Power conversion system with galvanically isolated high frequency link

• US 7,679,941 B2
• Filed: 06/06/2007
• Issued: 03/16/2010
• Est. Priority Date: 06/06/2007
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Raju, Ravisekhar Nadimpal, Stevanovic, Ljubisa Dragoljub, Ritter, Allen Michael, Datta, Rajib, Zhang, Richard S.
• Primary Examiner(s): Patel; Rajnikant B
• Application Number:
  US11/810,837
• Publication Number:
  US 20080304300A1
• Time in Patent Office: 1,014 Days
• Field of Search: 363 34- 44, 363/65, 363/72, 363/95, 363/97, 363/132, 363/98, 307/66, 307/105, 307/71
• US Class Current: 363/37
• CPC Class Codes: H02M 1/0074 Plural converter units whose inputs are connected in series
• CPC Class Codes: H02M 1/009 having two or more independently controlled outputs for DC-DC converter with intermediate AC H02M3/33561
• CPC Class Codes: H02M 7/217 using semiconductor devices only
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

A power conversion system has a three-phase AC input, where each AC input phase is linked to a string of cascaded single-phase AC-DC converters placed in series with a three-phase AC-DC converter. Each single-phase AC-DC converter in one embodiment includes a silicon carbide (SiC) pulse width modulated MOSFET H-bridge that placed in series with the three-phase AC-DC converter that includes a silicon (Si) SCR bridge. The single-phase AC-DC converters and the three-phase AC-DC converter together in one embodiment include a mixed silicon-carbide (SiC) and silicon (Si) device topology.

Claims

1. A power conversion system comprising a three-phase AC input, each AC input phase being linked to a string of cascaded single-phase H-bridge converters placed in series with a three-phase AC-DC converter.

2. The power conversion system according to claim 1, wherein each single-phase converter or three-phase converter comprises two-level or multi-level phase legs.

3. The power conversion system according to claim 2, wherein the multi-level phase legs are neutral point clamped or flying capacitor based.

4. The power conversion system according to claim 1, wherein DC outputs from the single-phase and three-phase AC-DC converters are coupled to modular DC-DC switch-mode converters with galvanic isolation.

5. The power conversion system according to claim 4, wherein outputs of the modular DC-DC switch-mode converters with galvanic isolation are connected to a common DC output bus.

6. The power conversion system according to claim 5, wherein the common DC output bus is connected to a DC-AC converter, such that the power conversion system serves as a transformer-like AC-AC converter with galvanic isolation.

7. The power conversion system according to claim 5, wherein the transformer-like AC-AC converter operates as a solid-state transformer or a power electronic transformer.

8. The power conversion system according to claim 4, wherein outputs of the modular DC-DC switch-mode converters with galvanic isolation are configured to provide multiple separately regulated DC outputs.

9. The power conversion system according to claim 4, wherein outputs of the modular DC-DC switch-mode converters with galvanic isolation are inverted to provide AC outputs.

10. The power conversion system according to claim 2, wherein outputs of the modular DC-DC switch-mode converters with galvanic isolation operate to provide multiple separately regulated DC outputs and single-phase or three-phase AC outputs at same or different frequencies to supply multiple load types.

11. The power conversion system according to claim 1, wherein the three-phase AC-DC converter comprises a passive rectifier bridge.

12. The power conversion system according to claim 11, wherein the passive rectifier bridge comprises a plurality of diodes.

13. The power conversion system according to claim 11, wherein the passive rectifier bridge comprises a plurality of silicon controlled rectifiers (SCRs).

14. The power conversion system according to claim 13, wherein SCRs in the passive rectifier bridge operate to limit inrush current during startup.

15. The power conversion system according to claim 1, wherein each single-phase AC-DC converter is configured to use pulse-width-modulated active rectification to allow control of its input AC current waveform.

16. The power conversion system according to claim 1, wherein any one of the single-phase AC-DC converters is bypassed or isolated at its AC input side for faults in the respective AC-DC converter or faults located downstream from the respective AC-DC converter, with controls of the remaining AC-DC converters within the string of AC-DC converters readjusted to allow continued power conversion system operation in the absence of the faulted AC-DC converter.

17. The power conversion system according to claim 1, wherein devices within the AC-DC converters comprise silicon semiconductors or silicon-carbide semiconductors configured for high frequency or high temperature operation.

18. The power conversion system according to claim 1, wherein the three-phase AC-DC converter is configured with active power devices to allow bidirectional power flow.

19. The power conversion system according to claim 18, wherein the active power device are configured within the cascaded single-phase H-bridge and in the three-phase bridge to switch at different frequencies to achieve a desired power quality and efficiency.

20. A power conversion system comprising a three-phase AC input, each AC input phase being linked to a string of cascaded single-phase AC-DC converters comprising a silicon carbide (SiC) pulse width modulated MOSFET H-bridge placed in series with a three-phase AC-DC converter comprising a silicon (Si) SCR bridge.

21. The power conversion system according to claim 20, wherein DC outputs from the single-phase and three-phase AC-DC converters are coupled to modular DC-DC switch-mode converters with galvanic isolation, and wherein the modular DC-DC switch-mode converters including rectifiers comprise a mixed SiC and Si device topology.

22. A power conversion system comprising a three-phase AC input, each AC input phase being linked to a string of cascaded single-phase AC-DC converters placed in series with a three-phase AC-DC converter, wherein the single-phase AC-DC converters and the three-phase AC-DC converter together comprise a mixed silicon-carbide (SiC) and silicon (Si) device topology.

23. The power conversion system according to claim 22, wherein DC outputs from the single-phase and three-phase AC-DC converters are coupled to modular DC-DC switch-mode converters with galvanic isolation, and wherein the modular DC-DC switch-mode converters including rectifiers comprise a mixed SiC and Si device topology.