JPH0226363B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a multi-wound pancake coil,
In particular, the present invention relates to a multi-thread pancake coil in which the cross-sectional dimensions of the conductor are improved to be smaller.

[Prior art]

Figure 1A is a plan view of a conventional pancake coil.
FIG. 1B is a sectional view taken along the line B--B, and this pancake coil 1 is used, for example, as an air-core poloidal coil for controlling plasma heating in a torus-shaped nuclear fusion device. Inside the pancake coil 1, there are an upper layer conductor 2 and a lower layer conductor 3.
A crossing portion 4 is provided to connect the two. Further, an opening portion 5 is formed at the end of both the conductors 2 and 3. The material pieces that make up the conductors 2 and 3 have a production limit, that is, the weight of the ingot of the material pieces is constant, so if the cross section of the material pieces is increased, the length of the material pieces must be shortened. It's becoming like that.

The pancake coil 1 used in the poloidal coil of conventional nuclear fusion devices is configured as described above, but as nuclear fusion devices have recently become larger, more complex, and more sophisticated, The cross-sectional dimensions of this device had to become larger, and this resulted in the following drawbacks.

(1) The length of the material pieces of the conductors 2 and 3 becomes shorter, the number of connection points between the conductors 2 and 3 increases, and the mechanical strength becomes weaker.

(2) The dimensions of the crossing portion 4 and the lead-out portion 5 are increased, which leads to the generation of an error magnetic field and reduces the conductor space factor.

(3) A large lateral load is required when bending a piece of material into a coil shape, making it difficult to manufacture.

[Summary of the invention]

This invention was made for the purpose of eliminating the above-mentioned drawbacks, and includes a plurality of electrically independent spiral coil-shaped conductors stacked in the radial direction and axial direction, and the lead portions of the conductors. By arranging the conductors so that their axial transition parts are not in the same position, the cross-sectional dimensions of the conductors can be reduced compared to conventional ones without changing the overall dimensions or magnetic performance. Therefore, the length of the material pieces constituting the conductor can be increased, the number of connection points between the material pieces can be reduced, and the multi-thread winding has effects such as high mechanical strength and less error magnetic field. It provides pancake coils.

[Embodiments of the invention]

An embodiment of the multi-thread pancake coil of the present invention will be described below with reference to the drawings. FIG. 2A is a plan view showing an embodiment of the present invention, and FIG. 2B is a sectional view taken along line BB in FIG. 2A. A multi-filament pancake coil 6 (hereinafter abbreviated as pancake coil) used as a poloidal coil in a nuclear fusion device is composed of a first conductor 7 and a second conductor 8, which are electrically independent from each other. . The first conductor 7 and the second conductor 8 are laminated alternately in the radial direction with insulators interposed therebetween, and are laminated in two stages in the axial direction with insulators interposed therebetween.
Transition portions 9, 1 of each stage between the first conductor 7 and the second conductor 8
0 are provided inside the pancake coil 6 so as to face each other. Lead portions 11 and 12 are provided at both ends of the first and second conductors 7 and 8, respectively.
are formed at positions apart from each other. and,
Current flows through the first and second conductors 7 and 8 through lead portions 11 and 12.

In the pancake coil 6 configured as described above, the cross-sectional area of the conductors 7 and 8 can be approximately halved compared to the conventional one described above, and the length of the material piece can be increased accordingly. The number of connection points between the material pieces can be reduced, and in particular, the connection points at the inner diameter portions of the conductors 7 and 8, where bending stress is large, can be eliminated. In addition, since the connection points and connection area between the material pieces are reduced, the pancake coil 6
This means that the thermal effects caused by welding during connection can be reduced accordingly. Furthermore, the first and second conductors 7 and 8
Since the transition portions 9, 10 and the outlet portions 11, 12 are spaced apart from each other, there is no need to secure a special space for the transition portions 9, 10 and the outlet portions 11, 12. Furthermore, since the material piece has a small cross-sectional area, it can easily be fabricated into a spiral coil shape.

In addition, in the above embodiment, the first conductor 7 and the second conductor 8
Although the pancake coil 6 has been described, the present invention is not limited to this, and a plurality of conductors may be further incorporated into this coil. Further, in the above embodiment, a multi-filament pancake coil used as a poloidal coil of a nuclear fusion device was explained, but the present invention is not limited to this, and other electrical devices may be used, and the same as in the above embodiment may be used. be effective.

〔Effect of the invention〕

As explained above, according to the multi-thread pancake coil of the present invention, a plurality of electrically independent spiral coil-shaped conductors are stacked and arranged in the radial direction and axial direction, respectively. Compared to the conventional method described above, the overall dimensions and magnetic performance are almost the same, and the cross-sectional dimensions of the material pieces that make up the conductor can be made smaller and their lengths made larger, so the connection points between the material pieces can be reduced. It is possible to eliminate connection points at the inner diameter portion of the conductor where the bending stress is particularly large, and the mechanical strength is increased. In addition, since the conductor cross-section is small, the dimensions of the lead-out and crossing parts are small, and the number of connection points between pieces of material is reduced, which reduces the influence of heat from welding, which in turn reduces the error magnetic field. .
Furthermore, since the material piece has a small cross-sectional area, it can be easily manufactured into a spiral coil shape.

In addition, since the lead-out portions of the conductors and the transition portions in the axial direction of the conductors are provided so that they are not located at the same position, the space between the conductors is effectively utilized, and the multi-thread pancake coil of the present invention has a high It also has the effect of achieving a conductor space factor.

[Brief explanation of drawings]

Figure 1A is a plan view of a conventional pancake coil.
FIG. 1B is a cross-sectional view taken along the line B-B in FIG. 1A, FIG. 2A is a plan view showing an embodiment of the invention, and FIG. 2B is a cross-sectional view taken along the line B-B in FIG. 2A. . 1, 6... Pancake coil, 2... Upper layer conductor, 3... Lower layer conductor, 4, 9, 10... Transition part,
5, 11, 12... Leading portion, 7... First conductor,
8...Second conductor. In each figure, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] 1. A plurality of spiral coil-shaped conductors each made of a plurality of material pieces are laminated electrically independently from each other in the radial direction and the axial direction, and A multi-thread pancake coil characterized in that the lead-out portion and the transition portion in the axial direction of the conductor are arranged so as not to be in the same position. 2. The multi-filament pancake coil according to claim 1, wherein the conductor is a conductor constituting a poloidal coil of a nuclear fusion device.