Power system utilizing flow batteries

• US 7,557,531 B2
• Filed: 12/19/2005
• Issued: 07/07/2009
• Est. Priority Date: 12/19/2005
• Status: Active Grant

• Current Assignee: T-Mobile Innovations LLC (Deutsche Telekom AG)
• Original Assignee: Sprint Communications Company LP (Deutsche Telekom AG)
• Inventors: Johnson, Larry L., Meyers, Jerry, Willets, Julie A.
• Primary Examiner(s): Berhane; Adolf
• Assistant Examiner(s): Fantu; Yalkew
• Application Number:
  US11/313,142
• Publication Number:
  US 20070138872A1
• Time in Patent Office: 1,296 Days
• Field of Search: 320/101, 320/167, 307/66
• US Class Current: 320/101
• CPC Class Codes: H02J 1/10 Parallel operation of dc sources
• CPC Class Codes: H02J 7/345 using capacitors as storage or buffering devices
• CPC Class Codes: H02J 9/061 for DC powered loads
• CPC Class Codes: Y02B 90/10 Applications of fuel cells in buildings

Abstract

The present invention is an energy generating system which uses an advanced aqueous-electrolyte energy storage system in conjunction with a commercial available primary source of power and a backup fuel cell.

Claims

1. A system for maintaining DC power to a circuit comprising:

a conversion device adapted to accept AC power from an AC source and convert said AC power into a primary source of DC power to said circuit in normal mode;

an energy storage device adapted to charge and discharge upon the circulation of a flowable electrolyte through an electrode, said device being included in said circuit as a secondary source of DC power for said circuit, wherein the AC source is connected directly into, and continually charges in normal mode, the energy storage device, and wherein the energy storage device is configured to be persistently on line, thereby automatically discharging to a DC bus when the AC source fails without activation;

a back feed diode that restricts flow from the circuit to the DC bus that presents DC power to facilities telecommunications equipment, thereby preventing dissipation of DC power from the DC bus to the circuit;

a fuel cell that provides DC power to the DC bus in parallel with the circuit when the AC source and the energy storage device can no longer carry load requirements of the DC bus; and

a control system to open automated valves that deliver hydrogen from a tank to the fuel cell upon recognizing that the energy storage device has drained below load requirements of the DC bus.

2. The system of claim 1 wherein the DC bus includes a capacitor which is adapted to bridge during delays in start up of the fuel cell.

3. The system of claim 1 wherein the back feed diode is located between said energy storage device and said fuel cell.

4. The system of claim 1 wherein said back feed diode being located between said capacitor and said energy storage device.

5. The system of claim 1 wherein said fuel cell comprises at least one proton exchange membrane (PEM).

6. The system of claim 1 wherein said energy storage device is a zinc-energy storage system.

7. The system of claim 6 wherein said zinc-bromine energy storage system uses polybromide complexes.

8. A power supply comprising:

a utility-provided primary source of power for at least one power-consuming device in normal mode, wherein the primary source or power provides AC power to a conversion device that converts the AC power to a primary source of DC power which is presented to a circuit;

an advanced aqueous-electrolyte energy storage system for providing a secondary source of DC power to backup said power-consuming device wherein the AC source is connected directly into, and continually charges in normal mode, the energy storage system, and wherein the energy storage system is configured to be persistently on line, thereby automatically discharging to the circuit when the primary source fails without activation;

fuel cells for providing an alternative additional source of backup power when the primary source of power and the energy storage system can no longer carry load requirements of said device; and

a back feed diode that restricts flow from the circuit to the device, thereby preventing dissipation of DC power from the device and the fuel cells to the circuit; and

a control system to open automated valves that deliver hydrogen from a tank to the fuel cells upon recognizing that the energy storage system has drained below load requirements of the power-consuming device.

9. The power supply of claim 8 including capacitors that perform a bridge function during delays in start up of the fuel cells, wherein each of the capacitors is electrically coupled with an output of one of the fuel cells, and wherein the capacitors are continuously charged when any one of the primary source of power, the energy storage system, or the fuel cells are operational.

10. The power supply of claim 9 wherein the back feed diode is interposed between said energy storage system and said capacitors.

11. The power supply of claim 8 wherein said fuel cells comprise at least one proton exchange membrane (PEM).

12. The power supply of claim 8 wherein said energy storage system is a zinc-bromine flow energy storage system.

13. The power supply of claim 12 wherein said zinc-bromine flow energy storage system uses polybromide complexes.

14. The power supply of claim 8 wherein said conversion device is an Insulated Gate Bipolar Transistor (IGTB).

15. The power supply of claim 14 wherein said IGTB is included in said energy storage system.

16. A method of supplying power comprising:

converting AC power provided from a first source to DC power for carrying a load of a power-consuming device in normal mode, wherein the first source comprises an AC utility;

using an advanced aqueous-electrolyte energy storage system as a second source of DC power for said power-consuming device in the event said first source is unavailable, wherein the AC source is connected directly into, and continually charges in normal mode, the energy storage system, and wherein the energy storage system is configured to be persistently on line, thereby automatically discharging to a DC bus when the primary source fails without activation;

providing a back feed diode that restricts flow from the circuit to the DC bus that presents DC power to the power-consuming device; and

providing a fuel cell in connection with the DC bus to provide an alternative third source of DC power for said power-consuming device in the event said first and second sources of DC power are both unavailable; and

providing a control system to open automated valves that deliver hydrogen from a tank to the fuel cell upon recognizing that the energy storage system has drained below load requirements of the power-consuming device.

17. The method of claim 16, wherein the back diode prevents loss of electrical power back into said energy storage system in the event said fuel cell is activated.

18. The method of claim 16 further comprising:

providing a capacitor to temporarily maintain power to said device in the event said first and second sources are unavailable and said fuel cell has not yet become operational.

19. The method of claim 16 further comprising:

using an IGBT to accomplish said converting step.