JP2000040426A - Superconducting reactor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily obtain desired current-carrying capacity by a superconducting reactor comprising high temperature superconductive wires. SOLUTION: The reactors 1a, 1b formed by winding a silver sheath tape wire as one cold superconductive material, into the shape of a pancake, are coaxially arranged and connected in parallel. The current-carrying capacity of each reactor 1a, 1b is determined on the basis of the current-carrying capacity of one silver sheath tape wire, and the total current-carrying capacity can be increased twice by connecting the reactors 1a, 1b in parallel. That is, by coaxially connecting a plurality of independent reactors in parallel to form the superconducting reactor, the desired current-carrying capacity can be easily obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a superconducting reactor for a current limiting device used in a power transmission and distribution system.

[0002]

2. Description of the Related Art Conventionally, a short circuit current flowing when a short circuit accident occurs in a power transmission and distribution system is interrupted by a circuit breaker. Since this short-circuit current is extremely large, strong electromagnetic force and a large amount of Joule heat are generated by this short-circuit current, causing large mechanical and thermal damage to power equipment and electric circuits. Current limiters are used to reduce the role of the circuit breaker.

As a current limiter for such a short-circuit current, a reactor that is relatively widely put into practical use is a reactor that limits a short-circuit current by inductance. Conditions required for such a reactor include low electric resistance when a load current is supplied and low heat generation, and quick response and high electric resistance when a short circuit occurs. In this regard, a current limiting reactor using a normal temperature superconductor is considered to be ideal in view of ease of cooling and the like.

FIG. 4 is a diagram showing a configuration example of a conventional superconducting reactor of this type, and FIG.
(B) is a sectional view thereof. The silver sheath tape wire 41, which is a high-temperature superconducting wire, is repeatedly wrapped around in the radial direction to form a pancake-shaped superconducting reactor. It is difficult to improve the current-carrying capacity per piece of the silver sheath tape 41 in which the high-temperature superconductor is made into a tape shape, and usually, as shown in FIG. The current carrying capacity is increasing. The superconducting reactor 4 having such a configuration has a characteristic that the magnetic field distribution at the time of energization has a strong radial component at the end as shown in FIG.

[0005]

As described above, in the pancake-shaped superconducting reactor 4 in which the number of windings is increased by repeating the winding in the radial direction, the number of silver sheath tape wires 41 in parallel is increased in order to increase the current carrying capacity. It is difficult to increase the number in production. Further, it is known that it is difficult to obtain a current capacity corresponding to the increase in the cross-sectional area even if the cross-sectional area per silver sheath tape wire is increased. Was difficult.

[0006] Here, in the silver sheath tape wire, the rate of decrease in the critical current density (Ic) of the superconductor greatly varies depending on the direction of the magnetic field as shown in FIG. In a pancake-shaped superconducting reactor, the rate of decrease in Ic due to the radial magnetic field component increases. On the other hand, in the conventional pancake-shaped superconducting reactor, the magnetic field component in the radial direction is strong at the end of the reactor as shown in FIG. There was a problem that it was difficult.

The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to provide a superconducting reactor which can easily obtain a desired current-carrying capacity by using a high-temperature superconducting wire. It is.

[0008]

Means for Solving the Problems To achieve the above object, a first aspect of the present invention is a superconducting reactor using a superconducting wire, in which one superconducting wire is wound in a pancake shape. A plurality is arranged coaxially and connected in parallel.

According to the first aspect of the invention, the current carrying capacity of the reactor in which one silver sheath tape wire, for example, a high temperature superconducting wire is wound in a pancake shape is limited to the current carrying capacity of the one high temperature superconducting wire. However, if a plurality of such reactors are coaxially arranged and connected in parallel, the current-carrying capacity can be freely increased, and a desired current-carrying capacity can be easily obtained.

A feature of the second invention is that the superconducting wire is a silver sheath tape wire.

A third feature of the present invention resides in that an iron core penetrating through the bores of the plurality of reactors is provided.

According to the third aspect of the present invention, when the superconducting reactor in which a plurality of reactors are arranged and connected in parallel remains an air core, the superconducting reactor is divided from the reactor at the center in the longitudinal direction and the reactor at the end due to the mutual inductance. A difference occurs in the ratio. However, by inserting an iron core into the bore of the reactor, the effect of mutual inductance between the reactors connected in parallel can be equalized, and by inserting an iron core, the radial component of the magnetic flux density at the reactor end can be reduced. Thus, the critical current density of the silver sheath tape wire can be prevented from lowering, and the current carrying capacity can be increased by preventing the current carrying capacity from lowering.

[0013] A feature of the fourth invention is that the flow division ratio of each reactor is equalized.

According to the fourth aspect of the invention, when the distribution ratio of the reactor is made uniform, the deviation of the magnetic flux density distribution is further improved, so that the current carrying capacity can be further increased.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a view showing one embodiment of a superconducting reactor according to the present invention. FIG. 1 (A) is a plan view thereof, and FIG. 1 (B) is a sectional view thereof. FIG. 1A shows the reactor from above, in which a single room temperature superconducting silver sheath tape wire 11 is wound in a pancake shape in the radial direction. FIG. 1B is a cross-sectional view of the superconducting reactor, in which reactors 1a and 1b each formed by winding one silver sheath tape wire 11 are coaxially arranged and connected in parallel to form a superconducting reactor. ing. Each of the reactors 1a and 1b is composed of one silver sheath tape wire 11, and its current carrying capacity is determined by the current carrying capacity of one silver sheath tape wire 11, so that the current carrying capacity required by the superconducting reactor is as described above. The reactors 1a and 1b are arranged coaxially and connected in parallel as shown in FIG. As a result, a current carrying capacity similar to that of a conventional reactor constituted by two silver sheath tape wires can be obtained. Although the reactors 1a and 1b are superconducting reactors, they are simply referred to as reactors here for convenience of explanation.

According to the present embodiment, reactor 1 composed of one normal-temperature superconducting silver sheath tape wire 11 is used.
Since the superconducting reactor is configured by arranging a and b coaxially and connecting them in parallel, the production is easy and the current carrying capacity can be easily increased.

Further, in order to further increase the current carrying capacity of the superconducting reactor, a required number of reactors each composed of a single normal temperature superconducting silver sheath tape wire 11 are coaxially arranged and connected in parallel. Thus, the adjustment of the current carrying capacity is extremely simple, and a desired current carrying capacity can be easily obtained.

FIG. 2 is a side view showing another embodiment of the superconducting reactor of the present invention. Reactors 1a to 1 each composed of one room-temperature superconducting silver sheath tape wire 11
Reference numeral 1e denotes superconducting reactors, which are arranged coaxially and connected in parallel. These reactors 1a to 1e
A ring-shaped iron core 12 penetrates through the bore portion. Although the reactors 1a to 1e are superconducting reactors, they are simply referred to as reactors here for convenience of explanation.

Next, the operation of this embodiment will be described. The self-inductance of the reactors 1a to 1e is La
~ Le, the mutual inductance between the reactors 1a ~ 1e is Mab, Mac, Mad ..., Mba, Mbc ... ~,
Assuming that Mdb, Mdc, and Mde, the reactors 2a and 2
The current distribution ratio between c is determined as follows.

Ic / Ia = (La−Mca−Mcb−M)
cd-Mce) / (Lc-Mab-Mac-Mad-M
ae) Here, Ia and Ic are current values flowing through the reactors 2a and 2c.

Here, if the iron core 12 is not arranged in FIG. 2, Mad and Mae are Mca, Mcb, Mc
Since the current is smaller than both d and Mce, the current flowing through reactor 1a becomes larger than reactor 1c. However, when the iron cores 12 are arranged as shown in FIG. 2, the mutual inductances Mab to Mde are substantially equal, so that the current shunt ratios of the reactors 2 a to 2 e are equalized. Further, by disposing the iron core 12 on the axis of the reactors 2a to 2e, the magnetic flux density distribution is improved.

FIG. 3 is a diagram showing a magnetic flux density distribution when the iron core 12 is arranged. Compared to FIG. 5 showing the magnetic flux density distribution when the iron core 12 is not arranged, it can be seen that the magnetic flux density is particularly small at the position of the reactor 1a corresponding to the end in the entire superconducting reactor. The reason is that the magnetic flux generated by the reactors 1 b to 1 e in FIG. 2 forms a loop by flowing through the iron core 12.

According to the present embodiment, the magnetic flux applied to the superconducting reactor is formed by penetrating iron core 12 into the bore of the superconducting reactor formed by arranging a plurality of reactors 1a to 1e coaxially and connecting them in parallel. The silver sheath tape wire 1 as shown in FIG.
1 can be prevented from lowering. In particular, in the reactor 1a, since the magnetic flux is applied perpendicularly to the wide surface of the silver sheath tape wire 11, the effect of preventing a decrease in the current carrying capacity is increased. Can be easily realized.

It is to be noted that since the magnetic flux density at the end of the reactor can be further reduced by the iron core 12 by equalizing the shunt ratio of the reactors 1a to 1e in FIG. Can be obtained.

[0025]

As described above in detail, according to the superconducting reactor of the present invention, a plurality of reactors each composed of one silver sheath tape wire are coaxially arranged and connected in parallel, so that high temperature can be achieved. A desired current carrying capacity can be easily obtained by using a superconducting wire.Furthermore, by arranging an iron core in the bores of the plurality of reactors, the magnetic flux density distribution of the superconducting reactor is improved, and the current carrying capacity is reduced. Is prevented, and a desired current-carrying capacity can be more easily obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing one embodiment of a superconducting reactor of the present invention.

FIG. 2 is a diagram showing another embodiment of the superconducting reactor of the present invention.

3 is a diagram showing an example of a magnetic flux density distribution of the superconducting reactor shown in FIG.

FIG. 4 is a diagram showing a configuration example of a conventional superconducting reactor.

5 is a diagram showing an example of a magnetic flux density distribution of the superconducting actuator shown in FIG.

FIG. 6 is a characteristic diagram showing Ic-B characteristics of a silver sheath tape wire.

[Explanation of symbols]

 1a, 1b reactor 11 silver sheath tape wire 12 iron core

Claims (4)

[Claims] 1. A superconducting reactor using a superconducting wire, wherein a plurality of reactors each formed by winding one superconducting wire in a pancake shape are coaxially arranged and connected in parallel. 2. The superconducting reactor according to claim 1, wherein said superconducting wire is a silver sheath tape wire. 3. The superconducting reactor according to claim 1, wherein an iron core penetrating through bores of the plurality of reactors is provided. 4. The superconducting reactor according to claim 3, wherein the split ratio of each reactor is equalized.