JPS63232404A - Ac superconducting coil - Google Patents

Abstract

PURPOSE:To prevent quenching effectively by forming cooling channels, into which a refrigerant flows, among arbitrary layers in the winding of an extremely fine multiconductor filament while burying clearances among a wire rod except the cooling channels with an insulator impregnated and cured. CONSTITUTION:There are cooling channels 4 among the layers of a wire rod 3 wound to a coil shape, and clearances among the wire rod except these cooling channels 4 is buried completely with insulators 5. A simple body consisting of a resin impregnated and cured may be used as the insulator 5, but the combination of the fibers of glass, aramid, nylon, etc., which are changed previously into a tape and wound on the wire rod, and a resin such as epoxy, formal, etc., impregnated to the fibers and cured is preferable. Accordingly, the movement of insulating materials among the wire rod is prevented positively, and heat is hardly generated partially due to the fine motion of the winding section, thus effectively avoiding quenching resulting from the heat generation.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a superconducting coil employed as a component in AC equipment such as transformers and generators used at commercial frequencies (50 to 60 Hz). .

[Conventional technology and its problems]

With the development of ultra-fine multicore superconducting wires, AC superconducting coils, which were conventionally limited to pulse applications of several Hz, are now being used in the commercial frequency range mentioned above.

By the way, in order to use a superconducting coil in alternating current, it is necessary to reduce the alternating current loss under energization and to prevent the coil from generating heat. In response to this requirement, many of the coils that have been made so far are of a type in which insulated superconducting wires are tightly wound or insulated spacers are inserted between layers, and these are made using liquid helium, which is a refrigerant. By keeping in contact with the body, it is cooled and heat generation is prevented.

However, in the coil of the above-mentioned structure, the fixing force of the wire is determined by the S tightening tension during winding, and the coil wire tends to move due to the T4 magnetic force when energized, so the overall winding Alternatively, there is a so-called quench phenomenon in which AC loss that exceeds the cooling capacity occurs due to heat generation due to local movements, causing the entire coil to transition from a superconducting state to a normal conducting state before the coil performance exceeds its maximum capacity. often observed.

On the other hand, in order to eliminate mechanical movement of the winding part, a method has been adopted in which the winding part is impregnated with epoxy resin or the like and the entire part is solidified with the resin. This is because the windings are wrapped in the impregnated resin, so direct cooling with liquid helium is limited to the surface of the windings, and AC losses generated internally at frequencies of several tens of Hz The heat cannot be dissipated sufficiently, so the aforementioned quench occurs. This kind of problem is particularly serious when the coil capacity becomes large; no matter how much AC losses are reduced, thermal energy accumulates over time, eventually leading to quenching.

Therefore, an object of the present invention is to provide a superconducting coil for alternating current that is effective as a countermeasure to such problems.

[Means for solving problems]

The coil of the present invention is composed of JT5 superconducting wires having ultra-fine multifilament filaments, and has a cooling channel between arbitrary layers of the winding through which a refrigerant flows,
Moreover, the gap between the wires except for the cooling channel is completely filled with an insulator that is hardened after being impregnated.

[Effect]

The insulator serves to solidify the windings together and prevent mechanical movement of the coil wire.

The interlayer cooling channels also serve to introduce a refrigerant into the interior of the coil and dissipate heat generated within the coil directly into the refrigerant.

Therefore, there is no mechanical action in the winding section and no heat generation due to it, and AC loss heat inside the winding section is also effectively transferred to the refrigerant, resulting in a coil with stable performance that is unlikely to quench. .

〔Example〕

Embodiments of the invention are shown in the accompanying drawings.

Dipole coils 1 and 3 in Fig. 1 to which this invention is applied
In both of the tluid coils 2 shown in the figure, superconducting wires having ultrafine multifilamentary filaments are used as coil wires. This is indicated by 3 in FIGS. 2 and 4. Cooling channels 4 are present between the layers of these wires wound into the desired coil shape, and the gaps between the wires except for the cooling channels 4 are filled with an insulator 5. Reference numeral 6 in FIG. 3 is a communication path provided between the coil and the flange of the winding frame 7 for the purpose of communicating the cooling channels between the layers of the tluid coil to the outside.

The insulator 5 may be a single piece of resin that is cured after being impregnated, but it may also be made of glass, aramid, nylon, or other fibers that have been made into a tape and wrapped around a wire, and epoxy, formal, or the like that has been impregnated and cured. Combinations with resins are preferred.

In addition, the cooling channel 4 is created by winding a spacer, which serves as a mold during winding, between the layers of the coil, and extracting it after the insulator part has hardened, or by melting and removing it.
A hollow tube may be used as the spacer, and the spacer may be produced by a method in which the tube remains even after the insulator portion is hardened. This cooling channel 4 is designed to increase cooling efficiency.
As shown in the figure, it is desirable to provide a large number of @ lines between each layer or every few layers.

The superconducting wire 3 used is such that the ultrafine multifilament is made of Nb5Ti or an alloy thereof, or a material in which a third element is added to the alloy, or Nb1Sn%V2.
Gas Nb3Si s v! Practical wires made of compound materials such as I(rSNbsAJ) are preferred because these wires have a small capacity (and can carry a large current).

Further, the multicore filament preferably has a diameter of 1 μm or less because magnetization loss (this is the main factor of AC loss) due to the thickness of the filament is extremely small.

〔effect〕

The coil of the present invention constructed as described above is particularly effective in the fields of AC transformers and generators used at commercial frequencies.

That is, in an AC transformer constructed by combining a plurality of coils, complex electromagnetic force acts on the coil windings due to the interaction of the coils, so subtle mechanical movements are likely to occur. For example, the insulating material between the wires reliably prevents the movement, so that local heat generation due to slight movement of the winding portion hardly occurs, and quenching caused by this is effectively prevented.

In addition, when a current of 50 to 60 Hz is applied, alternating current loss is constantly generated inside the coil, but that heat is quickly absorbed by the refrigerant that flows into the cooling channel between the layers.
Quenching caused by poor cooling efficiency is also prevented.

Further, when used in a generator, particularly as an armature winding, the coil becomes large, so there is an increased need for stabilization of the S wire in place and efficient cooling.

According to the present invention, it is possible to sufficiently meet this demand and greatly contribute to making a generator completely superconducting.

[Brief explanation of the drawing]

Fig. 1 is a simplified plan view of a dipole coil to which the present invention is applied, Fig. 2 is a plan view showing a part of its winding section in detail, and Fig. 3 is a simplified plan view of a truid coil to which the present invention is applied. FIG. 4 is a sectional view taken along line A--A in FIG. 3 and showing a part of the portion in detail. 1... Dipole coil, 2... Tluid coil, 3... Superconducting wire, 4...
・Cooling channel, 5... Insulator, 6...
・Communication path, 7... winding frame. Patent applicant Sumitomo Electric Industries, Ltd. Agent Kama 1) Text 2 Figure 1 Figure 3. Figure 2 Figure 4

Claims (3)

[Claims] (1) Constructed by winding a superconducting wire having ultra-fine multifilamentary filaments, having a cooling channel between any layers of the winding through which a refrigerant flows, and gaps between the coil wires excluding this cooling channel. An AC superconducting coil characterized in that the coil is completely filled with an insulator containing a cured resin after being impregnated. (2) The AC superconducting coil according to claim (1), wherein the insulator is a combination of resin and organic or inorganic fibers. (3) The AC superconducting coil according to claim (2), wherein a large number of the cooling channels are provided between each layer of the winding or between every few layers.