Electrical machine with electronic power unit for conversion

• US 7,781,925 B2
• Filed: 03/14/2008
• Issued: 08/24/2010
• Est. Priority Date: 03/20/2007
• Status: Expired due to Fees

• Current Assignee: Alstom Technology Ltd. (Alstom SA)
• Original Assignee: Alstom Technology Ltd. (Alstom SA)
• Inventors: Lacaze, Alain
• Primary Examiner(s): Leung; Quyen
• Assistant Examiner(s): Kim; John K
• Application Number:
  US12/048,443
• Publication Number:
  US 20080231127A1
• Time in Patent Office: 893 Days
• Field of Search: 310/68.R, 310/68.D, 310/71, 310/89, 363/148, 363/150
• US Class Current: 310/71
• CPC Class Codes: H02K 11/33 Drive circuits, e.g. power electronics H02K11/38 takes precedence
• CPC Class Codes: H02M 5/272 for variable speed constant frequency systems
• CPC Class Codes: H02M 5/297 for conversion of frequency
• CPC Class Codes: H02M 7/003 Constructional details, e.g. physical layout, assembly, wiring or busbar connections
• CPC Class Codes: H02P 27/04 using variable-frequency supply voltage, e.g. inverter or converter supply voltage

Abstract

A matrix converter for the conversion of a polyphase alternating current into a desired alternating output current in which m phases of the polyphase alternating current are converted into alternating output current with n (n<m) phases of a load by a multiple number of controllable bidirectional switches. The converter includes at least one stage, and in that at least one stage of the converter each phase of the polyphase alternating current is controlled by a controllable bidirectional switch. The at least one stage of the converter is formed by a two-dimensional array of stage stacks of switching elements which stage stacks are arranged substantially parallel to each other along a stack direction perpendicular to the plane of the matrix converter, and wherein the input of the stage stacks is provided by bus bars located on one side of the stage stacks.

Claims

1. A matrix converter for the conversion of a polyphase alternating current into a desired alternating output current, wherein the polyphase alternating current has m phases, the alternating output current having n phases, with n<

m, the converter comprising;

at least one stage comprising a plurality of controllable bidirectional switches, in which at least one stage each phase of the polyphase alternating current is controlled by a controllable bidirectional switch, the at least one stage defining a matrix converter plane;

wherein said at least one stage comprises a two-dimensional array of stage stacks of switching elements, which stage stacks are arranged substantially parallel to each other along a stack direction parallel to the matrix converter plane;

bus bars located on one side of the stage stacks and substantially in a plane parallel to the matrix converter plane, the bus bars providing input to the stage stacks; and

grid bus bars located on the other side of the stage stacks and substantially in a plane parallel to the plane of the matrix converter, the grid bus bars collecting the output of the stage stacks.

2. A matrix converter according to claim 1, wherein the bus bars are arranged substantially orthogonal to the grid bus bars.

3. A matrix converter according to claim 1, comprising m/n bus bars and 2n grid bus bars.

4. A matrix converter according to claim 1, wherein the at least one stage comprises at least two stages;

wherein, in at least one stage, each phase of the polyphase alternating current is controlled by a controllable bidirectional switch and is the first stage and is configured and arranged to be directly connected to a generator;

wherein the at least two stages comprises at least one grid stage including m/n groups of controllable bidirectional switches, each of said m/n groups comprising n parallel bidirectional switches configured and arranged to be individually connected to each of the phases of the alternating output current, wherein the at least one grid stage is the last stage of the converter and is configured and arranged to be directly connected to a transformer or a load;

wherein the at least one grid stage comprises a two-dimensional array of grid stage stacks of switching elements, which grid stage stacks are arranged substantially parallel to each other along a stack direction perpendicular to the matrix converter plane, and further comprising;

bus bars providing input to the grid stage stacks, the bus bars located on one side of the grid stage stacks and substantially in a plane parallel to the matrix converter; and

grid bus bars collecting output of the grid stage stacks, the grid bus bars located on the other side of the grid stage stacks and substantially in a plane parallel to the matrix converter plane.

5. A matrix converter according to claim 4, wherein the grid stage comprises a regular arrangement of k rows with 2n stacks, and 2n columns orthogonal to said k rows.

6. A matrix converter according to claim 5, wherein the bus bars are parallel to the rows and the grid bus bars are parallel to the columns.

7. A matrix converter according to claim 4, wherein, in said first stage, m/k of the m phases of the polyphase alternating current are controlled in k generator stacks of switchable elements, and wherein the generator stacks are oriented parallel to the grid stage stacks and located in an additional column on one side of the matrix of the grid stage stacks parallel to the direction of the columns.

8. A matrix converter according to claim 7, further comprising:

a collecting generator stage conductor which collects the output of each generator stack, the collecting generator stage conductor leading upwards and connected to the bus bars.

9. A matrix converter according to claim 1, wherein adjacent grid bus bars are connected and form n phases.

10. A matrix converter according to claim 1, wherein m is an integer multiple of n, wherein the at least one stage comprises two stages, wherein one of the two stages in which each phase (6) of the polyphase alternating current is controlled by at least one controllable bidirectional switch is the first stage and is configured and arranged to be directly connected to a generator, and wherein the other of the two stages is a grid stage which comprises m/n groups of controllable bidirectional switches, each group comprising n parallel bidirectional switches configured and arranged to be individually connected to each of the phases of the alternating output current, said grid stage configured and arranged to be directly connected to a transformer or a load.

11. An electrical machine comprising:

a stator;

a rotor rotatably and coaxially mounted within the stator;

a housing within which the stator and the rotor are substantially located; and

a matrix converter according to claim 1 configured and arranged to convert polyphase alternating current;

a cubicle separate from and outside said housing, wherein the matrix converter is located in the separate cubicle, and wherein the separate cubicle is located substantially radially adjacent to the stator.

12. An electrical machine according to claim 11, wherein the axis of the stator is substantially horizontal and the cubicle is located on top of the housing.

13. An electrical machine according to claim 11, wherein the electrical machine is a generator, wherein the stator includes end windings on one side of the stator and conductors from said end windings, and wherein the matrix converter comprises stator side input connections substantially in one plane with said stator end windings, wherein said plane is perpendicular to the axis of the rotor, and the end windings conductors extend to the matrix converter input connections substantially in said plane.

14. An electrical machine according to claim 13, wherein the matrix converter switchable elements stacks are located in a direction substantially perpendicular to the matrix converter plane, said matrix converter plane being arranged substantially tangential to the stator.

15. An electrical machine according to claim 11, wherein:

the matrix converter is mounted in the cubicle so that it is vibrationally decoupled from the stator and from the rotor, or

the cubicle is mounted on the housing so that it is vibrationally decoupled from the stator and from the rotor;

or

both.

16. An electrical machine according to claim 15, wherein at least one of the matrix converter and the cubicle is suspended, mounted on a damped support, or both, for vibrational decoupling.

17. An electrical machine according to claim 11, wherein the electrical machine comprises a horizontally oriented generator comprising said rotor, stator, and housing, said stator comprising end windings and generator phase conductors, the matrix converter including an input, said generator configured and arranged to generate a polyphase output available at the stator end windings, wherein said polyphase output is conducted by said generator phase conductors to the matrix converter input, wherein the cubicle is positioned on top of the housing, and wherein the generator phase conductors comprise vertical portions and optionally circumferential portions.

18. An electrical machine according to claim 17, wherein the housing comprises a top opening, wherein the cubicle comprises a bottom wall including a feed through opening, and wherein the generator phase conductors are mounted to lead through the feed through opening of the cubicle to the matrix converter input.

19. An electrical machine according to claim 18, wherein the matrix converter comprises a first stage in which m/k of m phases of the polyphase alternating current of the generator are controlled in k stacks of said switchable elements, and wherein groups of m/k generator phase conductors are jointly guided upwards for feeding into the matrix converter.

20. A matrix converter according to claim 5, wherein the k rows have alternating polarity.

21. A matrix converter according to claim 5, wherein the 2n columns have equal polarity.

22. A matrix converter according to claim 10, wherein from the generator m phases are forming the input of the first stage, wherein m/n phases are forming the output of the first stage, wherein groups of n, preferably adjacent, output phases of the first stage are connected, and wherein each of the thus formed m/n conductors (13) is connected with each of the bidirectional switches (4) of a corresponding group (12) of the grid stage (9) of the converter.

23. A matrix converter according to claim 22, wherein the groups of n output phases of the first stage are adjacent to each other.

24. An electrical machine according to claim 14, wherein said matrix converter plane is realistic above the housing.