Super-conducting cable

FIELD: electrical engineering.

SUBSTANCE: invention relates to electrical engineering, particularly to super-conducting cable capable to absorb thermal compression of super-conducting wire. Super-conducting cable comprises a super-conducting wire coiled to form a super-conducting layer (layer-conductor) (13), reverse conductor (17), a layer of strain relaxation (12), an insulating layer or an outer strain relation layer (16) arranged on the super-conducting layer outer side and cable carcass, (11) arranged on the strain relaxation layer inner side.

EFFECT: superconducting layer compression absorption by cooling superconducting wire with coolant.

9 cl, 4 dwg, 1 tbl

 

The technical field

[0001] the Present invention relates to a superconducting cable. The invention in particular relates to a superconducting DC cable, capable of absorbing thermal contraction of the superconducting wire.

Prior art

[0002] as a superconducting cable was proposed superconducting cable shown in figure 4. Superconducting cable 100 is made with a design, which includes three cable cores 10 in the insulating pipe 20 (see, for example, patent reference 1, patent reference 2).

[0003] Cable lived successively from its center includes a frame 11, a conductive layer 13, an insulating layer 16A, the shielding layer 17A, a protective layer 18. Conductive layer 13 is formed by spiral winding a superconducting wire in many layers. Usually use a superconducting wire of ribbon-like form, in which many of staple fibres containing oxide superconducting material, is located in matrix silver shell or the like, an Insulating layer 16A is formed by winding insulating paper. The shielding layer 17A is formed by spiral winding a superconducting wire like conducting layer 13 on top of the insulating layer 16A. In addition, the protective layer 18 is used, the insulating paper or so what.

[0004] in Addition, the insulating pipe 20 is made with a construction in which the insulating element (not shown) is located between the twin tubes containing the inner tube 21 and outer tube 22, and inside these double tubes vacuumized. The corrosion resistant layer 23 is formed on the outer side of the insulating pipe 20. In addition, the application state is a state in which the refrigerant is in the form of liquid nitrogen or the like fills and circulates through the space formed inside the frame 11 (when it is hollow) or between the inner pipe 21 and the housing 10, and the refrigerant is impregnated in the insulating layer 16A.

[0005] Patent reference 1:

Posted publication of Japanese patent: JP-A-2003-249130 (1)

Patent reference 2:

Posted publication of Japanese patent: JP-A-2002-140944 (2)

Disclosure of invention

The problem addressed by the invention

[0006] meanwhile, in the above-described superconducting cable during operation of the superconducting wire is cooled by the refrigerant to an extremely low temperature, while being compressed, and therefore, requires a structure with absorption of the magnitude of this compression. However, there was discovered a simple structure as a mechanism of absorption the amount of compression.

[0007] Although according to the structure, which includes 3 cable core, can the be taken the measure of the opposition to absorb compression by loosening twisted lived, in the case of a superconducting cable with a single dwelling, this countermeasure cannot be taken. Consequently, it is possible to deal with this by allowing mechanical strain affect the superconducting wire in accordance with the compression upon cooling or providing a sliding peripheral end portion of the superconducting cable according to thermal contraction of the cable.

[0008] However, in the first case, the voltage compression allow you to work on superconducting wire and, therefore, there is a case in which, depending on the intensity of the voltage in the superconducting wire there is a strong tension, the superconducting wire is destroyed or heat insulating pipe applies lateral pressure to the curved part of the cable in accordance with compression of the cable, reducing heat insulating function. In the latter case, a mechanism for sliding the peripheral end of the superconducting cable, and it is necessary to apply a large-scale action against the compression. In particular, responses to compression using the sliding mechanism is not suitable for long superconducting cable line connected with many of superconducting cables through connections.

[0009] This invention was created in view of the above situation, and it is the main challenge to create a superconducting cable capable of with a simple structure to absorb the amount of compression of the superconducting wire cooling.

[0010] furthermore, another object of the invention is to create a superconducting DC cable, can, by a simple structure to absorb the amount of compression of the superconducting wire cooling.

[0011] furthermore, another object of the invention is to create a superconducting cable capable of with a simple structure to absorb the amount of compression of the superconducting wire cooling, and allowing as much as possible to reduce the amount of superconducting wire.

Means for solving these problems

[0012] the Invention solves the above problem by giving the mechanism of thermal compression superconducting layer directly to the cable conductor.

[0013] According to the invention proposed a superconducting cable, comprising: a superconducting wire, comprising a superconducting layer by spiral winding, and a layer of stress relaxation provided on the inner side of the superconducting layer, and the amount of compression in the direction of the diameter of the superconducting layer in accordance with the cooling of the superconducting wire refrigerant is absorbed by the layer of stress relaxation.

[014] By providing a layer of stress relaxation on the inner side of the superconducting layer, when the superconducting wire shrinks when cooled, can be eliminated excessive stretching of the superconducting wire by absorption of at least part of the value corresponding to the amount of compression of the diameter of the superconducting layer (the amount by which the diameter of the coiled superconducting wire is reduced by cooling) in accordance with data compression.

[0015] Below will be explained in detail an element of a superconducting cable according to the invention.

[0016] the Superconducting cable according to the invention usually consists of a cable core and an insulating tube containing the cable core. Of them lived cable is constructed with a base structure comprising a layer of stress relaxation layer, a conductor, an insulating layer. Typically lived cable provided with a frame, comprising forming the cable element. Otherwise may be provided by an external layer conductor (shielding layer)that hold the coils of the layer, cushioning layer.

[0017] the Frame is designed to maintain a layer of a conductor having a given shape, and can be used ribbon-like element formed with a tubular shape or a spiral, or structural element having the structure of twisted wire. A preferred material is a nonmagnetic metal is ical material, of copper, aluminum or the like, otherwise also can be used in a variety of plastic materials. When the frame is tubular in form, from the point of view of flexibility, it is preferable to form it of a corrugated tube. When the frame has a tubular shape, the inside of the frame may form a channel for the flow of refrigerant.

[0018] the Layer of stress relaxation is a layer designed to absorb the magnitude of heat of compression of the superconducting layer. The superconducting layer is a layer formed by spiral winding a superconducting wire, and includes a layer conductor or the outer layer conductor (shielding layer), as mentioned above. The superconducting layer is thermally shrinks when cooled refrigerant to an extremely low temperature during operation of the cable. In accordance with thermal contraction of the superconducting wire compression also occurs in the direction of the diameter, and therefore, when the layer stress relaxation provided on the inner side of the superconducting layer is compressed accordingly, thermal contraction of the superconducting wire, the operation of the superconducting wire may be limited by excessive stretching.

[0019] the Layer of stress relaxation can be provided with the amount of compression that is capable of POG is omati, at least part of the amount of compression of the diameter of the superconducting layer when it is exposed to refrigerant effects of extremely low temperature. That is, the layer stress relaxation can be formed so as to absorb the amount of compression of the superconducting layer in the direction of diameter in accordance with the cooling layer of stress relaxation and the components of the cable element provided on the inner side of the layer of stress relaxation, or may be formed so as to absorb the amount of compression of the superconducting layer in the direction of diameter in accordance with the cooling-only layer of stress relaxation.

[0020] In the first case, the compression of the superconducting layer is absorbed by the compression layer as stress relaxation, and comprising a cable element, and therefore, the layer stress relaxation itself can be thinner. As a typical example of constituting the cable element provided on the inner side of the layer of stress relaxation, specifies the frame. In the latter case, the amount of compression of the diameter of the superconducting layer is absorbed by the layer stress relaxation, and therefore the material or the structure of the constituent element on the inner side of the layer of stress relaxation, for example, the frame can be chosen freely.

[0021] the location of the layer relaxation voltage is of Ajani is on the inside of the superconducting layer. For example, it is possible to provide a layer of stress relaxation of the inner side layer wire (on the outer side of the frame) as a layer of stress relaxation inner side or to provide a layer of stress relaxation on the inner side of the outer layer of the conductor (shielding layer) as a layer of stress relaxation outside. When the layer stress relaxation is provided on the inner side of the outer layer of the conductor, can be used an insulating layer by itself, or layer of stress relaxation can be formed separately, in addition to the insulating layer. When the insulating layer itself is used as a layer of stress relaxation of the external side, there is no need to provide another layer of stress relaxation than the insulating layer, in order to contribute to the minor diameter of the cable core.

[0022] as a material constituting the layer stress relaxation, can preferably be used at least one of Kraft paper, plastic tapes and composite tape of Kraft paper and plastic tape. As the plastic tape may preferably be used polyolefin, in particular polypropylene, tape. Although Kraft paper is usually inexpensive, the amount of shrinkage during cooling is small, and although to posita tape of Kraft paper and polypropylene dear, the amount of shrinkage when cooling large. In particular, in the case of composite tape, when using a composite tape having a greater thickness polypropylene, can be guaranteed a large amount of compression, and even when the amount of compression of the diameter of the superconducting wire is large, can be formed in the layer stress relaxation without the application of excessive tension to the superconducting wire. Otherwise, as Kraft paper corrugated Kraft paper or moistened Kraft paper can guarantee a large amount of compression. In addition, the layer stress relaxation, having a thickness capable of absorbing at least part of the amount of compression of the diameter of the superconducting wire can be formed of these materials individually or in combination.

[0023] the Layer conductor is a conductive part formed of a superconducting wire. For example, layer conductor is formed by spiral winding a superconducting wire on the outside of the frame in several layers. As a concrete example of the superconducting wire is superconducting wire ribbon-like form, in which many of staple fibres containing oxide superconducting material phase V, are arranged in matrix silver shell or the like, the Superconducting wire can be numot is N. in one layer or in several layers. In addition, when formed of multiple layers, may be provided in the interlayer insulating layer. As the interlayer insulating layer is indicated interlayer insulating layer provided by winding insulating paper of Kraft paper or the like, or composite paper PPLP (manufactured Sumitomo Denki Kogyo K.K. registered trademark) or the like

[0024] an Insulating layer is formed of an insulating material having a withstand voltage isolation corresponding to the voltage layer of the conductor. For example, can preferably be used at least one of Kraft paper, plastic tape and composite tape of Kraft paper and plastic tape.

[0025] Among the above respective materials structure with the formation of an insulating layer of Kraft paper has the lowest cost. When the composite tape and Kraft paper are used, compared with the case of the formation of the insulating layer of the composite tape, the amount of expensive composite tape can be reduced, and the cost of the cable can be reduced.

[0026] In particular, when using composite tape obtained by laminating Kraft paper and polypropylene, it is preferable to use a composite tape having a ratio k of the thickness of the polypropylene film is about the entire thickness of the composite tape in 60% or more. Because of the difference in specific resistance Kraft paper and polypropylene film comprising the composite tape, the electric field intensity largely account for the plastic film, excellent in characteristics withstand voltage. Therefore, when increasing footprint in the insulating layer in the share of plastic film characteristics withstand voltage (in particular, the characteristic of withstanding DC voltage) of the insulating layer can be improved, and the thickness of the insulating layer can be reduced.

[0027] in Addition, when provided below the outer layer of the conductor, as a layer of stress relaxation is preferable to use the actual insulating layer. Although the layer of stress relaxation can be formed separately from the insulating layer while using the insulating layer as such as a layer of stress relaxation to absorb the amount of compression of the diameter of the outer layer of the conductor it is possible to limit the increase of the outer diameter of the superconducting cable.

[0028] In another case, on at least one of the inner and outer peripheries of the insulating layer, i.e. the layer between the conductor and the insulating layer or between the insulating layer and the shielding layer may be formed of semi-conductive layer. When forms is the formation of the inner semi-conducting layer in the first case and the outer semi-conducting layer in the latter case, effectively stabilizes the electric function.

[0029] the Outer layer of the conductor can be provided on the outer side of the insulating layer. In particular, in the superconducting DC cable external layer conductor is a structure necessary for the implementation of the power transmission single-pole system. While in the superconducting AC cables require shielding layer for shielding the magnetic flux flowing to the outer periphery of the layer of the conductor, in order to reduce loss of alternating current in the superconducting wire, the superconducting DC cable conductor return line should be formed by the outer layer conductor on the plot corresponding to the shielding layer of superconducting AC cables. That is, when providing the outer layer of the conductor (conductor return line)containing superconducting wire on the outer side of the insulating layer, the conductor can be the path of direct current when the unipolar transmission, and the outer layer conductor may be used as the path of the current return line. The outer layer of the conductor must be run with the design, have the same maximum current, and maximum allowable current layer of the conductor. In addition, the superconducting cable may be stranded type, containing the centre of the leads in the insulating tube, and can also be used in single pole power transmission system or a bipolar system of electricity transmission. In the latter case, the outer layer of the conductor in the cable according to the invention is attached to the neutral wire.

[0030] it Is preferable that the step of winding a superconducting wire, comprising a layer conductor or the outer layer conductor, was 4 to 6 times the diameter of the winding of the superconducting wire. The diameter of the winding is called the diameter of the element, a coiled superconducting wire, i.e. the inner diameter of the layer formed of a superconducting wire. When the constraint relations of the step winding diameter of the winding, as described above, you can get a short step can reduce the amount of compression of the wire, when the superconducting wire shrinks upon cooling, and to obtain the step of winding, is also able to limit the amount of superconducting wire.

[0031] In the superconducting AC cables in order to reduce the loss of AC power, making the currents of the respective layers of superconducting wire wound in multiple layers, equal education, equal currents), regulate the step of winding the superconducting wire in the respective layers. For example, a short step through a long step combine within the range not damaging berprestasi wire during winding the superconducting wire and bending wires. Therefore, the limiting step of winding is significant.

[0032] on the other hand, in the case of superconducting DC cable there is no need to take into account the formation of the same current, and therefore the restriction on the choice of the step of winding is not significant, the step of winding can be selected relatively freely, and all layers can nakativaetsa with the same step.

[0033] When the step of winding the superconducting wire is reduced, the amount of shrinkage in diameter, when the superconducting wire shrinks during cooling, that is, the value that must be absorbed by the layer stress relaxation decreases and therefore, the layer stress relaxation can be easily formed. However, when the pitch of the winding is reduced, the amount of superconducting wire is increased, leading to a rise in value, and therefore, it is important to choose the step of winding, as far as possible by limiting the increase in the amount of superconducting wire. Therefore, by limiting the relationship of the step winding diameter of the winding, as described above, it is possible to obtain a superconducting cable with a short step, can reduce the amount of shrinkage in diameter, when the superconducting wire shrinks during cooling, and step, relative to limiting the number ispolzovanie the superconducting wire. Especially preferred step of winding the superconducting wire 5 times the diameter of the winding.

[0034] the Preferred step of winding the superconducting wire can be calculated as follows. First, we study the relationship between attitude(pitch/diameter)of the step winding diameter of the winding superconducting wire constituting the superconducting layer, and the amount of compression in diameter when cooled superconducting wire. Then examine the relationship between attitude (pitch/diameter)and the amount of superconducting wire. Next, select the step winding and the winding diameter of the superconducting wire capable of making the amount of shrinkage in the diameter of the superconducting wire is equal to or less than the average of the module is, and is able to make use of superconducting wires is equal to or smaller than the average of the modulus value.

[0035] In another case on the outer side of the superconducting layer can be formed by holding the turns of the layer. When forming the holding layer coils on the outer side of the superconducting layer can be expected operation of attaching the superconducting layer to the inner side. Using the operation of attaching the compression of the superconducting layer in diameter can proceed smoothly. The material holding the coils of the layer can be formed Mat is Yalom, able to give the specified strength of attachment on the superconducting layer, for example, may preferably be used a metal strip, in particular, copper tape or the like

[0036] When using the holding coils of the layer, also preferably placed cushioning layer between the holding coils of the layer and the superconducting layer. When holding the coils of the layer using a metal tape, usually metal, silver or the like is used for the superconducting wire, and therefore forms the contact between the metals between the holding coils of the layer and the superconducting layer, and there is the possibility of damage to the superconducting wire. Therefore, when the shock-absorbing layer is placed between the two layers can be prevented damage to the superconducting wires by eliminating direct contact of metals. As a specific material of the cushioning layer may preferably be used an insulating paper or carbon paper.

[0037] it is also preferable to provide a protective layer on the outermost periphery of the cable core. The protective layer is attached to the function of mechanical protection of the outer layer of conductor and insulation from the insulating pipe. As a material of the protective layer can be applied insulating paper of Kraft paper or the like, or plastics the new tape.

[0038] on the other hand, thermal insulating tube can be formed using any structure provided that the structure is a structure capable of supporting thermal insulation of refrigerant. For example, it notes the location of the insulating element between the twin tubes of the double structure comprising an outer tube and an inner tube, and the vacuum gap between the inner pipe and the outer pipe. Usually between the inner pipe and the outer pipe is superisolated obtained by laminating a metal foil and plastic mesh. In the inner space of the inner pipe contains at least a layer of a conductor, and it is filled with refrigerant in liquid nitrogen or the like for cooling the layer of the conductor.

[0039] the Refrigerant can support the superconducting wire in the superconducting state. Currently, the most practical to use as a refrigerant in liquid nitrogen, but otherwise, it is possible to use liquid helium, liquid hydrogen, or the like, In particular, in the case of liquid nitrogen can be formed in the cable, which is the isolation liquid which does not swell polypropylene, and excellent in characteristics withstand voltage DC or characteristics withstand voltage Imp., even when the and the insulating layer consists of a composite tape with high k, that is, having a greater thickness polypropylene.

[0040] This invention is applicable to superconducting cables AC and DC. In particular, it is preferable to apply the invention to a superconducting DC cable, in which the limiting step of winding a superconducting wire in the superconducting layer is small, as described above. However, even in the case of AC cables, for example, (1) when the layer conductor and the shielding layer are formed respectively sole layers, (2) when the layer conductor and a shielding layer formed of several layers, the need to adjust the step is small, and preferred responses to thermal compression short step can be adopted as a step of winding a superconducting wire. Therefore, even in the case of AC cable mechanism of the absorption of the heat of compression can be attached to the cable conductor.

The results of the invention

[0041] According to the superconducting cable according to the invention can be achieved the following results.

[0042] (1) While providing a layer of stress relaxation on the inner side of the superconducting layer, when the superconducting wire is compressed by cooling at least part of the value corresponding to the amount of compression in diameter with erprobte layer, corresponding to this compression can be absorbed by a layer of stress relaxation. Therefore, can be excluded functioning of the superconducting wire with excess tension and may be limited to the reduction of the superconducting characteristics.

[0043] (2) the Mechanism of absorption values of the heat of compression can be performed in the cable conductor with a simple structure by providing a layer of stress relaxation on the inner side of the superconducting layer. Therefore, it is not necessary to use large-scale construction with slip peripheral end portion of a cable or the like, making the whole structure is able to absorb the amount of heat of compression of the superconducting wire.

[0044] (3) While providing a mechanism for the absorption of the heat of compression in the cable conductor, the amount of compression of the superconducting wire can be absorbed not only in the superconducting cable, but also in single-core superconducting cable, which is considered difficult to provide conventional absorption mechanism.

[0045] (4) When providing a layer of stress relaxation, absorbing the magnitude of the compression ratio of the diameter of the outer layer of the conductor through the insulating layer as such, there is no need to re-form the layer of stress relaxation for the outer layer of the conductor, and an increase in dia is the ETP of the cable can be restrained.

[0046] (5) During the step of winding a superconducting wire, 4 to 6 times larger than the diameter of the winding may be formed of a superconducting cable capable of absorbing the amount of compression of the superconducting wire in a simple structure and capable of reducing the amount of superconducting wire as possible.

[0047] (6) the provision of the holding coils of the layer on the outer side of the superconducting layer, the amount of shrinkage in diameter can be smoothly absorbed by the layer of stress relaxation by pressing the superconducting layer to the inner peripheral side, making a smooth flow compression in diameter in accordance with thermal contraction of the superconducting wire.

Brief description of drawings

[0048] [Figure 1] Figure 1 is a view in cross section of a superconducting cable according to the invention.

[Figure 2] Figure 2 is a graph showing the relationship between attitude (pitch/diameter)and the amount of shrinkage in diameter when cooled superconducting wire.

[Figure 3] Figure 3 is a graph showing the relationship between attitude (pitch/diameter)and the amount of superconducting wire.

[Figure 4] Figure 4 is a view in section of a conventional superconducting cable according to the prior art.

Description reference position and about the values

[0049] 100 superconducting DC cable

10 lived, frame 11, 12 layer stress relaxation inside, 13 layer-conductor 14A, 14B cushioning layers 15A, 15C holding the turns of the layers 16 insulating layer/outer layer of stress relaxation, 16A of the insulating layer 17, the conductor return line, 17A shielding layer, protective layer 18, 20 of the insulating tube 21 and the inner tube, outer tube 22, 23 corrosion resistant layer

The best option of carrying out the invention

[0050] Alternative embodiments of the invention will be explained as follows.

[0051] (Option 1)

[The structure]

As shown in figure 1, the superconducting cable 100 DC according to the invention consists of a single cable core 10 and the insulating tube 20 containing the core 10.

[0052] [Lived]

Lived 10 sequentially from its center includes a frame 11, a layer 12 of stress relaxation inside layer conductor 13, cushioning layer 14A, the holding coils of the layer 15A, an insulating layer (also the outer layer of stress relaxation) 16, the outer layer conductor (conductor return line 17), a shock-absorbing layer 14C, the holding coils of the layer 15 and a protective layer 18.

[0053] <Frame>

To perform frame 11 is corrugated stainless steel tubing. When applied to the hollow frame 11, igonorant can be a channel for the flow of refrigerant (in this case liquid nitrogen).

[0054] <a Layer of stress relaxation of the interior side>

The layer 12 of stress relaxation of the inner part formed by winding on the frame 11 of the composite tape PPLP (registered trademark), manufactured Sumitomo Denki Kogyo K.K. formed by laminating Kraft paper and polypropylene film. In this case, the selected material and its thickness, is capable of absorbing the amount of compression in diameter when cooled below a layer of conductor 13. More specifically, is used PPLP with respect to k the thickness of the polypropylene film to the thickness of the entire composite tape, equal to 60%.

[0055] <Layer-conductor>

To perform layer wire 13 is used ribbon wire with Bi2223 phase in the shell of Ag-Mn having a thickness of 0.24 mm and a width of 3.8 mm Layer conductor 13 is formed by winding such a tape wire on layer 12 stress relaxation inner side in several layers. In this case, the superconducting wire wound on it in 4 layers.

[0056] <a Cushioning layer and a holding layer coils>

Cushioning layer 14A formed on the layer of the conductor 13, and then it formed the holding coils of the layer 15A. Cushioning layer 14A is formed by winding several layers of Kraft paper layer conductor, and holding the coils of the layer 15A is formed by winding copper tape. Amortiziruemoe 14A prevents contact between the metal layer and the conductor retaining layer coils 15A, and holding the coils of the layer 15A makes smooth flow compression in diameter layer of the conductor 13 when cooled by attaching a layer of a conductor 13 to the inner peripheral side by the shock-absorbing layer 14A.

[0057] <an Insulating layer/outer layer of stress relaxation>

An insulating layer 16 formed on the holding coils of the layer 15A. In this case, the insulating layer 16 is formed PPLP with a value of k equal to 60%. The insulating layer 16 attached to the function of the electrical insulation layer of the conductor 13, and also given the function of the outer layer of stress relaxation to absorb the amount of compression in diameter in accordance with cooling below the outer layer of the conductor. During the formation of the outer layer of stress relaxation by the insulating layer 16 is not necessary to separately form the outer layer of stress relaxation, and therefore may be limited to an increase of the external diameter of the cable core.

[0058] in Addition, although not shown, the inner peripheral side of the insulating layer formed with an inner semi-conducting layer, and its outer peripheral side is formed with an external semi-conductive layer. Any of these semiconductor layers is formed by winding carbon paper.

[0059] <Outer layer-conductor (conductor return line)>

Outer layer-conductor (Prov is'dnik return line 17) is provided on the outer side of the insulating layer 16. If required DC path for the return current, and therefore, when the unipolar transmission is provided a conductor 17 return line, used as a path for the reverse current. Conductor return line 17 is formed of a superconducting wire like layer conductor 13 and has a bandwidth in the transmission that is similar to the bandwidth of the layer of conductor 13.

[0060] <a Cushioning layer and a holding layer coils>

Then on the outer layer conductor formed cushioning layer 14C, and then it formed the holding coils of the layer 15V. Cushioning layer 14C and the holding coils of the layer 15 are formed from materials similar to the materials of the cushioning layer 14A and the retaining layer coils 15A provided on the outer side of the layer of the conductor 13. Cushioning layer 14B prevents contact between the metal conductor return line 17 and the retaining layer coils 15V and makes smooth the flow of compression in the diameter of the conductor 17 return line by attaching the conductor return line 17 to the inner peripheral side by the shock-absorbing layer 14C.

[0061] <a Protective layer>

The outer side of the conductor 17 a return line provided with a protective layer 18 formed of an insulating material. In this case, the protective SL is th 18 is formed by winding Kraft paper. Through the protective layer 18 of the conductor 17 and the return line can be protected mechanically, thermally insulated pipe (inner pipe 21) can be isolated, and can be prevented bypass the reverse current on the heat insulating tube 20.

[0062] <thermal Insulating pipe>

thermal insulating pipe 20 contains a double pipe including an inner tube 21 and outer tube 22, and between the inner and outer tubes 21, 22 is formed of a vacuum heat insulating layer. Inside the vacuum heat-insulating layer is the so-called superisolated formed by laminating a plastic mesh and metal foil. The space formed between the inner side of the inner pipe 21 and the housing 10, is a channel for the flow of refrigerant. In addition, the corrosion resistant layer 23 may be formed on the outer periphery of the insulating pipe 20 using polyvinyl chloride or the like as necessary.

[0063] (Example of trial calculation)

Then, in the manufacture of superconducting cable perform the following test calculation in order to make the amount of superconducting wire as small as possible, while keeping in mind the formation of a short step superconducting wire so that it was possible to make as small as possible the size of the Atiyah in diameter.

[0064] First studied the relationship between the step of winding diameter and the winding of the superconducting wire, comprising a superconducting layer, attitude (pitch/diameter), and the amount of compression of the diameter of the superconducting wire. In this case, the diameter of the winding is formed in 3 ways: 20 mm ⊘, 30 mm ⊘, 40 mm ⊘and the amount of compression of the diameter, when the superconducting wire is compressed by 0.3% when cooled during operation, a test is calculated using the coefficients of linear expansion of the respective materials. The result of the calculation is shown in graph 2.

[0065] As shown in this graph, when the "attitude (pitch/diameter)remains the same, it is known that the larger the diameter of the winding, the less the amount of compression of the diameter. In addition, it is also known that, when the diameter of the winding remains the same, the less "attitude (pitch/diameter), the less the amount of compression of the diameter. The result shows that the amount of shrinkage of the diameter, you need to consume less, when you select a short step.

[0066] Then investigated the relationship between attitude (pitch/diameter)and the amount of superconducting wire. In this case, the amount of superconducting wire, when the superconducting wire is located along the longitudinal direction of the wrapped object, i.e. to the Yes superconducting wire is longitudinally in line, is 1.0, and shows how the amount of superconducting wire changes when "attitude (pitch/diameter)" changes in relative value. The result of this is shown in graph 3.

[0067] As shown in the graph, it is seen that, although the amount used of the superconducting wires are not greatly increases up to the "attitude (pitch/diameter)in about 6,0, the amount of superconducting wire increases rapidly when this ratio is less than 4.0.

[0068] From these two results of test calculations it is clear that "attitude (pitch/diameter)can be made comprising about from 4.0 to 6.0, when the amount of compression of the superconducting wire cooling brought up easily absorbed level, and also made a small amount of superconducting wire.

[0069] Table 1 summarizes the components of the materials and the sizes of the respective parts of the superconducting cable (50 kV, 10000 (A) according to the invention, constructed on the basis of the result of trial calculation. In addition, the steps of winding a superconducting wire layer of the conductor and the outer layer of the conductor 5 times larger than the diameters of the winding. Namely, steps 210 mm in the layer Explorer and approximately 274 mm in the outer layer of the conductor.

[0070]

[Table 1]
an elementmaterialouter diameter (mm) and other
framecorrugated stainless steel tubing30
layer stress relaxation inner sidePPLP42 (thickness: 6 mm)
layer-Explorersuperconducting wire with Bi2223 phase46,4 (4 layers)
cushioning layer/holding coils of the layerKraft paper/copper tape47,4
an insulating layer/a layer of stress relaxation outer sidePPLP54,7 (thickness: 3 mm)
the outer layer conductorsuperconducting wire with Bi2223 phase57,5 (layer 3)
cushioning layer/holding coils of the layerKraft paper/copper tape59,5
the protective layerKraft paper61,7 (thickness 1 mm)
external cable diameter116

[0071] In the design according to table 1, when the cooling shrinks the diameter of the frame as such. When she is given the ratio of 0,3%, the amount of compression of the diameter of the Arkasa becomes equal to 0,09 mm On the other hand, the amount of compression of the diameter of the superconducting wire in the ratio of 0.3% is 0.45 mm in terms of diameter of the winding 42 mm and the pitch of the winding 210 mm, Therefore, shows that only 20% of the value of the compression ratio of the diameter of the layer of the conductor can be absorbed by the amount of compression of the diameter of the frame. Therefore, it is seen that, when the amount of compression of the diameter of the layer stress relaxation inner side is equal to 0.36 mm, 100% of the amount of compression of the diameter of the layer of the conductor can be absorbed with a total value of the compression ratio of the diameter of the carcass layer and the stress relaxation inside. In addition, it is seen that, when the layer stress relaxation inner side has a value of the compression ratio of the diameter of 0.45 mm, the full value of the compression ratio of the diameter of the layer of the conductor can be absorbed only by a layer of stress relaxation inside.

[0072] Although the explanation is given in detail and with reference to particular embodiments, the person skilled in the art it is obvious that the invention may be changed or modified without deviating from the essence and scope of the invention.

In addition, this application is based on patent application Japanese patent application Japan No. 2004-350327), filed December 2, 2004, and its content is incorporated here by reference.

Industrial applicability

[0073] the Superconducting cable according to the invention may be riment as a means of power transmission. In particular, the superconducting cable according to the invention can be preferably applied as a solid means of power transmission DC.

1. Superconducting cable containing a superconducting wire, comprising a superconducting layer by spiral winding; and a layer of stress relaxation provided for in cable vein on the inner side of the superconducting layer, and the amount of compression in the direction of the diameter of the superconducting layer in accordance with the cooling of the superconducting wire refrigerant is absorbed by the layer of stress relaxation.

2. Superconducting cable according to claim 1, additionally containing

component cable element, provided on the inner side of the layer of stress relaxation, while the amount of compression in the direction of the diameter of the superconducting layer in accordance with the cooling of the superconducting wire refrigerant is absorbed by the layer of stress relaxation and the components of the cable element.

3. Superconducting cable according to claim 1, in which the superconducting layer includes a layer conductor, and a layer of stress relaxation includes a layer of stress relaxation inner side, is formed on the inner side of the layer of the conductor.

4. Superconducting cable according to claim 3, in which when the layer stress relaxation the use insulating layer, provided on the outer side of the layer of the conductor, as a layer of stress relaxation outer side, and a superconducting layer includes an outer layer conductor formed on the outer side of the insulating layer.

5. The superconducting cable of claim 1, wherein the step of winding the superconducting wire is 4-6 times larger than the diameter of winding a superconducting wire.

6. Superconducting cable according to claim 1, in which component cable element includes a frame, and this frame is either corrugated tube or spiral ribbon-like element.

7. Superconducting cable according to claim 1, in which the layer of stress relaxation is formed of at least one of Kraft paper, plastic tapes and composite tape of Kraft paper and plastic tape.

8. Superconducting cable according to claim 1, additionally containing holding the turns of the layer on the outer side of the superconducting layer.

9. Superconducting cable according to any one of claims 1 to 8, and this superconducting cable is a superconducting DC cable.



 

Same patents:

FIELD: electrical engineering.

SUBSTANCE: invention is related to the field of electric engineering, in particular, to superconductive cable, which contains frame (2), layer (3) of superconductive conductor formed around external periphery of frame (2), insulating layer (4) formed around external periphery of conductor layer (3), screening layer (6) formed around external periphery of insulating layer (4), and normally-conductive metal layer (5) formed between insulating layer (4) and screening layer (6). Normally-conductive metal layer (5) is located inside the screening layer (6), has inductivity higher than of screening layer (6).

EFFECT: provides suppression of temperature rise in case of accidents, such as short circuits, and reduction of AC losses in normal mode of operation, since high currents flow through screening layer.

10 cl, 3 dwg

FIELD: electricity.

SUBSTANCE: thermo stabilised superconductors are implemented in the shape of matrix from metal or alloy, containing fibers of superconducting material and combination of rare-earth metals with extremely high heat capacity at low temperatures. At that superconductor contains at least two metallic tubes of unconditioned cross-section filled by combination of rare-earth metals and distance between tubes is not less then two tube linear dimensions. Superconductor has external envelope made from metal with high conducting properties. Tubes with combination of rare-earth metals can be distributed either by section of conductor as in matrix or by envelope.

EFFECT: extension of superconductor capabilities by means of increasing of its heat-absorbing abilities.

4 dwg

FIELD: chemistry; electric wire.

SUBSTANCE: material in the form of oxide superconducting wire, which comprises oxide superconducting part and metal coating thereon, distinguishing itself by the fact that the above metal coating material during stress-strain relationship test features relative rupture strain of 30% or more.

EFFECT: material in the form of superconducting wire features high critical current density and is less susceptible to vertical cracking or breaking during manufacture.

14 cl, 3 dwg, 1 tbl, 10 ex

FIELD: applied superconductivity.

SUBSTANCE: proposed composite superconductor that can be used to manufacture superconductors for superconducting windings suffering heavy mechanical loads (at operating pressure across conductor higher than 100 MPa) as well as for superconducting windings and devices operating under variable conditions, such as superconducting inductive energy storage devices, dipole and quadrupole magnets for charged particle accelerators, has superconducting material fibers, matrix of high-conductivity metal, such as copper and rare-earth intermetallide possessing high thermal capacity at low temperatures. Composite superconductor is provided with metal sheath accommodating rare-earth intermetallide; mentioned wires and conductor are welded together. Metal sheath can be made in the form of hollow cylindrical conductor or flat strip with hollow interlayer, their hollow spaces being designed to dispose rare-earth intermetallide. Composite superconductor is made in the form of a few multiple-fiber composite superconducting wires twisted around hollow cylindrical conductor accommodating rare-earth intermetallide. Composite superconductor can be made in the form of flattened single-lay strand of several multiple-fiber composite superconducting wires and several hollow cylindrical conductors of same diameter accommodating intermetallide which alternately vary within strand. Rectangular-section conductor is made of high-conductivity metal and has longitudinal groove.

EFFECT: enlarged functional capabilities.

7 cl, 8 dwg

The invention relates to high-temperature superconductivity and can be used for single core and multi-core composite conductors based on ceramics (Bi, Pb)(2)Sr(2)Ca(2)Cu(3)O(y) with high superconducting properties

FIELD: applied superconductivity.

SUBSTANCE: proposed composite superconductor that can be used to manufacture superconductors for superconducting windings suffering heavy mechanical loads (at operating pressure across conductor higher than 100 MPa) as well as for superconducting windings and devices operating under variable conditions, such as superconducting inductive energy storage devices, dipole and quadrupole magnets for charged particle accelerators, has superconducting material fibers, matrix of high-conductivity metal, such as copper and rare-earth intermetallide possessing high thermal capacity at low temperatures. Composite superconductor is provided with metal sheath accommodating rare-earth intermetallide; mentioned wires and conductor are welded together. Metal sheath can be made in the form of hollow cylindrical conductor or flat strip with hollow interlayer, their hollow spaces being designed to dispose rare-earth intermetallide. Composite superconductor is made in the form of a few multiple-fiber composite superconducting wires twisted around hollow cylindrical conductor accommodating rare-earth intermetallide. Composite superconductor can be made in the form of flattened single-lay strand of several multiple-fiber composite superconducting wires and several hollow cylindrical conductors of same diameter accommodating intermetallide which alternately vary within strand. Rectangular-section conductor is made of high-conductivity metal and has longitudinal groove.

EFFECT: enlarged functional capabilities.

7 cl, 8 dwg

FIELD: chemistry; electric wire.

SUBSTANCE: material in the form of oxide superconducting wire, which comprises oxide superconducting part and metal coating thereon, distinguishing itself by the fact that the above metal coating material during stress-strain relationship test features relative rupture strain of 30% or more.

EFFECT: material in the form of superconducting wire features high critical current density and is less susceptible to vertical cracking or breaking during manufacture.

14 cl, 3 dwg, 1 tbl, 10 ex

FIELD: electricity.

SUBSTANCE: thermo stabilised superconductors are implemented in the shape of matrix from metal or alloy, containing fibers of superconducting material and combination of rare-earth metals with extremely high heat capacity at low temperatures. At that superconductor contains at least two metallic tubes of unconditioned cross-section filled by combination of rare-earth metals and distance between tubes is not less then two tube linear dimensions. Superconductor has external envelope made from metal with high conducting properties. Tubes with combination of rare-earth metals can be distributed either by section of conductor as in matrix or by envelope.

EFFECT: extension of superconductor capabilities by means of increasing of its heat-absorbing abilities.

4 dwg

FIELD: electrical engineering.

SUBSTANCE: invention is related to the field of electric engineering, in particular, to superconductive cable, which contains frame (2), layer (3) of superconductive conductor formed around external periphery of frame (2), insulating layer (4) formed around external periphery of conductor layer (3), screening layer (6) formed around external periphery of insulating layer (4), and normally-conductive metal layer (5) formed between insulating layer (4) and screening layer (6). Normally-conductive metal layer (5) is located inside the screening layer (6), has inductivity higher than of screening layer (6).

EFFECT: provides suppression of temperature rise in case of accidents, such as short circuits, and reduction of AC losses in normal mode of operation, since high currents flow through screening layer.

10 cl, 3 dwg

FIELD: electrical engineering.

SUBSTANCE: invention relates to electrical engineering, particularly to super-conducting cable capable to absorb thermal compression of super-conducting wire. Super-conducting cable comprises a super-conducting wire coiled to form a super-conducting layer (layer-conductor) (13), reverse conductor (17), a layer of strain relaxation (12), an insulating layer or an outer strain relation layer (16) arranged on the super-conducting layer outer side and cable carcass, (11) arranged on the strain relaxation layer inner side.

EFFECT: superconducting layer compression absorption by cooling superconducting wire with coolant.

9 cl, 4 dwg, 1 tbl

Power cable line // 2366016

FIELD: electrical engineering.

SUBSTANCE: in a line for transmitting and distributing direct current a power cable line is provided, which makes easier supply of electricity to various devices used for operation of that line. The power cable line comprises power cables (1lg, 1r, 1p, 1m, 1n), which transmit and distribute direct current, a unit (2) for superimposing an alternating current component on these cables, and an electricity tap off unit (3), meant for tapping off power of the superimposed alternating current component from this cable. Unit (2) superimposes the alternating current component on the power cable, and electrical energy of the alternating current is transmitted together with electrical energy of direct current on the power cable. The tap off unit (3), located at a certain section of the cable, taps off this alternating current component and transmits it to different devices.

EFFECT: invention allows for designing a cable, which makes easier tapping off electrical energy during transmission of direct current.

4 cl, 13 dwg

FIELD: physics; conductors.

SUBSTANCE: invention relates to making composite superconductors with improved current-carrying capacity and can be used, particularly, for making superconducting magnet windings. According to the invention, the multi-layer tape nanostructure composite based on a superconducting niobium-titanium alloy contains alternating layers of niobium and niobium alloy-(25-45) wt % titanium, with layer thickness of not more than 50 nm. The thickness of each niobium layer is 50-70% of the alloy layer thickness.

EFFECT: obtaining a composite with critical current density of 58000 A/cm2 in a magnetic field with flux density of 6 T.

2 cl, 3 tbl

FIELD: physics; conductors.

SUBSTANCE: invention relates to making composites with improved current-carrying capacity and can be used, particularly, for making superconducting magnet windings. According to the invention, the method of making multi-layer tape nanostructure composites based on a niobium-titanium alloy for composite superconductors involves multi-cycle rolling, each cycle of which involves assembling a packet from alternating plates of niobium and a niobium-titanium alloy, attaching the plates to each other into a packet through diffusion welding at temperature 800-900C and pressure 20-40 MPa for 0.5-3 hours, hot vacuum rolling and cold rolling. In the first cycle, the initial plates are components of the composite, and in the second and following cycles - plates, obtained from the previous cycle. To stabilise the superconductor before the last rolling cycle, the welded packet is put into a copper casing. Thickness of the copper casing is 3-25% of the thickness of the packet.

EFFECT: increased critical current density.

2 cl, 2 tbl, 6 ex

FIELD: metallurgy.

SUBSTANCE: on surface of plate made from titanium it is located powder of high-temperature superconducting (HTSC) compound and it is implemented cold deformation by means of rolling with receiving of preferred-orientation scales of HTSC compound. Scales are separated from substrate, it is collected multilayer packet from scales with alternating spacers from silver and it is pressed with formation of multilayer composite silver-HTSC-silver. Composite is placed into envelope made of silver, it is rolled with receiving of band of specified geometry and is thermal treated at temperatures in the range 800-930C during 20-100 hours.

EFFECT: increasing current-carrying ability of band and filling factor by superconductor.

2 ex

FIELD: electricity.

SUBSTANCE: invention relates to electrical engineering, specifically to thermo-stabilised superconductors based on the Nb3Sn compound and methods of making the said superconductors. The thermo-stabilied superconductor based on the Nb3Sn compound is made in form of a matrix from a metal or alloy, containing superconducting material fibre, metal tubes filled with a rare-earth metal compound with extremely high heat capacity at low temperatures, an outer hollow copper cylinder and a thin cylindrical shell made from titanium and/or niobium placed coaxially between the matrix and the outer hollow copper cylinder. The metal tubes are tightly pressed to each other in the gap between the cylinder and the shell in the first version, or in a gap made in the radial direction in the wall of the cylinder in the second version. The method of making such thermo-stabilised superconductors is described.

EFFECT: wider functional capabilities of a thermally insulated superconductor due to presence in the superconductor of a rare-earth intermetallic compound with extremely high heat capacity at helium temperatures, which increases mean heat capacity of the superconductor by 5-6 times.

12 cl, 11 dwg

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