Converters For High Power Applications

• US 20080055947A1
• Filed: 08/27/2007
• Published: 03/06/2008
• Est. Priority Date: 08/30/2006
• Status: Active Grant

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Smedley, Keyue, Wen, Jun
• Granted Patent: US 7,663,268 B2
• Time in Patent Office: Days
• US Class Current: 363/65
• CPC Class Codes: H02M 5/458 using semiconductor devices only
• CPC Class Codes: H02M 7/487 Neutral point clamped inverters
• CPC Class Codes: H02M 7/49 Combination of the output voltage waveforms of a plurality of converters
• CPC Class Codes: H02P 25/22 Multiple windings; Windings for more than three phases

Abstract

Multilevel high power converters, referred to as hexagram converters, which preferably include a combination of six three-phase converter modules, are provided herein. The three-phase converter modules are interconnected and can be configured as any three-phase converter for any given application. One or more inductors can be used in the interconnections between the six modules to suppress potential circulating currents. Numerous applications exist in which the described converters can be implemented.

Claims

1. A power system, comprising:

a multilevel power converter, comprising six three-phase converter modules, each module comprising an AC port having at least three terminal nodes and a DC port having at least two terminal nodes, wherein each module is coupled to two different modules by way of first and second terminal nodes, respectively, of the at least three terminal nodes of the AC port.

2. The system of claim 1, wherein each module is coupled to the two different modules by way of an inductive path.

3. The system of claim 2, wherein each module comprises a plurality of semiconductor switches.

4. The system of claim 3, wherein at least one semiconductor switch is coupled between each of the at least three terminal nodes of the AC port and a terminal node of the DC port.

5. The system of claim 4, wherein each semiconductor switch is configured as one of the following:

an IGBT, an IGCT, or a GTO.

6. The system of claim 3, wherein each module comprises a plurality of diodes.

7. The system of claim 3, wherein each module comprises:

a first branch having a first and a second semiconductor switch coupled in series between a first and a second terminal node of the DC port, a first terminal node of the AC port being coupled between the first and second switches;

a second branch having a third and a fourth semiconductor switch coupled in series between the first and second terminal nodes of the DC port, a second terminal node of the AC port being coupled between the third and fourth switches; and

a third branch having a fifth and a sixth semiconductor switch coupled in series between the first and second terminal nodes of the DC port, a third terminal node of the AC port being coupled between the fifth and sixth switches.

8. The system of claim 7, wherein each module is coupled with a controller configured to control operation of the converter.

9. The system of claim 8, wherein the controller is configured to output a plurality of control signals to each module.

10. The system of claim 9, wherein each switch is configured to receive one of the control signals output from the controller.

11. The system of claim 10, wherein the controller is configured to output one separate control signal for each switch.

12. The system of claim 6, wherein each module further comprises a fourth branch having a load capacitor coupled between the first and second terminal nodes of the DC port.

13. The system of claim 4, wherein each module is coupled with a controller configured to control operation of the converter.

14. The system of claim 13, wherein the controller is configured to output a plurality of control signals to each module.

15. The system of claim 14, wherein the controller is configured to output one separate control signal for each switch.

16. The system of claim 1, further comprising:

a first interconnection comprising a first inductor and being coupled with a first AC terminal of a first module and a first AC terminal of a second module;

a second interconnection comprising a second inductor and being coupled with a second AC terminal of the first module and a first AC terminal of a sixth module;

a third interconnection comprising a third inductor and being coupled with a second AC terminal of the second module and a first AC terminal of a third module;

a fourth interconnection comprising a fourth inductor and being coupled with a second AC terminal of the third module and a first AC terminal of a fourth module;

a fifth interconnection comprising a fifth inductor and being coupled with a second AC terminal of the fourth module and a first AC terminal of a fifth module; and

a sixth interconnection comprising a sixth inductor and being coupled with a second AC terminal of the fifth module and a second AC terminal of the sixth module.

17. The system of claim 16, wherein a third AC terminal of each module is an AC output terminal coupled with external circuitry.

18. The system of claim 1, wherein each module is coupled with a controller configured to control the operation of the respective module.

19. The system of claim 1, wherein the controller is configured to generate a plurality of driving signals for the converter based on at least one received reference signal and at least one feedback signal.

20. The system of claim 1, wherein each module comprises fault protection circuitry.