Power system for multiple power sources

• US 10,404,071 B2
• Filed: 01/12/2018
• Issued: 09/03/2019
• Est. Priority Date: 03/14/2013
• Status: Active Grant

• Current Assignee: Combined Energies, LLC
• Original Assignee: Combined Energies, LLC
• Inventors: Vogel, John Anthony, Connolly, Eoin
• Primary Examiner(s): Pham, Emily P
• Application Number:
  US15/870,259
• Publication Number:
  US 20180138714A1
• Time in Patent Office: 599 Days
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/0068 Battery or charger load switching, e.g. concurrent charging and load supply H02J7/0013 takes precedence
• 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: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers
• 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 power conversion system comprising:

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

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

a synchronous, multi-leg bridge,

wherein the power conversion system is configured to receive power from a variable, low voltage DC source and convert the power to a more constant, higher voltage DC power.

2. The power conversion system according to claim 1 further including a plurality of DC-AC converters.

3. The power conversion system according to claim 2 further including 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.

4. The power conversion system according to claim 3, wherein each of the plurality of transformers has a turns ratio of greater than 1:

5.

5. The power conversion system according to claim 3, wherein the power conversion system is electronically coupled to an electrical grid and the plurality of transformers are designed and configured to provide isolation from the electrical grid.

6. The power conversion system according to claim 3, wherein the power conversion system includes a plurality of synchronous buck converters, each electrically coupled to a corresponding respective one of the plurality of transformers.

7. The power conversion system according to claim 6, wherein a combined output of the plurality of synchronous buck converters is a continuous output current and a voltage ratio of less than one.

8. The power conversion system according to claim 1, wherein the power conversion system has a boost ratio of greater than 5:

1.

9. The power conversion system according to claim 1, wherein the power conversion system is bi-directional.

10. The power conversion system according to claim 1, wherein conversion efficiency increases as input voltage from the low voltage DC source decreases.

11. The power conversion system according to claim 1, wherein the power conversion system has a configurable boost ratio that varies with a DC-voltage output set point and a DC-voltage input from the low voltage DC source.

12. A method for converting power from a low voltage DC source, comprising:

receiving a low voltage DC signal through an input current filter;

splitting the low voltage DC signal into a plurality of low voltage DC signals;

converting each of the plurality of low voltage DC signals to corresponding ones of a plurality of low voltage AC signals;

converting each of the plurality of low voltage AC signals to corresponding ones of a plurality of higher voltage AC signals;

summing the plurality of higher voltage AC signals to form a high voltage AC signal; and

converting the high voltage AC signal to a high voltage DC signal.

13. The method for converting power according to claim 12, further including outputting the high voltage DC signal to an electrical grid.

14. A power conversion system for converting a variable, low voltage DC signal to a more constant, higher voltage DC signal, the power conversion system comprising:

an input current filter;

a plurality of DC-AC converters electrically coupled to the input current filter;

a plurality of transformers, each of the plurality of transformers electrically coupled to a corresponding respective one of each of the plurality of DC-AC converters;

a plurality of synchronous rectifiers, each of the plurality of synchronous rectifiers electrically coupled to a corresponding respective one of the plurality of transformers;

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

an output filter,

wherein the plurality of DC-AC converters, the plurality of transformers, and the plurality of synchronous rectifiers are configured to form a plurality of interleaved, full-bridge DC-DC boost converters.

15. The power conversion system according to claim 14, wherein each of the plurality of transformers has a turns ratio of greater than 1:

5.

16. The power conversion system according to claim 14, wherein the plurality of DC-DC boost converters collectively have a boost ratio of greater than 5:

1.