JPH0561869B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to the structure of a rotor of a superconducting rotating electric machine.

[Conventional technology]

Conventionally, this kind of rotor is known as, for example, Japanese Patent Application Laid-open No. 57-
There is one disclosed in Japanese Patent No. 22372, and its configuration is shown in FIG. In FIG. 4, 1 is a torque tube, 2 is a coil mounting shaft forming the center of the torque tube 1, 3 is a superconducting field coil fixed to the coil mounting shaft 2, and 4 is a torque tube 1.
and a room-temperature damper surrounding the coil mounting shaft 2; 5 is a low-temperature damper disposed between the room-temperature damper 4 and the coil mounting shaft 2; 6 and 7 are mounted on the outer periphery and side surface of the coil mounting shaft 2, respectively; 8 and 9 are drive side and non-drive side end shafts, 10 is a bearing that pivotally supports these end shafts 8 and 9, and 11 is a slip for supplying field current. ring, 12 is a heat exchanger formed or placed in the torque tube 1, 13 is a side radiation shield,
14 is a vacuum section.

In the rotor of the superconducting rotating machine having the above configuration, the superconducting field coil disposed on the coil mounting shaft 2 is cooled to an extremely low temperature to bring the electric resistance to zero and eliminate excitation loss. This superconducting field coil 3 generates a strong magnetic field, and a stator (not shown) generates alternating current power. In order to cool and maintain this superconducting field coil 3 at an extremely low temperature, liquid helium is introduced from the center of the non-drive side end shaft 9 through a pipe (not shown) formed by a helium outer cylinder 6 and a helium end plate 7. The torque tube 1 is made of a thin-walled cylinder and supplies the liquid helium to the liquid helium container section in which the helium is stored, while maintaining the inside of the rotor at a high vacuum in the vacuum section 14, and transmitting rotational torque to the ultra-low temperature superconducting field coil 3 and the coil mounting shaft 2. The most common structure is to provide a heat exchanger 12 and to reduce as much as possible the heat that enters the cryogenic part through the torque tube 1. Furthermore, in order to reduce the heat that enters due to radiation from the sides, the side radiation shield 13
is provided.

On the other hand, the normal temperature damper 4 and the low temperature damper 5 have the function of shielding harmonic magnetic fields from the stator, protecting the superconducting field coil 3, and attenuating rotor vibrations caused by disturbances in the power system.
Generally, the normal temperature damper 4 functions as a vacuum outer cylinder, and the low temperature damper functions as a radiation shield for the helium container. In FIG. 4, piping constituting a helium introduction and discharge system inside the rotor and a helium introduction and discharge device connected to the rotor are omitted.

FIG. 5 is a cross-sectional view taken along the line V-V in FIG. helium vapor space, 17
18 is a slot for accommodating the superconducting field coil 3 formed on the coil mounting shaft 2;
19 is a wedge for fixing the superconducting field coil 3; 20 is a helium flow path provided between the coil mounting shaft 2 and the helium outer cylinder 6;
1 is a helium flow hole provided in communication with the liquid reservoir 15 and the slot 17, and 22a and 22b are through holes formed in the ground insulation 18, each having a circular shape, for example. A superconducting field coil used in such a rotor is disclosed in, for example, Japanese Patent Laid-Open No. 186960/1983, and its configuration is shown in FIG.
In the figure, 3 is a superconducting field coil, and 3a is a superconducting wire formed by twisting a plurality of superconducting strands, etc., and is wound in multiple rows and in multiple layers. 23
24 is inter-row insulation inserted between the rows of these superconducting wires 3a, and 24 is inter-layer insulation inserted between the layers of superconducting wires 3a. The superconducting field coil 3 has one superconducting wire 3a and is wound while inserting inter-column insulation 23 between the rows of the superconducting wire 3a and interlayer insulation 24 between the layers of the superconducting wire 3a. After winding, the superconducting wire 3a is treated with an epoxy resin and formed into a mold shape to prevent short circuits of the superconducting wire 3a.

In general, in superconducting rotary pressure machines, there is an important technical problem in how to cool the superconducting field coil to a cryogenic temperature. In order to bring a superconducting field coil into a superconducting state, it is necessary to cool it below the superconducting transition temperature, and currently, helium is used as a cooling medium to maintain the absolute temperature at 1K to 20K. On the other hand, in such extremely low temperature conditions, the specific heat of the superconducting field coil is extremely small, so the superconducting field coil is heated by a small amount of heat generated within the superconducting field coil or by a small amount of heat entering the superconducting field coil. There is always a risk that the temperature of the coil will rise and exceed the superconducting transition temperature. Therefore, in the design of superconducting rotating electric machines, it is important to suppress the temperature rise of the superconducting field coil by quickly removing the minute amount of heat generated within the superconducting field coil or the slight amount of heat entering the superconducting field coil. This is a great point.

Next, the cooling operation will be explained. Heat generated by slight heat generation within the superconducting field coil 3 or slight heat intrusion into the superconducting field coil 3 exists in a slight gap between the outer circumferential side of the superconducting field coil 3 and the ground insulation 18. It is absorbed by helium. Helium, which expands due to heat absorption and has a reduced density, passes through the through hole 22a of the ground insulation 18 due to the natural convection of the centrifugal force field, and exits to the liquid reservoir 15 through the helium flow hole 21 of the coil mounting shaft 2. On the other hand, the helium shortage occurring around the superconducting field coil 3 is compensated for by helium flowing from the helium channel 20 around the superconducting field coil 3 through the gap between the wedge 19 and the through hole 22b of the ground insulation 18.
The endothermically expanded helium is cooled in the liquid reservoir 15 by partially evaporating it. The cooled helium enters around the superconducting field coil 3 from another helium flow hole 21 through the through hole 22a of the ground insulation 18, and further passes through the through hole 22b of the earth insulation 18 and the gap between the wedge 19 and enters the helium flow path. Appears on the 20th.

By performing the smooth natural circulation as described above, the superconducting field coil 3 is cooled, and the superconducting field coil 3 is kept below the superconducting transition temperature.

[Problem that the invention seeks to solve]

However, in the conventional device described above, the superconducting field coil 3 is cooled only from its outer peripheral surface, and when heat is generated in the superconducting wire 3a inside the superconducting field coil 3, the heat of the superconducting wire 3a is Through heat conduction through the interlayer insulation 23, interlayer insulation 24, and other superconducting wires 3a, the helium on the outer periphery of the superconducting field coil 3 cools and removes the heat, resulting in a poor cooling effect and a drop in the temperature of the superconducting wire 3a. There was a problem in that the superconductivity increased, causing superconducting breakdown (quenching).

The present invention has been made to solve the above-mentioned problems, and an object thereof is to provide a rotor for a superconducting rotating electrical machine that enhances the cooling effect and does not cause superconductor breakdown.

[Means for solving problems]

In the rotor of the superconducting rotating electric machine according to the present invention, the inter-row insulation between the superconducting wires of the superconducting field coil is made of a holed insulating material, and the interlayer insulation is made of a grooved insulating material.

[Effect]

The rotor of the superconducting rotating electric machine in this invention is
Liquid helium, which is a refrigerant to bring the superconducting field coil into a superconducting state, generates a superconducting field through the holes in the interrow insulation made of holed insulating material and the grooves in the interlayer insulation made of grooved insulating material. Directly cools the superconducting wire of the magnetic coil.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. In FIGS. 1 to 3, 3 is a superconducting field coil, and 3a is a superconducting wire formed by stranding a plurality of superconducting wires, which are wound in multiple rows and in multiple layers. Reference numeral 25 denotes an inter-row insulation which is inserted between the rows of the superconducting wires 3a and is made of a holed insulating material made of, for example, an epoxy micarta board and has a plurality of holes 25a. It is made of insulating material. 26 is inserted between the layers of the superconducting wire 3a, and in FIG.
6a, which is an interlayer insulation made of a grooved insulating material made of, for example, an epoxy-based mical plate, and is arranged in plural numbers in the longitudinal direction of the superconducting field coil 3. In addition, the superconducting field coil 3 is
An inter-column insulation 25 having one superconducting wire 3a and having a hole 25a between the rows of the superconducting wire 3a, and an inter-layer insulation 2 having a groove 26a between the layers of the superconducting wire 3a.
6 is wound while inserting each,
The superconducting wire 3a is surrounded by the intercolumn insulation 25 and the interlayer insulation 26, and short circuits of the superconducting wire 3a are prevented. Further, the superconducting field coil 3 was not treated with epoxy resin. Also, superconducting wire 3
Since a is made of twisted wire or the like, there is a slight gap between the superconducting wire 3a and the intercolumn insulation 25 and the interlayer insulation 26.

Next, the cooling operation will be explained. Liquid helium, which is a coolant for bringing the superconducting field coil 3 into a superconducting state, flows on the outer surface of the superconducting field coil 3 and also in the slight gaps between the superconducting wire 3a and the inter-column insulation 25 and the inter-layer insulation 26. , hole 2 of inter-row insulation 25
5a, it flows to the surface of the superconducting wire 3a through the groove 26a of the interlayer insulation 26, and all the superconducting wires 3a of the superconducting field coil 3 are directly cooled by liquid helium. Therefore, even if heat is generated in the superconducting wire 3a, the heat is quickly removed by the liquid helium around the superconducting wire 3a, and the temperature rise in the superconducting wire 3a is extremely small, and superconductor breakdown does not occur.

In the above embodiment, the grooves 26a of the interlayer insulation 26 are provided on both sides, but they may be provided on one side.

〔Effect of the invention〕

As explained above, in this invention, the inter-row insulation between the superconducting wires of the superconducting field coil is made of a holed insulating material, and the interlayer insulation is made of a grooved insulating material, so that the superconducting field coil is brought into a superconducting state. Liquid helium, the refrigerant for the superconducting field coils, directly cools the superconducting wires of the superconducting field coils through the holes in the interrow insulation made of holed insulating material and the grooves in the interlayer insulation made of grooved insulating material. It is possible to obtain a highly reliable rotor for a superconducting rotating electric machine with improved cooling effect and without superconductor breakdown.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing a superconducting field coil in a rotor of a superconducting rotating electric machine according to an embodiment of the present invention, Fig. 2 is an enlarged view of the main part of Fig. 1, and Fig. 3 is a - line in Fig. 2. 4 is a vertical sectional view showing a rotor of a conventional general superconducting rotating electric machine, and FIG. 5 is a sectional view taken along line V-V in FIG. 4.
FIG. 6 is a sectional view showing a conventional superconducting field coil. In the figure, 2 is a coil mounting shaft, 3 is a superconducting field coil, 3a is a superconducting wire, 25 is an inter-row insulation, 2
6 is interlayer insulation. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] 1. A rotor for a superconducting rotating electric machine having a superconducting field coil formed by winding multiple rows and layers of superconducting wire, and a coil mounting shaft that holds the superconducting field coil, A rotor for a superconducting rotating electric machine, wherein the inter-row insulation between the superconducting wires of the superconducting field coil is made of a holed insulating material, and the interlayer insulation is made of a grooved insulating material. 2. A rotor for a superconducting rotating electric machine according to claim 1, wherein the insulating material with holes is made of an epoxy micarta plate. 3. A rotor for a superconducting rotating electrical machine according to claim 1 or 2, wherein the grooved insulating material is made of an epoxy micarta plate.