Power conversion system with a DC to DC boost converter

• US 9,413,271 B2
• Filed: 03/02/2014
• Issued: 08/09/2016
• Est. Priority Date: 03/14/2013
• Status: Active Grant

• Current Assignee: Combined Energies, LLC
• Original Assignee: Combined Energies, LLC
• Inventors: Vogel, John Anthony
• Primary Examiner(s): Pham, Emily P
• Application Number:
  US14/194,773
• Publication Number:
  US 20140268931A1
• Time in Patent Office: 891 Days
• US Class Current: 1/1
• CPC Class Codes: H02M 3/285 Single converters with a plurality of output stages connected in parallel parallel operation of a plurality of converters in dc distribution networks H02J1/10
• CPC Class Codes: H02M 3/3376 with automatic control of output voltage or current
• CPC Class Codes: H02M 7/539 with automatic control of output wave form or frequency H02M7/5375 - H02M7/5387 take precedence
• CPC Class Codes: Y02E 10/76 Power conversion electric or electronic aspects

Abstract

A voltage booster allowing for increased utilization of low voltage, high current, unregulated DC power (“LVDC source”), such as, but not limited to, fuel cells, batteries, solar cells, wind turbines, and hydro-turbines. LVDC generation systems employing a variable low voltage DC-DC converter of the present disclosure may be used without a power inverter in applications requiring high voltage DC inputs and can also allow for the employment of common, low cost, reliable, low voltage energy storage chemistries (operating in the 12-48 VDC range) while continuing to employ the use of traditional inverters designed for high voltage power supplies. An embodiment of the DC boost converter includes a plurality of interleaved, isolated, full-bridge DC-DC converters arranged in a Delta-Wye configuration and a multi-leg bridge.

Claims

1. A DC to DC boost converter (DDBC) for converting power received from a variable, low voltage DC source, the DDBC comprising:

a plurality of interleaved, isolated, full-bridge DC-DC converters arranged in a Delta-Wye configuration and a multi-leg bridge;

an input current filter and a plurality of DC-AC converters, wherein said plurality of DC-AC converters are electronically coupled to said input current filter and configured to receive a discontinuous input current; and

a plurality of transformers, wherein each of said plurality of transformers is electronically coupled to a corresponding respective one of said plurality of DC-AC converters.

2. The DDBC according to claim 1, wherein the DDBC has a boost ratio of greater than 5:

1.

3. The DDBC according to claim 1, wherein the DDBC converter is bi-directional.

4. The DDBC according to claim 1, wherein the DDBC conversion efficiency increases as the DC input voltage decreases.

5. The DDBC according to claim 1, wherein the DDBC has a configurable boost ration that varies with a DCV output set point and a DCV input from the variable, low voltage DC source.

6. The DDBC according to claim 1, further including a control system, said control system designed and configured to de-rate the power conversion system to a lower power rating.

7. The DDBC according to claim 6, wherein said control system includes a control loop and a feedback loop, wherein said control loop monitors a continuous current output and a discontinuous input current and determines a power draw command based upon said continuous current output and said discontinuous input current, and wherein said feedback loop regulates said continuous current output.

8. The DDBC according to claim 1, wherein each of said plurality of transformers has a turns ratio greater than 1:

5.

9. The DDBC according to claim 1, wherein the DDBC is electronically coupled to an electrical grid and said plurality of transformers are designed and configured to provide isolation from the electrical grid.

10. The DDBC according to claim 1, wherein the DDBC further includes a plurality of synchronous buck converters electrically coupled to a corresponding respective one of said plurality of transformers.

11. The DDBC according to claim 10, wherein the combined output of said plurality of synchronous buck converters is a continuous output current and a voltage ratio of less than one.

12. A power conversion system having a power rating, the power conversion system comprising:

a low voltage power source having an initial output voltage;

a DC-DC boost converter (DDBC) coupled to said power source; and

an inverter coupled to said DC-DC boost converter, wherein said DC-DC boost converter is designed and configured to provide a continuous output current, a voltage ratio less than one, and to receive a discontinuous input current; and

a control system, said control system designed and configured to de-rate the power conversion system to a lower power rating, and wherein said control system includes a control loop and a feedback loop, wherein said control loop monitors said continuous current output and said discontinuous input current and determines a power draw command based upon said continuous current output and said discontinuous input current, and wherein said feedback loop regulates said continuous current output.

13. The power conversion system according to claim 12, wherein said DDBC extends the useful life of said low voltage power source.

14. The power conversion system according to claim 13, wherein said DDBC provides said continuous output current to said inverter when said low voltage power source has a reduced output voltage, said reduced output voltage being as much as about 80% of said initial output voltage.

15. The power conversion system according to claim 12, wherein said DDBC is a plurality of interleaved, isolated, full-bridge DC-DC converters arranged in a Delta-Wye configuration that is followed by multi-leg bridge.

16. The power conversion system according to claim 12, wherein said DDBC improves power conversion of power from said low voltage power source as the voltage of said low voltage power source decreases.

17. The power conversion system according to claim 12, wherein said DDBC includes a plurality of interleaved, isolated, fullbridge DC-DC converters arranged in a Delta-Wye configuration and a multi-leg bridge.

18. The power conversion system according to claim 17, wherein said DDBC further includes an input current filter, a plurality of DC-AC converters, and a plurality of transformers, wherein said plurality of DC-AC converters are electronically coupled to said input current filter and wherein each of said plurality of transformers is electronically coupled to a corresponding respective one of said plurality of DC-AC converters.

19. The power conversion system according to claim 12, wherein said low voltage power source is a fuel cell.

20. The power conversion system according to claim 12, wherein said low voltage power source is a battery.