JPH08130134A - Superconducting coreless transformer - Google Patents

Abstract

PURPOSE: To obtain a superconducting transformer capable of obtaining a high linkage coefficient without using core by winding, in a form of coil, two superconducting wires combined together and insulated each other around a bobbin made of a non-magnetic material and by using one of the wires of the coil as a primary side of a transformer and other wire as a secondary side of the transformer. CONSTITUTION: Two superconducting wires such as NbTi are mutually insulated each other and wound in parallel, thereby forming a primary coil 1 and a secondary coil 2 of a transformer. When a voltage is applied between both the terminals 1a and 1b of the primary coil 1 and to electrify the primary coil 1, a voltage is induced at the secondary coil 2, and a current can be obtained between both the terminals 2a and 2b. Also, instead of winding both the superconducting wires of the primary coil 1 and secondary coil 2 in parallel, both the superconducting wires may be twisted together and wound around. Moreover, instead of using a cylindrical hollow bobbin 3 for easy cooling, a toroidal coil type may be created by using a circular ring type bobbin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-efficiency superconducting ironless transformer which is constructed without using an iron core in place of the superconducting iron core type transformer.

[0002]

2. Description of the Related Art Conventionally, a superconducting transformer has a primary-side superconducting coil and a secondary-side superconducting coil connected by an iron core.
Install the iron core in an oil tank at room temperature and cool it with an air cooler to prevent heat generated by the iron core from entering the cryogenic side.
It has a complicated structure that separates it from the superconducting coil.

[0003]

In such a conventional superconducting transformer, the core of the iron core is used to connect the primary-side superconducting coil and the secondary-side superconducting coil. Due to the hysteresis, heat is generated with loss due to the AC magnetic field. Since cooling this heat generation at a very low temperature brings about a decrease in overall efficiency, the iron core part is separated from the superconducting coil and installed in an oil tank at room temperature for air cooling. Therefore, there are problems that the structure of the transformer becomes extremely complicated and that it is difficult to downsize the device because the iron core portion is required.

An object of the present invention is to provide a superconducting ironless core transformer which can obtain a high coupling coefficient without using an iron core.

[0005]

A superconducting ironless core transformer according to the present invention is an ironless core type which does not use an iron core which causes a main loss, and is insulated to improve the coupling between coils. The superconducting wire for the primary coil and the superconducting wire for the secondary coil are wound together on a bobbin made of a non-magnetic material.

The primary side coil and the secondary side coil do not have the same length, but only the common winding part in which two superconductors are wound together, and only one superconductor is wound. It consists of a single winding part that is rotated.

Further, the above-mentioned superconducting ironless core transformer is covered with a superconductor to prevent leakage of a magnetic field to the outside of the transformer due to the shielding effect of the diamagnetism of the superconductor.

[0008]

In the present invention, the two superconducting wires forming the primary side coil and the secondary side coil are wound together.
When an alternating current is passed through the coil on the next side, a voltage is induced in the other coil.

Since the common winding section and the single winding section are provided, the required output voltage ratio can be obtained by changing the winding ratio of both sections.

Furthermore, since the whole is covered with a superconductor, leakage of the generated magnetic field is prevented.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. [Embodiment 1] FIG. 1 is a perspective view of a cylindrical superconducting ironless core transformer according to a first embodiment of the present invention. In the figure, 1 and 2 are, for example, NbTi superconducting wires, which are insulated from each other, and are a primary coil and a secondary coil of a transformer which are wound together in parallel.
a and 1b are both terminals of the primary coil 1, 2a and 2b are both terminals of the secondary coil 2, and 3 is a cylindrical bobbin made of a non-magnetic material such as porcelain which is hollow for easy cooling. is there.

Next, the operation will be described. When a voltage is applied between both terminals 1a and 1b of the primary coil 1 and a current is passed through the primary coil 1, a voltage is induced in the secondary coil 2 and a current is obtained between both terminals 2a and 2b. You can

In the above embodiment, the superconducting wires of the primary coil 1 and the secondary coil 2 are wound together in parallel, but this is done by twisting both superconducting wires. You may do it. Further, instead of the cylindrical bobbin 3 as shown in FIG. 2, a toroidal type bobbin 3A may be used. [Embodiment 2] FIG. 3 shows a second embodiment of the present invention. This embodiment includes a common winding part 10 in which two superconducting wires are wound together and a single winding part 20 in which one superconducting wire is wound. The single winding part 20 is commonly wound. The line portion 10 is connected in series to one of the two superconducting wires. 1
Reference numeral c indicates a terminal of the individual winding section 20.

In this configuration, for example, the primary coil 1
When a voltage is applied between the terminal 1a of the secondary coil 2 and the terminal 1c of the individual winding section 20, a required voltage is obtained between the terminals 2a and 2b of the secondary coil 2. In this case, the primary side and the secondary side may be exchanged. Then, the voltage ratio between the primary side and the secondary side can be appropriately selected by selecting the winding ratio of the common winding part 10 and the individual winding part 20. It is needless to say that the common winding portion 10 and the single winding portion 20 can be provided also in the case of the toroidal type shown in FIG. Further, the single winding part 20 can be wound on the common winding part 10 in a stacked manner. [Embodiment 3] FIG. 4 is a partially broken perspective view showing a third embodiment of the present invention. In this embodiment, the whole superconducting ironless core transformer of the embodiment shown in FIG. 1 is covered with a bulky superconductor 4. As a result, the magnetic field generated from the transformer is completely shielded by the diamagnetic effect of the superconductor 4. In this embodiment, the superconductor 4 is constructed so that it can be divided into two parts, front and rear, as shown in the figure. When the two are fitted and integrated together, a space 5 is formed, and this space 5 is shown in FIG. A superconducting ironless core transformer is housed. The space 5 may be filled with a non-magnetic material such as resin or a non-conductive material.

FIG. 5 is a sectional perspective view of the toroidal type embodiment of FIG. 2 shielded by the superconductor 4. The superconductor 4 is vertically divided into two parts, which are exactly shown in FIG. It is formed to accommodate a toroidal type superconducting ironless core transformer. The operation and effect are the same as those in FIG. Note that the bobbin 3A, the primary coil 1, the secondary coil 2 and the like are shown by solid lines for the sake of explanation.

FIG. 6 is a sectional view of an embodiment in which the superconducting ironless core transformer shown in FIG. 3 is shielded by a superconductor. In FIG. 6, a superconductor 4B surrounding the space 5 and the outer periphery of the bobbin 3 and a superconductor 4A further enclosing the superconductor 4B.
It is composed of According to this configuration, the primary coil 1
The desired operation, that is, a predetermined voltage ratio e ₂ / e ₁ can be obtained by replacing the secondary coil 2 with the secondary coil 2. In addition, the above-mentioned e ₁ and e ₂ are respective terminal voltages of the primary side coil 1 and secondary side coil 2, and Φ is a magnetic flux.

In each of the above-mentioned embodiments, since NbTi is used as the coil wire, it is necessary to operate at liquid helium temperature. However, if a good coil wire can be achieved with an oxide superconductor, liquid nitrogen temperature operation is possible. And the maintenance of the transformer structure and cooling becomes very easy.

FIG. 7 shows an example of measuring the coupling coefficient of the superconducting ironless core transformer of the present invention. The superconducting wire used is an NbTi wire having a diameter of 0.112 mm and a copper ratio of 1 and is insulated. Two superconducting wires of the primary coil 1 and the secondary coil 2 are provided on the acrylic cylindrical bobbin 3. Is wound in parallel for 745 turns, and is 10 Hz to 100 Hz.
The measurement was performed at a frequency of Hz. From this figure, at temperatures of 77K and 300K above 4.2K, the coil winding is not in the superconducting state, so that a current flows through the copper as the stabilizing material. Therefore, at a high temperature, as in a general ironless core transformer using a copper wire, the coupling coefficient becomes almost zero and the transformer cannot serve its function as the frequency becomes lower. However, it can be seen that in the superconducting state, a coupling coefficient of 100% can be obtained over almost the previous frequency range.

FIG. 8 shows the efficiency of the transformer when the power is consumed on the secondary side by using the cylindrical superconducting ironless core transformer. In this example, the same superconducting ironless core transformer as that used in FIG. 7 is used, and a load R of 0.062Ω, 0.085Ω, and 0.105Ω is connected to the secondary coil 2. It can be seen that the efficiency is considerably high in the high frequency band as well as near the commercial frequency.

[0020]

As described above, the present invention comprises a superconducting wire in which two wires are wound together in a coil shape and insulated from each other on a bobbin made of a non-magnetic material, and one of them is used. Since the coil is the primary side of the transformer and the other coil is the secondary side of the transformer, a coupling coefficient of 100% is obtained over a wide frequency band, and high efficiency is obtained over a wide frequency band. And so on.

Further, a common winding portion made of a superconducting wire which is wound in a coil shape and insulated from each other on a bobbin made of a non-magnetic material, and 1 on the bobbin.
Two superconducting wires are wound around the single winding part connected in series to one superconducting wire of the common winding part, and one of the two superconducting wires serves as the primary side of the transformer. Since the other side is configured as the secondary side, the required transformation ratio can be obtained by adjusting the number of turns of the primary side coil and the secondary side coil.

Further, since the entire coil is covered with the superconductor, the magnetic field generated in the coil can be shielded to prevent the influence of the magnetic field to the outside and the coupling coefficient in the low frequency region can be increased.

[Brief description of drawings]

FIG. 1 is a perspective view showing a structure of a cylindrical superconducting ironless core transformer according to a first embodiment of the present invention.

FIG. 2 is a plan view showing the structure of a toroidal type superconducting ironless core transformer according to the first embodiment of the present invention.

FIG. 3 is a perspective view showing the structure of a cylindrical superconducting ironless core transformer according to a second embodiment of the present invention.

FIG. 4 is a partially cutaway perspective view showing the structure of a cylindrical superconducting ironless core transformer according to a third embodiment of the present invention.

FIG. 5 is a sectional perspective view showing a structure of a toroidal type superconducting ironless core transformer according to a third embodiment of the present invention.

FIG. 6 is a sectional view showing a structure of a cylindrical superconducting ironless core transformer according to a third embodiment of the present invention.

FIG. 7 is a characteristic diagram showing the measurement results of the coupling coefficient of the superconducting ironless core transformer of the present invention.

FIG. 8 is a characteristic diagram showing measurement results of efficiency of the superconducting ironless core transformer of the present invention.

[Description of Reference Signs] 1 primary coil 1a to 1c terminal 2 secondary coil 2a, 2b terminal 3 cylindrical bobbin 3A annular bobbin 4, 4A, 4B superconductor 5 space 10 common winding portion 20 Single winding Φ magnetic flux

Claims (3)

[Claims] 1. A superconducting wire in which two wires are wound together in a coil shape and insulated from each other on a bobbin made of a non-magnetic material, one coil of which is the primary side of a transformer, A superconducting ironless core transformer characterized in that another coil is configured as the secondary side of the transformer. 2. A common winding part composed of superconducting wires which are wound together in a coil shape on a bobbin made of a non-magnetic material and insulated from each other, and one superconducting wire on the bobbin. And a single winding part connected in series with one of the superconducting wires of the common winding part. One of the two superconducting wires is the primary side of the transformer and the other is 2 A superconducting ironless core transformer characterized by being configured as a secondary side. 3. The superconducting ironless core transformer according to claim 1 or 2 is covered with a superconductor and shielded by a diamagnetic effect of the superconductor so as to prevent the generated magnetic field from leaking to the outside. A superconducting ironless core transformer.