RU178606U1 - HOLDER FOR HIGH TEMPERATURE SUPERCONDUCTIVE TAPE - Google Patents

Abstract

The utility model relates to the field of electrical engineering, namely to conductive devices using high-temperature superconducting wires (HTSC) in the form of multilayer tapes, in particular to insulating holders of these wires, used, for example, in interturn insulation. The holder for the high-temperature superconducting tape contains at least one tape-like element consisting of a flat tape and two corrugated tapes symmetrically placed along the edges of the flat tape in the longitudinal direction and fastened with a flat tape, where the said flat and corrugated tapes form a groove providing laying it contains a high-temperature superconducting tape with a gap and is made of an insulating material that is resistant to cryogenic media. The technical result is a clear fixation of the superconducting wire at a distance necessary for electric strength under cryogenic conditions with the possibility of thermal expansion of the superconductor without fatal deformations for the wire while simplifying the design. 3 s.p. piano, 2 ill., 1 ave.

Description

The field of technology.

The utility model relates to the field of electrical engineering, namely to conductive devices using high-temperature superconducting wires (HTSC) in the form of multilayer tapes, in particular to insulating holders of these wires, used, for example, in interturn insulation.

The level of technology.

HTSC tape is a complex composite material and is divided into 1st and 2nd generation tapes, depending on the production methods. The separation into two types is based on the production methods: the first generation tapes are obtained by the metallurgical method, and the second by physical and chemical (precipitation).

2nd generation HTSC tapes exhibit superconducting properties even at temperatures below 95 ° K, have a high current-carrying ability (current density above 500 A / mm ² ), and also a large resistivity in the normal state (10 ^-8 - 10 ^-7 Ohm⋅ m).

Second-generation HTSC tapes are understood to mean complex composite structures, the main components of which are a metal substrate, buffer layers deposited on it, and RBa ₂ Cu ₃ O ₇ superconducting material (where R is a rare-earth element). Additional layers based on silver or copper, solder and other materials may be applied depending on the purpose of the HTSC tape and the production conditions.

Currently, the active use of HTSC tapes of both 1st and 2nd generation in various electrical devices, for example, in current limiters (KEPRI 154 kV, SuperLimiter 115 kV manufactured by Siemens, Augsburg 12 kV, etc.), power cables (AmpaCity project in Essen, Germany, the LIPA project in the USA, etc.), magnets (manufactured by Sumitomo Electric Industries, Babcock Noell Gmbh, etc.), engines (36.5 MW engine for AMSC ships), and many promising projects to create superconducting induction drives (SPIN) and wind generators based on HTSC tapes (on Example, a pan-European project Suprapower).

The use of HTSC tapes in electrical devices often involves their electrical isolation from each other, and accurate positioning of the tapes is necessary for the devices to work flawlessly.

For these needs in the prior art, for example, in current limiters with superconductors stacked in bifilars, interturn insulation is used, in which HTSC tapes are positioned using various holders made of electrically insulating and cryogenic material resistant. The last requirement is due to the need to wash the HTSC tape cryogenic medium - liquid nitrogen.

One of the solutions to ensure the necessary simultaneous fixation of HTSC tapes and electrical insulation is the use of an electrical insulating tape glued to the HTSC tape from the substrate side through a prepreg based on synthetic resins with microcrystalline filler with high thermal conductivity (RU 154188).

The authors of this utility model claim that with such a geometry of the device reliable fixation of the HTSC tape and its almost complete washing with liquid nitrogen from the protective layer is ensured.

When using such a holder in superconducting current limiters, it improves the heat transfer from the HTSC tape, which contributes to a faster restoration of the superconducting state from normal, and allows the reuse of the current limiter in a few seconds.

As a result of the rigid fastening of two materials (electrical insulating tape and prepreg based on synthetic resins) during cooling, materials with different intensities and different sizes are compressed, which with high probability can lead to mechanical fractures of the superconductor, fatal for it and for the whole device as a whole.

In the application US 2009264294 discloses the closest technical solution to the proposed. An application for a superconducting current limiter describes a holder for an HTSC tape. The holder comprises a flat strip and a corrugated strip located on the flat and connected together, for example, by adhesion. The corrugated strip is made with recesses in the center of the strip, the boundaries of which form a “bed” for the HTSC tape - the HTSC tape fits into the recesses and is securely fixed in them at some distance from the flat strip. The application notes that such a tape holder due to the presence of recesses provides very accurate positioning of the tape.

However, the known holder design has the following significant drawback. During operation of devices with superconducting wires, for example, in current-limiting devices, sharp current surges can occur. When a sharp current surge occurs, the superconducting wire goes into a normal state with a large resistance, which limits the current and protects the circuit devices. The transition time to the normal state is less than 2 ms, and thus, extremely fast heating of the superconducting wire occurs, and deformation resulting from this heating due to thermal expansion. The presence of recesses with sharp edges in the upper corrugated part of the holder, on which the superconducting wire in the known holder rests, allows the tape to bend along them with small bending radii, which will lead to sharp bends. It is known that deformations (bending diameter less than 6 mm for HTSC 2nd generation and less than 30 mm for HTSC 1st generation) adversely affect superconducting wires without the possibility of recovery. In addition, the known design, assuming the presence of an upper corrugated tape with recesses, is a rather complicated structure to manufacture.

The technical problem of the closest analogue is the complexity of the holder design, namely, the complexity of the corrugated tape, as well as the possibility of damage to the HTSC tape in places where it rests on the walls of the recesses.

Utility Model Disclosure

This technical problem is eliminated by the claimed utility model, according to which the holder for a high-temperature superconducting tape contains at least one tape-like element consisting of a flat tape and two corrugated tapes symmetrically placed along the edges of the flat tape in the longitudinal direction and fastened with a flat tape where the aforementioned flat and corrugated tapes form a groove for laying a high-temperature superconducting tape with a gap in it and are made of electrical insulation This material is resistant to cryogenic media.

In particular embodiments of the utility model, the holder may comprise flat and corrugated ribbons made of polylactide.

The corrugated tape in the holder can be fastened with a flat tape with the possibility of formation of passages for washing the high-temperature tape with a cryogenic medium.

The holder may include a tape-wound element wound into a roll.

A brief description of the drawings.

In FIG. 1 shows a photograph of the holder (general view), FIG. 2 is a schematic illustration of a spiral holder.

Positions mean the following:

1. flat tape

2. corrugated tape

3. groove

4. external passage

5. inner passage

The utility model is implemented as follows.

In FIG. Figure 1 shows a photograph of a ribbon-like element consisting of a flat ribbon (1) and two corrugated ribbons (2). Under the corrugated tapes in the prior art refers to ribbons with wave-like folds.

The corrugated tapes (2) are attached to the flat tape (1) along its edges and form a groove (3) into which the HTSC tape (not shown) fits.

The corrugations in the tape (2) form the passages for supplying cryogenic liquid, while the liquid can wash the tape along the external passages (4) formed by the outer sides of the corrugations and along the internal passages (5) formed by the inner sides of the corrugations.

Corrugations can be in the cross section of any shape - trapezoidal, triangular, sinusoidal, etc. The shape of the corrugations will not affect the quality of washing the tape with a cryogenic medium.

Important, however, for the implementation of this utility model is that all the components of the holder must be made of cryogenic temperature-resistant insulating material.

Such materials, in particular, include some plastics - textolite, ABS plastic, etc.

However, we achieved the best results in terms of duration of use with polylactide.

Polylactide is a biodegradable biocompatible thermoplastic aliphatic polyester, the monomer of which is lactic acid. Annually renewable resources such as corn and sugarcane serve as raw materials for production.

The holder can be made in the form of a ribbon-like element wound into a roll (see Fig. 2).

This embodiment of the holder can be used for the manufacture of bifilar coils used in many superconducting devices.

From this figure it can be seen that such a holder is very compact in shape: the groove (3) can be made of any unlimited length, and a large number of passes (4) and (5) allows you to organize a very effective cooling of the tape.

This form of holder is not exhaustive for a true utility model.

In particular, the holder may also be a stack of ribbon-shaped elements mounted on top of each other. This embodiment of the utility model can be used to increase the current carrying capacity of the device in the absence of the need to create additional modules that will add additional costs and increase the overall size of the device.

For the same purposes, a stack of HTSC tapes can be installed in one holder.

Example.

To test the performance of plastic PLA were made several tape holders of finite length on a 3D printer.

For HTSC tapes with a width of 12 mm, the characteristics of the holder were as follows: substrate thickness 0.4 mm, corrugated tape thickness 0.2 mm, substrate width 30 mm, corrugated tape width 8 mm, total height of the entire holder 3 mm, groove width 14 mm and depth 0. 2 mm.

Several tapes were stacked and placed in one holder - if the critical current of one tape 12 mm wide is about 500 A, then due to the small thickness of the HTSC tapes (about 0.1 mm), the stack allows you to put more tapes in the same holders and increase the current in device while maintaining electrical strength.

The collected stack was placed in a cryostat with washer fluid. Tests showed that the washer fluid easily penetrates to the tape and washes it from all sides, with no damage to the tape during current surges.

Thus, as follows from the above description of the utility model, it has the following advantages: with the same washability of the superconducting wire, as in the well-known patent, the holder is located on a flat surface along the superconducting wire, which during thermal expansion does not lead to sharp bending of the wire, and prevents destructive deformations for superconductors. In addition, this holder is easy to manufacture, can be produced in large quantities in a short time, and at a price it is much cheaper than prepreg, fiberglass and teflon used in similar products.

Claims (4)

1. A holder for a high-temperature superconducting tape, characterized in that it contains at least one tape-like element consisting of a flat tape and two corrugated tapes, symmetrically placed along the edges of the flat tape in the longitudinal direction and fastened with a flat tape, where said flat and corrugated tapes form a groove that provides for the laying of a high-temperature superconducting tape with a gap in it, and are made of an insulating material that is resistant to cryogenic media. 2. The holder according to claim 1, characterized in that the flat and corrugated tapes are made of polylactide. 3. The holder according to claim 1, characterized in that the corrugated tape is fastened with a flat tape with the possibility of formation of passages for washing the high-temperature tape with a cryogenic medium. 4. The holder according to claim 1, characterized in that it includes a ribbon-shaped element wound into a roll.

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