JP3442923B2 - Superconducting device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a superconducting device, and more particularly to a superconducting device in which a superconducting coil having a non-inductive winding structure is housed in a container made of a conductive material containing a low temperature refrigerant liquid.

[0002]

2. Description of the Related Art As is well known, when a current exceeding a critical current value peculiar to the wire of a superconducting wire is about to flow, the superconducting wire is almost instantly changed (quenched) to a normal conducting state. When the state is changed to the normal conduction state in this way, the state of zero resistance up to now is switched to the high resistance state.

Focusing on the phenomenon peculiar to such a superconducting wire,
Recently, the development of superconducting fault current limiters used in electric power systems has been actively conducted. The superconducting fault current limiter uses a resistance-action type in which a superconducting coil with a non-induction winding is directly used as a current limiting element, and a superconducting coil with a non-induction winding is used as a trigger coil, and a reactor installed in parallel with this trigger coil. There is a commutation operation type in which a current is commutated to a current limiting element such as a current limiting element. In either type, in a steady state, a system in which the current of the power system is directly passed through the superconducting coil having a non-induction winding structure is adopted.

Examples of the superconducting coil having a non-induction winding structure include, for example, a series structure in which two coils are connected in series so as to cancel the generated magnetic fields, and a parallel structure in which parallel connection is performed so as to cancel the generated magnetic fields. There is a configuration, but in order to reduce the density of the current flowing in the superconducting wire, the parallel configuration is used exclusively.

FIG. 12 shows a typical example of a resistance operation type superconducting fault current limiter used in a power system. In addition,
Although it has a three-phase configuration when it is actually used in a power system, it is shown as a single-phase configuration in this figure.

The main part of this superconducting fault current limiter is the heat insulating container 1.
And a superconducting coil 2 having a non-induction winding structure housed in the heat insulating container 1, and the heat insulating container 1 together with the superconducting coil 2.
A cryogenic refrigerant liquid 3 typified by liquid helium that is housed inside to cool the superconducting coil 2 by immersion, a cryogenic refrigerator 4 that recondenses the vaporized gas of the cryogenic refrigerant liquid 3, and both ends of the superconducting coil 2. With two current leads 5 for connecting to the electric power system.

The heat insulating container 1 includes an inner tank 11 for containing the superconducting coil 2 and the cryogenic refrigerant liquid 3, an outer tank 12 arranged so as to surround the inner tank 11, the outer tank 12 and the inner tank. 11
And a vacuum heat insulating layer 13 formed between The inner tank 11 is usually formed of stainless steel so that it can sufficiently withstand an increase in internal pressure caused by evaporation of the cryogenic refrigerant liquid 3 due to Joule heat when the superconducting coil 2 is quenched and the current limiting operation is performed. ing.

In the example shown in FIG. 12, the vacuum heat insulating layer 13 is used.
The heat shield plate 14 is disposed in the cryogenic refrigerator 4, for example, the intermediate cooling stage (5
It is thermally connected to about 0K).

As shown in FIG. 13, for example, the superconducting coil 2 has a superconducting wire 17 having a critical temperature of, for example, several ten K and a critical current value of about twice the rated current peak value of the power system. A first layer coil 18 and a second layer coil 19, which are wound in opposite directions, are arranged concentrically so as to share a straight central axis, and the first layer coil 18 and the second layer coil 19 are arranged. Are connected in parallel using the superconducting wire 20 and the vacuum introduction terminals 21 and 22, and are made non-inductive.

In the example of FIG. 12, each of the two current leads 5 has a structure in which an oxide superconducting lead 23 and a copper lead 24 are connected in series. The connecting portions of the oxide superconducting lead 23 and the copper lead 24 are electrically connected to the cooling stage 26 of the auxiliary refrigerator 25 at a temperature of about 50 K in an electrically insulated state. Also, each copper lead 2
One end side of 4 is an inner tank 11, a heat shield plate 14, an outer tank 12
Is airtightly and electrically penetrated to be connected to the power system.

In the superconducting fault current limiter configured as above,
The current of the power system flows through the superconducting coil 2 as it is. Since the superconducting coil 2 has a non-inductive winding structure, the inductance is almost zero and the resistance value is zero, so that it does not act as a load.

If a current exceeding a critical current value is about to flow through the superconducting wire 17 constituting the first layer coil 18 and the second layer coil 19 due to a short circuit accident in the power system, the first layer coil 18 Then, the second layer coil 19 is instantly quenched, and as a result, the first layer coil 18 and the second layer coil 19 serve as high resistance elements to suppress an increase in the system current. At this time, a large amount of Joule heat is generated in the inner tank 11, so that the cryogenic refrigerant liquid 3 evaporates. This evaporated component is gradually recondensed by the cryogenic refrigerator 4. The limited system current is cut off by a circuit breaker (not shown).

By the way, in the superconducting fault current limiter configured as described above, in order to suppress the capacity of the cryogenic refrigerator 4, it is necessary to sufficiently reduce the heat load entering the inner tank 11 in a steady state. Is desired. The heat load that penetrates includes AC loss of the superconducting coil 2, heat that enters from the outside due to heat conduction through the current leads 5, and eddy current loss in the wall of the inner tank 11.

Among these heat loads, the eddy current loss generated on the wall of the inner tank 11 is generated for the following reason. That is, even if the superconducting coil 2 which is a current limiting element is configured to have no induction winding, there is usually a slight difference between the magnetic flux generated in the first layer coil 18 and the magnetic flux generated in the second layer coil 19. On the other hand, the inner tank 11 is formed of stainless steel which is a conductive material from the viewpoint of ensuring the yield strength when the internal pressure rises during current limiting as described above. Therefore, when the magnetic flux emitted from the superconducting coil 2 is magnetically coupled to the wall of the inner tank 11 made of stainless steel, an eddy current loss is generated on this wall due to the magnetic flux having the above-mentioned difference. This eddy current loss is not negligible.

In order to reduce such eddy current loss, it is conceivable that the inner tank 11 is made large and the distance between the wall of the inner tank 11 and the superconducting coil 2 is made sufficiently large. If the structure is adopted, not only the capacity of the cryogenic refrigerator 4 is increased but also the entire size is increased.

Therefore, as shown in FIG. 13, a cylindrical electromagnetic shield 27 made of a good conductive material such as copper or aluminum is arranged so as to surround the superconducting coil 2. It is considered that an eddy current flowing in the inner tank 11 generates a magnetic flux in a direction that cancels the above-mentioned difference magnetic flux, thereby reducing the eddy current loss generated in the wall of the inner tank 11.

However, even those that take such measures have the following problems. That is, the first layer coil 18 and the second layer coil 19 that form the superconducting coil 2 are magnetically coupled to the electromagnetic shield body 27 independently of each other. The strength of the coupling is close in distance, that is, the second layer coil 19 located outside.
Is stronger than the first layer coil 18. The strength of this bond is
It acts to lower the apparent impedance of the second layer coil 19. For this reason, the current value of the second layer coil 19 becomes larger than the current value of the first layer coil 18, and the magnetic flux having the above-mentioned difference is further increased. As a result, the eddy current loss in the electromagnetic shield body 27 is increased this time, and depending on the conditions, the eddy current loss in the electromagnetic shield body 27 is larger than the eddy current loss generated in the wall of the inner tank 11 when the electromagnetic shield body 27 is not provided. In some cases, the eddy current loss was larger.

[0018]

As described above, a multi-layer structure in which a container made of a conductive material containing a low temperature refrigerant liquid is non-inductively wound and connected so as to cancel out the alternating magnetic fields generated in the respective layers from each other. In the conventional superconducting device that accommodates the superconducting coil, the electromagnetic shield body made of a good conductive material is arranged so as to surround the superconducting coil in order to reduce the eddy current loss generated in the wall of the container. Due to the presence of the shield, the inductance balance between the layers is disturbed, which causes a problem that the eddy current loss cannot be effectively reduced.

Therefore, the present invention can solve the above-mentioned inconvenience and effectively reduce the eddy current loss in the container wall, which is a problem when a container made of a conductive material is used. It is an object of the present invention to provide a superconducting device that can contribute to reduction.

[0020]

In order to achieve the above object, in a superconducting device according to the invention of claim 1, a container made of a conductive material for containing a cold / cold refrigerant liquid and a multi-layered structure having a concentric shape. A superconducting coil of a non-induction winding structure, which is formed in the above and is connected so as to cancel out the alternating magnetic field generated in each layer and accommodated in the container, and is arranged in the container so as to surround the superconducting coil. An electromagnetic shield body made of a good conductive material and a balance adjustment body made of a conductive material which is arranged inside the superconducting coil and balances the alternating magnetic field generated in each layer of the superconducting coil.

The balance adjusting body may also serve as a part of the winding frame of the superconducting coil. In order to achieve the above object, in the superconducting device according to the invention of claim 3, a container made of a conductive material for containing a low-temperature refrigerant liquid and a multi-layered structure having a concentric circular shape are formed, and alternating layers generated in each layer. A superconducting coil of a non-induction winding structure, which is connected so as to cancel out a magnetic field between each other and is housed in the container, and a superconducting coil that surrounds the superconducting coil and reduces mutual induction with the superconducting coil.
An electromagnetic shield made of a good conductive material is disposed sufficiently close to the inner surface of the container to be crushed .

In order to achieve the above object, in a superconducting device according to the invention of claim 4, the superconducting device is composed of a container made of a conductive material for containing a cold / cold refrigerant liquid, and an even number of coil blocks arranged coaxially. Each coil block is formed in an even numbered layer structure having a concentric circular shape, and in each coil block, an alternating magnetic field generated in each layer is canceled by each other, and a current flows between the coil blocks with reference to the axis. A superconducting coil having a non-induction winding structure housed in the container by connecting the layers of adjacent blocks so that even-numbered current paths having equal directional conditions are formed through the coil blocks, and surrounding the superconducting coil. And an electromagnetic shield body made of a good conductive material disposed in the container.

To achieve the above object, in a superconducting device according to a fifth aspect of the present invention, a container made of a conductive material for containing a cold / cold refrigerant liquid and a concentric four-layer structure are formed, and the innermost portion is formed. The first circuit is configured by connecting both layers in series in order to pass an alternating current in the same direction in the circumferential direction on the first layer located on the first layer and the outermost fourth layer on the second layer. And 3
A second circuit is formed by connecting both layers in series so that the direction of the alternating current flowing in the layer in the circumferential direction is opposite to that of the first circuit, and the first circuit and the second circuit are connected in parallel. And a superconducting non-induction winding structure housed in the container with the cross-sectional area between the first and second layers set substantially equal to the cross-sectional area between the third and fourth layers. A coil and an electromagnetic shield made of a good conductive material and arranged in the container so as to surround the superconducting coil are provided.

In order to achieve the above object, in the superconducting device according to the invention of claim 6, it is formed in a four-layer structure sharing a straight central axis with a container made of a conductive material for containing a low-temperature refrigerant liquid, The first circuit is configured by connecting both layers in series in order to pass an alternating current in the same direction in the circumferential direction on the innermost first layer and the outermost fourth layer. A second circuit is formed by connecting both layers in series so that the direction of the alternating current flowing in the circumferential direction in the third layer is opposite to that in the first circuit, and the second circuit is formed. The circuit is connected in parallel, and the axial center of each layer has the smallest diameter for the first and second layers, and the axial center of each layer has the largest diameter for the third and fourth layers. And a superconducting coil having a non-inductive winding structure formed in a shape to be housed in the container and the superconducting coil. Wherein and a good-material made of an electromagnetic shielding member disposed in the container useless.

In order to achieve the above object, in a superconducting device according to the invention of claim 7, a container made of a conductive material for containing a low temperature refrigerant liquid and a toroidal shape in opposite directions are provided on the outer circumference of an annular winding frame. A superconducting coil having a non-induction winding structure, which is formed in a wound two-layer structure and is connected in parallel with the two layers and accommodated in the container, and is arranged in the container so as to surround the superconducting coil. And an electromagnetic shield made of a good conductive material.

In order to achieve the above object, in a superconducting device according to the invention of claim 8, a container made of a conductive material for containing a low-temperature refrigerant liquid and a multi-layer structure each of which has a concentric shape are formed. Three superconducting coils of non-induction winding structure that are connected so as to cancel each other's alternating magnetic fields and are housed coaxially in the container, and surround these three superconducting coils integrally. And an electromagnetic shield body made of a good conductive material disposed in the container.

In order to achieve the above object, in a superconducting device according to the invention of claim 9, a container made of a conductive material for containing a low-temperature refrigerant liquid and a plurality of layers each having a concentric circular shape are formed, Three non-induction winding constructions which are connected so as to cancel out the alternating magnetic fields generated in each layer, have their axes parallel to each other in the container, and have each axis positioned at each vertex of an equilateral triangle. And the electromagnetic shield made of a good conductive material, which is arranged in the container so as to integrally surround these three superconducting coils.

With the above structure, it is possible to prevent the balance of the currents flowing through the layers forming the superconducting coil from being disturbed by the electromagnetic shield, or to reduce the magnetic flux itself passing through the wall of the container made of a conductive material. . As a result, it is possible to reduce the eddy current loss that occurs in the container and the wall of the container.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows only a main part of a superconducting device according to a first embodiment of the present invention, in which the present invention is applied to a resistance operation type superconducting fault current limiter. When it is actually used in a power system, it has a three-phase structure, but in this figure, only the single-phase component is taken out and only the elements accommodated in the inner tank of the heat insulating container are shown.

In the figure, 31 indicates an inner tank in the heat insulating container. As described above, the inner tank 31 is made of stainless steel so as to sufficiently withstand the rise in internal pressure caused by Joule heat when the current limiting operation is performed.

In the inner tank 31, a superconducting coil 32 of non-induction winding, which constitutes a current limiting element, and a cryogenic refrigerant liquid 33 represented by liquid helium, which immerses and cools the superconducting coil 32, are housed.

The superconducting coil 32 is made of glass fiber reinforced plastic having epoxy resin as a matrix, alumina fiber, polyethylene fiber or a plastic reinforced with a mixed fiber thereof, and the ratio of the inner radius r to the outer radius R is 0.
The critical temperature of the winding frames 34, 35 formed on the outer peripheral surface and having the spiral groove for winding and the flow channel groove for cooling is, for example, several ten K and the critical current value is the rated current wave of the power system. A first layer coil 37 and a second layer coil 38, which are formed by winding superconducting wires 36 of, for example, about twice the high value, in opposite directions are concentrically arranged so as to share a central axis, and these first layer coils are arranged. 37 and the second layer coil 38 are connected in parallel using a superconducting wire 39, a connection terminal 40, and vacuum introduction terminals 41a and 41b, so as to be inductive.

The vacuum introduction terminals 41a and 41b are provided in the inner tank 31.
Is connected to two current leads (not shown) for liquid-tightly and insulatingly penetrating the bottom wall thereof to connect to the power system. The structure of the current leads and the cooling structure are the same as those of the conventional example shown in FIG.

On the outside of the superconducting coil 32, an electromagnetic shield body 43 formed of a good conductive material such as copper, aluminum or a superconducting material in a cylindrical shape is concentrically arranged so as to surround the superconducting coil 32. Further, inside the superconducting coil 32, a balance adjusting body 44, which is also cylindrically formed of a good conductive material such as copper, aluminum or a superconducting material, is concentrically arranged. As will be described later, the balance adjuster 44 is provided with the electromagnetic shield 43 so that the first layer coil 3 is
7 has a function of suppressing an imbalance between the current flowing through the coil 7 and the current flowing through the second layer coil 38.

The electromagnetic shield body 43 and the balance adjusting body 44 may be formed by winding a wire rod of the above-mentioned material in a closed loop structure. With such a configuration,
The unbalance between the current flowing through the first layer coil 37 and the current flowing through the second layer coil 38 due to the presence of the electromagnetic shield body 43 can be suppressed by the balance adjusting body 43, and the electromagnetic shield body 43 is prevented from losing an original eddy current loss. The suppression function can be exerted.

That is, in order to simplify the explanation,
The superconducting coil 32 without considering the balance adjuster 44
And the electromagnetic shield 43 are modeled as an electric circuit. Current I ₁ flowing through the first layer coil 37, current I ₂ flowing through the second layer coil 38, the current I ₃ flowing through the electromagnetic shield member 43 is given as a solution of the following equation.

[0037]

[Equation 1]

In the equations (1) to (3), V is the voltage across the superconducting coil 32, L ₁ is the self-inductance of the first layer coil 37, L ₂ is the self inductance of the second layer coil 38, and L ₃ Is the self-inductance of the electromagnetic shield 43, R ₃ is the resistance of the electromagnetic shield 43, M ₁₂ is the mutual inductance between the first layer coil 37 and the second layer coil 38, M ₁₃ is the first layer coil 37 and the electromagnetic. Mutual inductance between shield layer 43, M ₂₁ is mutual inductance between second layer coil 38 and first layer coil 37, and M ₂₃ is mutual inductance between second layer coil 38 and electromagnetic shield body 43. , M ₃₁ is a mutual inductance between the electromagnetic shield body 43 and the first layer coil 37, and M ₃₂ is a mutual inductance between the electromagnetic shield body 43 and the second layer coil 38.

Since the second layer coil 38 is structurally closer to the electromagnetic shield body 43 than the first layer coil 37, the mutual induction with respect to the electromagnetic shield body 43 is large. That is, M
_{Since 23} is large, the presence of the electromagnetic shield 43 acts to reduce the induced voltage of the second layer coil 38. As a result, the current I ₂ flowing in the second layer coil 38 becomes larger than the current I ₁ flowing in the first layer coil 37, and the magnetic flux generated in the first layer coil 37 and the magnetic flux generated in the second layer coil 38 are The difference between Therefore, the eddy current loss in the electromagnetic shield 43 is increased.

However, as shown in FIG. 1, when the balance adjusting body 44 is provided inside the superconducting coil 32, the first layer coil 37 is structurally closer to the balance adjusting body 44 than the second layer coil 38. Becomes Therefore, the first layer coil 37 has a greater mutual induction with respect to the balance adjusting body 44 than the second layer coil 38. Now, assuming that the mutual inductance between the first layer coil 37 and the balance adjusting body 44 is M _14, and the current flowing through the balance adjusting body 44 is I ₄ ,
The voltage V across the first layer coil 37 is expressed by the following equation (1):

[0041]

[Equation 2] It will be the value which added.

That is, the balance adjuster 44 acts to reduce the induced voltage of the first layer coil 37. As a result, the current of the first layer coil 37 increases. Therefore, by providing the balance adjusting body 44, the current of the first layer coil 37 can be increased by an amount commensurate with the increase of the current of the second layer coil 38 caused by the presence of the electromagnetic shield body 43. Since the current flowing through 37 and the current flowing through the second layer coil 38 can be balanced, it is possible to suppress an increase in eddy current loss in the electromagnetic shield 43 caused by the imbalance. That is, with the above configuration, it is possible to suppress the eddy current loss that occurs in the wall of the inner tank 31 while suppressing the eddy current loss in the electromagnetic shield body 43.

Although the electromagnetic shield 43 is provided only on the outer circumference of the superconducting coil 32 in the above example, it may be provided on both sides in the axial direction. Further, as in the above example, if the ratio of the inner radius r of the winding frames 34, 35 to the outer radius R is set to 0.98 or less, the superconducting wire 36 is superconducted again after the current limiting operation to change the system current. It is possible to prevent the occurrence of quenching that tends to occur when the power is re-energized.

That is, when a short-circuit accident occurs in the electric power system, the superconducting coil 32 is quenched and the resistance is increased to perform the current limiting operation. At this time, Joule heat evaporates the liquid helium as the cryogenic refrigerant liquid 33. As a result, a high pressure gas region is generated around the reel. The pressure at this time is 5-10 kg / cm ²
Also reaches. Therefore, when the wall thickness of the reels 34, 35 is thin, the reels are elastically deformed.

When such elastic deformation occurs, the superconducting wire 36 is easily displaced from a mechanically stable position, and when the superconducting wire 36 undergoes a superconducting transition again and a system current is re-energized after the current limiting operation, the superconducting wire 36 is superconducted by electromagnetic force. The line 36 is easy to move to the next stable position. If the winding moves even slightly, frictional heat is generated accordingly. Generally, since the specific heat of a substance is extremely small under extremely low temperature such as liquid helium, even a slight frictional heat will raise the superconducting wire 36 to a temperature at which it transitions to the normal conducting state.
Therefore, it may be difficult to re-energize after the current limiting operation.

If the ratio of the inner radius r and the outer radius R of the reels 34 and 35 is set to 0.98 or less, even if the high-pressure gas region of the above-mentioned level occurs around the reels, Since elastic deformation can be suppressed, quenching that occurs during re-energization after current limiting operation can be suppressed, and the stability of the device can be improved.

In FIG. 3, glass fiber reinforced plastic is used as the material, the outer diameter is 250 mm, the axial length is 400 mm, and the inner diameter is 0 to 247 m.
At 11 m, 11 kinds of bobbin each having spiral groove for winding and flow channel groove for cooling on the outer surface are wound with a superconducting wire with a wire diameter of 2.5 mm into a solenoid with a constant tension. The results of measuring the quench current Iq and the amount of strain generated in the reel during quenching by immersing the superconducting coil in liquid helium are shown.

As can be seen from this figure, the amount of strain changes depending on the ratio of the inner diameter to the outer diameter of the winding frame, and the quench current I
q is also changing. For example, the ratio of inner diameter to outer diameter is 0.99.
In this case, the quench was performed at about 1800 A, whereas when the ratio of the inner diameter to the outer diameter was 0, that is, when a solid bobbin was used, it was possible to energize up to 2500 A without quenching.
From this, it is effective to reduce the ratio of the inner diameter to the outer diameter of the winding frame as much as possible.

As a means for increasing the mechanical strength of the bobbin, as shown in FIG. 2, the inner part 45 of the bobbin is formed of a good conductive material such as copper or aluminum or a metal material such as stainless steel. The outer portion 46 may be a winding frame 47 having a composite structure formed of glass fiber reinforced plastic. In this case, the inner portion 45 formed of a metal material may also be used as the balance adjustment body 44 shown in FIG.

FIG. 4 shows only a main part of a superconducting device according to a second embodiment of the present invention, and also an example in which the present invention is applied to a resistance operation type superconducting fault current limiter. In this figure, the same functional parts as in FIG. 1 are designated by the same reference numerals. Therefore, detailed description of the overlapping portions will be omitted.

In this example, instead of providing the balance adjusting body, the electromagnetic shield body 43 is arranged as far as possible from the superconducting coil 32 and arranged sufficiently close to the inner surface of the inner tank 31.

With such a configuration, the first layer coil 3
7 and the second layer coil 38, the mutual induction between the electromagnetic shield body 43 and the difference between the two can be reduced. Therefore, the presence of the electromagnetic shield body 43 causes the current flowing through the first layer coil 37 and the second layer coil 37. It is possible to prevent the current flowing through the coil 38 from being unbalanced. For this reason, it is possible to suppress an increase in eddy current loss in the electromagnetic shield 43 caused by the imbalance.

FIG. 5 shows the distance between the superconducting coil 32 and the electromagnetic shield 43 and the first and second layer coils 37, 38.
An actual measurement example is shown in which the relationship with the current flowing in is investigated.
This is an example in which the first layer coil 37 has a diameter of 220 mm and 38 turns, the second layer coil 38 has a diameter of 240 mm and uses 38 turns of the superconducting coil 32, and a copper cylinder is used as the electromagnetic shield 43. .

As can be seen from FIG. 5, when the inner diameter of the electromagnetic shield 43 is about 265 mm, the current imbalance of each layer coil is large, but the electromagnetic shield 4 having an inner diameter of about 360 mm 4 is large.
By using 3, it is possible to balance the currents of the coil layers. By using the electromagnetic shield 43 having an inner diameter of 400 mm or more, the current of each layer coil can be settled to a value determined by the self-inductance and the mutual inductance.

Although the electromagnetic shield 43 is provided only on the outer circumference of the superconducting coil 32 in the example shown in FIG. 4, it may be provided on both sides in the axial direction. FIG. 6 shows only a superconducting device according to a third embodiment of the present invention, and also only a main part of an example in which the present invention is applied to a resistance operation type superconducting fault current limiter. In this figure, the same functional parts as in FIG. 1 are designated by the same reference numerals. Therefore, detailed description of the overlapping portions will be omitted.

In this example, a coil block 53 composed of a first layer coil 51 and a second layer coil 52 arranged concentrically around a linear axis and a concentric circle around the linear axis are also provided. The coil block 56 composed of the first-layer coil 54 and the second-layer coil 55, which are arranged in the same manner, is arranged coaxially.

Here, the first in the coil block 53
The layer coil 51 and the second layer coil 55 in the coil block 56 are wound in the same direction, and the second layer coil 52 in the coil block 53 and the first layer coil 54 in the coil block 56 are in the opposite directions. Is wound on.

Then, the first in the coil block 53
The layer coil 51 and the second layer coil 55 in the coil block 56 are connected in series to configure the first circuit 57, and the second layer coil 52 in the coil block 53 and the first layer coil 54 in the coil block 56 are connected. The second circuit 58 is connected in series to form the second circuit 58 and the second circuit 58.
The circuit 58 and the circuit 58 are connected in parallel to form a non-inductive superconducting coil 59.

In the case of this example, a cylindrical electromagnetic shield 43 concentrically with the superconducting coil 59 is arranged outside the superconducting coil 59, and nothing is arranged inside the superconducting coil 59.

With such a configuration, the arrangement conditions of the first circuit 57 and the second circuit 58 with respect to the electromagnetic shield body 43 can be made equal, so that the first circuit 57 and the second circuit 58 with respect to the electromagnetic shield body 43. Mutual induction effect can be equalized. Therefore, since the current flowing through the first circuit 57 and the current flowing through the second circuit 58 can be equalized, the eddy current loss generated in the electromagnetic shield 43 is suppressed and the eddy current loss generated in the wall of the inner tank 31 is suppressed. Can be suppressed.

In FIG. 6, each coil block is formed in a two-layer structure having a concentric circular shape, and two coil blocks are coaxially arranged. However, each coil block has a concentric circular shape. Formed in an even layer structure of two or more layers,
Arrange two or more even numbered coil blocks coaxially,
In each coil block, an even number of current paths are formed so that the alternating magnetic fields generated in each layer are canceled by each other, and the direction conditions in which the current flows are the same between the coil blocks through each coil block. Thus, the layers of the adjacent blocks may be connected to form a non-induction winding superconducting coil.

In the example shown in FIG. 6, the electromagnetic shield 43 is provided only on the outer circumference of the superconducting coil 39, but it may be provided on both sides in the axial direction. FIG. 7 shows only a superconducting device according to a fourth embodiment of the present invention, and also only a main part of an example in which the present invention is applied to a resistance operation type superconducting fault current limiter. In this figure, the same functional parts as in FIG. 1 are designated by the same reference numerals. Therefore, detailed description of the overlapping portions will be omitted.

In this example, the first to fourth layer coils 61, 62, 63 and 64 are arranged in a concentric shape. Here, the first layer coil 61 and the fourth layer coil 64 are wound in the same direction, and the second layer coil 62 and the third layer coil 63 are wound in the opposite direction.

The first layer coil 61 and the fourth layer coil 64 are connected in series to form a first circuit 65, and the second layer coil 62 and the third layer coil 63 are connected in series. Two
The circuit 66 is configured to include the first circuit 65 and the second circuit 66.
And are connected in parallel to form a superconducting coil 67 having a non-inductive structure.

Further, in this example, the cross-sectional area between the first layer coil 61 and the second layer coil 62 and the cross sectional area between the third layer coil 63 and the fourth layer coil 64 are made equal. With such a configuration, the magnetic flux emanating from between the first layer coil 61 and the second layer coil 62 is generated between the third layer coil 63 and the fourth layer coil 64 as indicated by a thick solid line 68 in the figure. Can be sucked into. Therefore, the amount itself of the magnetic flux that tries to reach the wall of the inner tank 31 can be significantly reduced. Therefore, it is possible to suppress the eddy current loss that occurs in the wall of the inner tank 31 while suppressing the eddy current loss that occurs in the electromagnetic shield body 43.

In the example shown in FIG. 7, the electromagnetic shield 43 is provided only on the outer circumference of the superconducting coil 67, but it may be provided on both sides in the axial direction. FIG. 8 shows only a superconducting device according to a fifth embodiment of the present invention, and also only a main part of an example in which the present invention is applied to a resistance operation type superconducting fault current limiter. Only the superconducting coil 70 is shown in this figure. The same functional parts as those in FIG. 1 are designated by the same reference numerals.

This superconducting coil 70 comprises first to fourth layer coils 71, 72, which are arranged in a concentric shape.
It is composed of 73 and 74. Here, the first layer coil 7
The first layer coil 74 and the fourth layer coil 74 are wound in the same direction, and the second layer coil 72 and the third layer coil 73 are wound in the opposite direction.

The first layer coil 71 and the fourth layer coil 74 are connected in series to form a first circuit 75, and the second layer coil 72 and the third layer coil 73 are connected in series. Two
The circuit 76 is configured to include the first circuit 75 and the second circuit 76.
And are connected in parallel to form a non-inductive superconducting coil 70.

The characteristic point of this example is that the first
Winding frames 77, 78 of the layer coil 71 and the second layer coil 72
Is formed in a drum shape with both ends in the axial direction having a large diameter and a central part having a small diameter. Further, the winding frames 79 and 80 of the third layer coil 73 and the fourth layer coil 74 have a small diameter and a central portion having a large diameter so that both ends in the axial direction substantially oppose both ends of the winding frames 77 and 78. It is shaped like a drum.

Also in this example, the superconducting coil 7
An electromagnetic shield (not shown) is arranged so as to surround 0. With such a configuration, the magnetic flux generated in the second circuit 76 passes through a path close to a circle, as indicated by a thick solid line 81 in the figure. Similarly, the magnetic flux generated in the first circuit 75 also passes through a path close to a circle. Therefore, the amount of the magnetic flux itself that tries to reach the wall of the inner tank can be significantly reduced. Therefore, it is possible to suppress the eddy current loss that occurs in the wall of the inner tank while suppressing the eddy current loss that occurs in the electromagnetic shield body.

FIGS. 9 (a) and 9 (b) show only a superconducting device according to a sixth embodiment of the present invention, and only a main part of an example in which the present invention is applied to a resistance operation type superconducting fault current limiter. Has been done. Only the superconducting coil 90 is shown in this figure. And
The same functional parts as in FIG. 1 are designated by the same reference numerals.

The superconducting coil 90 has a two-layer structure in which the superconducting wires 36 are wound in a toroidal shape in opposite directions on the outer circumference of an annular winding frame 91, and an inner layer coil 92 and an outer layer coil 93 are provided.
And are connected in parallel to form a non-inductive winding.

In this example also, the superconducting coil 9
An electromagnetic shield (not shown) is arranged so as to surround 0. With such a configuration, most of the magnetic flux generated in the inner layer coil 92 and the outer layer coil 93 can be passed through the annular passage centered on the winding frame 91. Therefore,
The amount of magnetic flux itself that tries to reach the wall of the inner tank can be greatly reduced. Therefore, it is possible to suppress the eddy current loss that occurs in the wall of the inner tank while suppressing the eddy current loss that occurs in the electromagnetic shield body.

FIG. 10 shows only a superconducting device according to a seventh embodiment of the present invention, and only a main part of an example in which the present invention is applied to a resistance operation type superconducting fault current limiter. This drawing shows the coil arrangement corresponding to the three-phase system. Further, in this figure, the same functional portions as those in FIG. 1 are indicated by the same reference numerals.

The U-phase superconducting coil 100, the V-phase superconducting coil 101, and the W-phase superconducting coil 102 each have a first-layer coil 37 and a second-layer coil 38 formed by winding superconducting wires 36 in opposite directions. Are arranged concentrically so as to be shared, and the first layer coil 37 and the second layer coil 38 are connected in parallel to each other so as to be non-inductive.

In this example, the U-phase superconducting coil 10
0, V-phase superconducting coil 101 and W-phase superconducting coil 1
02 is coaxially arranged on the straight center axis. Both ends of each superconducting coil are connected in parallel using the superconducting wire 39, the connecting terminal 40, and the vacuum introducing terminals 41a and 41b to be non-inducted and guided to the outside of the inner tank 31.

Further, in this example, the U-phase superconducting coil 100, the V-phase superconducting coil 101 and the W arranged coaxially.
An electromagnetic shield body 103 made of a good conductive material is arranged so as to cover the phase superconducting coil 102 and the end portion in the axial direction.

Since the phases of the currents flowing through the U-phase superconducting coil 100, the V-phase superconducting coil 101 and the W-phase superconducting coil 102 are deviated by 120 °, the superconducting coils of each phase are arranged coaxially as in this example. If so, the generated magnetic fluxes can be superimposed and canceled. Therefore,
The amount of magnetic flux that causes eddy current loss can be greatly reduced. Therefore, it is possible to suppress the eddy current loss that occurs in the wall of the inner tank 31 while suppressing the eddy current loss that occurs in the electromagnetic shield body 103.

11 (a) and 11 (b) show only the superconducting device according to the eighth embodiment of the present invention, and only the main part of an example in which the present invention is applied to a resistance operation type superconducting fault current limiter. It is shown. This drawing shows the coil arrangement corresponding to the three-phase system. Further, in this figure, the same functional portions as those in FIGS. 1 and 9 are denoted by the same reference numerals.

The U-phase superconducting coil 100, the V-phase superconducting coil 101, and the W-phase superconducting coil 102 each have a central axis consisting of a first-layer coil 37 and a second-layer coil 38 formed by winding superconducting wires 36 in opposite directions. Are arranged concentrically so as to be shared, and the first layer coil 37 and the second layer coil 38 are connected in parallel to each other so as to be non-inductive.

In this example, the U-phase superconducting coil 10 is used.
0, V-phase superconducting coil 101 and W-phase superconducting coil 1
No. 02 is arranged such that the central axes thereof are parallel to each other and the central axes are located at the vertices of an equilateral triangle as shown in FIG. 11 (b). Then, both ends of each superconducting coil have a superconducting wire 39, a connection terminal 40, and vacuum introduction terminals 41a, 41.
They are connected in parallel using b and are de-inducted and guided to the outside of the inner tank 31.

Further, in this example, the U-phase superconducting coil 10 is used.
0, V-phase superconducting coil 101 and W-phase superconducting coil 1
The electromagnetic shield body 104 formed of a good conductive material is arranged so as to cover the periphery where 02 is arranged and the end portion in the axial direction.

Since the phases of the currents flowing through the U-phase superconducting coil 100, the V-phase superconducting coil 101 and the W-phase superconducting coil 102 are shifted by 120 °, the superconducting coils of each phase are arranged on the same plane as 120 °. If the spatial phases are shifted by each degree, the generated magnetic fluxes can be superposed and cancelled. Therefore, the amount of magnetic flux itself that causes eddy current loss can be significantly reduced. Therefore, it is possible to suppress the eddy current loss that occurs in the wall of the inner tank 31 while suppressing the eddy current loss that occurs in the electromagnetic shield body 104.

[0084]

As described above, according to the present invention,
In a container made of a conductive material containing a low-temperature refrigerant liquid, a multi-layer superconducting coil that is non-inductively wound and connected so as to cancel out the alternating magnetic field generated in each layer is generated, and it is generated on the wall of the container. When an electromagnetic shield made of a good conductive material is placed so as to surround the superconducting coil to reduce the eddy current loss, the presence of the electromagnetic shield disrupts the inductance balance between the layers, which causes eddy current loss. The increase can be effectively reduced.

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional view of a main part of a superconducting device according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing one form of a reel.

FIG. 3 is a diagram showing a result of actually measuring a relationship between a wall thickness of a reel and a quench current.

FIG. 4 is a schematic vertical cross-sectional view of a main part of a superconducting device according to a second embodiment of the present invention.

FIG. 5 is a diagram showing the results of actual measurement of the relationship between the distance between the superconducting coil and the electromagnetic shield and the current in each layer.

FIG. 6 is a schematic vertical cross-sectional view of a main part of a superconducting device according to a third embodiment of the present invention.

FIG. 7 is a schematic vertical cross-sectional view of a main part of a superconducting device according to a fourth embodiment of the present invention.

FIG. 8 is a schematic vertical cross-sectional view of a main part of a superconducting device according to a fifth embodiment of the present invention.

FIG. 9A is a schematic plan view of a main part of a superconducting device according to a sixth embodiment of the present invention, and FIG.
-A line cutting arrow view

FIG. 10 is a schematic vertical sectional view of a main part of a superconducting device according to a seventh embodiment of the present invention.

11A is a schematic vertical cross-sectional view of a main part of a superconducting device according to a seventh embodiment of the present invention, and FIG. 11B is a sectional view taken along line BB in FIG. 11A.

FIG. 12 is a schematic vertical sectional view of a superconducting fault current limiter which is one of application examples of the superconducting device.

FIG. 13 is a diagram for explaining a conventional means for reducing eddy current loss during steady state in the same superconducting fault current limiter.

[Explanation of symbols]

31 ... Inner tank 32, 59, 67, 70, 90 ... Superconducting coil 33 ... Cryogenic refrigerant liquid 34, 35, 47, 77, 78, 79, 80, 91 ... Reel 36 ... Superconducting wires 37, 51, 54, 61, 71 ... First layer coil 38, 52, 55, 62, 72 ... Second layer coil 39 ... Superconducting wire 40 ... Terminal 41a, 41b ... Vacuum introduction terminal 43, 103 ... Electromagnetic shield body 44 ... Balance adjusting body 57, 65, 75 ... First circuit 58, 66, 76 ... Second circuit 100 ... U-phase superconducting coil 101 ... V-phase superconducting coil 102 ... W-phase superconducting coil

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masahiko Nakade 1-3-1, Uchisaiwaicho, Chiyoda-ku, Tokyo Within TEPCO (72) Inventor Takashi Yazawa Komukai-Toshiba, Kawasaki-shi, Kanagawa 1 Toshiba Research & Development Center Co., Ltd. (72) Inventor Tsutomu Kurusu 1 Komukai-cho, Komukai-shi, Kawasaki-shi, Kanagawa Toshiba Research & Development Center Co., Ltd. (72) Innovator Shunji Nomura Toshiba, Komukai Toshiba Town No. 1 in Toshiba Research and Development Center Co., Ltd. (72) Inventor ▲ Tsuru ▼ Kazuyuki Eiichi No. 1 in Toshiba Town Fuchu, Tokyo Fuchu factory No. 1 (72) Inventor Jun Matsuzaki 1 Toshiba Town, Fuchu, Tokyo Address In Toshiba Fuchu factory (72) Inventor Kenji Tasaki 1 Komukai Toshiba-cho, Sachi-ku, Kawasaki-shi, Kanagawa Inside Toshiba R & D Center (56) References JP-A-9-27417 (JP, A) JP-A-9-129938 (JP, A) JP-A-1-173534 (JP, A) JP-A-1-190217 (JP, A) JP-A-6 -223641 (JP, A) JP-A-7-272960 (JP, A) JP-A-3-145922 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H02H 9/00- 9/04 H01F 6/06 H01F 7/22

Claims (9)

(57) [Claims] 1. A container made of a conductive material for containing a low-temperature refrigerant liquid,
A superconducting coil having a non-induction winding structure, which is formed in a multi-layered structure having a concentric shape, is connected so as to cancel out the alternating magnetic field generated in each layer, and is housed in the container, and the superconducting coil. An electromagnetic shield body made of a good conductive material arranged in the container so as to surround it, and a balance adjustment body made of a conductive material arranged inside the superconducting coil to balance the alternating magnetic field generated in each layer of the superconducting coil. A superconducting device comprising: 2. The superconducting device according to claim 1, wherein the balance adjusting body also serves as a part of a winding frame of the superconducting coil. 3. A container made of a conductive material for containing a low-temperature refrigerant liquid,
A superconducting coil having a non-induction winding structure, which is formed in a multi-layered structure having a concentric shape, is connected so as to cancel out the alternating magnetic field generated in each layer, and is housed in the container, and the superconducting coil. Enclose and interact with the superconducting coil
A superconducting device, comprising: an electromagnetic shield made of a good conductive material, which is arranged sufficiently close to the inner surface of the container to reduce the conduction . 4. A container made of a conductive material for containing a low temperature refrigerant liquid,
Each coil block is composed of an even number of coil blocks arranged coaxially, and each coil block is formed into an even layer structure having a concentric circular shape. In each coil block, the alternating magnetic fields generated in each layer are canceled by each other. In addition, each coil block is housed in the container by connecting each layer of adjacent blocks so that even-numbered current paths are formed through the respective coil blocks in which the direction conditions of the current flow with respect to the axis are all equal. A superconducting device comprising: a superconducting coil having a non-inductive winding structure; and an electromagnetic shield body made of a good conductive material and arranged in the container so as to surround the superconducting coil. 5. A container made of a conductive material for containing a low temperature refrigerant liquid,
It is formed in a four-layer structure having a concentric shape, and both layers are formed in order to pass an alternating current in the same direction in the circumferential direction on the innermost first layer and the outermost fourth layer. The first circuit is configured by connecting in series, and both layers are connected in series so that the direction of the alternating current flowing in the second layer and the third layer in the circumferential direction is opposite to that in the first circuit. Two circuits are formed, and the first
Circuit and the second circuit are connected in parallel and the first layer and the second circuit
A superconducting coil of non-induction winding structure housed in the container with a cross-sectional area between the third layer and the fourth layer set to be substantially equal to the cross-sectional area between the third layer and the fourth layer, and surrounding the superconducting coil. 2. A superconducting device, comprising: an electromagnetic shield body made of a good conductive material, which is disposed in the container. 6. A container made of a conductive material for containing a low-temperature refrigerant liquid,
It is formed in a four-layer structure that shares a straight central axis, and both are arranged so that an alternating current in the same direction in the circumferential direction flows through the innermost first layer and the outermost fourth layer. The layers are connected in series to form a first circuit, and both layers are connected in series so that the alternating current flowing in the second and third layers in the circumferential direction is in the direction opposite to that of the first circuit. To form a second circuit, connect the first circuit and the second circuit in parallel, and in the first layer and the second layer, a shape in which the axial center portion of each layer has the smallest diameter is provided. As for the fourth layer, a superconducting coil having a non-inductive winding structure is formed in a shape in which the axial center portion of each layer has the largest diameter, and is housed in the container, and is arranged in the container so as to surround the superconducting coil. And an electromagnetic shield body made of a good conductive material. 7. A container made of a conductive material for containing a low temperature refrigerant liquid,
A superconducting coil having a non-induction winding structure, which is formed in a two-layer structure in which toroidal windings are wound in opposite directions on the outer periphery of an annular winding frame, and the two layers are connected in parallel and housed in the container. A superconducting device, comprising: an electromagnetic shield made of a good conductive material, which is arranged so as to surround the superconducting coil. 8. A container made of a conductive material for containing a low temperature refrigerant liquid,
Each is formed in a multi-layer structure having a concentric shape, and is connected so as to cancel the alternating magnetic field generated in each layer, and is housed coaxially in the container. A superconducting device comprising: a superconducting coil; and an electromagnetic shield made of a good conductive material, which is arranged in the container so as to integrally surround these three superconducting coils. 9. A container made of a conductive material for containing a low temperature refrigerant liquid,
Each is formed in a multi-layered structure having a concentric circular shape, and is connected so as to cancel out the alternating magnetic field generated in each layer to make each axis parallel in the container, and to each vertex of an equilateral triangle. 3 of non-induction winding configuration with the shaft positioned
A superconducting device comprising: one superconducting coil; and an electromagnetic shield made of a good conductive material, which is arranged in the container so as to integrally surround these three superconducting coils.