JP2601318B2 - Superconducting magnetic circuit - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a magnetic circuit for transmitting AC magnetic flux using a magnetic shielding effect of a superconductor.

(Prior art) A magnetic flux generated by a primary coil like a transformer
In a device that transmits energy to the secondary coil, it is ideal that all of the magnetic flux generated by the primary coil can be transmitted to the secondary coil.

However, as is well known, when only the primary coil and the secondary coil are used, much of the magnetic flux generated in the primary coil spreads and escapes without interlinking with the secondary coil, so that the energy transfer efficiency is greatly reduced. In order to prevent this, a magnetic circuit is generally provided by an iron core penetrating the primary coil and the secondary coil.

However, in this method, it is impossible to transmit a magnetic flux of 2 Tesla or more as is well known due to magnetic saturation and the like. For this reason, the amount of transmitted energy is naturally limited, and when the transmitted magnetic flux is an alternating magnetic flux, the generation of iron loss cannot be avoided, so that the energy transmission efficiency is further reduced.

The present inventor has previously proposed a magnetic circuit utilizing a superconductor exhibiting an extremely excellent magnetic shielding effect due to a negative effect exhibited in a superconducting state (see Japanese Patent Application No. 63-22113).

In this magnetic circuit, a loop-shaped hollow container (1) as shown in, for example, a partially cutaway perspective view shown in FIG. 1 is formed of a superconducting material, and a magnetic shielding effect is exerted by leaving the container in a superconducting state. Magnetic circuit space (1
a), for example, the magnetic flux generated by the primary coil (2) provided at one end inside is transmitted to the secondary coil (3) provided at the other end while being enclosed so as not to spread and escape. Things.

According to this method, in principle, there is no limitation on the amount of magnetic flux transmission based on saturation or the like as in a magnetic circuit using an iron core, and the spread and escape of the magnetic flux are extremely small. In addition, since there is no generation of iron loss, a large amount of energy can be efficiently transmitted as compared with a magnetic circuit using an iron core.

In FIG. 1, (4) prevents generation of a current I generated in the circumferential direction of the loop-shaped hollow container (1) by the transmitted magnetic flux.
This is an insulating layer for preventing attenuation of the transmission magnetic flux.

(Problems of the prior art) However, it is difficult to make a loop-shaped container made of a superconducting material, particularly a large container, and the container is expensive because it requires a certain thickness or more to have mechanical strength. Of course, in particular, when the magnetic flux to be transmitted is an alternating current, it is not possible to prevent the loss in the loop-shaped hollow container, so that the energy transmission efficiency is reduced accordingly.

(Object of the Invention) The present invention has been made to provide a superconducting magnetic circuit for transmitting an AC magnetic flux which is easy to manufacture and has a small AC loss.

(Means of the present invention for solving the problems) The feature of the present invention is that an AC superconducting wire, that is, a superconducting filament having a diameter as small as possible is embedded in a superconductivity base material made of, for example, a copper-nickel alloy. A known AC superconducting wire woven in the form of a tape in which the wire is twisted with a pitch as short as possible to reduce the AC loss, and this is wound and formed to form a loop-shaped hollow container. is there. Next, the present invention will be specifically described with reference to examples.

(Example) FIG. 2 is an explanatory view of an example of the present invention. As shown in FIG. 2 (a), a superconducting material tape (7) having a width which is easy to wind is woven using the AC superconducting wire as the warp (5) and the weft (6). In this case, the super electric wire may be insulated by enamel or the like. On the other hand, as shown in FIG. 2 (b), the straight pipe (8a) and the hollow curved pipe (8b) are formed by insertion connection.
a) Or, the required number of turns of the primary coil (2) and the secondary coil (3) are accommodated and fixed in a curved tube, and the coil (2)
An insulating loop-shaped hollow container forming material (8) is prepared, which is drawn out of the tube as connection conductors (2a) and (3a), both ends of which are provided with required insulation.

Then, as shown in FIG. 2 (c), an insulating tape (9) wider than the separately prepared superconducting material tape (7), for example, a glass fiber tape and a superconducting material tape (7) are superimposed on each other and required. The hollow container forming material (8) is spirally wound over the entire length of the peripheral surface of the hollow container forming material (8) so as to overlap the width (10). And finally, the surface is protected by the hollow container forming material (8).
In order to prevent the gap between the superconducting material tapes (7) wound thereon and the looseness of the winding, etc., a resin material such as an epoxy resin is impregnated and solidified to form as shown in FIG. 2 (d). Such a superconducting magnetic circuit is, for example, a cloth-shaped superconducting material (7) having a required area on the surface of a hollow container forming material (8), or a cloth-shaped superconducting material (7) and a circuit for preventing generation of a circulating current. It can also be formed by laminating a cloth-like insulating material (9) with an epoxy resin adhesive.

Further, for example, a superconducting tape (7) impregnated with a low-conductivity material such as solder, or a superconducting tape (7) and an insulating tape (9) superposed on each other are adhered to each other with an epoxy resin or the like. It can be formed by using any appropriate method such as forming by winding to form a loop-shaped hollow container.

In the case where the superconductor used for magnetic shielding including the example of FIG. 2 performs at a low temperature, the loop-shaped hollow container made of the superconducting material must be cooled by being housed in a low-temperature container or the like. No.

(Effects of the Invention) As described above, in the present invention, a loop-shaped hollow container serving as a magnetic circuit is formed by winding a superconducting material for alternating current, and a superconducting tape and an insulating tape are overlapped and wound. Prevent the generation of flowing current. Therefore, a superconducting magnetic circuit that has low AC loss and does not weaken the magnetic flux to be transmitted generated in the axial direction in the magnetic circuit can be configured. It is easier to manufacture than one made by providing layers.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a conventional superconducting magnetic circuit, and FIG. 2 is a circuit diagram of one embodiment of the present invention. (1) ... loop-shaped hollow container made of superconducting material, (2) ...
... primary coil, (3) ... secondary coil, (4) ... insulating layer for preventing circulating current, (5) ... warp by AC superconducting wire, (6) ... weft by AC superconducting wire, (7) ...
Superconducting material tape, (8) ... hollow insulating hollow container,
(9) ... Insulating tape for preventing circulating current, (10) ... Overlap, (11) ... Resin material.

Claims (3)

(57) [Claims] 1. A superconducting magnetic circuit, wherein a loop-shaped hollow container is formed using a cloth-like superconducting material in which AC superconducting wires are woven as warps and wefts to form a magnetic circuit. 2. The superconducting magnetic circuit according to claim 1, wherein the surface of the insulating loop-shaped hollow container is covered with a cloth-like superconducting material. 3. The superconducting magnetic circuit according to claim 1, wherein a loop-shaped hollow container is formed by laminating an insulating tape with a cloth superconducting material.