Topologies for multiple energy sources

• US 20040100149A1
• Filed: 11/22/2002
• Published: 05/27/2004
• Est. Priority Date: 11/22/2002
• Status: Active Grant

• Current Assignee: Virginia Tech Intellectual Properties, Inc.
• Original Assignee: Virginia Tech Intellectual Properties, Inc.
• Inventors: Lai, Jih-Sheng
• Granted Patent: US 7,138,730 B2
• Time in Patent Office: Days
• US Class Current: 307/82
• CPC Class Codes: H02J 9/062 for AC powered loads
• CPC Class Codes: H02M 1/0074 Plural converter units whose inputs are connected in series
• CPC Class Codes: H02M 3/1582 Buck-boost converters H02M3/1584 takes precedence
• CPC Class Codes: H02M 7/5387 in a bridge configuration

Abstract

A boost converter and a buck-boost converter supply power to a load from a series connection between a first and a second power source.

Claims

1. A system comprising:

a first power source having a first-source positive terminal and a first-source negative terminal;

a second power source having a second-source positive terminal and a second-source negative terminal;

an output capacitor having an output-capacitor positive terminal operably coupled with the second-source positive terminal and an output-capacitor negative terminal operably coupled with the first-source negative terminal;

a series electrical connection between the first-source positive terminal and the second-source negative terminal;

a boost converter having a boost-converter input operably coupled with the series electrical connection and the first-source negative terminal, and a boost-converter output operably coupled with the output-capacitor positive and negative terminals; and

a buck-boost converter having a buck-boost-converter input operably coupled with the series electrical connection and the second-source positive terminal, and a buck-boost-converter output operably coupled with the output-capacitor positive and negative terminals.

2. The system of claim 1 wherein the boost converter and the buck-boost converter share an inductor electrically connected with the series electrical connection.

3. The system of claim 1 wherein the boost converter having a boost-converter input operably coupled with the series electrical connection and the first-source negative terminal, and a boost-converter output operably coupled with the output-capacitor positive and negative terminals comprises:

a first diode having a first-diode anode (+) and a first-diode cathode (−

), the first-diode cathode (−

) operably coupled with the output-capacitor positive terminal;

a first switch operably coupled between the first diode anode (+) and the first-source negative terminal; and

an inductor operably coupled between the series electrical connection and the first-diode anode (+).

4. The system of claim 1 wherein the buck-boost converter having a buck-boost converter input operably coupled with the series electrical connection and the second-source positive terminal, and a buck-boost converter output operably coupled with the output-capacitor positive and negative terminals comprises:

a first diode having a first-diode anode (+) and a first-diode cathode (−

), the first-diode anode (+) operably coupled with the output-capacitor negative terminal;

a first switch operably coupled between the first diode cathode (−

) and the second-source positive terminal; and

an inductor operably coupled between the series electrical connection and the first-diode cathode (−

).

5. The system of claim 1, further comprising:

a switch of the buck-boost converter operably coupled with a diode of the boost converter such that the diode of the boost converter is not forward biased when the switch of the buck-boost converter is transferring current.

6. The system of claim 1, further comprising:

a switch of the boost converter operably coupled with a diode of the buck-boost converter such that the diode of the buck-boost converter is not forward biased when the switch of the boost converter is transferring current.

7. The system of claim 1, further comprising:

an energy storage component connected in electrical parallel with the first power source.

8. The system of claim 7, further comprising:

a bi-directional dc-dc converter having an input operably coupled with the first power source and an output operably coupled with the energy storage component.

9. The system of claim 1, further comprising:

an energy storage component connected in electrical parallel with the second power source.

10. The system of claim 9, further comprising:

a bi-directional dc-dc converter having an input operably coupled with the second power source and an output operably coupled with the energy storage component.

11. The system of claim 1, further comprising:

a 3-phase inverter operably coupled with the output capacitor.

12. The system of claim 1 wherein the first power source comprises:

at least one of a fuel cell, a battery, an electrolytic capacitor, and an ultra capacitor.

13. The system of claim 1 wherein the second power source comprises:

at least one of a fuel cell, a battery, an electrolytic capacitor, and an ultra capacitor.

14. An electrical power supply to supply electrical power between a first power source, a second power source, and a load, the electrical power supply comprising:

a first node couplable to the first power source;

a second node couplable to the second power source, the second node in series connection with the first node;

a third node couplable to the load;

a boost converter coupled between the first node and the third node; and

a buck-boost converter coupled between the second node and the third node, wherein the buck-boost converter is operable to provide power from the second node to the third node at a first time, and the boost converter is operable to provide power from the first node to the third node at a second time.

15. The electrical power supply of claim 14 wherein the second power source is rechargeable.

16. The electrical power supply of claim 14 wherein the buck-boost converter is further operable to provide power from the third node to the second node at a third time.

17. The electrical power supply of claim 14, further comprising:

an inverter electrically coupled between the third node and the boost and the buck-boost converters.

18. A system for use with a first power source and a second power source, said system comprising:

a boost converter having a boost-converter-input positive terminal and a boost-converter-input negative terminal and boost-converter-output terminals operably coupled with an output capacitor having output-capacitor positive and negative terminals;

a buck-boost converter having a buck-boost-converter-input positive terminal and a buck-boost-converter-input negative terminal and buck-boost-converter-output terminals operably coupled with the output-capacitor positive and negative terminals; and

a series electrical connection between the boost-converter-input positive terminal and the buck-boost-converter-input negative terminal.

19. The system of claim 18 wherein the boost converter and the buck-boost converter share an inductor electrically connected with the series electrical connection.

20. The system of claim 18 further comprising:

a 3-phase inverter operably coupled with the output capacitor.

21. The system of claim 20 further comprising:

a 3-phase load operably coupled with the 3-phase inverter.

22. The system of claim 18 wherein the first power source comprises:

at least one of a fuel cell, a battery, an electrolytic capacitor, and an ultra capacitor operably coupled with the buck-boost converter.

23. The system of claim 18 wherein the second power source comprises:

at least one of a fuel cell, a battery, an electrolytic capacitor, and an ultra capacitor operably coupled with the buck-boost converter.

24. A method for use with an electrical power supply, the method comprising:

coupling a first-power-source negative terminal with an output-capacitor negative terminal;

coupling a first-power-source positive terminal with a second-power-source negative terminal;

coupling a second-power-source positive terminal with an output-capacitor positive terminal;

coupling a buck-boost converter input with the second-power-source negative terminal and the second-power-source positive terminal;

coupling a buck-boost converter output with the output-capacitor positive and negative terminals;

coupling a boost converter input with the first-power-source positive terminal and the first-power-source negative terminal; and

coupling a boost converter output with the output-capacitor positive and negative terminals.

25. The method of claim 24, further comprising:

coupling a 3-phase inverter with the output capacitor positive and negative terminals.

26. The method of claim 25, further comprising:

coupling a 3-phase load with the 3-phase inverter.

27. A method of providing power comprising:

charging an output capacitor by boosting a first voltage of a series connection between a first-power-source positive terminal and a second-power-source negative terminal when a first power source has output voltage within a defined tolerance; and

charging the output capacitor by boosting and reversing the polarity of a second voltage of the series connection between the first-power-source positive terminal and the second-power-source negative terminal when the first power source has output voltage outside of the defined tolerance.

28. The method of claim 27 wherein the charging an output capacitor by boosting a first voltage of a series connection between a first-power-source positive terminal and a second-power-source negative terminal when a first power source has output voltage within a defined tolerance comprises:

charging the output capacitor with a boost converter when the output voltage of the first power source is greater than or equal to a specified threshold.

29. The method of claim 27 wherein the charging the output capacitor by boosting and reversing the polarity of a second voltage of the series connection between the first-power-source positive terminal and the second-power-source negative terminal when the first power source has output voltage outside of the defined tolerance comprises:

charging the output capacitor with a buck-boost converter when the output voltage of the first power source is less than a specified threshold.

30. The method of claim 27 wherein the first power source comprises:

at least one of a fuel cell, a battery, an electrolytic capacitor, and an ultra capacitor.

31. The method of claim 27 further comprising:

providing the second voltage from a second power source, wherein the second power source includes at least one of a fuel cell, a battery, an electrolytic capacitor, and an ultra capacitor.

32. A method of providing power comprising:

charging an output capacitor by boosting and reversing a polarity of a first voltage of a series connection between a first-power-source positive terminal and a second-power-source negative terminal when a second power source has output voltage within a defined tolerance; and

charging the output capacitor by boosting a second voltage of the series connection between the first-power-source positive terminal and the second-power-source negative terminal when the second power source has output voltage outside of the defined tolerance.

33. The method of claim 32 wherein the charging an output capacitor by boosting and reversing a polarity of a first voltage of a series connection between a first-power-source positive terminal and a second-power-source negative terminal when a second power source has output voltage within a defined tolerance comprises:

charging the output capacitor with a buck-boost converter.

34. The method of claim 32 wherein the charging the output capacitor by boosting a second voltage of the series connection between the first-power-source positive terminal and the second-power-source negative terminal when the second power source has output voltage outside of the defined tolerance comprises:

charging the output capacitor with a boost converter.

35. A system comprising:

a first power source node having a first-node positive terminal and a first-node negative terminal;

a second power source node having a second-node positive terminal and a second-node negative terminal;

an output capacitor having an output-capacitor positive terminal operably coupled with the second-node positive terminal and an output-capacitor negative terminal operably coupled with the first-node negative terminal;

a series electrical connection between the first-node positive terminal and the second-node negative terminal; and

an inductor electrically connected to the series electrical connection, the inductor forming a part of a boost converter and the inductor forming a part of a buck-boost converter.

36. The system of claim 35 wherein the inductor electrically connected to the series electrical connection, the inductor forming a part of a boost converter and the inductor forming a part of a buck-boost converter further comprises:

a boost-converter diode and a boost-converter switch electrically connected with the inductor;

a buck-boost-converter diode and a buck-boost-converter switch electrically connected with the inductor; and

the boost-converter switch connected in electrical parallel with the buck-boost-converter diode such that the buck-boost-converter diode is not forward biased when the boost-converter switch is transferring current.

37. The system of claim 35, wherein the inductor electrically connected to the series electrical connection, the inductor forming a part of a boost converter and the inductor forming a part of a buck-boost converter comprises:

a boost-converter diode and a boost-converter switch electrically connected with the inductor;

a buck-boost-converter diode and a buck-boost-converter switch electrically connected with the inductor; and

the buck-boost-converter switch connected in electrical parallel with the boost-converter diode such that the boost-converter diode is not forward biased when the buck-boost-converter switch is transferring current.

38. The system of claim 35, further comprising:

a 3-phase inverter operably coupled with the output capacitor.

39. The system of claim 35 wherein the first power source node comprises:

a connector configured for detachably connecting to at least one terminal of at least one of a fuel cell, a battery, an electrolytic capacitor, and an ultra capacitor.

40. The system of claim 35 wherein the second power source node comprises:

a connector configured for permanently connecting to at least one terminal of at least one of a fuel cell, a battery, an electrolytic capacitor, and an ultra capacitor.