KR102241808B1 - Superconducting cable - Google Patents

Abstract

In the present invention, in a superconducting cable using a superconducting wire including a magnetic metal substrate (Ni-W series) as a superconducting conductor layer and a superconducting shielding layer, AC loss generated during AC power transmission can be minimized. It relates to a superconducting cable.

Description

Superconducting cable {SUPERCONDUCTING CABLE}

The present invention relates to a superconducting cable. In more detail, the present invention relates to a superconducting cable using a superconducting wire including a magnetic metal substrate (Ni-W series) as a superconducting conductor layer and a superconducting shielding layer. It relates to a superconducting cable that can minimize the.

The superconducting wire has a large power transmission capability even at a low voltage because the electrical resistance converges to zero at a constant temperature.

A superconducting cable provided with such a superconducting wire uses a method of cooling using a refrigerant such as nitrogen and/or a method of insulating a vacuum layer to form and maintain a cryogenic environment.

Such a superconducting cable may generally include a superconducting shielding layer for shielding electromagnetics or the like induced by the superconducting conductor layer together with a superconducting conductor layer made of a superconducting wire for power transmission. Like the superconducting layer, the superconducting shielding layer is also composed of an expensive superconducting wire.

That is, electromagnetic waves induced by power transmitted from the superconducting conductor layer may be shielded through the superconducting shielding layer.

The first generation superconducting wire of the BSCCO system developed so far can be manufactured by a relatively simple machining method, but due to the crystal orientation characteristics of the BSCCO (Bi-2223, Bi-2212) superconducting wire, the critical current density (Jc) at a temperature of 77 K There is a limit to improving the value to more than 100,000 A/cm ² , and since Ag, the sheath material of the wire rod is expensive in the cost configuration, it is difficult to lower the price for performance, and the manufacture and use of the first-generation superconducting wire has recently decreased.

On the other hand, the second-generation superconducting wire is called a coated conductor (hereinafter referred to as CC) because the oxide film is deposited in multiple layers on a metal substrate.

The 2nd generation superconducting wire of YBCO or REBCO system has high critical current characteristics in a magnetic field and a much higher critical current density than the 1st generation BSCCO wire, which can replace the 1st generation high-temperature superconducting wire from the early 1990s. It is attracting attention as a next-generation superconducting wire, and various manufacturing processes are being actively developed.

In general, the second-generation superconducting wire may be formed of several layers of oxide thin films and protective layers deposited on a metal substrate.

In order to allow a large amount of supercurrent to flow in the second-generation superconducting wire, since supercurrent is limited at the grain boundary, it is important to increase the crystal orientation by aligning the crystal grains of the superconducting wire in both axes in the process. The 2nd generation superconducting wire mainly deposits YBCO or REBCO (RE=Sm, Gd, Nd, Dy, Ho) materials, and the superconducting properties of the 2nd generation superconducting wire are the composition and density of the superconducting layer of the resulting superconducting wire, and the orientation of crystals. Depends heavily on your back.

The metal substrate of the second-generation superconducting wire uses different materials depending on the deposition method of the buffer layer, and hastelloy (alloy such as hastelloy, SUS, etc.) or Ni-W alloy in which metal crystals are oriented in both axes in advance through rolling and recrystallization heat treatment. A substrate (RABiTS, Rolling Assisted Bi-axially Textured Substrate) is typically used.

When the metal substrate of the second-generation superconducting wire is a Ni-W alloy substrate composed of a magnetic material, etc., a problem of AC loss may occur when the superconducting cable transmits AC power.

A superconducting cable in which a superconducting wire is used may generally include a superconducting conductor layer composed of a superconducting wire for power transmission and a superconducting shielding layer for shielding electromagnetics etc. induced by the superconducting conductor layer.

In recent years, in order to increase the power transmission capability of a superconducting cable, the superconducting conductor layer and the superconducting shielding layer are each composed of a multilayer superconducting wire in many cases.

When a superconducting conductor layer and a superconducting shielding layer are provided as a multilayer superconducting wire, the problem of AC loss may worsen depending on the direction or orientation of the superconducting conductor layer and the metal substrate of the superconducting wire constituting each layer. I can.

Regarding the AC loss of a superconducting wire, Japanese Laid-Open Publication No. JP2012-256508 discloses a technology for minimizing the AC loss by reducing the width of the superconducting wire constituting the superconducting conductor layer, but specifically the direction or orientation of the superconducting wire. There is no recognition or suggestion of a technical solution related to the problem, and Japanese Patent Registration JP5192741 discloses a technical problem and a technical solution related to an AC loss, but there is a big difference between the present invention and the technical solution. The effect of the invention is also questioned, and Japanese Patent No. JP5385746 discloses a layer-by-layer structure of a superconducting wire constituting a superconducting cable, but discloses or suggests a technical solution for solving the technical problem according to the present invention. Does not exist at all.

The present invention is a superconducting cable capable of minimizing AC loss that may occur during AC power transmission by adjusting the superconducting conductor layer and the direction of the metal substrate of a multilayer superconducting wire material constituting the superconducting conductor layer and the superconducting shielding layer of the superconducting cable. It is a task to be solved to provide.

In order to solve the above problems, the present invention provides a former, at least one superconducting conductor layer including a plurality of superconducting wires arranged side by side in the longitudinal direction of the former so as to surround the outside of the former, and an insulating layer surrounding the superconducting conductor layer. , A core portion including at least one superconducting shielding layer comprising a plurality of superconducting wires disposed in parallel in the longitudinal direction of the former so as to surround the outside of the insulating layer, provided outside the core portion, and the core portion A cooling unit provided with a circulation passage of a liquid refrigerant for cooling, an insulating unit provided outside the cooling unit and configured by winding an insulating material multiple times, and a plurality of spacers provided outside the insulating unit at a spaced position. A superconducting wire comprising a vacuum unit provided, the superconducting conductor layer and the superconducting shielding layer comprising a metal substrate layer and a superconducting layer comprising a superconducting material deposited in a plurality of layers on the metal substrate layer, , A superconducting cable, characterized in that the metal substrate layer of the superconducting wire constituting the outermost superconducting conductor layer among the superconducting conductor layers is disposed in the direction of the center of the superconducting cable, and the superconducting layer is disposed in the radial direction of the superconducting cable. I can.

In this case, the superconducting conductor layer is composed of a plurality of layers, the metal substrate layer of the superconducting wire constituting the plurality of superconducting conductor layers is disposed in the center direction of the superconducting cable, and the superconducting layer is disposed in the radial direction of the superconducting cable. I can.

In addition, a superconducting layer of a superconducting wire constituting the innermost superconducting shielding layer among the superconducting shielding layers may be disposed in the direction of the center of the superconducting cable, and the metal substrate layer may be disposed in the radial direction of the superconducting cable.

Here, the superconducting shielding layer is composed of a plurality of layers, the superconducting layers of the superconducting wire constituting the multi-layered superconducting shielding layer are all arranged in the direction of the center of the superconducting cable, and all the metal substrate layers are arranged in the radial direction of the superconducting cable. Can be.

In addition, the superconducting conductor layer may be composed of four layers, and the superconducting shielding layer may be composed of two layers.

In addition, the superconducting wire of the superconducting conductor layer and the superconducting shielding layer may be a second-generation superconducting wire including a metal substrate layer made of a nickel alloy material.

In addition, in order to solve the above problems, the present invention provides a foamer, at least one superconducting conductor layer provided outside the former, an insulating layer surrounding the superconducting conductor layer, and at least one superconducting layer provided outside the insulating layer. A shielding layer; wherein the superconducting wire constituting the superconducting conductor layer and the superconducting shielding layer is deposited in a plurality of layers on a metal substrate layer and a metal substrate layer, and comprises a superconducting layer including a superconducting material, and the superconducting It is possible to provide a superconducting cable in which the outermost superconducting conductor layer among the conductor layers and the metal substrate layer of the superconducting wire constituting the innermost superconducting shielding layer of the superconducting shielding layer and the superconducting layer are disposed in opposite directions.

In addition, the superconducting conductor layer is composed of a plurality of layers, the superconducting layers of the superconducting wire constituting the plurality of superconducting conductor layers are all arranged in the radial direction of the superconducting cable, and the metal substrate layer is arranged in the center direction of the superconducting cable. I can.

In this case, the superconducting shielding layer is composed of a plurality of layers, the superconducting layers of the superconducting wire constituting the plurality of superconducting shielding layers are all arranged in the direction of the center of the superconducting cable, and all the metal substrate layers are in the radial direction of the superconducting cable. Can be placed.

In addition, in order to solve the above problems, the present invention provides a former, at least one superconducting conductor layer surrounding the outside of the former, an insulating layer surrounding the superconducting conductor layer, and at least one or more superconducting shielding layers surrounding the outside of the insulating layer. A superconducting wire material comprising a core part including a superconducting layer and constituting the superconducting shielding layer is deposited in a plurality of layers on a metal substrate layer and a metal substrate layer, and comprises a superconducting layer including a superconducting material, and the superconducting Among the conductor layers, the metal substrate layer of the superconducting wire constituting the outermost superconducting conductor layer is disposed in the direction of the center of the superconducting cable, the superconducting layer is disposed in the radial direction of the superconducting cable, and constitutes the innermost superconducting shielding layer among the superconducting shielding layers. A superconducting cable may be provided, wherein the superconducting layer of the superconducting wire is disposed in the center direction of the superconducting cable, and the metal substrate layer is disposed in the radial direction of the superconducting cable.

Here, the superconducting conductor layer and the superconducting shielding layer are composed of a plurality of layers, the superconducting layers of the superconducting wire constituting the plurality of superconducting conductor layers are all arranged in the radial direction of the superconducting cable, and the metal substrate layer is the center of the superconducting cable. The superconducting layers of the superconducting wire material constituting the plurality of superconducting shielding layers may be disposed in a direction, and all of the superconducting layers may be disposed in the direction of the center of the superconducting cable, and all metal substrate layers may be disposed in the radial direction of the superconducting cable.

In addition, the superconducting wire of the superconducting conductor layer and the superconducting shielding layer may be a second-generation superconducting wire including a metal substrate layer made of a nickel alloy material.

According to the superconducting cable according to the present invention, a superconducting wire including a magnetic metal substrate (Ni-W series) is generated during AC power transmission by optimizing the direction or orientation of the superconducting wire constituting the superconducting conductor layer and the superconducting shielding layer. AC loss can be minimized.

In addition, according to the superconducting cable according to the present invention, it is possible to improve the stability of a power system including a superconducting cable by minimizing a decrease in critical current due to a change in a magnetic field of a superconducting wire constituting the superconducting conductor layer and the superconducting shielding layer.

1 shows a perspective view of a superconducting cable stripped in stages according to the present invention.
2 shows a cross-sectional view of the superconducting cable shown in FIG.
3 is a conceptual diagram of an embodiment of a superconducting cable according to the present invention.
4 is a conceptual diagram of another embodiment of a superconducting cable according to the present invention.
5 shows another embodiment of a superconducting cable according to the present invention.
6 is a cross-sectional view illustrating a state in which the superconducting cable shown in FIG. 5 is installed in a horizontal direction.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided so that the disclosed content may be thorough and complete, and the spirit of the present invention may be sufficiently conveyed to those skilled in the art. The same reference numbers throughout the specification indicate the same elements.

FIG. 1 is a perspective view of a superconducting cable separated by steps according to the present invention, and FIG. 2 is a cross-sectional view of the superconducting cable shown in FIG.

The basic structure of the superconducting cable according to the present invention will be described.

A superconducting cable includes a former 110, at least one superconducting conductor layer 130 including a plurality of superconducting wires arranged in parallel in the longitudinal direction of the former 110 so as to surround the outside of the former 110, and the superconducting conductor At least one or more superconducting shielding layers comprising an insulating layer 140 surrounding the layer 130 and a plurality of superconducting wires disposed in parallel in the longitudinal direction of the former 110 so as to surround the outside of the insulating layer 140 In order to cool the core part 100, the core part 100 including 180, provided outside the core part 100, and a refrigerant flow path of the liquid refrigerant for cooling the core part 100 The cooling unit 200 provided, the inner metal pipe 300 provided outside the cooling unit 200, the heat insulation provided outside the inner metal pipe 300, and forming a heat insulating layer in which the insulating material 401 is wound in several layers In order to vacuum insulate the part 400 and the cooling part 200, a vacuum part 500 having a plurality of spacers 560 at spaced positions outside the heat-insulating part 400, and the vacuum part 500 An external metal pipe 600 provided on the outside, and a sheath part 700 provided outside the external metal pipe 600 to form a sheath layer, and between the heat insulating part 400 and the external metal pipe 600 The average separation distance may be configured to be larger than the diameter of the spacer 560 provided in the vacuum part 500.

Each of the components constituting the superconducting cable is sequentially reviewed as follows. The former 110 serves as a frame for forming a shape while providing a place to mount a flat, flat and long superconducting wire around the former 110, and may be a path through which an accident current flows. The former 110 may have a shape obtained by compressing a plurality of copper (Cu) wires 111 having a circular cross section in a circular shape.

Specifically, basically, the former 110 has a round cylindrical shape, and serves as a frame for raising a flat and long superconducting wire. The diameter of the former 110 is determined so that the superconducting wire is not lifted in consideration of the width of the superconducting wire and has a structure as close as possible to a circular shape when the superconducting wires are placed on the former 110.

As shown in Figs. 1 and 2, the former may be configured in a form in which the center is full, but the former 110 is formed in a hollow cylindrical shape and serves as a frame for raising the superconducting wire, and at the same time, a refrigerant is contained therein. It can be configured to act as a path for movement, and each of the wires 111 constituting the former can be made of copper, etc., and by connecting each wire in parallel with a superconducting wire, it is returned to the power system when a fault current occurs. It can also be configured to act as a conductor.

Depending on the capacity of the fault current, a cross-sectional area of a conductor such as copper constituting an element wire may be determined, and in the case of a high voltage, the copper element wire may be compressed into a circular shape to form a stranded wire.

The surface of the former 110 is inevitably convex because the form of a stranded wire obtained by compressing the circular wires 111 of a cross section of several strands constituting the former 110 into a circular shape. Accordingly, the smoothing layer 120 may be coated on the outside of the former 110 in order to smooth the convex surface of the former 110. The smoothing layer 120 may be formed of semiconductive carbon paper or brass tape.

Although not shown in the drawing, a cushion layer may be further provided between the smoothing layer 120 and the superconducting layer 130. The cushion layer may be provided to protect the superconducting conductor layer by using a semiconducting carbon paper tape.

A first superconducting conductor layer 130a in which a layer is formed by being surrounded by a plurality of superconducting wires 131 may be provided outside the former 110 flattened by the smoothing layer 120. The first superconducting conductor layer 130a may be installed so that a plurality of superconducting wires are adjacent to each other and surround the smoothing layer 120.

In addition, as shown in FIG. 1, the superconducting conductor layer 130 may be configured as a multilayer according to the capacity of a current to be transmitted or distributed through a superconducting cable.

In the embodiment illustrated in FIG. 1, it is shown that a total of two superconducting conductor layers 130a and 130b are provided. In addition, if the superconducting conductor layers are simply stacked and arranged, the current capacity does not increase according to the skin effect of the current. In order to prevent such problems, when a superconducting conductor layer is provided as a multilayer, an insulating layer 140 may be provided between the superconducting conductor layers 130a and 130b. The insulating layer 140 may be formed in the form of an insulating tape, and is disposed between the superconducting conductor layers 130a and 130b to be stacked to insulate the superconducting conductor layers 130a and 130b from each other to achieve a skin effect of the stacked superconducting wire. Can be prevented. The conduction directions of the superconducting conductor layers multilayered by the insulating layer 140 may be matched.

In the embodiment shown in FIG. 1, the superconducting conductor layer 130 is an example composed of two layers of a first superconducting conductor layer 130a and a second superconducting conductor layer 130b. A conductor layer may be provided.

In addition, the superconducting wires constituting each of the superconducting conductor layers 130a and 130b may be connected in parallel with respective wires constituting the former 110. This is to allow the current flowing through the superconducting wire to flow to the element wire of the former 110 in case of an accident such as destruction of a superconducting condition. When the superconducting condition is not satisfied in this way, the resistance of the superconducting wire increases, and the result is to prevent heat generation or damage of the superconducting wire.

An inner semiconducting layer 150 may be provided outside the second superconducting conductor layer 130b provided outside the first superconducting conductor layer 130a. The inner semiconducting layer 150 may be provided to reduce the concentration of an electric field in each region of the superconducting conductor layer 130 and to even out the surface electric field. Specifically, it may be provided to relieve concentration of an electric field generated at the edge of the superconducting wire and to evenly distribute the electric field. This is the same for the outer semiconducting layer 170 to be described later.

The inner semiconducting layer 150 may be provided in a manner in which a semiconducting tape is wound.

An insulating layer 160 may be provided outside the inner semiconducting layer 150. The insulating layer 160 may be provided to increase the dielectric strength of the superconducting cable. In general, XLPE (Cross Linking-Polyethylene) or oil filled cable is used to insulate high-voltage cables, but superconducting cables are cooled at cryogenic temperatures for superconductivity of superconducting wires. There is a problem, and since the oil filled cable may cause environmental problems, etc., the superconducting cable according to the present invention may use an insulating paper made of ordinary paper as the insulating layer 160, and the insulating layer 160 Silver insulating paper may be configured in a manner of winding a plurality of times.

Kraft paper or PPLP (Polypropylene Laminated Paper) is mainly used for the insulating paper. In the case of superconducting cables among various ground insulation materials, PPLP insulation paper is used in consideration of the ease of winding and dielectric strength characteristics.

An outer semiconducting layer 170 may be provided outside the insulating layer 160. The outer semiconducting layer may also be provided to reduce the concentration of the electric field by region of the superconducting layer 130 and to even out the surface electric field, and the outer semiconducting layer 170 may also be provided in a manner in which a semiconducting tape is wound. .

In addition, a superconducting shielding layer 180 may be provided outside the outer semiconducting layer 170. The method of forming the superconducting shielding layer 180 may be the same as the method of forming the superconducting conductor layer 130. When the surface of the outer semiconducting layer 170 is uneven, a smoothing layer (not shown) may be provided as needed, and superconducting wires for forming the superconducting shielding layer 180 outside the smoothing layer are respectively circumferentially directed. Can be placed side by side.

It is possible to minimize the leakage magnetic field by designing so that the current flowing through the shielding layer composed of the second-generation superconducting wire is about 95% of the current flowing through the superconducting conductor layer.

A core exterior layer 190 serving as an exterior of the core unit 100 may be provided outside the superconducting shielding layer 180. The core outer layer 190 may include various tapes or binders, and the outer role and the role of binding all the components of the core portion 100 so that the core portion 100 can be exposed to a cooling layer to be described later. And can be composed of metal tapes such as SUS material.

In this way, the core portion 100 of the superconducting cable may be configured, and in FIGS. 1 and 2, the smoothing layer and the semiconducting layer are shown to be composed of a single layer of the same material, but various sublayers according to need Can be added.

A cooling part 200 may be provided outside the core part 100. The cooling unit 200 may be provided to cool the superconducting wire of the core unit 100, and the cooling unit 200 may have a circulation passage for a liquid refrigerant therein. Liquid nitrogen may be used as the liquid refrigerant, and the liquid refrigerant (liquid nitrogen) circulates through the coolant flow path in a cooled state to have a temperature of -200 degrees below zero, and a superconducting wire provided in the core part of the cooling unit The cryogenic temperature, which is the superconducting condition of, can be maintained.

The cooling flow path provided in the cooling unit 200 may allow a liquid refrigerant to flow in one direction, and may be recovered from a junction box of a superconducting cable, recooled, and supplied to the cooling flow path of the cooling unit 200 again.

An inner metal tube 300 may be provided outside the cooling unit 200. The inner metal tube 300, together with the outer metal tube 600 to be described later, serves as an exterior of a superconducting cable to prevent mechanical damage to the core part 100 during installation and operation of the superconducting cable. The superconducting cable is wound around a drum for easy manufacture and transport, and since the cable wound around the drum is unfolded and installed during installation, bending stress or tensile stress may be continuously applied to the superconducting cable.

In order to maintain the initial performance even in a situation in which such mechanical stress is applied, an inner metal tube 300 may be provided. Accordingly, the inner metal tube 300 has a corrugated structure in which ridges and depressions are repeated in the longitudinal direction of the superconducting cable to reinforce stiffness against mechanical stress, and the inner metal tube 300 is made of a material such as aluminum. Can be.

Since the inner metal tube 300 is provided outside the cooling unit 200, it may be a cryogenic temperature corresponding to the temperature of the liquid refrigerant. Accordingly, the inner metal tube 300 may be classified as a low temperature metal tube.

In addition, the inner metal tube 300 may be provided with a heat insulating part 400 including a heat insulating layer wound in several layers on an outer circumferential surface of a metal film having a high reflectivity and thinly coated with a polymer having a low thermal conductivity. The heat insulating layer may be provided to form a multi-layer insulation (MLI) and to block heat intrusion toward the inner metal pipe 300.

In particular, since the inner metal tube 300 is made of a metal material, heat intrusion or heat exchange by conduction is easy, so that the heat insulator 400 can minimize heat exchange or heat intrusion mainly due to conduction, and a metal having a high reflectivity. Due to the film material, it is possible to obtain an effect of preventing heat exchange or heat intrusion due to radiation.

The number of layers of the heat insulating part 400 can be adjusted to minimize heat intrusion. If it is composed of many layers, the radiant heat shielding effect increases, but it is important to use an appropriate number of layers because the conductive heat shielding effect and the heat shielding effect due to convection decrease as the thickness of the vacuum layer decreases.

A vacuum part 500 may be provided outside the heat insulating part 400. The vacuum unit 500 may be provided to minimize heat transfer due to convection or the like in the direction of the heat insulating layer, which may occur when the heat insulation by the heat insulating unit 400 is insufficient.

The vacuum part 500 may be formed by forming a spaced space outside the heat insulating part 400 and vacuumizing the spaced space.

The vacuum part 500 is a space provided to prevent heat intrusion from outside at room temperature toward the core part by convection, and may include at least one spacer 560 to form a physical space. The separation space in the entire area of the superconducting cable to prevent contact of the heat insulation part 400 inside the vacuum part 500 with an external metal tube 600 provided outside the spaced space in the vacuum part 500 At least one spacer 560 may be provided within.

The spacer 560 may be disposed along the longitudinal direction of the superconducting cable, and may be wound around the core part 100, specifically, the heat insulating part 400 in a spiral or circular shape.

As shown in FIG. 1, a plurality of spacers 560 may be provided, and the number of spacers 560 may be increased or decreased according to the type or size of a superconducting cable. The superconducting cable according to the present invention may be provided with 3 to 5 spacers. The spacer may form a spaced space to prevent heat exchange due to conduction, and the structure of the spacer may be composed of a single layer or a multilayer.

The material of the spacer 560 may be made of polyethylene (FEP, PFA, ETFE, PVC, P.E, PTFE).

In addition, the spacer 560 may be made of fluorinated polyethylene (PTFE, Poly Tetra Fluoro Ethylene) material, or made of a general resin or polyethylene material, and then the surface may be coated with fluorinated polyethylene or the like. In this case, the fluorinated polyethylene may be Teflon.

Teflon is a type of fluorine resin, and Teflon forms a very stable compound due to the strong chemical bonding of fluorine and carbon, so it has almost perfect chemical inertness, heat resistance, non-adhesion, excellent insulation stability, and low coefficient of friction. have. In addition, since Teflon has a certain degree of flexibility, the heat insulation part 400 is wrapped in a spiral shape, and may be wound and disposed in the length direction of the superconducting cable, and has a certain degree of strength, so that the heat insulation part 400 and the outside It is utilized as a spacing means to prevent contact of the metal tube 600, and may play a role of physically maintaining a spacing space constituting the vacuum unit 500. The diameter of the spacer 560 may be 4 millimeters (mm) to 8 millimeters (mm). The cross-sectional shape of the spacer 560 may be in various shapes such as a circle, a triangle, a square, and a star.

An external metal tube 600 may be provided outside the vacuum part 500 provided with the spacer 560. The outer metal tube 600 may be formed of the same shape and material as the inner metal tube 300, and the outer metal tube 600 has a larger diameter than the inner metal tube 300, It can enable the formation of spaced spaces. A detailed description of the spacer 560 will be delayed.

In addition, a sheath part 700 performing an exterior function for protecting the inside of the superconducting cable may be provided outside the outer metal tube 600. The sheath part may be a sheath material constituting the sheath part 700 of a conventional power cable. The sheath part 700 may prevent corrosion of the metal pipe 600 and the like therein, and may prevent damage to the cable due to external force. The sheath part 700 may be made of a material such as polyethylene (PE) and polyvinyl chloride (PVC).

As shown in FIG. 2, it is shown that the spacer 560 provided in the vacuum part 500 is provided with four spacers 560 to surround the heat insulating part 400 provided outside the inner metal tube 300.

3 is a conceptual diagram of an embodiment of a superconducting cable according to the present invention.

The embodiment shown in FIG. 3 shows an example in which two superconducting conductor layers and one superconducting shielding layer are provided.

The superconducting wire constituting the superconducting cable according to the present invention is a second generation superconducting wire, and shows an embodiment in which a metal substrate made of a nickel-tungsten (Ni-W) alloy is used.

The two superconducting conductor layers may be composed of an inner first superconducting conductor layer and an outer second superconducting conductor layer.

For convenience of illustration on the drawing, each superconducting wire is provided on a metal substrate layer and a metal substrate layer made of a nickel alloy material such as nickel-tungsten (Ni-W), and a superconducting layer (layer) or a superconducting material It is illustrated and described in a simplified manner as consisting of a superconducting layer including a plurality of films added by a method such as vapor deposition or the like.

The superconducting wire constituting the superconducting cable according to the present invention may be a second-generation superconducting wire, and the superconducting material provided in the superconducting layer of the superconducting wire is mainly YBCO or REBCO (RE=Sm, Gd, Nd, Dy, Ho) material, etc. I can.

Specifically, the phenomenon in which the electrical resistance becomes '0' below a certain temperature is called a superconductivity phenomenon, and a superconductivity phenomenon at a relatively high temperature compared to the absolute temperature near 100K (-173°C) rather than absolute zero (-273°C). What represents is called a high temperature superconductor (High Temperature Superconductor). The superconducting wire used in the power cable field uses a high-temperature superconductor, and the first-generation wire with BSCCO as the main material and the second-generation wire with Coated Conductor (CC) type with YBCO or ReBCO as the main material were introduced.

Reasons for the recent use of second-generation superconducting wires In the case of first-generation superconducting wires, it is difficult to lower the cost of superconducting wires by using Ag as a base material, and second-generation superconducting wires have better AC loss characteristics, whereas first-generation superconducting wires have a filament structure. The second-generation superconducting wire has the advantage that the layer structure is more efficient in terms of hysteresis loss.

The second-generation superconducting wire may include a metal substrate layer, a buffer layer, a superconducting layer, and a protective layer in detail. The metal substrate layer is used as a base member of the wire rod, serves to maintain the mechanical strength of the superconducting wire, and may be a material such as Hastelloy or Nickel-Tungsten (Ni-W). The buffer layer may serve as a buffer for depositing a superconducting layer on a metal substrate. The superconducting layer is used as a path for conducting current when energized, and the material of the protective layer may be formed of a silver (Ag) or copper (Cu) alloy layer. The silver (Ag) alloy layer may be positioned between the superconducting layer and the copper (Cu) alloy layer to enable deposition, and the copper (Cu) alloy layer may play a role of reinforcing mechanical strength. Each alloy layer may have different thicknesses and materials depending on the application device.

In addition, for convenience of explanation, the superconducting wire is largely divided into a metal substrate layer and a superconducting layer. Accordingly, it can be understood that the buffer layer is provided between the metal substrate layer and the superconducting layer, and the protective layer is provided outside the superconducting layer.

As already mentioned, the superconducting material provided in the superconducting layer of the superconducting wire may be mainly YBCO or REBCO (RE=Sm, Gd, Nd, Dy, Ho) material.

In the embodiment shown in FIG. 3, the metal substrate layers 130a-1 and 130b-1 of the first superconducting conductor layer 130a and the second superconducting conductor layer 130b of the superconducting conductor layers are in the direction of the center of the superconducting cable. The superconducting layers 130a-2 and 130b-2 of the first superconducting conductor layer 130a and the second superconducting conductor layer 130b are disposed in the radial direction of the superconducting cable.

And, in the embodiment shown in Figure 3, the superconducting of the superconducting layer (130a-2) and the second superconducting conductor layer (130b) of the superconducting wire constituting the first superconducting conductor layer (130a) provided on the inside of the superconducting cable. When a current flows through the layer 130b-2, each of the superconducting layers 130a-2 and 130b-2 flows outside the first superconducting conductor layer 130a and the second superconducting conductor layer 130b. A circular magnetic field may be formed by electric current.

The reason why a circular magnetic field is formed outside each of the first superconducting conductor layer 130a and the second superconducting conductor layer 130b is that when the direction of current flowing through the superconducting wire constituting each layer is the same, each layer This is because the vertical components of the magnetic field between adjacent superconducting wires constituting the are canceled each other.

And, unlike the above-described superconducting conductor layer, the metal substrate layer 180-1 of the superconducting wire constituting the superconducting shielding layer 180 is disposed in the radial direction of the superconducting cable, and the superconducting layer 180 constituting the superconducting shielding layer 180 The superconducting layer 180-2 of the wire rod is disposed in the direction of the center of the superconducting cable.

In addition, when a current is applied to the superconducting layers 130a-2 and 130b-2 of the superconducting wire constituting the first superconducting conductor layer 130a and the second superconducting conductor layer 130b, the superconducting shielding layer 180 The superconducting layer 180-2 of the constituting superconducting wire is the current direction of the superconducting layers 130a-2 and 130b-2 of the superconducting wire constituting the first superconducting conductor layer 130a and the second superconducting conductor layer 130b. A current is induced in a direction opposite to that, and the induced magnetic field may be formed in a circular shape along the inside of the first superconducting conductor layer 130a and the second superconducting conductor layer 130b, and the first superconducting conductor layer 130a ), the main magnetic field of the boundary region of the second superconductor layer 130b and the superconducting shielding layer 180 and the inner and outer regions may be determined by the position of the superconducting layer of the superconducting conductor layer or the superconducting wire constituting the superconducting shielding layer. have.

That is, the magnitude of the magnetic field at a specific point may be determined according to the presence or absence of a superconducting conductor layer or a superconducting layer constituting the superconducting shielding layer existing in a short distance, and whether the superconducting layer and the metal substrate layer of the superconducting wire are magnetic.

This is because it can be assumed that the amount of a magnetic field generated by flowing a current through the superconducting layer of the superconducting wire constituting the superconducting conductor layer or the superconducting shielding layer and propagating to other regions through the ferromagnetic metal substrate layer is insignificant.

Therefore, in the case of simplifying and expressing the magnetic field line by the induced magnetic field, the boundary region of the first superconducting conductor layer 130a, the second superconducting conductor layer 130b, and the superconducting shielding layer 180, the superconducting conductor layer, and the superconductor The main magnetic fields in the inner and outer regions of the shielding layer may be expressed as B1, B2, and B3, respectively.

Since each magnetic field (B1, B2, B3) is affected by the trajectory of the magnetic force line by the metal substrate layer composed of a magnetic material, the trajectory of the magnetic force line by the magnetic field and the superconducting wire constituting each superconducting conductor layer or superconducting shielding layer The direction of the metal substrate layer of should be well determined.

For example, the metal substrate layer 130b-1 and the superconducting layer 130b-2 of a superconducting wire constituting the second superconducting conductor layer 130b, which is the outermost conductor layer among the superconducting conductor layers shown in FIG. 3 When the direction of is reversed, that is, the metal substrate layer 130b-1 of the superconducting wire constituting the second superconducting conductor layer 130b faces the radial direction of the superconducting cable, and the superconducting layer 130b-2 moves the center direction. If facing, the magnetic field B2 formed by the second superconducting conductor layer 130b and surrounding the second superconducting conductor layer 130b is distorted or canceled by the ferromagnetic properties of the adjacent metal substrate layer 130b-1, and the magnitude of the magnetic field It will induce a change, and distortion or cancellation of the magnetic field may cause the loss of the alternating current transmitted in reverse.

Among the magnetic fields formed by a specific superconducting conductor layer, the main magnetic field having a significant size is formed in a circumferential direction in the boundary region adjacent to the superconducting layer and the metal substrate layer of the superconducting wire constituting the superconducting layer, and the opposite metal The magnetic field formed over the substrate layer can be seen to be canceled or interfered by the ferromagnetic field of the metal substrate layer or the magnetic field formed by the superconducting conductor layer adjacent to the superconducting conductor layer.

The change of the magnetic field line of the magnetic field eventually decreases the critical current or allowable current of the superconducting conductor layer itself, causes AC loss, and furthermore, when a current exceeding the critical current flows, it may cause various failures or accidents. have.

If the superconducting conductor layer is composed of three or more superconducting conductor layers, the superconducting conductor layer intervening in the middle is inevitably affected by the magnetic field by the superconducting conductor layers stacked adjacent to each other even if the direction is reversed. . However, even if the superconducting conductor layer is stacked in multiple layers, the superconducting conductor layer located on the outermost side has the most serious problem of AC loss if the superconducting layer is disposed in the opposite direction to that of FIG. 3 so that the superconducting layer is in the center direction of the superconducting cable. I can guess.

The superconducting shielding layer 180 should minimize the size of the external magnetic field. Accordingly, as shown in FIG. 3, the metal substrate layer 180-1 of the superconducting shielding layer 180 is preferably disposed outside in the radial direction.

As can be seen from the embodiment shown in FIG. 3, in the case of a superconducting conductor layer, a magnetic field by each superconducting conductor layer is formed to surround each conductor layer, and a magnetic field by an induced current flowing through the superconducting shielding layer is superconducting shielding. It may be formed in a circular shape inside the layer.

Therefore, in the case of the superconducting shielding layer 180, as in the case of the superconducting conductor layer, the metal substrate layer 180-1 of the superconducting wire constituting the superconducting shielding layer 180 is disposed in the radial direction rather than the center direction of the superconducting cable. Only then can the superconducting shielding layer 180 minimize AC loss due to interference with a magnetic field.

4 is a conceptual diagram of another embodiment of a superconducting cable according to the present invention.

The embodiment shown in FIG. 4 shows an example in which two superconducting conductor layers and one superconducting shielding layer are provided. The description that is duplicated with the description with reference to FIG. 3 will be omitted. The embodiment shown in FIG. 3 coincides with the embodiment shown in FIG. 3 in that the superconducting conductor layer is a plurality of layers, but differs in that the number of superconducting conductor layers is four in order to increase the power transmission capacity. .

In addition, as the number of superconducting conductor layers increased, the number of superconducting shielding layers increased to two.

As can be seen from the aforementioned contents, the metal substrate layer 180a-1 and the superconducting layer of a superconducting wire constituting the innermost first superconducting shielding layer 180a among the two superconducting shielding layers 180a and 180b. When the position of 180a-2) is changed, the magnetic field formed by the first superconducting shielding layer 180a is affected by the metal substrate layer 180a-1 of the superconducting wire constituting the first superconducting shielding layer 180a. In response to, a part of the horizontal direction magnetic field will be strengthened in the vertical direction component, and thus the AC loss related to the induced current increases as in the superconducting conductor layer, thereby reducing the shielding ability.

Therefore, when both the superconducting conductor layer and the superconducting shielding layer are composed of multiple layers, the metal substrate layer of the superconducting wire constituting the outermost superconducting conductor layer is disposed to face the center direction of the superconducting cable, and the superconducting shielding layer is the innermost superconducting layer. When the superconducting layer of the superconducting wire constituting the shielding layer is disposed inward to face the center direction of the superconducting cable, the outermost superconducting conductor layer and the innermost superconducting shielding layer can minimize AC loss due to a magnetic field.

In addition, it is experimentally to minimize AC loss by configuring the direction of the metal substrate layer and the superconducting layer of each of the plurality of superconducting conductor layers and the plurality of superconducting shielding layers to correspond to the outermost superconducting conductor layer and the innermost superconducting shielding layer. Confirmed.

Accordingly, it is preferable that the plurality of superconducting conductor layers 130 and the plurality of superconducting shielding layers 180 are stacked to face the same direction.

In conclusion, the direction of the metal substrate layer and the superconducting layer of the superconducting wire constituting the outermost superconducting layer of the superconducting conductor layer and the innermost superconducting shielding layer of the superconducting shielding layer are reversed, and in more detail, the superconducting conductor layer The metal substrate layer of the superconducting wire constituting the superconducting wire is disposed in the center direction of the superconducting cable, the superconducting layer of the superconducting wire is disposed in the radial direction of the superconducting cable, and as shown in FIG. 4, the superconducting conductor layer and the superconducting shielding layer are In the case of a multilayer structure, the metal substrate layers of the superconducting wire constituting the plurality of superconducting conductor layers are all arranged in the direction of the center of the superconducting cable, the superconducting layer is arranged in the radial direction of the superconducting cable, and the plurality of layers of superconducting shielding It can be concluded that the superconducting layer of the superconducting wire constituting the layer is all arranged in the direction of the center of the superconducting cable, and all the metal substrate layers are arranged in the radial direction of the superconducting cable is a condition to minimize the AC loss.

5 shows another embodiment of a superconducting cable according to the present invention, and FIG. 6 shows a cross-sectional view of a state in which the superconducting cable shown in FIG. 5 is installed in a horizontal direction. Descriptions duplicated with the description with reference to FIGS. 1 to 4 will be omitted. 5 and 6 illustrate a three-phase superconducting cable in which the number of core portions 100 provided in the superconducting cable is three.

In addition, the embodiment shown in FIGS. 5 and 6 is different from the embodiment shown in FIGS. 1 and 2, in FIG. 4 in which four superconducting conductor layers are provided in each core portion and two shielding layers are provided. This is an example to which the illustrated description can be applied.

Therefore, in the embodiment shown in FIGS. 5 and 6, when both the superconducting conductor layer and the superconducting shielding layer are composed of a plurality of layers, as described with reference to FIG. 4, the superconducting conductor layer 130 is an outermost superconducting conductor layer ( If the metal substrate layer of 130d) is disposed to face the center direction of the superconducting cable, and the superconducting shielding layer is disposed outward so that the superconducting layer of the superconducting wire constituting the innermost superconducting shielding layer faces the radial direction of the superconducting cable, The outermost superconducting conductor layer and the innermost superconducting shielding layer can minimize AC loss due to a magnetic field.

Accordingly, the plurality of layers of the superconducting conductor layer 130 and the plurality of layers of the superconducting shielding layer 180 may be stacked to face the same direction.

The three-phase superconducting cable may have a structure in which each core part 100 is not independently provided with a cooling part 200 but a structure in which the cooling part 200 is shared outside the three core parts 100, and the The vacuum unit 500 outside the cooling unit 200 may also have a shared structure.

Although the present specification has been described with reference to preferred embodiments of the present invention, those skilled in the art will variously modify and change the present invention within the scope not departing from the spirit and scope of the present invention described in the claims described below. You will be able to do it. Therefore, if the modified implementation basically includes the elements of the claims of the present invention, all should be considered to be included in the technical scope of the present invention.

1000: superconducting cable
100: core part
130: superconducting conductor layer
180: superconducting shielding layer
200: cooling unit
300: inner metal tube
400: insulation
500: vacuum part
560: spacer
600: external metal tube
700: sheath

Claims (12)

Former, at least one superconducting conductor layer including a plurality of superconducting wires arranged in parallel in the longitudinal direction of the former to surround the outside of the former, an insulating layer surrounding the superconducting conductor layer, the former to surround the outside of the insulating layer A core portion including at least one superconducting shielding layer composed of a plurality of superconducting wires disposed side by side in the longitudinal direction of the;
A cooling part provided outside the core part and provided with a circulation passage for a liquid refrigerant for cooling the core part;
A heat insulating unit provided outside the cooling unit and configured by winding an insulating material a plurality of times; And,
Includes; a vacuum unit provided outside the heat insulating unit and provided with a plurality of spacers at spaced positions,
The superconducting wire constituting the superconducting conductor layer and the superconducting shielding layer includes a metal substrate layer and a superconducting layer deposited on the metal substrate layer in a plurality of layers and comprising a superconducting material,
Of the superconducting conductor layers, a metal substrate layer of a superconducting wire constituting the outermost superconducting conductor layer is disposed in the direction of the center of the superconducting cable, and the superconducting layer is disposed in the radial direction of the superconducting cable,
Superconducting cable, characterized in that the superconducting layer of the superconducting wire constituting the innermost superconducting shielding layer among the superconducting shielding layers is disposed in a direction of the center of the superconducting cable, and the metal substrate layer is disposed in a radial direction of the superconducting cable. The method of claim 1,
The superconducting conductor layer is composed of a plurality of layers, the metal substrate layer of the superconducting wire constituting the plurality of superconducting conductor layers is disposed in the center direction of the superconducting cable, and the superconducting layer is disposed in the radial direction of the superconducting cable. Superconducting cable. delete The method of claim 1,
The superconducting shielding layer is composed of a plurality of layers, and the superconducting layers of the superconducting wire constituting the multi-layered superconducting shielding layer are all arranged in the direction of the center of the superconducting cable, and all the metal substrate layers are arranged in the radial direction of the superconducting cable. Superconducting cable characterized by. The method according to claim 2 or 4,
The superconducting conductor layer is composed of four layers, the superconducting shielding layer is a superconducting cable, characterized in that composed of two layers. Former;
At least one or more superconducting conductor layers provided outside the former;
An insulating layer surrounding the superconducting conductor layer; And,
Includes; at least one or more superconducting shielding layers provided outside the insulating layer,
The superconducting wire constituting the superconducting conductor layer and the superconducting shielding layer is deposited in a plurality of layers on the metal substrate layer and the metal substrate layer, and includes a superconducting layer including a superconducting material,
The outermost superconducting conductor layer among the superconducting conductor layers and the metal substrate layer of the superconducting wire constituting the innermost superconducting shielding layer of the superconducting shielding layer and the superconducting layer are arranged in opposite directions,
The superconducting conductor layer is composed of a plurality of layers, the superconducting layers of the superconducting wire constituting the plurality of superconducting conductor layers are all arranged in the radial direction of the superconducting cable, and the metal substrate layer is arranged in the center direction of the superconducting cable. Superconducting cable. delete The method of claim 6,
The superconducting shielding layer is composed of a plurality of layers, and the superconducting layers of the superconducting wire constituting the multi-layered superconducting shielding layer are all arranged in the direction of the center of the superconducting cable, and all the metal substrate layers are arranged in the radial direction of the superconducting cable. Superconducting cable characterized by. Including; a core portion including a foamer, at least one superconducting conductor layer surrounding the outside of the former, an insulating layer surrounding the superconducting conductor layer, and at least one superconducting shielding layer surrounding the outside of the insulating layer,
The superconducting wire constituting the superconducting conductor layer and the superconducting shielding layer is deposited in a plurality of layers on the metal substrate layer and the metal substrate layer, and includes a superconducting layer including a superconducting material,
Among the superconducting conductor layers, the metal substrate layer of the superconducting wire constituting the outermost superconducting conductor layer is disposed in the direction of the center of the superconducting cable, the superconducting layer is disposed in the radial direction of the superconducting cable, and the innermost superconducting shielding layer among the superconducting shielding layers A superconducting cable, characterized in that the superconducting layer of the superconducting wire constituting the is disposed in the center direction of the superconducting cable, and the metal substrate layer is disposed in the radial direction of the superconducting cable. The method of claim 9,
The superconducting conductor layer and the superconducting shielding layer are composed of a plurality of layers, and the superconducting layers of the superconducting wire constituting the plurality of superconducting conductor layers are all arranged in the radial direction of the superconducting cable, and the metal substrate layer is toward the center of the superconducting cable. A superconducting cable, characterized in that the superconducting layers of the superconducting wire material constituting the plurality of superconducting shielding layers are all disposed in the center direction of the superconducting cable, and all the metal substrate layers are disposed in the radial direction of the superconducting cable. delete delete

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