled, and non-defective products can be collected.

  At least one end side of the protective cover may be configured to be extendable and contractible in the cylinder axis direction via a bellows structure. In this way, since the attachment corresponding positions of both ends of the cable with respect to the corrugated pipe, which is a heat insulating pipe of the cable, can be adjusted at the time of the assembling work on site, the assembling work becomes easy.

  The protective cover may be slidably supported in the container axial direction within the refrigerant container. In this way, the stress can be absorbed by sliding the protective cover even if stress is applied to the connection portion in the cable axial direction due to shrinkage caused by cooling by the refrigerant during use. Stress concentration can be avoided. Further, since it is not necessary to regulate the position in the axial direction of the protective cover with respect to the refrigerant container, the assembly work at the site is facilitated.

  The protective cover may be supported by a slidable member or a rotating member. For example, if the protective cover is supported by a sliding member such as Teflon (registered trademark) or a roller, the resistance during sliding can be reduced.

  The protective cover may be formed of any one of copper, copper alloy, aluminum, or aluminum alloy. As described above, when the protective cover is formed of a metal material, for example, by taking a potential bond to the refrigerant container, the floating electrode can be prevented. Also, the required strength can be obtained.

  The protective cover may be formed of an electrically insulating material. In this case, since the protective cover is not charged, it is not necessary to take a potential bond. For example, if it is formed of FRP or the like, the production and assembly are facilitated.

  The protective cover may be formed in a half crack shape. By forming the whole or a part of the protective cover into a half-break shape, the assembling / disassembling work of the protective cover is facilitated, and the non-defective product can be collected.

  The protective cover may be divided in the axial direction. In this way, the protective cover can be easily assembled and disassembled, and non-defective products can be collected.

  The protective cover may be formed such that the central portion in the axial direction is larger in diameter than both side portions. If it does in this way, the connection part of the cable cores which become bulky can be stored in the axial center part well.

  The formers drawn from the cable cores connected to each other are compressed and connected via a connection sleeve, and the superconducting conductors are conductively connected to each other by a superconducting wire arranged vertically on the connection sleeve. You may do it. If it does in this way, cable cores will be connected in the state where required tensile strength was ensured by compression connection of formers via a connection sleeve. And the conductor resistance in a connection part decreases by the connection of the superconducting conductors via a superconducting wire. Since such a connection portion is housed and supported by the cylindrical protective cover, it is not necessary to use a bulky epoxy unit as in the prior art, and the connection portion structure can be significantly reduced in size.

  The superconducting cable may be a single-core superconducting cable having a single cable core, and a connecting portion between the single-core cable cores may be housed and supported in the protective cover. If such an intermediate connection structure is applied to the connection between single cable cores, compactness can be achieved, and the conductor resistance at the connection portion can be reduced, thereby increasing the capacity. Can be dealt with.

  The superconducting cable is a multi-core batch type superconducting cable having a plurality of cable cores, and the connecting portions of the plurality of cable cores are collectively stored and supported in the protective cover. Good. If such an intermediate connection structure is applied to a multiconductor batch type superconducting cable such as a 3-core batch type, compactness can be achieved, and conductor resistance at the connection portion can be reduced, It can cope with large capacity. Further, the repulsion between the cable cores when a short-circuit current flows can be suppressed by the protective cover.

  In the intermediate connection structure of the superconducting cable of the present invention, the connection portion between the cable cores that are mechanically inflection points is housed and supported by the cylindrical protective cover, so that the connection portion is constrained so as not to bend. As described above, the load can be evenly dispersed and supported in a stable state. Thereby, the conventional bulky epoxy unit is unnecessary, and the connection part structure can be remarkably downsized. In addition, since the support state of the connection part between the cable cores is stabilized, for example, a connection structure in which the formers are compression-connected with a connection sleeve and the superconducting conductors are directly connected to each other via the superconducting wire is possible. Become. Thereby, the conductor resistance in a connection part can be reduced significantly and energization of a large current is attained.

  Hereinafter, an intermediate connection structure for a superconducting cable according to an embodiment of the present invention will be described in detail with reference to the drawings.

[Embodiment 1]
FIG. 1 is a half sectional view of an intermediate connection structure of superconducting cables, and FIG. 2 is a half sectional view showing a connection structure between superconducting conductors. In this intermediate connection structure, for example, a cylindrical protective cover 3 that accommodates and supports a connection portion J between the cable cores 2 and 2 of a three-core collective superconducting cable 1 is held in a fixed state in the refrigerant container 4. . The protective cover 3 is such that the load can be evenly distributed and supported in a stable state as a state in which the connection portion J between the cable cores 2 and 2 that are mechanically inflection points is restrained from being bent. It is set to length. With such a configuration, the support state of the connection portion J between the cable cores 2 and 2 is stabilized. Therefore, in the connection portion J, for example, as shown in FIG. And the superconducting conductors 9 and 9 can be directly connected to each other via the superconducting wire 10 disposed vertically on the connecting sleeve 8. That is, the required connection strength can be ensured by compressing and connecting the formers 7 and 7 exposed from the stripped insulating paper 6 via the connection sleeve 8. Therefore, the conventional bulky epoxy unit is not required, and the connecting portion structure between the cable cores 2 and 2 can be remarkably reduced in size. Further, the superconducting conductors 9 and 9 are connected to each other through the superconducting wire 10 having a low resistance without using a central conductor or a multiband formed of a high-resistance aluminum alloy or the like that has been conventionally used. The conductor resistance can be significantly reduced. Thereby, it is possible to energize a large current. 2 is housed in the protective cover 3 in a state in which a reinforcing insulating paper (not shown) is wound for each cable and three cores are bundled together.

  The other configuration will be described. The refrigerant container 4 for storing the protective cover 3 is formed into a cylindrical shape by, for example, a stainless material, so as to facilitate assembly / disassembly operations, and to enable good product recovery. In the cylinder axis direction, the center portion 4a and the both side portions 4b are divided. Each of the portions 4a and 4b is formed in a half crack shape, and the central portion 4a is further divided into left and right at the center. Each divided part is assembled by welding or the like. The central portion 4a is formed to be larger in diameter than both side portions 4b, and three support brackets 11 each having an elongated bolt hole for fixing the protective cover 3 in four axial directions are provided at intervals of 120 °. Is provided. A corrugated tube 12 containing a three-core cable core 2 is inserted and fixed in a sealed state at the ends of the both side portions 4b, and on both sides in the outer diameter direction from the corrugated tube 12 via a hose. A pair of vacuum port attachment ports 13 for inserting a vacuum port (not shown) to be drawn out is provided, and a refrigerant injection port 14 is provided on the outer periphery. A hanging metal fitting e with a female thread is provided on the outer periphery of each portion 4a, 4b.

  The protective cover 3 that accommodates and supports the connection portion J between the cable cores 2 and 2 is formed into a cylindrical shape by, for example, copper, copper alloy, aluminum, aluminum alloy, or the like. In order to enable the collection of non-defective products, it is divided into a central portion 3a and both side portions 3b in the cylinder axis direction. Each of the portions 3a and 3b is formed in a half-crack shape, and both end portions 3b are connected to the central portion 3a via a telescopic bellows structure 5, and the central portion 3a is laterally left and right in the center. It is divided. Each divided part is assembled by welding or the like. Three support brackets 15 with elongated bolt holes are provided at intervals of 120 ° at four axial positions on the outer periphery of the protective cover 3 corresponding to the support bracket 11 of the refrigerant container 4. In FIG. 1, the correspondence between the support brackets 11 and 15 is enlarged and displayed at different angles.

  With such a configuration, after positioning the protective cover 3 on the refrigerant container 4, the support bracket 15 of the protective cover 3 is bolted in correspondence with the support bracket 11 of the refrigerant container 4, so that the protective cover 3 is It can be detachably fixed to the container 4. The end portions of both end portions 3b are connected to the end portions of the inner pipe of the corrugated pipe 12 inserted into the refrigerant container 4, so that the refrigerant can be introduced into the protective cover 3, and the hose from the corrugated pipe 12 A vacuum port (not shown) pulled out through is inserted into the vacuum port attachment port 13. In the assembly work at the site, it is preferable that the remaining part of the refrigerant container 4 is assembled by welding or the like after the work of fixing the protective cover 3 to the refrigerant container 4 is completed. Further, instead of bolt fastening, the protective cover 3 may be detachably supported by the refrigerant container 4 by uneven fitting.

  In such a configuration, first, since the central portion 3a of the protective cover 3 is formed to have a diameter larger than that of the both side portions 3b, the connecting portion J between the cable cores 2 and 2 that are bulky together is formed in the central portion. It can be stored well in 3a. And the connection part J of the 3 core cable cores 2 and 2 pulled out from the corrugated pipe | tubes 12 and 12 fixed to the both ends of the refrigerant | coolant container 4 is not restrained mechanically, but in the protective cover 3 It is stored and supported in a lump so that bending does not occur with the load evenly distributed. Accordingly, the axial stress acting on the connection portion J due to thermal fluctuation is absorbed by the expansion and contraction absorption margin caused by the twisting of the three cores of the cable core 2, and the connection portion J that becomes the inflection point. Bending deformation is prevented. Thus, in the intermediate connection structure of the superconducting cable in which the protective cover 3 is supported in the refrigerant container 4 in a fixed state, propagation of the scale bug (vertical buckling) that occurs in the cable core 2 due to cooling of the refrigerant or the like. Can be prevented. Further, the repulsion of each cable core 2 when a short-circuit current flows can be suppressed by the protective cover 3. Since both end portions 3b of the protective cover 3 are configured to be extendable in the cylinder axis direction with respect to the central portion 3a via the extendable bellows structure 5, both ends with respect to the corrugated tube 12 are assembled at the site. Since the corresponding position of the part 3b can be adjusted, the assembling work becomes easy. Note that the protective cover 3 is prevented from being a floating electrode by forming a potential bond to the refrigerant container 4, and a stable electric field can be formed around the connection portion J. Further, instead of the metal material, the protective cover 3 may be formed of an electrically insulating material such as FRP having good moldability. In that case, it is not necessary to ground, manufacturing and assembling becomes easy, and cost reduction can be realized.

[Embodiment 2]
FIG. 3 is a half sectional view of the protective cover in the intermediate connection structure of the superconducting cable. In this example, the protective cover 3 is supported in the refrigerant container 4 so as to be slidable in the container axial direction. The protective cover 3 is formed into a cylindrical shape by, for example, copper, copper alloy, aluminum, aluminum alloy, or the like, and in order to facilitate assembly / disassembly operations and to enable non-defective product collection, The central portion 3a and both side portions 3b are divided into the half portions, and the divided portions are assembled by welding or the like. The central part 3a is formed larger in diameter than both side parts 3b, and a connection part between cable cores as shown in FIG. 2 is accommodated and supported in the central part 3a. Three support brackets 16 each including a semispherical piece member 16a made of Teflon are provided at intervals of 120 ° at four axial positions on the outer periphery of the protective cover 3. The point that each of the top members 16a is in sliding contact with the inner surface of the refrigerant container 4 so that the protective cover 3 is slidably supported with little resistance in the centered state with respect to the refrigerant container 4. Different. Instead of the top member 16a, the protective cover 3 may be supported by a rotating member such as a roller. About another point, it is comprised similarly to previous embodiment.

  According to such a configuration, as in the previous embodiment, the protective cover 3 is configured so that the load is evenly constrained so as not to cause bending at the connection portion between the cable cores that are dynamically inflection points. The length is set such that it can be dispersed and supported in a stable state. With such a configuration, since the support state of the connecting portion between the cable cores is stabilized, for example, as shown in FIG. 2, in the connecting portion J, the formers 7 formed by twisting copper wires are connected to the connecting sleeve 8. And the superconducting conductors 9 and 9 can be directly connected to each other via the superconducting wire 10 arranged vertically on the connection sleeve 8. Therefore, the conventional bulky epoxy unit is not required, and the connecting portion structure between the cable cores 2 and 2 can be remarkably reduced in size. In addition, in the connecting portion J, the superconducting conductors 9 and 9 are connected to each other through the superconducting wire 10 having a low resistance without using a central conductor or a multi-band formed of a conventionally used high resistance aluminum alloy or the like. Since the conductive connection is made, the conductor resistance can be remarkably reduced. Thereby, it is possible to energize a large current. Since the protective cover 3 is slidably supported in the cylinder axis direction with respect to the refrigerant container 4, the cable shaft is connected to the connection portion J due to contraction of the cable core 2 accompanying cooling with the refrigerant during operation. Even if stress is applied in the direction, the stress can be absorbed by sliding the protective cover 3, so that stress concentration at the connection portion J can be avoided. Such an intermediate connection structure can also be applied to a three-core type cable core, but is suitable for a single-core superconducting cable with little axial expansion / contraction allowance. It should be noted that the present invention is not limited to the embodiment, and can be freely improved, changed, etc. as necessary without departing from the gist of the invention.

  Since the intermediate connection structure of the superconducting cable of the present invention can be made compact and can cope with an increase in capacity, it can be suitably applied to an increase in capacity of a large-capacity transmission line system or an existing transmission line system.

It is a half sectional view of an intermediate connection structure of a superconducting cable according to an embodiment of the present invention. It is a half sectional view showing a connection structure between the superconducting conductors. The protection cover in the intermediate connection structure of the superconducting cable which concerns on the same another embodiment is shown, (a) is a side view of a protection cover, (b) is the front view. It is a half sectional view of an intermediate connection structure of a superconducting cable using a conventional epoxy unit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Superconducting cable 2 Cable core 3 Protective cover 3a Center part 3b Both side part 4 Refrigerant container 4a Center part 4b Both side part 5 Bellows structure 6 Insulating paper 7 Former 8 Connection sleeve 9 Superconducting conductor 10 Superconducting wire 11 Support bracket 12 Corrugated pipe 13 Vacuum port Mounting port 14 Refrigerant inlet 15 Support bracket 16 Support bracket 16a Top member 31 Insulating paper 32 Cable conductor 33 Epoxy unit 33a Flange part 34 Central conductor 35 Reinforced insulating paper 36 Junction box body case 36a Mounting flange 37 Internal space J Connection part e Hanging Lowering bracket

Claims (7)

An intermediate connection structure of a superconducting cable for supporting a connection part between the cable cores of the superconducting cable in a refrigerant container,
A tubular protective cover to retract and support the connection portion between the cable core, the so slidably supported in the axial direction of the container in the refrigerant container, wherein arranged to Rukoto into the coolant container Intermediate connection structure for superconducting cables. The intermediate connection structure for a superconducting cable according to claim 1 , wherein the protective cover is supported by a sliding member or a rotating member. 3. The superconducting cable intermediate connection structure according to claim 1, wherein the protective cover has a central portion in the axial direction larger in diameter than both side portions. 4.   The intermediate connection structure for a superconducting cable according to any one of claims 1 to 3, wherein the protective cover is formed of an electrically insulating material.   The intermediate connection structure for a superconducting cable according to any one of claims 1 to 4, wherein the protective cover is formed in a half-break shape. The formers drawn from the cable cores connected to each other are compressed and connected via a connection sleeve, and the superconducting conductors are conductively connected to each other by a superconducting wire arranged vertically on the connection sleeve. The intermediate connection structure for a superconducting cable according to any one of claims 1 to 5.
Sequential structure.   The superconducting cable is a multi-core batch type superconducting cable having a plurality of cable cores, and the connection portions of the plurality of cable cores are collectively stored and supported in the protective cover. The intermediate connection structure of a superconducting cable according to any one of claims 1 to 6.

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