Apparatus and method for employing a DC source with an uninterruptible power supply

• US 7,652,393 B2
• Filed: 09/14/2006
• Issued: 01/26/2010
• Est. Priority Date: 09/14/2006
• Status: Active Grant

• Current Assignee: American Power Conversion Corporation (Schneider Electric SE)
• Original Assignee: American Power Conversion Corporation (Schneider Electric SE)
• Inventors: Moth, Klaus
• Primary Examiner(s): Fureman; Jared J
• Assistant Examiner(s): RUTLAND WALLIS, MICHAEL
• Application Number:
  US11/521,068
• Publication Number:
  US 20080067872A1
• Time in Patent Office: 1,230 Days
• Field of Search: 307/23, 307/64, 307/65, 307/66
• US Class Current: 307/64
• CPC Class Codes: H02J 9/062 for AC powered loads
• CPC Class Codes: Y02B 10/70 Hybrid systems, e.g. uninterruptible or back-up power supplies integrating renewable energies

Abstract

At least one aspect is directed to an uninterruptible power supply including an I/O and an output in electrical communication with the I/O. The UPS also includes electronic circuitry which is adapted to, in a first mode of operation, receive power from the I/O and convert the AC power to DC power. The electronic circuitry is also adapted to, in a second mode of operation, receive DC power and to provide AC power to the I/O. The electronic circuit is further adapted to, in the first mode of operation, convert the DC power to AC power and to provide the AC power at the output.

Claims

1. An uninterruptible power supply comprising:

an AC I/O;

an output in electrical communication with the AC I/O;

electronic circuitry coupled to the AC I/O and the output and comprising a first circuit and a second circuit, wherein the first circuit includes a DC I/O and an input coupled to the DC I/O via the first circuit, the input adapted to be connected to a battery;

a DC bus including a positive bus and a negative bus each coupled to the DC I/O, wherein the DC bus couples the first circuit to the second circuit; and

a DC power source, different than the battery, coupled to the DC bus,

wherein the first circuit is adapted to, in a first mode of operation, receive AC power from the AC I/O and convert the AC power to DC power, and in a second mode of operation, receive DC power from the DC power source at the DC I/O, convert the DC power to AC power and provide AC power to the AC I/O, and

wherein the second circuit is further adapted to, in the first mode of operation, convert the DC power to AC power and provide the AC power at the output.

2. The uninterruptible power supply of claim 1, wherein the electronic circuitry is further adapted to receive power from an external AC power source in the first mode of operation.

3. The uninterruptible power supply of claim 1, wherein the DC power source comprises an extended-runtime DC source.

4. The uninterruptible power supply of claim 1, wherein the second circuit is adapted to receive DC power from the DC power source and provide AC power to the output in the second mode of operation.

5. The uninterruptible power supply of claim 1, wherein, in the second mode of operation, the electronic circuitry is configured to supply power to a first load from the AC I/O and supply power to a second load from the output.

6. The uninterruptible power supply of claim 5, wherein, in the first mode of operation, an external AC power source is configured to supply power to both the first load and the AC I/O.

7. The uninterruptible power supply of claim 1, wherein the electronic circuitry is further adapted to draw a current from the AC power source that is substantially in phase with a voltage of the AC power source.

8. The uninterruptible power supply of claim 1, wherein the first circuit comprises a circuit that is configured to operate as a boost converter in the first mode of operation, and wherein at least a portion of the circuit that is configured to operate as the boost converter is also configured to be included in a buck converter circuit in the second mode of operation.

9. The uninterruptible power supply of claim 8, wherein the first circuit comprises a rectifier coupled to the AC I/O, and wherein the first circuit is adapted to bypass the rectifier during the second mode of operation.

10. The uninterruptible power supply of claim 8, wherein the at least a portion of the circuit comprises an inductor, wherein the inductor is employed in the first circuit to store energy from at least one of the battery and the AC power source in the first mode of operation, and wherein the inductor is employed in the first circuit to store energy from the DC power source in the second mode of operation.

11. The uninterruptible power supply of claim 8, wherein the first circuit comprises a first boost circuit coupled to the positive bus and a second boost circuit coupled to the negative bus, and wherein the first circuit further comprises a first buck circuit coupled to the positive bus and a second buck circuit coupled to the negative bus.

12. The uninterruptible power supply of claim 10, wherein the first circuit comprises a switch coupled in series between the DC bus and the inductor, and wherein the switch is operated to couple the inductor to the DC power source in the second mode of operation.

13. The uninterruptible power supply of claim 10, wherein the first circuit includes power factor correction circuitry.

14. The uninterruptible power supply of claim 10, wherein the first circuit comprises a rectifier coupled to the AC I/O and the inductor, and a switch connected in parallel to the rectifier, wherein the switch is configured to bypass the rectifier in the second mode of operation.

15. A method of supplying power to two or more electrical loads using an AC power source and an uninterruptible power supply that includes an AC I/O, an output, a first module in electrical communication with the AC I/O and including a DC I/O and an input coupled to the DC I/O via the first module, a second module in electrical communication with the output of the uninterruptible power supply, and a DC bus including a positive bus and a negative bus each coupled to the DC I/O, the method comprising acts of:

supplying, in a first mode of operation, power from the AC power source to the AC I/O of the uninterruptible power supply;

supplying power from the AC power source to a first load in the first mode of operation;

supplying power to a second load from the output of the uninterruptible power supply in the first mode of operation;

supplying, in a second mode of operation, power to the first load from the AC I/O of the uninterruptible power supply;

supplying power from at least one of a battery power source and the AC power source to the first module in a first mode of operation, wherein the battery power source is connected to the input of the first module;

supplying, in the first mode of operation, power from the battery to the DC I/O via the first module and from the DC I/O to the second module via the DC bus; and

supplying power from a DC power source, different than the battery power source, to both the first load and the second load in the second mode of operation, wherein the DC power source is connected to the DC bus.

16. The method of claim 15, further including circuitry connected to the AC I/O that is configured to provide for 4-quadrant operation of the UPS.

17. The method of claim 15, further comprising an act of supplying power to the second load from the output of the uninterruptible power supply in the second mode of operation.

18. The method of claim 17, wherein the DC power source is an extended-runtime DC source.

19. The method of claim 18, wherein the DC power source is at least one of a DC generator, a fuel cell, and a photovoltaic power source.

20. The method of claim 15, further comprising detecting loss of power from the AC power source and providing power from a DC generator to the first load and the second load.

21. The method of claim 20, wherein the method further comprises an act of providing power from the DC generator to the DC bus.

22. The method of claim 17 further comprising an act of determining whether the DC power source has a capacity to supply power to the first load and the second load.

23. The method of claim 22 further comprising an act of entering the second mode of operation when it is determined that the DC power source has the capacity to supply power to the first load and the second load.

24. A UPS system for supplying power to two or more electrical loads, the system comprising:

an AC I/O adapted to connect to a first power source and a first load;

a first circuit including a DC I/O adapted to connect to a second power source and an input coupled to the DC I/O via the first circuit, the input adapted to connect to a battery;

an output adapted to connect to a second load;

a second circuit adapted to convert DC power from a DC power source, different than the battery, to AC power and provide AC power at the output;

a DC bus including a positive bus and a negative bus each coupled to the DC I/O, wherein the DC bus couples the first circuit to the second circuit; and

means for receiving power from the first power source via the AC I/O during a first mode of operation, and supplying power from the second power source to the first load via the AC I/O during a second mode of operation,

wherein the system is adapted to supply power from the output to the second load during both the first mode of operation and the second mode of operation.

25. The UPS system of claim 24, further comprising a circuit that is configured to operate as a boost converter in the first mode of operation, and wherein at least a portion of the circuit that is configured to operate as the boost converter is also configured to operate as a buck converter in the second mode of operation.

26. The UPS system of claim 25, wherein the at least a portion of the circuit comprises an inductor, wherein the inductor is employed to store energy from at least one of the battery and the first power source in the first mode of operation, and wherein the inductor is employed to store energy from the second power source in the second mode of operation.

27. The UPS system of claim 26, further comprising a switch coupled in series between the DC bus and the inductor, and wherein the switch is operated to couple the inductor to the second power source in the second mode of operation.

28. The UPS system of claim 26, further comprising a rectifier coupled to the AC I/O and the inductor, and a switch connected in parallel to the rectifier, wherein the switch is configured to bypass the rectifier in the second mode of operation.

29. The UPS system of claim 24, wherein the AC I/O is adapted for connection to an AC power source, and wherein the DC I/O is adapted for connection to the DC power source.

30. The UPS system of claim 29, wherein the DC I/O is adapted for connection to an extended-runtime DC power source.

31. The UPS system of claim 29, wherein the DC I/O is adapted for connection to a DC generator.

32. The UPS system of claim 24, wherein the means for receiving power includes means for drawing a current from the first power source that is substantially in phase with a voltage of the first power source.

33. The UPS system of claim 32 wherein during the first mode of operation the means for receiving power operates as a boost converter, and wherein during the second mode of operation the means for receiving power operates as a buck converter.

34. The UPS system of claim 33, wherein the means for receiving power includes a rectifier wherein the rectifier is bypassed during the second operation.

35. The UPS system of claim 24, further comprising:

means for converting DC power to AC power which is supplied to the output,

wherein the DC power which is converted includes DC power supplied from at least one of the battery, the second power source, and the means for receiving power.