JP4273525B2 - Terminal structure of superconducting equipment - Google Patents

Description

  The present invention relates to a terminal structure of a superconducting device that is arranged between a room temperature side and a cryogenic side and enables large-capacity power transmission by a superconducting device such as a superconducting cable.

  As a terminal structure of a superconducting device, for example, a structure shown in FIG. 5 is known (see Patent Document 1). FIG. 5 is a schematic configuration diagram showing a terminal structure of a conventional superconducting device. In this terminal structure, the end portion of the superconducting cable and the end portion of the normal conducting conductor on the room temperature side are connected by the conductor portion. For example, as shown in FIG. 5, there is one in which a connecting conductor 210 is connected to an end portion of a superconducting cable, and an end portion of the connecting conductor 210 is connected to a conductor portion 220 via a joint portion 270.

  This terminal structure includes a refrigerant tank 230 in which the connection conductor 210 and one end of the conductor portion 220 (connection side to the connection conductor 210) are disposed, a vacuum container 240 that covers the refrigerant tank 230, and the room temperature of the vacuum container 240. And a soot tube 250 protruding from the side.

  The connection conductor 210 and the conductor portion 220 are usually formed of a normal conductive material such as copper or aluminum, and the conductor portion 220 is disposed from the refrigerant tank 230 through the vacuum vessel 240 to the soot tube 250. Note that a heat insulating layer is formed around the refrigerant tank 230 by the vacuum container 240. The conductor part 220 is disposed in a bushing 260 made of an insulating material such as FRP.

  The refrigerant tank 230 is provided with a joint portion 270 and filled with a liquid refrigerant such as liquid nitrogen that cools the connecting conductor 210 connected to the joint portion 270 and the low temperature side of the conductor portion 220. The soot tube 250 accommodates the other end side of the conductor portion 220 and is filled with an insulating fluid such as insulating oil.

JP 2002-238144 JP

  The superconducting cable is cooled to a very low temperature (for example, about 77 K) with a liquid refrigerant such as liquid nitrogen, thereby reducing the resistance by making the superconducting conductor portion in a superconducting state and enabling large current transmission. On the other hand, since the power equipment outside the superconducting cable line is used at room temperature, power is supplied to the power equipment by drawing current from the cryogenic temperature to the room temperature at the end of the superconducting cable. Electric power is supplied to the superconducting cable side.

  However, since the outside of the superconducting cable line is at room temperature, current cannot be drawn out in the superconducting state, and current is drawn out to the room temperature side through the cooled connection conductor 210 and conductor part 220 made of normal conducting material. I am doing so.

  Therefore, a large current is passed through the connecting conductor 210 and the conductor portion 220 that connect the superconducting cable and the room temperature side in order to supply electric power equivalent to that of the superconducting cable to the room temperature side. Therefore, by increasing the cross-sectional area (outer diameter) of the conductor portion 220 (normal conductive conductor) and cooling the conductor portion 220 with liquid refrigerant, the resistance is reduced and the normal temperature is obtained by connecting with the normal conductive conductor. It is devised to reduce the sum of the heat transfer resulting from the temperature difference between the cable side and the superconducting cable side and the Joule loss due to the current flowing through the normal conductor.

  Further, in the conventional terminal structure of a superconducting device, a penetration part is formed in the refrigerant tank 230 and the vacuum vessel 240 so as to penetrate the conductor part 220 in order to draw the conductor part 220 from the low temperature part to the normal temperature part. Since a high voltage is applied to the conductor portion 220, it is necessary to ensure insulation when penetrating the refrigerant tank 230 and the vacuum vessel 240. Therefore, the conductor portion 220 is made of an insulating member such as rubber or FRP. A conductor portion is disposed in the bushing 260.

  In the above terminal structure, the liquid refrigerant in the refrigerant tank is controlled so as to maintain the temperature of the refrigerant at a predetermined temperature by cooling with the cooling apparatus while circulating between the cooling apparatus provided outside the refrigerant tank. is doing.

  Furthermore, since a voltage is applied to the low temperature side end of the conductor part and the connection conductor in the refrigerant tank, the end of the conductor part and the connection conductor are arranged so that the electric field is below a predetermined electric field inside the refrigerant tank. Predetermined insulation is ensured by separating from the container of the refrigerant tank.

  However, in the terminal structure, since the liquid refrigerant in the refrigerant tank is circulated by the cooling device, there is a portion where the refrigerant flows in the refrigerant tank. If the refrigerant moves in the refrigerant tank due to the circulation of the refrigerant or the like, the electric insulation strength is lowered, and in some cases, there is a risk of discharging.

  In particular, when a superconducting cable is used for DC power transmission, at the terminal, electric charge is likely to accumulate in the refrigerant in the refrigerant tank, and if the refrigerant moves due to the circulation of the refrigerant, the refrigerant in the DC electric field has an electric insulation strength. There is a high possibility that the discharge will decrease.

  Accordingly, an object of the present invention is to provide a terminal structure of a superconducting device capable of preventing electric discharge by minimizing an electric field applied to a portion through which a refrigerant flows in a refrigerant tank.

  The present invention is a terminal structure of a superconducting device for connecting a superconducting cable and a room temperature side in order to transmit power between the superconducting cable and a room temperature side, for direct current power transmission or for AC power transmission. Can be used.

  The terminal structure of the superconducting device of the present invention includes a refrigerant tank in which a refrigerant is stored, a conductor part having one end arranged in the refrigerant tank and the other end arranged on the normal temperature side, and a conductor part arranged in the refrigerant tank. And a refrigerant distribution part that is formed on the outer periphery of the refrigerant distribution part and that circulates the refrigerant. And the boundary of a distribution state relaxation part and a refrigerant | coolant distribution part is earth | grounded.

  For example, one end of the conductor portion is connected to the normal conducting conductor on the room temperature side, and the other end is disposed in the refrigerant tank. The refrigerant tank side end portion of the conductor portion may be connected to a connecting conductor connected to the superconducting conductor of the superconducting cable, or may be connected to the superconducting conductor of the superconducting cable without passing through the connecting conductor. Also good.

  Note that the connection between the conductor portion and the connection conductor is preferably a braided conductor on the connection conductor side of the connection conductor, and the end portion of the braided conductor is connected to the conductor portion. Moreover, it is preferable that a conductor part is set as the structure which provides a bushing around it.

  The connecting conductor may be a superconducting conductor or a normal conducting conductor. When a normal conductive conductor is used, it is formed of a normal conductive material such as copper or aluminum. In the case of a superconducting conductor, for example, a configuration in which a wire made of a Bi2223 series superconducting material is spirally wound on a solid former, a configuration in which the same wire is wound on a hollow former, and the like can be given.

  A bushing is disposed around the conductor portion, and is provided from the inside of the refrigerant tank to a position protruding from the main body case. This bushing may be configured such that the outer periphery of the conductor portion is directly covered with an insulating material, or may be configured by casting an insulating material on the outer periphery of a metal cylinder such as stainless steel.

  Examples of the insulating material include an insulating rubber material such as ethylene propylene rubber, reinforced fiber plastic (FRP), and the like. FRP is preferable because it has higher insulation performance.

  A part of the conductor portion is disposed in the refrigerant tank. For example, a conductor part, a bushing formed around a part of the conductor part, and a connecting conductor connected to the conductor part are arranged. And the conductor part, bushing, and connection conductor which are arrange | positioned in a refrigerant tank are cooled with a refrigerant | coolant. An example of the refrigerant stored in the refrigerant tank is liquid nitrogen.

  It is preferable that the refrigerant in the refrigerant tank can be circulated and cooled by a cooling device. The cooling device is provided outside the main body case, and the refrigerant in the refrigerant tank is taken out of the main body case through the refrigerant supply passage, cooled by the cooling device, and then circulated so as to be returned to the refrigerant tank through the refrigerant supply passage. .

  In the refrigerant tank, between the wall part of the refrigerant tank and the conductor part, a circulation state relaxation part that is formed around the conductor part disposed in the refrigerant tank and that relaxes the circulation of the refrigerant, and the circulation state relaxation And a refrigerant circulation part that circulates the refrigerant. And the boundary of a distribution state relaxation part and a refrigerant | coolant distribution part is earth | grounded. The grounding can be performed, for example, by covering the outermost part of the distribution state relaxation portion with a conductive material and grounding the conductive material portion. By this grounding, the electric field applied to the refrigerant circulation part can be made smaller than the electric field applied to the circulation state relaxation part during voltage application.

  As specific configurations of the distribution state relaxation unit and the refrigerant distribution unit, for example, a partition wall that partitions the distribution state relaxation unit and the refrigerant distribution unit in the refrigerant tank is provided, and the inside of the partition wall in which the conductor unit is disposed Can be used as a distribution state relaxation part, and the outer side of a partition wall can be used as a refrigerant distribution part. In this case, the partition wall is grounded.

  This partition wall makes it difficult for the refrigerant stored in the space formed inside the partition wall to flow. With this partition wall, the electric field design may be performed only in the inner space. In addition, with this partition wall, a distribution | circulation state relaxation part can also be formed by arrange | positioning an insulator around a conductor part so that it may mention later, or using the connection cable which has an insulator as a conductor part.

  The partition wall may partition the circulation state relaxation part and the refrigerant circulation part in a communication state, or may partition the circulation state relaxation part and the refrigerant circulation part in a non-communication state. In the case of partitioning in the communication state, a communication portion that communicates the inside and the outside of the partition wall can be formed to such an extent that a refrigerant flow hardly occurs inside the partition in the coolant tank. In the case where the communication portion is formed, the refrigerant can be gradually cooled through the communication portion so that the refrigerant in the inner space hardly flows.

  The partition wall is formed of a conductor such as stainless steel, and grounding the partition wall relaxes the flow of the refrigerant in the circulation state relaxation part and eliminates the electric field disturbance. The electric field applied to the refrigerant circulation part can be reduced, and discharge can be prevented.

  When the distribution state relaxation unit and the refrigerant distribution unit are partitioned in a non-communication state, it is preferable to control the respective refrigerant pressures of the distribution state relaxation unit and the refrigerant distribution unit with a pressure control mechanism.

  When the distribution state relaxation unit and the refrigerant distribution unit are partitioned into a non-communication state and the refrigerant pressure is controlled, the distribution state relaxation unit is controlled to have a higher pressure than the refrigerant distribution unit. If the distribution state relaxation unit is at a higher pressure, the boiling point of the refrigerant in the distribution state relaxation unit can be higher than that of the refrigerant distribution unit (for example, 77K → 85K). Vaporization can be prevented. Since the temperature gradient can be set so that the temperature of the refrigerant in the refrigerant circulation portion is lower than the temperature of the refrigerant in the circulation state relaxation portion, the cooling effect of the circulation state relaxation portion is improved.

  As another configuration of the circulation state relaxation portion, for example, it can be configured by arranging an insulator impregnated with a refrigerant around a conductor portion arranged in the refrigerant tank. In this case, it is preferable to arrange an insulator around the portion where the bushing is not provided on the outer periphery of the conductor portion arranged in the refrigerant tank.

  When the conductor portion is configured in this way, specifically, it is preferable to form an insulator so as to cover all the conductor portions where the bushing is not provided from the portion to which the bushing voltage is applied. At this time, the insulator is continuous from the bushing to the conductor part and the connecting conductor so that the conductor part reaches the cable side opening of the refrigerant tank, for example, the connecting conductor connected to the conductor part. Is preferably arranged.

  As the insulator, insulating paper impregnated with a refrigerant is used, and the insulating paper is wound around the outer periphery of the low-temperature side end portion of the conductor portion. When connecting the connection conductor to the conductor portion, it is preferable to wrap the insulating paper around the connection conductor. Examples of the insulating paper include semi-synthetic insulating paper such as kraft paper and PPLP (registered trademark).

  Further, the insulating paper is impregnated with a refrigerant, and an electrode layer is formed on the outermost part of the insulator, and the electrode layer is grounded. In this case, a circulation state relaxation part is formed inside the electrode layer, and a refrigerant circulation part is formed outside the electrode layer. By providing the insulator and the electrode layer in this manner and grounding the electrode layer, the refrigerant in the insulator is less likely to flow, and even if an electric field is applied to the refrigerant in the insulator, the electric field is disturbed. It does not occur and discharge can be reliably prevented.

  Another example of the configuration of the circulation state mitigating unit is one in which at least a part of the conductor unit is configured by a connection cable including a superconducting conductor and a first insulator.

  The connecting cable preferably includes a superconducting conductor having the same structure as the superconducting cable and a first insulator. And a 2nd insulator is arrange | positioned at the both ends of the cable for connection, and a 1st insulator and a 2nd insulator are impregnated with a refrigerant | coolant, and a distribution | circulation state relaxation part is comprised.

  The second insulator is disposed, for example, in a range from a portion to which the bushing voltage is applied to the room temperature side end of the connection cable, and in the vicinity of the superconducting cable side end of the connection cable.

  The vicinity of the superconducting cable side end of the connection cable refers to, for example, a range from the cable side end of the first insulator in the connection cable to the vicinity of the cable side opening of the refrigerant tank.

  The superconducting conductor having the same structure as the superconducting cable means a configuration in which a wire made of Bi2223 series superconducting material is spirally wound on a former, and the former may be a hollow type or a solid type. The insulator is configured by winding the above-described insulating paper around a superconducting conductor.

  Also in this case, the insulator formed around the conductor is impregnated with the refrigerant, and an electrode layer is formed on the outermost part of the insulator. Also in this case, the circulation state relaxation part is formed inside the electrode layer, and the refrigerant circulation part is formed outside the electrode layer. Since the electrode layer is grounded, even if an electric field is applied to the refrigerant, the electric field is not disturbed in the flow state relaxation portion, and a stable insulation strength can be obtained, and discharge can be reliably prevented.

  The superconducting cable connected to the terminal structure of the present invention may be a single-phase superconducting cable having one cable core having a superconducting conductor or a multiphase superconducting cable having a plurality of the cable cores. In the latter case, for example, a three-core one-piece three-phase superconducting cable in which three cable cores are twisted and stored in a heat insulating tube can be used. A known single-phase superconducting cable or multiphase superconducting cable may be used.

  As described above, in the terminal structure of the superconducting device of the present invention, the refrigerant tank includes a circulation state relaxation part and a refrigerant circulation part, and a boundary between the circulation state relaxation part and the refrigerant circulation part is grounded, and the refrigerant circulation part It is configured so that almost no electric field is applied.

  As a result, even if a voltage is applied from the conductor part to the refrigerant by the flow state relaxation part, almost no flow occurs in the refrigerant around the conductor part, and a decrease in electrical insulation strength due to the refrigerant around the conductor part can be prevented. .

  In particular, in the case of the terminal structure of a DC power transmission superconducting device, electric charge is likely to accumulate in the refrigerant in the refrigerant tank, so that when the refrigerant moves, the electric insulation strength of the refrigerant in the DC electric field decreases. However, according to the present invention, electric charge is accumulated in the circulation state relaxation part, and the boundary between the circulation state relaxation part and the refrigerant circulation part is grounded, so that discharge can be prevented.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a first embodiment of the present invention.

(First embodiment)
FIG. 1 is a schematic overall configuration diagram showing a terminal structure of a superconducting device of the present invention according to a first embodiment, and this embodiment is a terminal structure of a superconducting device for direct current power transmission. This terminal structure includes a connection conductor 12, a conductor portion 21, a main body case 13, and a soot tube 14. The connection conductor 12 is electrically connected to the end portion of the cable superconducting conductor 101 included in the superconducting cable 10. The conductor portion 21 connects the connecting conductor 12 and the normal conducting conductor 11 on the room temperature side. The main body case 13 forms a vacuum container, and the refrigerant tank 3 is disposed inside. The soot tube 14 is attached to the main body case 13.

  The main body case 13 and the refrigerant tank 3 are made of stainless steel, and a heat insulating layer is formed around the refrigerant tank 3 by evacuating the main body case 13. The heat insulation layer formed around the refrigerant tank 3 efficiently maintains the cryogenic state of the refrigerant tank 3.

  The refrigerant tank 3 is filled with a refrigerant such as liquid nitrogen, and a reservoir 44, a pump 42, and a cooling device 41 provided outside the main body case 13 are communicated with the refrigerant tank 3 through the refrigerant supply passage 43. In the present embodiment, first, the refrigerant in the refrigerant tank 3 is taken out of the main body case by the pump 42 and temporarily stored in the reservoir 44, and the refrigerant is supplied from the reservoir 44 to the cooling device 41. The refrigerant cooled by the cooling device 41 by the pump 42 is returned to the refrigerant tank 3, so that the refrigerant in the refrigerant tank 3 is circulated and cooled.

  In the present embodiment, a bushing 15 is disposed around the conductor portion 21, one end of the conductor portion 21 is disposed in the refrigerant tank 3, and the other end of the vertical tube 14 is interposed through the heat insulating layer of the main body case 13. It is arranged to be inserted inside.

  The bushing 15 is configured by covering the outer periphery of a conductive metal cylinder with an insulating member such as FRP having excellent insulating properties. The space formed inside the soot tube 14 is filled with an insulating fluid such as insulating oil.

  In this embodiment, the connecting conductor 12 is a normal conductive conductor made of a normal conductive material such as copper or aluminum. The connecting conductor 12 may be a superconducting conductor in which a wire made of Bi2223 series superconducting material is spirally wound on a former.

  The braided conductor 16 is connected to the inner end of the refrigerant tank of the conductor portion 21, and the braided conductor 16 has one end connected to the end of the connection conductor 12 and the other end connected to the end of the conductor portion 21. The The periphery of the braided conductor 16 is covered with a shield cover 17 made of copper. Although not shown, insulating paper such as kraft paper is wound around the outer surface of the shield cover 17. By covering the shield cover 17 made of metal with an insulating material without directly exposing it to the refrigerant, the insulating performance can be improved and the insulating strength can be ensured.

  As the superconducting cable used in the present embodiment, for example, a single-phase superconducting cable 10 in which one cable core 100 is housed in a heat insulating tube 102 is used. Although not shown, the heat insulating tube 102 of the cable 10 has a structure in which a heat insulating material is disposed between a double tube composed of an outer tube and an inner tube, and the inside of the double tube is evacuated. The cable core includes a former, a superconducting conductor, an electrical insulating layer, a shield layer, and a protective layer in order from the center.

In the present embodiment, the end of the superconducting conductor 101 for the cable of the superconducting cable 10 is connected to the connecting conductor 12, and the connecting conductor 12 is connected to the end of the conductor 21 via the braided conductor 16. ing. Note that the connection between the end of the cable superconducting conductor 101 and the connection conductor 12 is performed in the cable connection side refrigerant tank 53 outside the refrigerant tank 3.

  An epoxy unit 51 having an insulating function and mechanical strength is disposed on the outer periphery of the connecting conductor 12 at a position facing the cable side opening 31 of the refrigerant tank 3. An insulating material 52 such as kraft paper is disposed on both sides of the epoxy unit 51 in the longitudinal direction on the outer periphery of the connecting conductor 12 and on the outer periphery of the cable superconducting conductor 101 of the exposed cable core 100.

  The connection side of the connection conductor 12 to the superconducting cable is stored in a cable connection side refrigerant tank 53 filled with a refrigerant such as liquid nitrogen, and the cable connection side refrigerant tank 53 is stored in the main body case 13.

  In the present embodiment, a partition wall 7 is provided in the refrigerant tank 3 to be partitioned into an inner space 61 in which the conductor portion 21 and the connecting conductor 12 are incorporated, and an outer space 62 provided outside the inner space 61. . The partition wall 7 is formed of the same stainless steel as that of the refrigerant tank 3, and the partition wall 7 forms the circulation state relaxation portion 8 in the inner space 61 and the refrigerant circulation portion 32 in the outer space 62.

  The partition wall 7 ends from the tapered portion of the bushing 15 disposed on the outer periphery of the conductor portion 21, and from the vicinity of the outer peripheral surface that becomes a straight portion to the cable side opening 31 of the refrigerant tank 3 of the connecting conductor 12, and the bushing 15 An L-shaped cylinder is formed so as to cover the conductor portion 21 and the connecting conductor 12. The partition wall 7 forms a communication portion 71 that allows the inner space 61 and the outer space 62 to communicate with each other at the bushing side opening. By this communication portion 71, the refrigerant flows in and out between the outer space 62 and the inner space 61. Further, the outer surface of the partition wall 7 is grounded.

  By providing the partition wall 7, the refrigerant stored in the inner space 61 formed inside the partition wall 7 is less likely to generate a refrigerant flow. In the outer space 62, the refrigerant is circulated and cooled by the cooling device 41. Cooling is carried out while moving.

  As described above, when the partition wall 7 is provided and the outer surface of the partition wall 7 is grounded, the disturbance of the electric field is suppressed and the insulation strength is ensured when the flow of the refrigerant in the inner space 61 is relaxed. . It is only necessary to design an electric field in the partition wall 7 using only the inner space 61. In particular, in this embodiment, since it is a terminal for direct current power transmission, electric charge is likely to accumulate in the refrigerant in the refrigerant tank, but the electric charge is accumulated in the circulation state relaxation unit 8 and the partition wall 7 is grounded. Can be prevented.

  In the above embodiment, a single-phase superconducting cable is shown, but a multiphase superconducting cable can also be used. This also applies to the following embodiments.

(Second embodiment)
In the second embodiment, as shown in FIG. 2, the partition wall is configured so that the inner space and the outer space cannot be communicated with each other, and the inside of the inner space (circulation state relaxation portion) and the outer space (refrigerant circulation portion). The pressure is individually controlled.

  The basic structure of the terminal structure shown in FIG. 2 is the same as the terminal structure of the superconducting device of the first embodiment shown in FIG. 1, and the same components are denoted by the same reference numerals and description thereof is omitted.

  In the present embodiment, the bushing side opening of the partition wall 7 is brought into contact with the inner wall surface of the refrigerant tank 3, and the other opening is brought into contact with the outer periphery of the cable side opening 31, so that the inner space 61 and the outer side The communication with the space 62 is prevented. The pressure control mechanism 9 controls the refrigerant pressure in each of the inner space 61 and the outer space 62.

  The pressure control mechanism 9 includes first pressure adjusting means 91 that controls the refrigerant pressure in the inner space 61 and second pressure adjusting means 92 that controls the refrigerant pressure in the outer space 62.

  The partition wall 7 is connected to a pressure adjusting passage 93 that is pulled out of the main body case 13. A first reservoir 94 is disposed at the end of the pressure adjusting passage 93. The first pressure adjusting means 91 is disposed near the first reservoir 94. The first pressure adjusting means 91 supplies, for example, helium gas into the first reservoir 94 and discharges it from the first reservoir 94. The first pressure adjusting means 91 is driven by control means (not shown) so that the refrigerant in the inner space 61 has a predetermined pressure.

  In addition, the pressure control of the refrigerant in the outer space 62 is performed by providing a second reservoir 95 between the refrigerant tank 3 and the pump 42 in the middle of the refrigerant supply passage 43, and adjusting the pressure in the second reservoir 95 to the second pressure. Adjustment is performed by the adjusting means 92. The second pressure adjusting means 92 also supplies, for example, helium gas into the second reservoir 95 and discharges it from the second reservoir 95. By adjusting the pressure in the second reservoir 95, the pressure of the refrigerant cooled by the cooling device 41 is set to a predetermined pressure, and the cooled refrigerant having the predetermined pressure is supplied to the refrigerant tank 3 by the pump 42. Yes.

  In the present embodiment, the pressure of the inner space 61 is set to be higher than the pressure of the outer space 62, that is, the refrigerant boiling point in the inner space 61 is, for example, 10K higher than the refrigerant boiling point in the outer space 62. The refrigerant pressure is controlled. By controlling the refrigerant pressure in this way, it is possible to prevent the refrigerant from evaporating even when the temperature of the refrigerant in the inner space 61 becomes higher than the temperature of the refrigerant in the outer space 62 due to cooling of the conductor.

(Third embodiment)
In the third embodiment shown in FIG. 3, the coolant is impregnated on the outer periphery of the bushing 15 and the low temperature side end of the conductor part 21 and the end of the connecting conductor 12 that are in contact with the refrigerant without using a partition wall. By disposing the insulator 81, the distribution state relaxation unit 8 is configured.

The basic structure of the terminal structure shown in FIG. 3 is the same as the terminal structure of the superconducting device of the first embodiment shown in FIG. 1, and the same components are denoted by the same reference numerals and description thereof is omitted. Note that the connection between the end of the cable superconducting conductor 101 and the connection conductor 12 is performed in the cable connection side refrigerant tank 53 outside the refrigerant tank 3.

  The third embodiment also includes a conductor portion 21, a bushing 15 in which the conductor portion 21 is built, a connecting conductor 12, a braided conductor 16 that connects the conductor portion 21 and the connecting conductor 12, and a connecting conductor 12. The configuration includes a superconducting conductor for cable 101 to be connected.

  In the present embodiment, the bushing 15, the conductor portion 21, the braided conductor 16, and the connecting conductor 12 are within a range from the portion where the voltage of the bushing 15 is applied to the cable side opening 31 of the refrigerant tank 3 in the connecting conductor 12. An insulator 81 is arranged so as to be continuous with the outer periphery of the substrate.

  Specifically, the low temperature side end of the conductor portion 21 is covered with the tapered portion of the bushing 15, and further, the braided conductor 16 and the connection conductor 12 are insulated from the connection end portion of the conductor portion to the epoxy unit 51. A body 81 is provided. This insulator 81 is also formed by winding insulating paper such as kraft paper around the outer periphery of the conductor.

  Although not shown, the outermost peripheral surface of the insulator 81 is covered with, for example, a braided material made of a conductive material such as copper through which a coolant can pass to form an electrode layer. The electrode layer is grounded from the ground wire lead portion 18 to the outside of the main body case.

  In the present embodiment, the circulation state relaxation part is formed inside the electrode layer, and the refrigerant circulation part is formed outside the electrode layer. Since the insulator 81 is provided and the electrode layer formed on the outer peripheral surface of the insulator 81 is grounded, the refrigerant impregnated in the insulator 81 hardly flows, and an electric field is generated in the refrigerant in the insulator. Even if it is applied, it has a stable insulation strength.

(Fourth embodiment)
In the fourth embodiment shown in FIG. 4, the conductor portion 21, the bushing 15, and the connection cable 22 are provided. In the present embodiment, the connection cable 22 is a part of the conductor portion 21. The connection cable 22 includes a connection superconducting conductor 23 and a first insulator 24 having the same structure as the superconducting cable.

  The basic structure of the terminal structure shown in FIG. 4 is the same as the terminal structure of the superconducting device of the first embodiment shown in FIG. 1, and the same components are denoted by the same reference numerals and description thereof is omitted. In the present embodiment, the connection superconducting conductor 23 is connected to the end of the cable superconducting conductor 101, and this connection is made via a connection member in the epoxy unit 51.

  In the fourth embodiment, the second insulators 82 and 83 are arranged around one end side of the connection cable 22 and around the other end. Specifically, in the range from the portion to which the voltage of the bushing 15 is applied to the end of the connecting cable 22 on the conductor side, the second insulation is provided on the outer periphery of the ends of the bushing 15, the conductor 21, and the connecting cable 22. Arrange the body 82. That is, the second insulator 82 is provided so as to cover the low temperature side end portion of the conductor portion 21 together with the tapered portion of the bushing 15 and further cover the connection end portion with the conductor portion of the connection cable 22.

  The connection cable 22 extends from the cable side opening 31 of the refrigerant tank 3 to the cable side end of the first insulator 24, that is, in the same manner as the insulation material 52 of the first embodiment. A second insulator 83 is arranged on the outer periphery of the superconducting cable side end of 22 and the outer periphery so as to cover the epoxy unit 51. Each of the first insulator 24 and the second insulators 82 and 83 is impregnated with a refrigerant to constitute the flow state relaxation portion 8.

  In the present embodiment, the connecting superconducting conductor 23 of the connecting cable 22 is formed by spirally winding a wire made of a Bi2223 series superconducting material on a former. Further, the first insulator 24 is configured by winding insulating paper such as kraft paper around the connection superconducting conductor 23.

Although not shown, the outermost peripheral surfaces of the second insulator 82, the first insulator 24, and the second insulator 83 are covered with a braided material made of a conductive material such as copper through which a refrigerant can pass, for example. An electrode layer is formed. The electrode layer is grounded from the ground wire lead portion 18 to the outside of the main body case.

  Also in this embodiment, the electrode layers provided on the outer surfaces of the first insulator 24 and the second insulators 82 and 83 are grounded. Also in this case, the circulation state relaxation part is formed inside the electrode layer, and the refrigerant circulation part is formed outside the electrode layer. Since the first insulator 24 and the second insulators 82 and 83 are impregnated with the refrigerant, even if an electric field is applied to the refrigerant in the insulator, the electric field is not disturbed, and the insulation strength can be ensured.

  The grounding of the boundary between the circulation state relaxation part and the refrigerant circulation part is achieved by grounding the outer surface of the refrigerant tank and electrically connecting the inner surface of the refrigerant tank and the boundary between the circulation state relaxation part and the refrigerant circulation part. The boundary may be grounded via In addition, an insulator provided on the outer periphery of the conductor portion is configured to be continuous with the insulator covering the superconducting conductor of the superconducting cable, and an electrode layer is formed continuously between the insulator covering the superconducting conductor and the insulator of the conductor portion. Then, this electrode layer may be grounded.

  Further, the configuration of the partition wall according to the second embodiment described above is combined with the configuration of the insulator according to the third embodiment or the fourth embodiment, so that the partition wall and the insulator constitute a flow state relaxation portion. Also good. In this case, it is preferable to form an electrode layer on the outermost part of the insulator and ground this electrode layer.

  The terminal structure of the present invention is suitable for forming a terminal portion of a superconducting cable connected to an electric device or a normal conducting cable used at room temperature, and is used for either a single-phase superconducting cable or a multiphase superconducting cable. be able to. Moreover, although it can utilize for any of an alternating current track and a direct current track, it is suitable when using for direct current power transmission.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic whole block diagram which concerns on 1st embodiment which shows the terminal structure of this invention superconducting equipment. It is a general | schematic whole block diagram which concerns on 2nd embodiment which shows the terminal structure of this invention superconducting equipment. It is a schematic partial block diagram which concerns on 3rd embodiment which shows the terminal structure of this invention superconducting equipment. It is a schematic partial block diagram which concerns on 4th embodiment which shows the terminal structure of this invention superconducting equipment. It is a schematic block diagram which shows the terminal structure of the conventional superconducting apparatus.

Explanation of symbols

10 Superconducting cable
100 Cable core 101 Superconducting conductor for cable 102 Insulated pipe
11 Normal conducting conductor 12 Connecting conductor 13 Body case 14 Steel pipe
15 Bushing 16 Braided conductor 17 Shield cover
18 Ground wire extension
21 Conductor 22 Connection cable
23 Superconducting conductor for connection 24 First insulator
3 Refrigerant tank 31 Cable side opening 32 Refrigerant circulation part
41 Cooling device 42 Pump 43 Refrigerant supply passage
44 Reservoir
51 Epoxy unit 52 Insulation material
53 Cable connection side refrigerant tank
61 inner space 62 outer space
7 Section wall 71 Communication part
8 Distribution Status Mitigation Department
81 Insulator 82,83 Second insulator
9 Pressure control mechanism
91 First pressure adjusting means 92 Second pressure adjusting means
93 Pressure adjusting passage 94 First reservoir 95 Second reservoir
210 Connecting conductor 220 Conductor 230 Refrigerant tank 240 Vacuum container
250 Steel pipe 260 Bushing 270 Joint part

Claims (6)

A refrigerant tank in which refrigerant is stored;
One end is disposed in the refrigerant tank and the other end is disposed on the room temperature side,
A partition wall that is provided in the refrigerant tank and divides into an inner space in which a conductor portion disposed in the refrigerant tank is built, and an outer space provided outside the inner space;
The outer space forms a refrigerant circulation part through which the refrigerant is circulated ,
The inner space forms a distribution state relaxation part in which the distribution of the refrigerant is relaxed more than the refrigerant distribution part by the partition wall ,
A terminal structure of a superconducting device characterized in that the partition wall is grounded . A refrigerant tank in which refrigerant is stored;
One end is disposed in the refrigerant tank and the other end is disposed on the room temperature side,
Is formed around the conductor portion disposed refrigerant tank, an insulator refrigerant is impregnated,
Comprising a this insulating electrode layer formed on the outermost,
In the refrigerant tank, a refrigerant circulation part is formed through which the refrigerant is circulated outside the electrode layer,
On the inner side of the electrode layer, the refrigerant is impregnated with the refrigerant to form a circulation state relaxation part where the circulation of the refrigerant is more relaxed than the refrigerant circulation part,
Terminal structure of a superconducting device you characterized in that grounding the electrode layer. A refrigerant tank in which refrigerant is stored;
One end is disposed in the refrigerant tank and the other end is disposed on the room temperature side,
One end is connected to the end of the conductor disposed in the refrigerant tank, and the other end is connected to the end of the superconducting conductor of the superconducting device, and provided on the outer periphery of the connecting superconducting conductor. a connection cable including a first insulation was,
A second insulator provided on the outer periphery of the connection portion between the conductor portion and one end of the connection superconducting conductor, and on the outer periphery of the connection portion between the superconducting conductor of the superconducting device and the other end of the connection superconducting conductor ;
The electrode layer formed on the outermost part of these first insulator and second insulator ,
In the refrigerant tank, a refrigerant circulation part is formed through which the refrigerant is circulated outside the electrode layer,
On the inner side of the electrode layer, the first insulator and the second insulator are impregnated with the refrigerant, thereby forming a circulation state relaxation portion in which the circulation of the refrigerant is relaxed more than the refrigerant circulation portion,
Terminal structure of a superconducting device you characterized in that grounding the electrode layer. The partition wall is configured such that the refrigerant is not in communication between the inner space and the outer space ,
First pressure adjusting means for controlling the refrigerant pressure in the inner space;
The terminal structure of a superconducting device according to claim 1, further comprising second pressure adjusting means for controlling the refrigerant pressure in the outer space . A partition wall is provided on the outer periphery of the electrode layer, and the partition wall is configured so that the refrigerant is in a non-communication state between the inside and the outside of the partition wall, and the coolant is circulated to the outside of the partition wall. A refrigerant distribution part is formed,
First pressure adjusting means for controlling the refrigerant pressure in the space inside the partition wall;
The terminal structure of a superconducting device according to claim 2 or 3, further comprising second pressure adjusting means for controlling a refrigerant pressure in a space outside the partition wall . Terminal structure of a superconducting apparatus as claimed in any one of claims 5, characterized in that used for connection of a superconducting cable for DC power transmission.

Images