MODULAR MULTI-LEVEL POWER CONVERSION SYSTEM WITH DC FAULT CURRENT LIMITING CAPABILITY

• US 20140347898A1
• Filed: 08/07/2014
• Published: 11/27/2014
• Est. Priority Date: 05/31/2012
• Status: Abandoned Application

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Raju, Ravisekhar Nadimpalli, Garces, Luis Jose, Zhang, Di, Rockhill, Andrew Allen, Gupta, Ranjan Kumar
• Application Number:
  US14/453,637
• Publication Number:
  US 20140347898A1
• Time in Patent Office: Days
• US Class Current: 363/35
• CPC Class Codes: H02M 1/32 Means for protecting converters other than automatic disconnection
• CPC Class Codes: H02M 5/4585 having a rectifier with controlled elements
• CPC Class Codes: H02M 7/217 using semiconductor devices only
• CPC Class Codes: H02M 7/483 Converters with outputs that each can have more than two voltages levels
• CPC Class Codes: H02M 7/4835 comprising two or more cells, each including a switchable capacitor, the capacitors having a nominal charge voltage which corresponds to a given fraction of the input voltage, and the capacitors being selectively connected in series to determine the instantaneous output voltage

Abstract

A power converter module is provided. The power converter module includes a first converter leg and a second converter leg. The first converter leg includes a first switching unit and a second switching unit coupled in series. The second switching unit is disposed in a reverse orientation with respect to an orientation of the first switching unit. The second converter leg includes a third switching unit and a diode coupled in series. The third switching unit is disposed in a reverse orientation with respect to the orientation of the first switching unit. The power converter also includes a first energy storage device operatively coupled between the first converter leg and the second converter leg. The power converter module further includes a second energy storage device operatively coupled between the first converter leg and the second converter leg.

Claims

1. A power converter module, comprising:

a first converter leg comprising;

a first switching unit and a second switching unit coupled in series, wherein the second switching unit is disposed in a reverse orientation with respect to an orientation of the first switching unit;

a second converter leg comprising;

a third switching unit and a diode coupled in series, wherein the third switching unit is disposed in a reverse orientation with respect to the orientation of the first switching unit;

a first energy storage device operatively coupled between the first converter leg and the second converter leg; and

a second energy storage device operatively coupled between the first converter leg and the second converter leg.

2. The power converter module of claim 1, wherein each of the first switching unit, the second switching unit, and the third switching unit comprises a switch and a switching diode operatively coupled to each other in an anti-parallel configuration.

3. The power converter module of claim 2, wherein the switch comprises an insulated gate bipolar transistor (IGBT), a mechanical switch, or a combination thereof.

4. The power converter module of claim 1, wherein the first switching unit is disposed between a first node and a second node of the first converter leg and the second switching unit is disposed between the second node and a third node of the first converter leg.

5. The power converter module of claim 1, wherein the third switching unit is disposed between a fourth node and a fifth node of the second converter leg and the diode is disposed between the fifth node and a sixth node of the second converter leg.

6. The power converter module of claim 1, wherein the first energy storage device is disposed between a first node of the first converter leg and a fourth node of the second converter leg in a first orientation, wherein the second energy storage device is disposed between a second node of the first converter leg and a fifth node of the second converter leg in a second orientation, and wherein the second orientation is opposite to the first orientation.

7. The power converter module of claim 1, wherein the second switching unit is operated with the third switching unit to provide a positive voltage across electrical terminals of the power converter module.

8. The power converter module of claim 1, wherein the second switching unit is operated with the first switching unit to provide a zero voltage across electrical terminals of the power converter module.

9. The power converter module of claim 1, wherein the diode and the first switching unit are configured to generate a negative voltage across electrical terminals of the power converter module to reduce a DC fault current.

10. The power converter module of claim 1, wherein the first converter leg further comprises a fourth switching unit, wherein the second converter leg further comprises a fifth switching unit, and wherein the fifth switching unit is disposed in a reverse orientation with respect to an orientation of the fourth switching unit.

11. The power converter module of claim 10, further comprising a third energy storage device in a first orientation and a fourth energy storage device in a second orientation operatively coupled between the first converter leg and the second converter leg, wherein the second orientation is opposite to the first orientation.

12. A power conversion system, comprising:

a plurality of phase units configured to convert power corresponding to a respective phase of an input power, wherein each phase unit comprises a plurality of power converter modules coupled in series to each other, and wherein each power converter module comprises;

a first converter leg comprising;

a first switching unit and a second switching unit coupled in series, wherein the second switching unit is disposed in a reverse orientation with respect to an orientation of the first switching unit;

a second converter leg comprising;

a third switching unit and a diode coupled in series, wherein the third switching unit is disposed in a reverse orientation with respect to the orientation of the first switching unit;

a first energy storage device operatively coupled between the first converter leg and the second converter leg; and

a second energy storage device operatively coupled between the first converter leg and the second converter leg.

13. The power conversion system of claim 12, wherein the power conversion system is a modular stacked multi-level power conversion system.

14. The power conversion system of claim 12, wherein each phase unit in the plurality of phase units is operatively coupled in parallel to other phase units in the plurality of phase units.

15. The power conversion system of claim 12, wherein the first converter leg further comprises a fourth switching unit, wherein the second converter leg further comprises a fifth switching unit, and wherein the fifth switching unit is disposed in a reverse orientation with respect to an orientation of the fourth switching unit.

16. The power conversion system of claim 15, further comprising a third energy storage device in a first orientation and a fourth energy storage device in a second orientation operatively coupled between the first converter leg and the second converter leg, and wherein the second orientation is opposite to the first orientation.

17. The power conversion system of claim 12, wherein the power conversion system is a high voltage direct current (HVDC) transmission system, an electrical power transmission, a power distribution system, an electrical machine control system, or a combination thereof

18. The power conversion system of claim 17, wherein the power conversion system comprises an alternating current (AC) to direct current (DC) power conversion system and a direct current (DC) to alternating current (AC) power conversion system.

19. A method for converting power, comprising:

operatively coupling a first switching unit and a second switching unit in series to form a first converter leg, wherein the second switching unit is disposed in a reverse orientation with respect to an orientation of the first switching unit;

operatively coupling a third switching unit and a diode in series to form a second converter leg, wherein the third switching unit is disposed in a reverse orientation with respect to the orientation of the first switching unit;

operatively coupling a first energy storage device and a second energy storage device between the first converter leg and the second converter leg to form a power converter module;

operatively coupling a plurality of power converter modules to form a power conversion system configured to convert an input power to an output power; and

limiting a fault condition in the power conversion system upon identifying the fault condition to minimize a fault current in the power converter.

20. The method of claim 19, wherein limiting the fault condition in the power conversion system comprises:

generating a negative voltage at corresponding electrical terminals of the plurality of power converter modules; and

directing a direct current fault current to flow through a negative voltage path to minimize a direct current fault current in the power conversion system.