RU2575645C2 - Rotating electric machine, in particular asynchronous double-current machine with power range from 20 mva up to 500 mva - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: rotating electric machine, in particular asynchronous double-current machine with power range from 20 MVA up to 500 MVA comprises rotor rotating in regard to the machine axis, stator surrounding the rotor concentrically. The rotor comprises shaft and imbricated core with rotor winding on it, and the above winding is coupled through connectors with contact rings placed from inside at the shaft end. At that connectors include mechanical connectors passing at right angle to the shaft in order to absorb forces occurring in result of centrifugal acceleration, which are connected to the front end of the rotor winding and are supported by auxiliary rim at the rotor imbricated core. The electric machine comprises additional electric connectors for actual current transmission, at that electrical connectors are coupled electrically in parallel to mechanical connectors.

EFFECT: higher reliability.

14 cl, 3 dwg

Description

FIELD OF TECHNOLOGY

The present invention relates to the field of electric energy production. In particular, the invention relates to a rotating electric machine, namely an asynchronous dual-power machine having a power range from 20 MVA to 500 MVA, according to the preamble of claim 1.

BACKGROUND OF THE INVENTION

Dual-supply asynchronous machines with a power range from 20 MVA to 500 MVA can be used to produce electricity with a variable speed of rotation of the machine. These machines are distinguished by the presence of a distributed three-phase winding on the rotor. The rotor winding contains individual rods that are nested in grooves in the rotor core plate package. These rods are interconnected in the frontal part of the winding, forming a winding. Current is supplied through at least three slip rings that are mounted on the rotor shaft at the end of the machine. A part of the machine is shown in FIG. 1 in a very simplified form. The asynchronous machine 10 shown in FIG. 1, has an axis 19. The central core 11, containing a shaft 11a on which the contact rings 17 are arranged, can rotate about the axis 19. Around the central core 11 is a lined rotor core 12 with an auxiliary rim 13 adjacent to the lined rotor core under the frontal part 14 rotor windings. The lined core of the rotor 12 is concentrically surrounded by the lined core of the stator 15, in which the stator winding is located, protruding outward at the end of the core 15 with the frontal part 16 of the stator winding.

Three phases of the rotor winding should be connected to the contact rings 17 at the end of the shaft 11a. To this end, conductors (not shown) are provided on the shaft 11a, which are connected, firstly, to the contact rings 17, and secondly, to the frontal parts 14 of the winding at the level of the ends of the frontal parts of the windings. Connectors 18 (shown by dashed lines in FIG. 1) installed at right angles to the shaft must be insulated so that it is possible to supply the rotor test voltage. The rated current of the rotor flows through the connectors 18, and in this case, the required temperature limit must not be exceeded. The connector system 18 must be sufficiently flexible in the axial direction (at the point of connection with the winding) and in the radial direction to compensate for the thermal expansion of the winding in the axial direction and the expansion of the rotor core in the radial direction. Finally, connectors 18 must be protected from large centrifugal forces.

SUMMARY OF THE INVENTION

Thus, the object of the invention is to provide a rotating electric machine of the aforementioned type, which satisfies the requirements set forth above.

This problem is solved by a rotating electric machine of the type mentioned in paragraph 1 of the claims.

According to the present invention, a rotating electric machine, in particular a dual-supply asynchronous machine with a power range of 20 MVA to 500 MVA, comprises a rotor that rotates about the axis of the machine, the rotor being concentrically surrounded by a stator and containing a lined rotor core, and a shaft where the lined rotor core carries on itself a rotor winding, which is located outside and connected through connectors to contact rings located on the end of the shaft. The invention is characterized in that these connectors contain mechanical connectors running at right angles to the shaft to absorb forces arising from centrifugal acceleration, and they are connected, firstly, to the frontal part of the rotor winding, and secondly, rely on an auxiliary the rim on the rotor core.

One of the configurations of the machine according to the present invention is characterized in that the mechanical connectors are connected to the frontal part of the rotor winding through the connections of the frontal part of the winding, and in that the connectors are supported on the auxiliary rim through an extended auxiliary rim, which protrudes in the axial direction, preferably consists of layered onto another plate and forms a closed ring.

Another configuration is characterized in that the mechanical connectors are located at the same height relative to the axis as the connections of the frontal parts of the windings. As a result, it is possible to reliably avoid bending mechanical stresses in the connectors.

Another configuration of the invention is characterized in that the mechanical connectors extend through the extended auxiliary rim in a radial direction, wherein the expanded auxiliary rim is bolted to the auxiliary rim to avoid bending stresses in the mechanical connectors.

According to the following configuration, the mechanical connectors are composed of an electrically conductive material that withstands high mechanical stress, in particular steel.

In particular, mechanical connectors can also be electrically connected to the front of the rotor winding or to the connections of the front of the rotor winding.

It is especially advantageous if the mechanical connectors are electrically isolated by the insulation surrounding them, and if the centrifugal forces that are absorbed by the mechanical connectors are transmitted through the ends (arranged at right angles) of the connectors and through the insulation blocks arranged on the inside of the auxiliary rim or extended auxiliary rim to the auxiliary rim or extended auxiliary rim.

Another configuration of the present invention is characterized in that additional electrical connectors are provided for actual current transmission, which are electrically connected in parallel with the mechanical connectors.

Preferably, the electrical connectors extend outside the auxiliary rim or the expanded auxiliary rim to improve cooling.

In particular, the electrical connectors may consist of materials that can be subjected to a small mechanical load, but which have good electrical conductivity, in particular copper.

Another configuration is characterized in that the electrical connectors are bent back at right angles on the inner side to transmit the resulting centrifugal forces through the insulation blocks to the inner side of the auxiliary rim or extended auxiliary rim, and characterized in that the electrical connectors are axially protected by outer end plates.

A further embodiment of the invention is characterized in that the electrical and mechanical connectors are electrically connected by the connections of the connectors, and in that the connections of the connectors are electrically connected with flexible adapters that make contact with the supply buses located on the shaft.

Flexible adapters are preferably U-shaped.

However, a flexible adapter design consisting of separate plates is also possible.

Adapters can also consist of a material that cannot be subjected to high mechanical stress, but which has good electrical conductivity, in particular copper.

According to another embodiment of the present invention, in order to avoid imbalance of the rotor, the connectors are arranged around the circumference, and these connectors do not perform a mechanical or electrical function.

BRIEF DESCRIPTION OF THE DRAWINGS

The following is a more detailed description of exemplary embodiments of the invention with reference to the drawings, in which:

FIG. 1 - part of an asynchronous machine in a very simplified form;

FIG. 2 is a longitudinal sectional view of a parallel arrangement of mechanical and electrical connectors according to an exemplary embodiment of the present invention; and

FIG. 3 is an axial plan view of the arrangement shown in FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

The main components of the supply lines of the rotor or connectors 18 according to an exemplary embodiment of the present invention are shown in FIG. 2 and 3. The current flows from the contact rings 17 through the shaft 11a, through the supply bus 28 on the shaft to the connection 26 of the connectors. The current connectors 18a, 18b create an electrical contact between the connectors 26 of the connectors and the connections 20 of the frontal part of the winding, which are connected to the rotor winding (frontal part 14 of the rotor winding). The following describes the details of the operation of the individual parts.

Connections 20 of the frontal part of the winding create contact between the connectors 18a, 18b and the corresponding connecting rods of the rotor winding; in this case, they can be connected to a plurality of connectors 18a, 18b distributed around the circumference. They must be configured (together with connectors 18a, 18) flexible enough to allow perception of axial thermal expansion (in the x direction of FIG. 2) of the winding.

Connectors 18a, 18b are a key point of the present invention. In FIG. 2 shows a basic separation into electrical connectors 18a and mechanical connectors 18b. The purpose of the mechanical connectors 18b is to absorb the forces of the connections 20 of the frontal part of the winding that result from centrifugal acceleration, and transfer these forces to the auxiliary rim 13. To this end, the auxiliary rim 13 is axially expanded by the expanded auxiliary rim 22. The mechanical connectors 18b extend radially direction (direction r in FIG. 2) through an expanded auxiliary rim 22, which contains plates folded with each other and forms a closed ring connected to the auxiliary Yelnia rim 13 by bolts 23. In order to avoid bending stresses in the connectors 18a, 18b, mechanical connectors 18b are preferably arranged at the same axial height as the compound 20 the end winding.

Mechanical connectors 18b consist of a material that can withstand high mechanical stress, and can also be used as an electrical conductor, if necessary, for example, of steel. The mechanical connectors 18b are also electrically connected to the connections 20 of the frontal part of the winding, and are involved in the transmission of current, this function being optional. If the mechanical connectors 18b are in direct contact with the electrical connectors 18a, they must be insulated accordingly. To this end, as shown in FIG. 2, insulation 29 is used first, which immediately surrounds the connectors 18a, 18b, and then the insulation unit 25 located on the inner circumference of the expanded auxiliary rim 22. The centrifugal forces that are absorbed by the mechanical connectors 18b are transmitted by the indicated mechanical connectors to the expanded auxiliary rim 22. Transmission forces takes place through the ends of the connectors 18a, 18b, which are arranged in a rectangle, on the insulation blocks 25, that is, on the inner side of the expanded auxiliary equipment yes 22.

Thanks to this procedure, it is possible to avoid large additional radial forces on the connecting bolts 23, and these additional radial forces occur if the connectors 18a, 18b were connected directly to the bolts 23 as a result of shear. In accordance with the desired tangential length of the connections of the frontal part of the winding, the connections of the winding are limited by one or more mechanical connectors 18b. In order to avoid unbalancing of the rotor due to the influence of the mass of the connectors 18a, 18b, "dummy connectors" can be provided distributed around the circumference, and these dummy connectors do not perform any mechanical or electrical function.

If only small currents need to be transmitted, this can simply be realized through the mechanical connectors 18b described above. However, in the case of high currents and associated large losses, the mechanical connectors will overheat. For this reason, it is preferable to provide electrical connectors 18a for actual current transmission. These electrical connectors are electrically connected in parallel with the mechanical connectors 18b, if the mechanical connectors are also involved in the transmission of current. Electrical connectors 18a extend outside the expanded secondary rim 22 (FIG. 2) and are therefore effectively cooled. As a result of rotation, mechanical forces also appear on these connectors 18a. However, unlike mechanical connectors 18b, the electrical connectors 18a do not have to absorb any additional forces, and therefore they can be made of materials, such as, for example, copper, which are able to withstand low mechanical stress but have good conductivity compared to mechanical connectors 18b. Electrical connectors 18a are bent backward at right angles on the inside to transmit centrifugal forces through insulation blocks 25 to the inside of the expanded secondary rim 22. Electrical connectors 18a are axially protected by outer end plates 24.

The connectors 18a, 18b are electrically connected using the connectors 26 of the connectors (Fig. 3) on the inside of the expanded auxiliary rim 22. The centrifugal forces arising in the connections 26 of the connectors are absorbed by the extended auxiliary rim 22. For this purpose, they are supported in the radial direction by means of additional units isolation. Connections 26 of the connectors are electrically connected to flexible adapters 27, which create contact with special supply busbars 28 of the shaft.

The supply lines 28 of the shaft are connected to conductors (not shown) in the shaft 11 a and are rigidly mounted on the shoulders of a star-connected rotor of an asynchronous machine. Since the multilayer laminated core 12 can expand during operation between the supply busbars 28 of the shaft and the connectors 18a, 18b, it is necessary to have a flexible connection in the radial direction. This problem is solved by using flexible adapters 27. To this end, these adapters may have a U-shape design, as shown in FIG. 3. If necessary, the flexible adapters 27 can also be constructed from separate plates to provide additional flexibility. These adapters 27 are not subjected to high mechanical loads, since the supply busbars 28 of the shaft are limited by the shoulders of the star-connected rotor, and the connectors 26 of the connections are limited by an expanded auxiliary rim 32. Therefore, they can be made of a material, such as, for example, copper, which cannot be subjected to large mechanical loads, but which have good conductivity.

LIST OF REFERENCE POSITIONS

10 - asynchronous machine

11 - central core

11a - shaft

12 - lined rotor core

13 - auxiliary rim

14 - the frontal part of the rotor winding

15 - charged stator core

16 - the frontal part of the stator winding

17 - a contact ring

18 - supply bus (connector) of the rotor

18a - electrical connector

18b - mechanical connector

19 - machine axis

20 - connection of the frontal part of the winding

21 - the outgoing tire (to the slip rings)

22 - extended auxiliary rim

23 - bolt

24 - end plate

25 - insulation block

26 - connector connection

27 - adapter (flexible)

28 - shaft supply bus

29 - insulation

Claims (14)

1. A rotating electric machine, in particular a dual-supply asynchronous machine (10) with a power range from 20 MVA to 500 MVA, containing a rotor (11, 11a, 12, 14) that rotates about the axis (19) of the machine, the rotor being concentrically surrounded the stator (15, 16) and contains the lined core (12) of the rotor, and the shaft (11a), where the lined core (12) of the rotor carries a rotor winding, which is located further outside and connected through connectors (18) to the contact rings (17) ) located further from the inside at the end of the shaft (11a), while the connectors (18) with hold mechanical connectors (18b) running at right angles to the shaft (11a) to absorb forces arising from centrifugal acceleration, and are connected, firstly, to the frontal part (14) of the rotor winding, and secondly, rely on an auxiliary rim (13, 22) on the lined core (12) of the rotor, characterized in that additional electrical connectors (18a) are provided for the actual transmission of current, the electrical connectors being electrically connected in parallel with the mechanical connectors (18b). 2. A rotating electric machine according to claim 1, characterized in that the mechanical connectors (18b) are connected to the frontal part (14) of the rotor winding through the connections (20) of the frontal part of the winding, and that they rely on the auxiliary rim (13) through an expanded auxiliary rim (22), which extends the auxiliary rim (13) in the axial direction and preferably consists of laminated plates on each other and forms a closed ring. 3. A rotating electric machine according to claim 1 or 2, characterized in that the mechanical connectors (18b) are located at the same axial height as the connections (20) of the frontal parts of the windings. 4. A rotating electric machine according to claim 2, characterized in that the mechanical connectors (18b) pass through the expanded auxiliary rim (22) in the radial direction, wherein the expanded auxiliary rim is connected to the auxiliary rim (13) by bolts (23) to avoid bending mechanical stresses in mechanical connectors (18b). 5. A rotating electric machine according to claim 1, characterized in that the mechanical connectors (18b) consist of an electrically conductive material that can be subjected to high mechanical stresses, in particular steel. 6. A rotating electric machine according to claim 5, characterized in that the mechanical connectors (18b) are also electrically connected to the frontal part (14) of the rotor winding or the connections (20) of the frontal part of the winding. 7. A rotating electric machine according to claim 6, characterized in that the mechanical connectors (18b) are electrically isolated by the insulation surrounding them (29), and in that the centrifugal forces that are absorbed by the mechanical connectors (18b) are transmitted through the ends located under the straight corners, connectors (18b) and through insulation blocks (25) located on the inside of the auxiliary rim (13) or the expanded auxiliary rim (22) to the auxiliary rim (13) or the expanded auxiliary rim (22). 8. A rotating electric machine according to claim 1, characterized in that the electrical connectors (18a) extend outside the auxiliary rim (13) or the expanded auxiliary rim (22) to improve cooling. 9. A rotating electric machine according to claim 8, characterized in that the electrical connectors (18a) are composed of materials that can be subjected to a small mechanical load, but which have good electrical conductivity, in particular copper. 10. A rotating electric machine according to claim 8, characterized in that the electrical connectors (18a) are bent back at right angles on the inner side to transmit the resulting centrifugal forces through the insulation blocks (25) to the inner side of the auxiliary rim (13) or extended auxiliary rim (22), and the fact that the electrical connectors (18a) are axially protected by external end plates (24). 11. A rotating electric machine according to claim 9 or 10, characterized in that the electrical and mechanical connectors (18a, 18b) are electrically connected by the connectors (26) of the connectors, and the fact that the connections (26) of the connectors are electrically connected to the flexible adapters (27) creating contact with the supply tires (28) located on the shaft (11a). 12. A rotating electric machine according to claim 11, characterized in that the flexible adapters (27) are U-shaped. 13. A rotating electric machine according to claim 11, characterized in that the flexible adapters (27) are constructed of individual plates. 14. A rotating electric machine according to claim 11, characterized in that the adapters (27) consist of a material that cannot be subjected to high mechanical stress, but which has good electrical conductivity, in particular copper.

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