System for generating electrical power

• US 20090278510A1
• Filed: 06/11/2008
• Published: 11/12/2009
• Est. Priority Date: 05/10/2008
• Status: Active Grant

• Current Assignee: Converteam Technology Ltd. (General Electric Company)
• Original Assignee: Converteam Technology Ltd. (General Electric Company)
• Inventors: Moehlenkamp, Georg, Bach, Wolfgang, Hussels, Peter
• Granted Patent: US 7,675,271 B2
• Time in Patent Office: Days
• US Class Current: 322/29
• CPC Class Codes: H02P 25/22 Multiple windings; Windings for more than three phases
• CPC Class Codes: H02P 27/16 using ac to ac converters without intermediate conversion to dc H02P27/05 takes precedence
• CPC Class Codes: H02P 9/08 Control of generator circuit during starting or stopping of driving means, e.g. for initiating excitation
• CPC Class Codes: H02P 9/42 to obtain desired frequency without varying speed of the generator

Abstract

Described is a system for generating electrical power, which system includes a turbine that is mechanically connected to a generator, which in turn is connected via a multiphase transformer to a load. In at least one embodiment, at least two counter-connected switching devices of the converter are assigned to each phase of the transformer. The transformer is provided on the side facing the converter with two winding arrangements in a star connection. Each of the windings of the first winding arrangement is connected to the switching devices belonging to one phase and switched in one direction. Each of the windings of the second winding arrangement is connected to the switching devices belonging to one phase and switched in the opposite direction. The star points of the two winding arrangements are connected via a direct current choke.

Claims

1. A system for generating electrical power, comprising:

a turbine, mechanically connected to a generator, the generator being electrically connected via a converter and a multiphase transformer to a load, wherein at least two counter-connected switching devices of the converter are assigned to each phase of the transformer, the transformer including two winding arrangements in a star connection on the side facing the converter, each of the windings of the first winding arrangement is connected to the switching devices belonging to one phase and switched in one direction, each of the windings of the second winding arrangement being connected to the switching devices of one phase and switched in the opposite direction, and the star points of the two winding arrangements being connected to each other via a direct current choke.

2. The system according to claim 1, wherein the generator includes a number of windings and wherein the converter includes, for each phase of the transformer, a number of counter-connected switching devices, which correspond to the number of the generator windings.

3. The system according to claim 1, wherein the switching devices of the converter are commutated in dependence on the generator in the generator mode.

4. The system according to claim 1, wherein the generator functions as a motor for the start-up of the turbine.

5. The system according to claim 4, wherein for low rotational speeds of the turbine, the switching devices of the converter are commutated during the motor function of the generator in dependence on the load.

6. The system according to claim 1, wherein the turbine is connected directly to the generator.

7. The system according to claim 1, wherein the generator is embodied as synchronous generator.

8. The system according to claim 1, wherein the converter is embodied as matrix converter.

9. The system according to claim 1, wherein the converter has a two-stage design.

10. The system according to claim 1, wherein the turbine is a gas turbine.

11. The system according to claim 2, wherein the switching devices of the converter are commutated in dependence on the generator in the generator mode.

12. The system according to claim 2, wherein the generator functions as a motor for the start-up of the turbine.

13. The system according to claim 5, wherein for low rotational speeds of the turbine, the switching devices of the converter are commutated during the motor function of the generator in dependence on the power supply grid.

14. The system according to claim 7, wherein the generator is embodied as synchronous generator with a polygonal embodiment of the windings.

15. The system according to claim 8, wherein the converter is embodied as direct converter.

16. The system according to claim 9, wherein the converter has a two-stage design for higher voltages.