DC-DC and DC-AC power conversion system

• US 7,787,270 B2
• Filed: 06/06/2007
• Issued: 08/31/2010
• Est. Priority Date: 06/06/2007
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: NadimpalliRaju, Ravisekhar, Stevanovic, Ljubisa Dragoljub, Ritter, Allen Michael, Datta, Rajib, Zhang, Richard S.
• Primary Examiner(s): Sterrett; Jeffrey L
• Assistant Examiner(s): Finch, III; Fred E
• Application Number:
  US11/810,825
• Publication Number:
  US 20080304296A1
• Time in Patent Office: 1,182 Days
• Field of Search: 363/34, 363 36- 37, 363/65, 363 67- 71
• US Class Current: 363/68
• CPC Class Codes: H02J 4/00 Circuit arrangements for mains or distribution networks not specified as ac or dc
• CPC Class Codes: H02M 1/007 Plural converter units in cascade push-pull DC/DC converters with pre-regulator H02M3/3374; DC-AC converters following a DC-DC stage including a high frequency transformer H02M7/4807; DC-AC converters following a DC-DC conversion stage generating periodically varying voltages H02M7/4826
• CPC Class Codes: H02M 1/14 Arrangements for reducing ripples from dc input or output
• CPC Class Codes: H02M 7/217 using semiconductor devices only

Abstract

A galvanic isolated DC-DC and DC-AC power conversion system is coupled to a plurality of DC sources which are derived from a combination of a plurality of single-phase and three-phase AC-DC converters. The DC-DC and DC-AC power conversion system in one embodiment is configured to provide mixed type outputs (mixed frequency, e.g. DC with 50 or 60 Hz, with 400 Hz; mixed voltage levels).

Claims

1. A galvanic isolated DC-DC or DC-AC power conversion system coupled to a plurality of non-isolated DC sources which are derived from a combination of a plurality of single-phase and three-phase AC-DC rectifiers, each single-phase and three-phase AC-DC rectifier feeding a galvanically isolated DC-DC converter configured with a high frequency transformer to provide intermediate stage galvanic isolation.

2. The galvanic isolated DC-DC or DC-AC power conversion system according to claim 1, wherein each galvanically isolated DC-DC converter is controlled to provide a constant DC output.

3. The galvanic isolated DC-DC or DC-AC power conversion system according to claim 1, wherein switching patterns of the galvanically isolated DC-DC converters cause interleaving of parallel DC-DC converter signals to minimize electromagnetic interference.

4. The galvanic isolated DC-DC or DC-AC power conversion system according to claim 1, wherein each galvanically isolated DC-DC converter is controlled to transfer ripple power at twice the fundamental frequency of a respective upstream single-phase AC-DC rectifier, such that DC link capacitors employed to buffer the ripple can be minimized.

5. The galvanic isolated DC-DC or DC-AC power conversion system according to claim 1, wherein each galvanically isolated DC-DC converter is configured with a phase-shifted, soft-switching PWM bridges to reduce associated semiconductor device switching stresses.

6. The galvanic isolated DC-DC or DC-AC power conversion system according to claim 1, wherein each galvanically isolated DC-DC converter is configured with semiconductor switches that operate in a synchronous rectification or bidirectional mode to allow reduction of semiconductor components and conduction losses.

7. The galvanic isolated DC-DC or DC-AC power conversion system according to claim 1, wherein any galvanically isolated DC-DC converter associated with an internal or external fault is isolated or bypassed, with controls of the remaining galvanically isolated DC-DC converters readjusted to allow continued operation of the power conversion system.

8. The galvanic isolated DC-DC or DC-AC power conversion system according to claim 1, wherein each galvanically isolated DC-DC converter comprises silicon semiconductors or silicon-carbide semiconductors or mix of SiC and Si power semiconductors that provide high frequency or high temperature operation.

9. The galvanic isolated DC-DC or DC-AC power conversion system according to claim 1, wherein each or some galvanically isolated DC-DC converters are controlled to provide a half-sinusoidal DC voltage waveform at a DC link of a direct AC inverter that results from a sinusoidal high frequency modulated waveform at a high frequency transformer and filtering action with leakage inductance of the high frequency transformer and/or with additional inductance and a DC link capacitor of the direct AC inverter.

10. The galvanic isolated DC-DC or DC-AC power conversion system according to claim 1, wherein the plurality of DC sources are configured to feed a common DC output through the galvanically isolated DC-DC converters that are configured in parallel at a common DC output.

11. The galvanic isolated DC-DC or DC-AC power conversion system according to claim 10, wherein the common DC output of the galvanically isolated DC-DC converters is further coupled to a DC-AC inverter to provide single-phase or three-phase AC power.

12. The galvanic isolated DC-DC or DC-AC power conversion system according to claim 11, wherein switching patterns of the galvanically isolated DC-DC converters cause interleaving of parallel DC-DC converter signals to minimize electromagnetic interference and switching ripple at the common DC output with reduced filtering needs.

13. The galvanic isolated DC-DC or DC-AC power conversion system according to claim 11, wherein each galvanically isolated DC-DC converter is controlled to transfer ripple power at twice the fundamental frequency from a respective upstream single-phase AC-DC rectifier, such that DC link capacitors employed to buffer the ripple can be minimized.

14. The galvanic isolated DC-DC or DC-AC power conversion system according to claim 11, wherein the galvanically isolated DC-DC converters employ phase-shifted, soft-switching PWM bridges to reduce switching stresses in associated semiconductor devices.

15. The galvanic isolated DC-DC or DC-AC power conversion system according to claim 11, wherein the galvanically isolated DC-DC converters employ semiconductor switches in a synchronous rectification or bidirectional mode to allow reduction of semiconductor components and conduction losses.

16. The galvanic isolated DC-DC or DC-AC power conversion system according to claim 11, wherein the galvanically isolated DC-DC converters comprise silicon semiconductors or silicon-carbide semiconductors or mixed SiC and Si power switches that provide high frequency and/or high temperature operation.

17. The galvanic isolated DC-DC or DC-AC power conversion system according to claim 11, wherein any galvanically isolated DC-DC converter associated with an internal or external fault is isolated or bypassed, with controls of the remaining galvanically isolated DC-DC converters readjusted to allow continued operation of the power conversion system.

18. The galvanic isolated DC-DC or DC-AC power conversion system according to claim 1, wherein each galvanically isolated DC-DC converter is controlled to provide a constant DC output or a half-sinusoidal DC voltage waveform at a DC link of a direct AC inverter such that the power conversion system provides mixed type outputs selected from mixed frequency and/or mixed voltage levels.

19. The galvanic isolated DC-DC or DC-AC power conversion system according to claim 18, wherein the mixed frequency output frequencies are selected from DC, 50 Hz, 60 Hz, and 400 Hz.

20. A galvanic isolated DC-DC or DC-AC power conversion system coupled to a plurality of non-isolated DC sources which are derived from a combination of three single-phase and three-phase AC-DC rectifiers, wherein the single-phase and three-phase AC-DC rectifiers together comprise a mixed silicon-carbide (SiC) and silicon (Si) device topology, each single-phase and three-phase AC-DC rectifier feeding a galvanically isolated DC-DC converter configured with a high frequency transformer to provide intermediate stage galvanic isolation.

21. The galvanic isolated DC-DC or DC-AC power conversion system according to claim 20, wherein each galvanically isolated DC-DC converter is controlled to provide a either constant DC or desired frequency AC modulated DC voltage output, and further wherein each galvanically isolated DC-DC converter comprises all SiC or mixed SiC and Si devices.

22. A galvanic isolated DC-DC or DC-AC power conversion system coupled to a plurality of non-isolated DC sources which are derived from a combination of a plurality of single-phase and three-phase AC-DC rectifiers, each single-phase and three-phase AC-DC rectifier feeding a galvanically isolated DC-DC converter configured with a high frequency transformer to provide intermediate stage galvanic isolation, wherein each galvanically isolated DC-DC converter comprises a pulse width modulated MOSFET H-bridge with all silicon-carbide (SiC) power switches or mixed SiC and Si power switches.

23. The galvanic isolated DC-DC or DC-AC power conversion system according to claim 22, wherein each galvanically isolated DC-DC converter comprises all SiC or mixed SiC and Si devices.