JPS5815464A - Superconductive field coil - Google Patents

Abstract

PURPOSE:To reduce the maximum value of the magnetic flux density of the end part by inserting flat conductors to the prescribed position of the end part and winding stabilized superconductive wire. CONSTITUTION:A spacer made of flat copper wire 7 having the same size as a stabilized superconductive conductor 6 is inserted and wound between the prescribed turns of the conductor 6 forming an end part 5 between the turns of the conductor 6. In this manner, the influence of the concentrated conductor 6 can be alleviated, thereby reducing the maximum value of the magnetic flux density in the vicinity of the bore side end e1 smaller than the conventional one. Since the flat conductor 7 having the ame size as the conductor 6 is used as the spacer, it is not necessary to select and machine the shape of the spacer itself.

Description

[Detailed description of the invention] The present invention relates to superconducting field windings.

When the superconducting field winding (hereinafter referred to as field winding) used in a superconducting generator is supported outside the cylindrical torque tube that constitutes the rotor, it is as shown in Figure 1. The field winding 1 is usually racetrack-shaped and saddle-shaped. The stabilized superconducting wire used in this field winding 1 is formed by embedding a large number of superconducting filaments in stabilized copper.
Its shape is rectangular in consideration of the space factor of the stabilized superconducting wire and workability during winding, and its surface is coated with a heat-resistant resin such as polyimide. The field winding 1 is manufactured by winding this stabilized superconducting wire around a cylindrical winding former in the form of a single earth track saddle, and then impregnating and hardening the wire with an epoxy resin. The field is 2
In the case of a rotor of a polar superconducting generator, two field windings 1a, 1b are arranged outside a cylindrical torque tube 2, as shown in FIGS. 2 and 3, and These field windings 1a and 1b are supported by a cylindrical torque tube 2 by a binding wire or a burnt surface of the cylinder 3, and are cooled to an extremely low temperature with liquid helium 4.

Liquid helium 4 is filled inside and outside the cylindrical torque tube 2, and the field winding 1. The field windings 1a and 1b are cooled by flowing through the inner and outer sides of the field windings 1a and 1b.

In this way, the field winding 1 (Ia, lb) is wound in a racetrack-like saddle shape. The vertical axis is the angle from the end to the other end of the saddle-shaped surface along the saddle shape, that is, the saddle angle θ, and the horizontal axis is the angle from a predetermined position in the axial direction of the field winding 1 to the end. When the field winding 1 is expanded with an axial distance l, it becomes as shown in FIG. As shown in the figure, the field winding 1 has a saddle angle of 0° to 1°.
80 degrees, and a saddle-shaped top portion, that is, an inner diameter end e1 and an outer diameter end e2 of the end portion 5 are formed at the saddle angle of 90 degrees. When the field winding is energized and the magnetic flux density of the field winding is measured, the magnetic flux density of the field winding 1 in the portion shown in FIG. 4 is illustrated as shown in FIG. 5. Fifth
In the figure, the vertical axis shows the magnetic flux density with the saddle angle θ as a parameter, and the horizontal axis shows the magnetic flux density when the predetermined axial distance to the end of the field winding 1 shown in Fig. 4 is taken. The relationship with axial distance is shown. As shown in the figure, the magnetic flux density increases as the axial distance approaches the end portion, regardless of the saddle angle, and is maximum (direct) near the inner diameter end e and the end portion, respectively. However, depending on the saddle angle, the magnetic flux density increases as the saddle angle approaches 90°.This is a part where the wound stabilized superconducting wires are densely packed, and therefore the stabilized superconducting wires are tightly wound. The magnetic flux density increases as the lines interact.

By the way, the magnetic flux density is large, and if it reaches close to the critical magnetic flux density of the stabilized superconducting wire used, the field winding will quench (destruction of the superconductor), so the current density of the field winding is not limited. If it's too big, it won't mate. Therefore, in order to reduce the maximum magnetic flux density (direction) near the end part where the magnetic flux density is high, a spacer is used between the windings of the stabilizing superconducting wire at the end part.
For example, it has been considered to manufacture field windings by inserting reinforced plastic (FM%P). This is because by inserting a spacer, the densely packed parts of the stabilized superconducting wire are relaxed and become coarse, and the maximum amplitude of the magnetic flux density is reduced. However, it was difficult to select the shape of the reinforced plastic resin to be inserted and to process it.
It was difficult to implement. Therefore, it has been desired to develop a method for manufacturing field windings that can easily reduce the maximum magnetic flux density (direction).

The present invention has been made in view of the following points, and its object is to provide a superconducting field winding that can easily reduce the maximum amplitude of magnetic flux density.

That is, the present invention includes inserting a spacer made of rectangular copper wire of the same size as the stabilized superconducting wire between predetermined turns of the stabilized superconducting wire forming the end portion when winding the stabilized superconducting wire. It is characterized by:

The present invention will be described above based on the illustrated embodiments. FIG. 6 shows an embodiment of the invention. Note that parts that are the same as those in the conventional model are given the same reference numerals, and therefore their explanations will be omitted. In this embodiment, when the stabilized superconducting wire 6 is wound, a spacer made of a rectangular copper wire 7 having the same size as the stabilized superconducting wire 6 is placed between predetermined turns of the stabilized superconducting wire 6 forming the end portion 5. was inserted and wound. That is, the rectangular conducting wire 7 having the same size as the stabilized superconductor m6 is connected to the end portion 5 near the inner diameter end e1.
The stabilized superconducting wire was inserted every few turns between the 60 turns of the stabilized superconducting wire. The inserted range was approximately half of the winding width between the inner end e and the outer end e2. After winding, it was impregnated with epoxy resin. By doing this, the inner diameter end e where the maximum magnetic flux density (if appears)
A densely packed part of the stabilized superconducting wire 6 in the vicinity of 1 is relaxed and becomes a phase. Therefore, the influence of the densely packed stabilized superconducting wires 6 is reduced, and the maximum fluctuation of the magnetic flux density near the inner end e1 becomes smaller than that of the conventional method. ￥1: Since the rectangular conducting wire 7 of the same size as the stabilized superconducting wire 6 was used as a spacer, there is no need to select or process the shape of the spacer itself, and when winding the stabilized superconducting wire 6, it is stable. The work is easy because the wire is bent along the bending of the chemically modified superconducting wire 6.

The results of examining the characteristics of the above embodiments will be described below. In Fig. 7, the vertical axis shows the magnetic flux density using the saddle angle θ as a parameter, and the horizontal axis shows the magnetic flux density when the predetermined axial distance at the end of the field winding 1 shown in Fig. 6 is taken. The relationship between magnetic flux density and axial distance is shown. As shown in the figure, the magnetic flux density increases as the axial distance approaches the end portion, regardless of the size of the saddle angle, and exhibits maximum directness near the inner circumferential end e and the portion, respectively. The tendency of these characteristics is the same as that of the conventional method, but the maximum magnetic flux density has decreased, and is about 80% of that of the conventional method.

In this way, according to this example, the maximum surface of the magnetic flux density was able to be lowered, but if current were to flow through a wire where the maximum surface of the magnetic flux density was the same as that of the conventional one, the stabilized superconducting wire From the relationship between the critical current density and the critical magnetic field, the current density increases as the magnetic flux density decreases, so the current density is approximately 4
It can be increased by 0%. Therefore, it can contribute to increasing the output and improving the reliability of superconducting generators.

As described above, in the present invention, since the stabilized superconducting wire is wound by inserting the rectangular conductive wire into a predetermined position of the end portion, the lengths of the stabilized superconducting wires at the end portion are combined with a simple operation, and the end portion is The maximum value of the magnetic flux density is reduced, and it is possible to easily obtain a superconducting field winding in which the maximum value of the magnetic flux density is reduced by one shift.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a conventional superconducting field winding; Fig. 2 is a perspective view of a conventional superconducting field winding in which the superconducting field winding is attached to a cylindrical torque tube; Figure 3 is the second
4 is a cross-sectional view along lines A and -A in the figure, FIG. 4 is a development view of a superconducting field winding according to the saddle angle and axial distance of a conventional superconducting field winding, and FIG. 5 is a diagram showing the saddle angle. Fig. 4 is a characteristic diagram showing the relationship between the magnetic flux density and axial distance of the superconducting field winding as a parameter, and Fig. 6 shows the saddle angle and axial direction of an embodiment of the superconducting field winding of the present invention. FIG. 7 is a characteristic diagram showing the relationship between the magnetic flux density and axial distance of the superconducting field winding of FIG. 6 using the saddle angle as a parameter. End part, 6... Stabilized superconducting wire, 7... Flat copper grass 10 7 Kaya Z (2) 1 piece 1" / rod 40 Otsu

Claims (1)

[Claims] 1. In a conductive field winding made by winding a rectangular stabilized superconducting wire in a racetrack saddle shape and impregnating it with epoxy resin after winding, the end portion of the stabilized superconducting wire is A superconducting field winding characterized in that a spacer made of rectangular copper wire having the same size as the stabilized superconducting wire is inserted between predetermined turns of the stabilized superconducting wire to be formed.