JPH02211051A - Rotor of superconducting rotary electric machine - Google Patents

Abstract

PURPOSE:To disperse a heating section in the direction of an axis and to make the distribution of temperature uniform in the vicinity of the end of a wedge by slipping connections of the wedge and conductive bars to a short-circuit ring in the direction of the axis between the connections to constitute a rotor. CONSTITUTION:A plurality of conducting bars 31 are so arranged to the extremely outer peripheral part of a rotor that they are placed in the circumferential direction, extending them in the direction of the axis of the rotor, and each end of them is short-circuited by a short-circuit ring 32. The conducting bars 31 are housed in a metallic support cylinder 3 and are held by a wedge 5 against centrifugal force. A connection 34 of the conducting bar 31 and the short-circuit ring 32 is formed a little to the axial center, and a connection 8 of the wedge 5 and the short-circuit ring 32 is separated from the connection 34. Accordingly, the connections 34 and 8 as a heating section are so dispersed that the centralization of heating can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a rotor for a superconducting rotating electric machine, and particularly to a damper thereof.

[Prior art] What is shown in FIG.
11 is a perspective view showing a conventional rotor shown in Publication No. 59, FIG. 11 is a sectional view along the groove of FIG. 1O (cross section on the groove extension line), and FIG. Figure XI-X
A sectional view taken along the I line is shown.

In the figure, a conductive bar (2) arranged around the outer periphery of the field winding and extending in the axial direction is designated by a symbol (1).
1) is a shorting ring that shorts the ends of (3) is a conductive bar (1)
(4) is a holding ring that holds the shorting ring (2) against the centrifugal force caused by the rotation of the rotor. These constitute a room temperature damper (10) with a squirrel cage damper. Here, the conductive bar (1) is resisted against centrifugal force,
The general method for holding the supporting cylinder (3) in the groove is to use a wedge (5), and the material for this wedge is similar to that of the conductive bar (1) and the shorting ring (2). Metal materials with low electrical resistivity are used.

Further, the shorting ring (2) is provided with a protrusion (6) that protrudes into the groove formed in the support cylinder (3), and is attached to overlap the conductive bar (1) in a stepwise manner. This overlapped part is held down by sea urchin and ji (5).

Therefore, the connection between the shorting ring (2) and the conductive bar (1) is made at the contact portion (7) of the stepped portion, and the connection with the wedge (5) is made at the contact portion of the protruding portion (6). (7
) is carried out at a contact part (8) which extends opposite to the contact point (8).

Note that a super-electric field winding and its supporting cylinder are provided on the inner peripheral side of the supporting cylinder (3), but these are omitted in FIGS. 1O to 12.

Moreover, FIG. 13 is a perspective view showing the structure of the contacts (7) and (8).

Next, the operation of the above-mentioned conventional device will be explained.

When the current in the generator's armature coil becomes unbalanced due to a system fault or the connection of an unbalanced load, the coil current contains an antiphase component, which causes a magnetic field from the armature coil to rotate in the opposite direction to the rotor. This causes an eddy current to be induced on the surface of the room-temperature damper.

This induced eddy current mainly flows within the squirrel cage damper.

That is, in the center of the normal temperature damper (10), a current flows through the conductive bar (1) and the wedge (5), and at the ends, this current flows into the short circuit ring (2).

The current value flowing through the wedge (5) and the conductive bar (1) is approximately the same level, and depending on the system fault conditions, the current value may be several hundred.
It may even reach 0A.

The current flowing from the 411 bar (1) and wedge (5) to the shorting ring (2) flows from the conductive bar (1) to the shorting ring (2) via the contact parts (7) and (8) between the two. However, due to the relationship between the current 1i flowing through the wedge (5) and the penetration depth, the inside of the wedge (5) is passed through the end of the wedge (5). Therefore, the current flows from the wedge (5) to the short circuit ring (2) in the area where the number of ends of the wedge (5) is cI11.
2) via the contact part (8).

In this way, the current flowing through the wedge (5) and the conductive bar (1) passes through the metal contacts (7) and (8) to the short circuit ring (
2), a large loss will occur at the contact portions (7) and (8) due to the electrical contact resistance of the contact portions (7) and (8).

In addition, at the base of the protrusion (6) of the shorting ring (2), the combined current of the wedge (5) and the conductive bar (1) flows through the conductive bar (
Since the water flows through the protrusion (6), which is about half the thickness of 1), the loss density in this part is several times that of other parts in the groove.

[Problems to be Solved by the Invention] A normal temperature damper for a rotor of a conventional superconducting rotating electric machine is configured as described above, and includes a wedge (5) and a short-circuit ring (2).
A current flow part (8) from the wedge (5) which is the contact part with the short circuit ring (2), and from the conductive bar (1) which is the contact part between the conductive bar (1) and the short circuit ring (2). Short circuit ring (2
) is provided at the same position in the axial direction within the dowel groove, so the contact portion (7) at the above location
The heat generated in (8) will be concentrated near the edge of the wedge (5), which may cause an excessive temperature rise when reverse-sequence current is applied, and the generator's reverse-sequence withstand capacity will be reduced by the temperature of this part. It is conceivable that the temperature rise may be a constraint, and therefore, conventional devices have been faced with the problem of avoiding such a temperature rise.

This invention was made to solve the above-mentioned problems, and its purpose is to obtain a rotor for a superconducting rotating electric machine that suppresses excessive heat generation near the end of the rotation shaft and has excellent negative phase withstand characteristics. do.

[Means for Solving the Problems] A normal temperature damper for a rotor of a superconducting rotating electrical machine according to the present invention is constructed by shifting the electrical contact portions of the conductive bar and the wedge to the short-circuit ring in the axial direction. It is something.

[Function] In the normal temperature damper of the present invention, the contact of the conductive bar and the wedge with the short-circuit ring is shifted in the axial direction, so that heat generation due to contact resistance is not concentrated in one place.
In addition, the temperature does not concentrate at the base of the protrusion of the short-circuit ring, and excessive temperature rise at the edge of the wedge can be suppressed.

[Example] Hereinafter, the present invention will be explained based on the drawings showing one example thereof.

Note that in the figure, symbols (3) to (5), and (8) are equivalent to those indicated by the same symbols in the above-mentioned conventional device.

In FIGS. 1 to 3 showing the first embodiment, the symbol (U)
is a conductive bar whose end extends to the end of the retaining ring (4), and (12) has a length approximately equivalent to the width of the retaining ring (4), and is an extension of the conductive bar (11). It is a conductive spacer provided between the parts, and both sides thereof, that is, the contact part (13) with the conductive bar (11), are bonded by brazing with a low-density alloy to form an electrical connection part. are doing.

In addition, the short circuit ring is a conductive spacer (12) and a conductive bar (1
1).

Since the first embodiment is configured as described above, the conductive bar (1
1) and the current induced in the wedge (5) flows in the groove in the axial direction. Of these, the wedge (5) chisel flow flows to the end of the wedge (5) regardless of the configuration of the conductive bar (11), and flows to the contact area (8) between the wedge (5) and the conductive bar (11). The fact that heat is generated is the same as in the conventional case.

On the other hand, the conductive bar (U) is an extension of the conductive bar (ll),
Since the short circuit ring is formed by the conductive spacer (12), there is no connection between the conductive bar (11) and the short circuit ring in the conventional structure, and therefore the contact portion (7) between the conductive bar (11) and the short circuit ring is can be eliminated, and the concentration of contact heat generation at the end of the wedge (5) can be eliminated.

Further, since the conductive bar (11) is extended while keeping the cross-sectional area the same, it is possible to eliminate an increase in heat generation due to current concentration at the root of the short-circuit ring protrusion.

In addition, in the above embodiment, the conductive bar (11) was brazed between the conductive bar (11) and the conductive spacer (12), but soldering may also be performed by adhesion using a low alloy alloy. Not even.

Furthermore, the conductive bar (11) is not brazed or soldered by adhesion using a low alloy metal, but the conductive bar (11) can be electrically contacted between the conductive bar (n) and the conductive spacer (12). A short circuit ring may also be formed.

FIG. 3 shows this state.

Next, in FIGS. 4 and 5 showing the second embodiment, the conductive spacer is inserted between the conductive bars (11) in place of the conductive spacer of the first embodiment, and is also covered on the top of the conductive bar (11). Covering portion (21a) that covers and contacts the top surface of the conductive bar (11)
A conductive spacer (21) is provided.

In such a configuration, the eddy currents flowing through the conductive bar (11), after flowing axially within the conductive bar (ti), reach the extension of the conductive bar (11) and reach the electrical contact surface ( 22
), it flows into the adjacent conductive spacer (21), and sequentially flows in the circumferential direction.

Therefore, heat generated by contact resistance can be dispersed from the edge of the wedge (5), and the short circuit ring (2) in the conventional structure can be dispersed.
It is possible to eliminate current concentration at the base of the protrusion.

Next, a third embodiment will be explained with reference to FIGS. 6 and 7.

The code (31) is a number C for the conventional conductive bar (1).
It is a conductive bar whose length is shortened by 1 or more, and (32)
Compared to the conventional short circuit ring (2), the protrusion into the groove (33
) is lengthened according to the shortening of the conductive bar (31). Therefore, the conductive bar (31) and the short-circuit ring (3
2), the wedge (5) is moved toward the center in the axial direction, and is separated from the contact portion (8) between the wedge (5) and the short-circuit ring (32).

Since this example is configured in this way, how can it be explained? l
The current induced in the t-bar (31) and wedge (5) flows in the groove in the axial direction.

Of these, the current flowing through the wedge (5) is
Regardless of the contact position between the wedge (5) and the short-circuit ring (5), the flow reaches the end of the edge (5), and the wedge (5) and the short-circuit ring (
It is the same as in the conventional case that heat is generated by flowing into the short circuit ring (32) at the contact portion (8) with the short circuit ring (32).

However, on the other hand, the contact portion (34) between the conductive bar (31) and the shorting ring (32) has moved toward the center in the axial direction within the groove. Therefore, heat generation due to contact resistance also occurs at this contact part (34).
occurs at the contact point (8
The heat generated in ) is different from the heat generated in . Therefore, local concentration of heat can be prevented.

In the third embodiment, the contact portion (34) between the conductive bar (31) and the shorting ring (32) was moved toward the center in the axial direction within the groove. And as shown in FIG. 9, the contact portion (41) may be moved toward the end.

That is, in the figure, the reference numeral (42) indicates the contact portion (41
) is extended from the contact part (8) to the end side, and its length Q is the same as the width of the shorting ring (43), and the shorting ring (43) is a conductive bar whose inner diameter Conductive bar on the side (
The extension of 42) is provided with a groove (44) in which an electrical connection is made with the conductive bar (42) by means of a contact (41).

Since this fourth embodiment is configured as described above,
The eddy current flowing through the conductive bar (42) flows into the short circuit IJiI (43) via the contact part (41), and its heat generating part becomes the contact part (41), and the heat generating part due to contact resistance moves in the axial direction. Although the current from the wedge (5) flows into the conductive bar (42) near the contact portion (8) as in the conventional case, the heat generating positions are distributed.

[Effects of the Invention] As described above, according to the present invention, the contact portions of the wedge and the conductive bar to the short-circuit ring are shifted in the axial direction from each other. The heat generated between the ring and the ring is dispersed in the axial direction, suppressing the concentration of heat generation at the edge of the wedge. Therefore, the temperature distribution near the edge of the wedge can be made uniform, and as a result, the reverse phase This has the effect of allowing the rotation of a superconducting rotating electric machine having a normal temperature damper with excellent current withstand capacity.

[Brief explanation of the drawing]

FIG. 1 is a sectional view taken along the groove showing the end of a normal temperature damper according to a first embodiment of the present invention, FIG. 2 is a sectional view taken along line 1-1 in FIG. 1, and FIG. 3 is a sectional view of the damper shown in FIG. FIG. 4 is a perspective view showing the circuit configuration; FIG. 4 is a sectional view taken along the groove showing the end of the normal temperature damper according to the second embodiment; FIG. 5 is a right side view showing the damper circuit configuration of FIG. 4; FIG. 7 is an exploded perspective view of FIG. 6, and FIG. 8 is a cross-sectional view along the groove showing the end of the room temperature damper according to the fourth embodiment. A sectional view, FIG. 9 is an exploded perspective view of FIG.
The figure is a perspective view showing the structure of a conventional rotor room temperature damper, Figure 11 is a sectional view taken along the groove in Figure 10, and Figure 12 is a
1, and FIG. 13 is an exploded perspective view of FIG. 11. (3)... Support cylinder, (5)... Wedge, (8) (1
3)(22)(34)(41)...Contact part, (11)(
31)(42)...conductive bar, (12)(21),...
・Conductive spacer, (32) (43)...Short ring, (33
)...Protrusion. In each figure, the same reference numerals indicate the same or corresponding parts. Figure 1 2nd leap

Claims (1)

[Claims] A superconducting field coil mounted on a coil mounting shaft, a support cylinder surrounding the superconducting field coil and having a plurality of grooves provided in the outermost circumference of the rotor in the axial direction, A cage comprising an inserted conductive bar, a wedge that fixes the conductive bar in the groove, and a shorting ring made of a ring-shaped conductor that short-circuits both ends of the conductive bar at each end. A rotor of a superconducting rotating electrical machine having a room-temperature damper with a type damper circuit, wherein the contact portions of the wedge and the conductive bar to the short-circuit ring are offset from each other in the axial direction. Child.