Superconductive cable

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

 

The present invention relates to a superconducting cable that contains a frame, the superconducting layers and the insulating layer. More precisely, the present invention relates to a superconducting cable, allowing discharge of high currents resulting from accidents short circuit and the like, in order to keep the dissipation in the superconducting layer, and also ensure the reduction of AC losses during the passage of normal current.

PRIOR art

Known superconducting cables, which includes a superconducting conductors, formed of high-temperature superconducting wires based on bismuth and the like. On figa shows a cross section of a three-phase superconducting cable three-core type, containing three cable cores, figv shows a General view of the veins. Superconducting cable 100 contains three stranded cable core 102, the prisoners inside the insulating tube 101.

Thermal insulation pipe 101 contains a double pipe consisting of a corrugated external pipe 101a and a corrugated inner tube 101b and insulating material (not shown)located between them, inside a double pipe vacuumed. Each cable has lived 102 includes, in order from the most inner part of the frame 200, the superconducting conductor 201 of the insulating layer 202, the shielding layer 203, and defectoscopy layer 204. The frame 200 is made of normally-conductive material such as copper or aluminum, is either a hollow profile, or solid. Superconducting conductor 201 formed by spiral winding superconducting wires in and around frame 200 in the form of multiple layers. Insulating layer 202 is formed by wrapping insulating material, such as semisynthetic insulating paper. The shielding layer 203 formed by spiral winding a superconducting wire, such superconducting conductor 201, and around the insulating layer 202. In normal conditions there is induced in the shielding layer 203 current, essentially the same amplitude as the current flowing through the superconducting conductor 201, in the direction opposite him. The magnetic field created by an induction current, can suppress the magnetic field generated by a superconducting conductor 201, essentially nullifying the magnetic field emerging from the cable core 102 to the outside. Usually, the space 103 defined by the inner pipe 101b and the respective cable cores 102, forms a channel for the flow of refrigerant. Additionally, the corrugated external pipe 101a formed reinforcing layer (protective covering external sheath) 104 PVC.

In Luceafarul, such as a short circuit or circuit to earth in power supply systems of a superconducting cable, will generate large currents. Therefore, there is a need to take measures to suppress emergency power such as the installation of current-limiting devices, since otherwise large currents in excess of the steady-state currents will flow through the superconducting cable. For example, at a nominal voltage of 350 MV and a rated current of 3 kA, the short circuit current of about 31.5 kA/s will be formed in case of accidents, short circuit, and exemplary line current of about 31.5 kA will take place within 1 second When large currents exceeding the critical value of the current flow through the superconducting conductor, he ceases to be superconducting, i.e. to transfer to a normal conductor, when this change will occur dzhoulevo heat loss. At the same time, large currents will be induced in the shielding layer, which will change the shielding layer, move it in a normal conductor, causing dzhoulevo loss. In particular, when there is a significant dzhoulevo loss, it can cause burnout superconducting wires, forming a superconducting conductor or shielding layer, or may suddenly raise their temperature to vaporize the refrigerant in the voids within the of wires, cause bloat (nitrogen bubbling) superconducting wires, and reducing the critical current value. Moreover, the evaporation of the refrigerant may cause dielectric breakdown. In this case, it will take a long time to repair damage caused by such accidents.

Therefore, the developed technology for placing a copper layer between the superconducting conductor and the insulating layer (see Japanese laid patent publication No. 2000-067663 (claims and Fig 1)or placing a copper layer on and around the outer circumference of the protective layer (see Japanese laid patent publication No. 2001-052542 (claims and Fig 1)to divert currents in the metal layers to contain the heat in the superconducting layers in the case of large currents caused by accidents, such as a short circuit. In Japanese laid patent publication No. 2002-008459 (claims and Fig 1) disclosed a configuration that includes multiple shielding layers and multiple copper layers provided on the outer circumference of the insulating layer, the shielding layers are located between the copper layers.

However, traditional techniques have a disadvantage in increasing the AC losses during the passage of normal currents

The methods disclosed in these publications include copper layer for discharge of the emergency currents in the copper layer to protect the superconducting layer in the event of an accident such as a short circuit, and reduce eddy current losses during the passage of normal current. However, these techniques use a configuration in which a copper layer is provided on the outer circumference of the superconducting layer of the superconducting conductor or shielding layer)formed of superconducting wires, i.e. the configuration in which the copper layer is present outside of the superconducting layers. Such configurations have the disadvantage that the currents will flow through the copper layer, instead of the superconducting layer during the passage of normal currents, the result will be an increase of loss of AC power and, in particular, increased heat losses.

In cable conductor deeper layer outside of the superconducting layers and the copper layer has a higher inductance during the passage of normal currents despite the accident, such as a short circuit. Therefore, in the standard configurations of the copper layer will have a lower inductance than the superconducting layers. Hence with the passage of normal currents, the currents will freely flow through the copper layer, increasing dzhoulevo on the ERI. In particular, in the third link, as it has more copper layers than the superconducting layers and copper layers are provided outside the respective superconducting layers, currents flowing through the copper layers, will cause a much greater loss of AC.

A BRIEF STATEMENT of the substance of the INVENTION

The technical task of the present invention is to provide a superconducting cable, providing suppression of temperature increase in case of accidents such as short circuit, and also ensure the reduction of AC losses during the passage of normal current.

Conducted various studies and as a result, it was found that dzhoulevo loss significantly more than the loss of eddy current, during the passage of normal current. Therefore, the task according to the present invention is solved by forming the protective layer of the superconducting metallic material on the inner circumference of the superconducting layers, in particular the inner circumference of the second superconducting layer to reduce dzhoulevo loss in steady state.

According to the present invention proposed a superconducting cable, containing the skeleton of a normal-conducting metal, the first superconducting layer formed around the outside is it the circumference of the frame, insulating layer formed around the outer circumference of the first superconducting layer, the second superconducting layer formed around the outer circumference of the insulating layer, and a normal-conducting metal layer formed between the insulating layer and the second superconducting layer.

Hereinafter the present invention will be described in more detail.

The present invention relates to the creation of superconducting cable that contains a cable core that includes in order from the most inner part of the frame, the first superconducting layer, insulating layer and the second superconducting layer. The superconducting cable can be either single-phase cable comprising one cable core, which is described above, and multiphase cable comprising a large number of cable conductors, which are described above. Such multiphase cable may be, for example, three-phase superconducting cable three-core type, which includes three twisted cable placed inside the insulating tube.

The first superconducting layer can be, for example, a layer of a superconducting conductor, the second superconducting layer can be, for example, the shielding layer. For the formation of the superconducting layers can be used wires of superconducting material is impressive. Superconducting wires can be wire manufactured through a sequence of processing operations powder-in-tube. For example, the superconducting wires can be wire manufactured by powder loading superconducting raw material on the basis of bismuth, such as superconducting raw material of Bi2223 or Bi2212 inside metal pipes made of silver or a silver alloy, then pull the wire to form the wire, binding the resulting wires, and then putting them into a single pipe for forming a multi-strand wire. The above-mentioned superconducting wire can be tape wires fabricated by means of additional rolling stranded wires. Superconducting wires can be wires, each of which is composed of a tube bundle formed of silver or a silver alloy, superconducting material, enclosed in a tube bundle.

In case of accidents, such as a short circuit, the cable according to the invention takes emergency currents in the armature or normal-conducting metal layer provided on the inner circumference of the second superconducting layer, and also prevents accidental currents in the superconducting layers. For example, when the superconducting layers are formed of superconducting wires, accounted for the Lenna mentioned tube bundle and a superconducting material, if the superconducting layers are transformed from superconducting patterns in normal-conductive structure due to temperature increase caused by the passage through them of the emergency current, the superconducting material will be transformed into an insulator, thereby causing currents to flow through the tube bundle. In order to suppress the heat generation caused by the current passing through the tube bundle, it is necessary that the superconducting wires contained a certain number of tubes in the bundle. On the other hand, if the ratio of the tube bundle in the superconducting wires is increased, the fraction of superconducting material is reduced, thereby reducing the critical current density. Therefore, in order to increase the critical current density, the diameter of the superconducting wire must be increased, i.e. the very superconducting cable must be made larger. This is undesirable when you want a compact cable configuration. Therefore, in order to implement the containment allocation of heat and reduction of critical current density in a balanced manner, it is desirable that the coefficient of the tube bundle was in the range from 1.5 or more and 3.0 or less. The term "coefficient of the tube bundle reflects the ratio of the cross-sectional area of the tube bundle to the cross-sectional area of the superconducting material (square the cross-section of the tube bundle/the cross-sectional area of the superconducting material).

Preferably, the above-mentioned superconducting layers were formed by spiral winding wires of superconducting material and were both single layer and multilayer. Preferably, the amount used of the superconducting wires was chosen so that the superconducting layers can be maintained in a superconducting state at the operating temperature, i.e. during the passage of normal current and maximum current. When the superconducting layers is made of a multilayer, it is desirable that the number of layers was determined similarly to the above. Moreover, when the superconducting layers is made of a multilayer, preferably between respective layers were located interlayer insulating layers by wrapping Kraft paper between them, as the supply of such interlayer insulating layer is to reduce the loss of AC. In addition, when the superconducting layers is made of a multilayer, the direction of winding step of winding a superconducting wire can be adjusted so that the respective layers are uniformly divided currents, to reduce the alternating current generated in the superconducting layers.

A distinctive feature of the present invention is that a protective layer made of a normally conductive metal is practical material (normal-conducting metal layer), provided between the insulating layer and the second superconducting layer, more specifically, on the inner side of the second superconducting layer. Additionally, there is no normal-conducting metal layer for the passage through it of the currents on the outer circumferences of the superconducting layers, in particular, on the outer circumference of the second superconducting layer. Normal-conducting metal may be a metal having a low electrical resistance (copper or aluminum have a resistivity ρ 2×10-7Ω·cm at 77 K) at temperatures near the temperature of the refrigerant used for the superconducting cable (if used as a refrigerant in liquid nitrogen at the temperature of liquid nitrogen). For example, this is normal-conducting metal may be copper, aluminum, silver, copper alloys, aluminium alloys or silver alloys. Normal-conducting metal layer may be formed using pipes made of these normally-conductive metallic materials. It is preferable to use a tape wire, is made by processing the same material in the form of a tape, or a round wire made by pulling the wires of the same material, to give shape with a circular cross section, because the use of so the x wire will facilitate the formation of a normal-conducting metal layer. For example, preferably, wire, made from a variety of normally-conductive metallic material, wound around the outer circumference of the insulating layer to form a normal-conducting metal layer. It is preferable to use a wire made of a normally conductive metal material for forming a normal-conducting metal layer, because the use of such wires will facilitate its formation and may facilitate the penetration of the refrigerant through the insulating layer, the first superconducting layer and the frame is provided under a normal-conducting metal layer.

In the case of multiple wires made of the above-mentioned normal-conducting metal material for forming a normal-conducting metal layer, it is preferable that each of the wires includes an insulating layer around its outer circumference. Currents flowing through the superconductive conductor, generate magnetic fields that induce eddy currents in normal-conducting metal layer. In order to suppress the occurrence of such eddy currents, it is preferable that the outer circumference of the normal-conducting metal wires were covered with insulating material. The insulation layer of the wire m which may be formed, for example, enamel.

Although the above-mentioned normal-conducting metal layer may be a single layer, normal-conducting metal layer made of a multilayer, may have an increased cross-sectional area to effectively divert emergency currents. In the case of wires of the normal-conducting metal material for forming a normal-conducting metal layer, the cross-sectional area of this layer can be arbitrarily adjusted by adjusting the number of wires in it. Thus, the use of wires is preferred because it is easier to satisfy than using pipes for forming the same layer. The larger the cross-sectional area normal-conducting metal layer, the large emergency currents can be given through it. However, normal-conducting metal layer having an excessively increased cross-sectional area will increase the size of the cable, and therefore normal-conducting layer should have a cross-sectional area, allowing only sufficient abstraction emergency current through it.

When normal-conducting metal layer formed in a multilayer configuration, preferably, h is usually used for the respective layers, components of the same metal layer were electrically isolated from one another. By isolating them from one another it is possible to reduce the eddy current loss between the respective layers constituting the normal-conducting metal layer. As a way electrical isolation of one layer from another, can be used a method of winding Kraft paper, Mylar paper, kapetanovic (trademark Kapton) tape to form the interlayer insulating layers.

In order to avert disaster currents in normal-conducting metal layer in case of accidents, such as a short circuit, it is necessary for normal-conducting metal layer was electrically connected to the superconducting layers. In the present invention normally conductive metal layer is provided on the inner side of the second superconducting layer, it is preferable that he was connected with the second superconducting layer. In this case, if the second superconducting layer and normal-conducting metal layer electrically connected to one another along the entire length of the superconducting cable (cable core), currents can flow through a normal-conducting metal layer as well as through a superconducting layers during the passage of normal currents that may result in increased p is Teri AC. Therefore, preferably, both layers are connected to one another only at both ends of the cable, and not the entire length. In addition, preferably, both layers were electrically isolated from one another in the middle of the cable, in order to restrain the increase of loss of AC power. It is preferable that the interlayer insulating layer was located between the second superconducting layer and normal-conducting metal layer on the entire length of the cable, then part of the interlayer insulating layer at both ends of the cable have been removed, and then the second superconducting layer and normal-conducting metal layer were connected to one another by means of soldering. The interlayer insulating layer may be formed, for example, by winding Kraft paper, malarney paper, Kapton etc-tape (trademark Kapton).

The frame around the inner circumference of the first superconducting layer can be made of a normally conductive metal, such as copper or aluminum, having a low electrical resistance at temperatures close to the temperature of the refrigerant used for the superconducting cable. The frame can have, for example, the profile of the hollow tube. However, as the framework will also take emergency currents in case of accidents, such as a short circuit, it is preferable that the frame was solid p is Ofili, having a large sectional area to facilitate the abstraction of emergency currents in the armature. When the frame has a solid profile, the configuration of the cable can be more compact. This full-profile frame can be formed, for example, by twisting many normal-conducting metal wires. The twist of many normal-conducting metal wires mechanical strength of the frame can be increased. Preferably, each of the normal-conducting metal wires constituting the frame also includes the insulation layer of the wire around its outer circumference, similar to the normal-conducting metal wires comprising a normally conductive metal layer, such as the insulation layer of the wire will reduce the eddy current loss. Preferably, the twisted normal-conducting metal wire was subjected to compression molding to give a cross-section of a rounded shape. Compression molding can be reduced intervals between the respective wires, thereby reducing the external diameter of the armature and miniaturizer the cable configuration. In addition, compression molding it is possible to reduce the concavity and convexity on the outer surface of the frame, smoothing it out the second surface. This prevents the first superconducting layer of uneven formation, when it is formed around the outer circumference of the frame that will reduce its impact on the form of the first superconducting layer.

Insulating layer around the outer circumference of the first superconducting layer can be formed, for example, by winding a semisynthetic insulating paper, such as PPLP- (trade mark) or Kraft paper. Preferably, the thickness of the insulating layer was set depending on the applied voltage in the cable lines or applied pulse voltage. Preferably, the reinforcing layer is provided around the outer circumference of the second superconducting layer. The reinforcing layer can be formed, for example, by winding Kraft paper or fabric tape.

Superconducting cable according to the present invention allows to obtain a certain result, namely, that, as provided for normal-conducting metal layer, large emergency currents caused by faults such as short circuit, disposed in the normal-conducting metal layer, which can prevent excessive temperature rise in the superconducting layers, due to flowing through them excessive alarm currents, or what integrity, due to such increases in temperature. In particular, the above-mentioned normal-conducting metal layer is placed inside the superconducting layers, inside the shielding layer, so that the inductance of the same metal layer was greater than that of the superconducting layer. This can suppress the currents flowing in the same metal layer, i.e. the currents will not be provided through the layer during the passage of normal current. Therefore, loss of alternating current in the superconducting layers can be reduced.

In addition, when a round wire with a round cross-section wire or tape made of a normally conductive metal used for the formation of normal-conducting metal layer, its formation can be facilitated, and the refrigerant can easily pass through the superconducting layer and the frame is provided under a normal-conducting metal layer. When each of the wires includes the insulation layer of the wire around the outer circumference of the metal part, the loss of the eddy current induced in normal-conducting metal layer may be reduced.

On the other hand, liquid nitrogen is used as a refrigerant for high-temperature superconducting cable and when the cable line is formed, liquid nitrogen circulare is via cable. Because there is a system using a cooling machine for cooling the heated due to the heat of the refrigerant during cooling of the relevant parts of the cable. When the superconducting cable according to the present invention is used in cable lines, equipped with a system, cooling machine must have a small capacity, reducing the cost of cooling and reducing the time required for cooling to the desired temperature, as the heat loss during the passage of normal current is small, as described above.

BRIEF DESCRIPTION of DRAWINGS

The invention is further explained in the description of the preferred variants of the embodiment with reference to the accompanying drawings, in which:

figure 1 depicts a General view of the cable core superconducting cable according to the present invention;

figa - cross section of a three-phase superconducting cable three-core type according to the invention;

figw - General view of the cable core according to the invention.

DESCRIPTION of the PREFERRED EMBODIMENT VARIANTS of the INVENTION

According to the present invention cable lived 1 (figure 1) contains, in order from the most inner part of the frame 2, the first superconducting layer 3 in the form of a superconducting conductor, the insulating layer 4, the second overprovide the third layer 6 in the form of a shielding layer and the reinforcing layer 7. The hallmark of the present invention is a copper layer 5 (normal-conducting metal layer)is provided around the inner circumference of the shielding layer, i.e. between the insulating layer 4 and the second supramodem layer 6.

In the described embodiment, as the frame 2 used full-profile frame, which is formed by twisting multiple normal-conducting metal wires, and then to give them to the cross-sectional circular shape by compression molding, each of the normal-conducting metal wire includes copper wire and the insulation layer of the enamel coating on the surface of the copper layer. Because the frame has a solid profile, he has a greater cross sectional area than the hollow profile frame. Therefore, in the case of high currents due to short circuits, large currents can be efficiently allocated in the frame, and cable configuration can be miniaturization. In addition, since the wires are insulated from one another, the eddy current loss can be reduced. Due to the fact that many of the wires are twisted and then subjected to compression molding, the frame has good mechanical strength, in addition, it is easy to form concentri the definition of the superconducting layer 3 around the outer perimeter of the frame 2. The frame 2 is electrically connected with the superconducting layer 3 on both ends of the cable core 1, which allows to take emergency currents in the frame 2 in case of accidents short circuits.

In the described embodiment, the first superconducting layer 3 and the second superconducting layer 6 (shielding layer) is formed by repeatedly winding a superconducting wire produced by the process energy in the pipe". More precisely, the first superconducting layer 3 and the shielding layer is formed by repeatedly winding a superconducting wire, the superconducting wire is formed from a tube bundle made of silver or a silver alloy and the superconducting material based on Bi2233 encased in a tube bundle. In particular, the superconducting wire used in the described embodiment, have a coefficient of the tube bundle in the range from 1.5 or more and 3.0 or less. Since the coefficient of the tube bundle satisfies the above range, it is possible to avoid reduction of the critical current density and to restrain the dissipation caused by the passage of currents failure, left in the tube bundle in the event of a transition to the normal state conductivity, due to short circuits.

The first superconducting layer 3 is formed by winding superconducting wires around and the frame 2, and the second superconducting (shielding layer) 6 is formed by winding the wires around and the copper layer 5. In this embodiment, the first superconducting layer 3 and the second superconducting (shielding layer) 6 is formed so as to provide a multi-layer structure. More precisely, the superconducting layer 3 is formed, which represents a four-layer structure, and superconducting (shielding) layer 6 is formed, which represents a two-layer structure. Interlayer insulating layers are provided between the respective layers forming the superconducting layer 3 and the superconducting (shielding) layer 6, by winding Kraft paper. The direction of winding and the step of winding in the respective layers are configured so that the respective layers are essentially uniformly divide the currents. The above configuration can effectively reduce the loss of the alternating current induced in the first superconducting layer and the second superconducting (shielding) layer.

Insulating layer 4 is formed by winding a semisynthetic insulating paper (PPLP brand company Sumitomo Electric Industries, Ltd.) on and around the superconducting layer 3.

Inside the superconducting layer 6 is provided copper layer 5, more precisely, between the insulating layer 4 and layer 6, preferable outside electric is otolaryngo layer 4, namely, between the superconducting (shielding) layer 6 and the reinforcing layer 7, so that the inductance of the copper layer 5 was greater than the shielding layer. This configuration minimizes the loss of AC during the passage of normal current and avert disaster currents in the copper layer 5 and the frame 2 in the case of a short circuit, in order to keep heat losses in the first superconducting layer 3 and the second superconducting (shielding) layer 6. Copper layer 5 is formed by winding a copper ribbon wire containing insulating layer of enamel coating on the outer perimeter, and around the insulating layer 4. Use tape wire facilitates the passage of the refrigerant through the frame 2, a superconducting layer 3 and insulating layer 4 placed under the copper layer 5. Moreover, the use of wire containing insulating layer, can reduce the eddy current loss in the copper layer 5, induced magnetic fields, induced currents flowing through the superconductive layer 3. To effectively remove emergency currents in the copper layer 5 in the case of short circuits, the copper layer 5 has a multilayer structure with a larger cross-sectional area (not shown). Between the layers that make up the copper layer 5 formed interlayer insulating layers by winding Kraft paper, to reduce the IC losses eddy current, induced between the layers.

Copper layer 5 may be formed by winding around the wire with a circular cross section, and such wire may include an insulating layer wire formed around its outer circumference. Copper layer 5 may also have a multilayer structure, and the respective layers constituting the multilayer structure may be electrically isolated from one another.

Between the copper layer 5 and the second superconducting (shielding) layer 6 interlayer insulating layer formed by winding Kraft paper the entire length of the cable core 1 (not shown). On both ends of the cable core 1 interlayer insulating layer provided between the copper layer 5 and layer 6, is partially removed, and the layer 6 and the copper layer 5 is electrically connected to one another by means of soldering. This configuration can prevent the increase of AC losses caused by currents flowing through the copper layer 5 during the passage of normal current, and to take emergency currents in the copper layer 5 in the case of short circuits.

In the described embodiment, the cable includes a reinforcing layer 7, formed by winding Kraft paper around and under the second superconducting (shielding) layer 6. On the reinforcing layer 7 is provided a protective layer formed by winding a fabric linen is.

The superconducting cable can be either single-phase superconducting cable having at least one cable core (figure 1)and three-phase superconducting cable having three conductors 1 (figure 2).

Three-phase superconducting cable three-core type 2 is made by twisting three cable conductors (figure 1). Tests were carried out on a short circuit. Hereinafter will be described the conditions for the production of the respective layers in the cable strand.

Cable lived has a diameter of 41 mm

For the frame used 37 copper wires with a diameter of 2.5 mm

Molded product after compression molding has a diameter of 15.6 mm

Kraft paper (thickness 0.1 mm) is wound around the outer circumference of the compression molded product in three layers to reduce the concavity and convexity of the surface (diameter after winding Kraft paper was 16.2 mm).

For the first superconducting layer and the second superconducting (shielding) layer were used superconducting wires based on Bi2223 factor of the tube bundle of 2.0.

The number of wires used in order from the innermost part of the

The first superconducting layer: 13, 14, 15 and 14.

The second superconducting (shielding) layer: 28 and 29.

Step the respective layers (the inner part)

The first superconducting layer 170 mm (Z-at the otka), 350 mm (Z-winding), 550 mm (S-winding) and 150 mm (S-winding).

The second superconducting (aranasi) layer: 350 mm (Z-winding) and 480 mm (Z-winding).

The thickness of the interlayer insulating layer made 0.15 mm

Insulating layer: thickness 7 mm

The copper layer were used tape wire cross-sectional area of 1 mm2.

Two-layer structure

The number of wires used (in order from the innermost part): 27 and 28.

The thickness of the interlayer insulating layer of 0.15 mm

Refrigerant: liquid nitrogen.

Current 31.5 kA was passed through a superconducting cable of the above-mentioned configuration for 1 second. In the temperature of the first superconducting layer and the second superconducting (shielding) layer were respectively 140 and max To 120 K. Then the temperature of the first superconducting layer and the second superconducting (shielding) layer had to be returned back to the values at which they were before the passage of current to the first superconducting layer and the second superconducting (shielding) layer are not damaged. Moreover, were identified dzhoulevo loss during the passage of normal current of 1000 A. as a result of 3% of the total current is flowed through the copper layer, and dzhoulevo losses amounted to 0.03 W/m For comparison was made of the superconducting cable containing copper layer in the Rog outer circumference of the shielding layer, instead of around the inner circle, then you have missed the same current to determine dzhoulevo loss. In the 6% of the total current is flowed through the copper layer, and dzhoulevo loss amounted to 0.13 W/m Therefore, it was proved that the superconducting cable according to the invention, which includes a copper layer around the inner circumference of the shielding layer, can reduce the loss of AC during the passage of normal current.

INDUSTRIAL APPLICABILITY

The present invention may provide suppression of temperature increase in the superconducting layer in case of accidents, such as a short circuit. Moreover, the present invention can reduce the loss of AC during the passage of normal current. Therefore, the present invention can be effectively used in the technique of Elektroenergetyczne.

1. Superconducting cable containing the frame (2) of normally conductive material, the first superconducting layer (3)formed around the outer circumference of the frame (2), insulating layer (4)formed around the outer circumference of the first superconducting layer (3), the second superconducting layer (6)formed around the outer circumference of the insulating layer (4), and the normally conductive metal layer (5)formed between the electricity is rationem layer (4) and the second superconducting layer (6).

2. Superconducting cable according to claim 1, characterized in that the second superconducting layer (6) and the normally conductive metal layer (5) are electrically isolated from one another in the middle of the cable and electrically connected to one another at both ends of the cable.

3. Superconducting cable according to claim 1, characterized in that the normally conductive metal layer (5) formed by winding a round wire with a circular cross section or tape wires made of a normally conductive metal.

4. Superconducting cable according to claim 3, characterized in that the said round wires contain insulating layers around their outer surfaces.

5. Superconducting cable according to claim 3, characterized in that the normally conductive metal layer (5) has a multilayer structure.

6. Superconducting cable according to claim 5, characterized in that the layers constituting the normally conductive metal layer (5), electrically isolated from one another.

7. Superconducting cable according to claim 1, characterized in that the first and second superconducting layers (3, 6) formed by winding a superconducting wire made of tube bundle made of silver or a silver alloy, while the superconducting material is enclosed in a tube bundle.

8. Superconducting cable according to claim 7, characterized in that the superconducting what the wires have a coefficient of the tube bundle in the range from 1.5 or more and 3.0 or less.

9. Superconducting cable according to claim 1, characterized in that the frame (2) formed by twisting multiple normally conductive metal wires, which contain insulating layers of wires around their outer surface.

10. Superconducting cable according to claim 1, characterized in that the frame (2) formed by twisting multiple normally conductive metal wires and their subsequent compression molding to give them the cross section of the circular form.



 

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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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