Superconductor cable and AC power transmission cable
There is provided a superconductive cable wherein an efficiency of an electric power transmission is increased to a maximum and the superconductive cable is miniaturized by strengthening a longitudinal magnetic field in a superconductive material. A superconductive cable 1 , which transmits an electric power by using superconductive material, includes a conductive portion 4 that is constructed by superconductive members spirally arranged at either a positive angle or a negative angle with respect to a standard direction defined as a longitudinal direction of the superconductive cable, and is characterized by the fact that the conductive portion 4 is composed of a plurality of layers, that the spiral angles in the respective layers are different from each other to the standard direction in order from an innermost layer 2 toward an outermost layer 3 , and that magnetic fields are produced by electric currents flowing into the conductive portion 4 in the same direction as a direction in which the electric currents flow.
1. A superconductive cable that transmits an electric power by using superconductive material, comprising
a conductive portion that is constructed by superconductive members spirally arranged at either a positive angle or a negative angle with respect to a standard direction defined as a longitudinal direction of the superconductive cable
characterized by the fact that said conductive portion comprises a plurality of layers, that the spiral angles of the respective layers gradually becomes larger in relation to said standard direction in order from an innermost layer toward an outermost layer, and that magnetic fields are produced by electric currents flowing into said conductive portion in the same direction as a direction in which the electric currents flow.
2. The superconductive cable as set forth in claim 1 , characterized by the fact that said spiral angles in the respective layers gradually becomes larger from each other to said standard direction in order from the innermost layer toward the outermost layer within an range from 0° to 60°.
3. The superconductive cable as set forth in claim 1 , characterized by the fact that the innermost layer of said conductive portion is arranged so as to be parallel to said standard direction.
4. The superconductive cable as set forth in claim 1 , characterized by the fact that each of the angles, at which said conductive portion is constructed, is regulated as an angle at which that each of the electric currents flowing through the conductive portion and a corresponding magnetic flux density are the same as each other.
5. The superconductive cable as set forth in claim 1 , characterized by the fact that said superconductive members are composed of a plurality of superconductive tapes, that said conductive portion is constructed from the superconductive tapes which are juxtaposed with each other, and that each of said superconductive tapes includes a stabilization layer which serves as a bypass for the electric current flowing into the corresponding superconductive tape.
6. The superconductive cable as set forth in claim 1 , characterized by the fact that said superconductive cable includes:
an inner layer portion that is defined by the layers in said conductive portion;
an outer layer portion which is defined as a conductive portion composed of superconductive members, with the superconductive members of the outer layer portion being spirally arranged with respect to the standard direction in the reverse spiral direction to the spiral direction in which the superconductive members of the inner layer portion are spirally arranged; and
an insulating layer provided between the inner layer portion and the outer layer portion.
7. The superconductive cable as set forth in claim 6 , characterized by the fact that said outer layer portion is composed of a plurality of layers, and that the spiral angles in the respective layers are different from each other to said standard direction in order from an innermost layer toward an outermost layer.
8. The superconductive cable as set forth in claim 7 , characterized by the fact that the innermost layer of said outer layer portion defined as the conductive portion are arranged so as to be parallel to said standard direction.
9. The superconductive cable as set forth in claim 6 , characterized by the fact that a direction in which an electric current flows into said inner layer portion and a direction in which an electric current flows into said outer layer portion are reverse to each other with respect to said standard direction.
10. An alternating current power transmission cable comprising three superconductive cables, each of which is set forth in claim 1 , characterized by the fact that said three superconductive cable are bundled in a three-phase manner.
11. The superconductive cable as set forth in claim 1 , characterized by the fact that each of said superconductive members at least includes a tape-like superconductive layer into which an electrical current flows in a superconductive state, that said superconductive members are juxtaposed with each other to thereby define said conductive portion, and that said tape-like superconductive layer has a thickness falling within a range from 0.1 μm to 0.4 μm.