Multiple energy storage device controller

• US 6,424,119 B1
• Filed: 04/19/2001
• Issued: 07/23/2002
• Est. Priority Date: 04/19/2001
• Status: Active Grant

• Current Assignee: American Power Conversion Corporation (Schneider Electric SE)
• Original Assignee: American Power Conversion Corporation (Schneider Electric SE)
• Inventors: Hoff, C. Michael, Cohen, Daniel C., Nelson, James E., Hopkins, Philip C.
• Primary Examiner(s): Tso, Edward H.
• Application Number:
  US09/838,757
• Time in Patent Office: 460 Days
• Field of Search: 320/116, 320/118, 320/119, 320/121, 320/122, 320/127, 320/128, 320/135, 320/137
• US Class Current: 320/116
• CPC Class Codes: H02J 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: H02J 9/06 with automatic change-over , e.g. UPS systems

Abstract

A system for controlling multiple energy storage devices in an uninterruptible power supply (UPS) system is provided. In one embodiment of the invention, the system generally includes a charger coupled to a direct current (DC) bus of the UPS system, and two or more energy storage circuits, each of which includes a power regulator coupled to the charger and coupled to the DC bus, at least one energy storage device coupled to the power regulator, and a processor coupled to the power regulator for controlling the charge and discharge of the at least one energy storage device. In another embodiment of the invention, digital communication between two or more controllers is accomplished over the DC bus through use of the Control Area Network (CAN) protocol.

Claims

1. A system for controlling multiple energy storage devices in an uninterruptible power supply (UPS) system, the system comprising:

a charger coupled to a direct current (DC) bus of the UPS system;

two or more energy storage circuits each comprising;

a power regulator coupled to the charger and coupled to the DC bus;

at least one energy storage device coupled to the power regulator; and

a processor coupled to the power regulator for controlling the charge and discharge of the at least one energy storage device.

2. The system of claim 1, wherein each energy storage circuit includes a charger.

3. The system of claim 1, wherein each energy storage circuit further includes a relay coupled in parallel with the converter for bypassing current around the converter.

4. The system of claim 1, wherein each processor digitally communicates with the other processors.

5. The system of claim 4, wherein each processor digitally communicates with the other processors over the DC bus.

6. The system of claim 1, wherein each energy storage circuit further comprises a controller coupled between each processor and the data bus, each controller communicating data to and from the processor coupled thereto and adapting the data to be communicated over the DC bus.

7. The system of claim 6, further comprising an RF transceiver coupled between the controller and the DC bus for receiving and transmitting a modulated RF signal on the DC bus.

8. The system of claim 6, wherein each controller digitally communicates using a control area network protocol.

9. The system of claim 1, further comprising a master processor coupled to the processor on each of the energy storage circuits for controlling each of the processors.

10. The system of claim 1, wherein the master processor digitally communicates with the other processors using a control area network protocol.

11. The system of claim 1, wherein for each energy storage circuit the processor has code embedded therein for carrying out the step of charging or discharging the at least one energy storage device of the energy storage circuit for causing a voltage level of the energy storage device to be equal to a voltage level of the DC bus.

12. The system of claim 1, wherein the processor has code embedded therein for causing the voltage on the DC bus to be indicative of an average state of charge of each of the energy storage devices.

13. The system of claim 12, wherein a first voltage range of the DC bus indicates that one or more of the energy storage devices is being charged and a second voltage range of the DC bus indicates that one or more of the energy storage devices is being discharged.

14. The system of claim 13, wherein the DC bus has a third voltage range being between the first and the second voltage ranges which indicates that each energy storage device is neither being charged nor discharged.

15. The system of claim 13, wherein the DC bus has a fourth voltage range being above the first and the second voltage ranges which indicates that the at least one energy storage devices are at a greater than capacity level.

16. The system of claim 15, further comprising the UPS system.

17. A system for controlling multiple energy storage devices in an uninterruptible power supply (UPS) system, the system comprising:

a charger coupled to a direct current (DC) bus of the UPS system;

a master processor; and

two or more energy storage circuits each comprising;

a DC to DC converter coupled to the charger and coupled to the DC bus;

at least one energy storage device coupled to the converter;

a processor coupled to the DC to DC converter that controls the charge and discharge of the at least one energy storage device; and

a controller coupled between the processor and the DC bus, the controller for communicating data to and from the process and communicates the date over the DC bus;

wherein the master processor is coupled to the processor on each of the energy storage circuits for controlling each of the processors.

18. The system of claim 17, further comprising one or more chargers, wherein each energy storage circuit includes a charger.

19. The system of claim 17, wherein each energy storage circuit further includes a relay coupled in parallel with the converter for bypassing current around the converter.

20. The system of claim 17, wherein each processor digitally communicates with the other processors using a control area network protocol.

21. The system of claim 17, further comprising an RF transceiver coupled between the controller and the DC bus for receiving and transmitting a modulated RF signal on the DC bus.

22. The system of claim 17, wherein for each energy storage circuit, the processor has code embeded therein for carrying out the method of charging or discharging the energy storage device of the energy storage circuit for causing a voltage level of the energy storage device equal to a voltage level of the DC bus.

23. The system of claim 17, wherein the processor has code embeded therein for causing the voltage on the DC bus to be indicative of an average state of charge of each of the energy storage devices.

24. The system of claim 23, wherein a first voltage range of the DC bus indicates that one or more of the energy storage devices is being charged and a second voltage range of the DC bus indicates that one or more of the energy storage devices is being discharged.

25. The system of claim 23, wherein the DC bus has a third voltage range being between the first and the second voltage ranges which indicates that each energy storage device is neither being charged nor discharged.

26. The system of claim 23, wherein the DC bus has a fourth voltage range being above the first and the second voltage ranges which indicates that the at least one energy storage devices are at a greater than capacity level.

27. The system of claim 17, further comprising the UPS system.

28. A method for controlling multiple energy devices in an uninterruptible power supply (UPS) system having an internal DC bus, the method comprising:

controlling a flow of energy from the DC bus to at least one of the energy devices to charge the at least one of the energy devices; and

controlling a flow of energy from the at least one of the energy devices to the DC bus to provide power from the energy device to the DC bus during a battery mode of operation of the UPS.

29. The method of claim 28, further comprising providing a regulator between the DC bus and the at least one of the energy devices.

30. The method of claim 29, further comprising bypassing current around the regulator if the power regulator malfunctions.

31. The method of claim 28, further comprising:

controlling a flow of energy from the DC bus to a second of the energy devices to charge the second of the energy devices; and

controlling a flow of energy from the second of the energy devices to the DC bus to provide power from the energy device to the DC bus during a battery mode of operation of the UPS.

32. The method of claim 31, wherein the controlling of the at least one energy device and the second energy device is done by using a first processor and a second processor, respectively.

33. The method of claim 28, further comprising communicating between the first processor and the second processor over the DC bus.

34. The method of claim 28, further comprising using RF signals to communicate over the DC bus between the first processor and the second processor.

35. The method of claim 28, the method further comprising charging and discharging the energy storage device of the energy storage circuit for causing a voltage level of the energy storage device equal to a voltage level of the DC bus.

36. The method of claim 28, the method further comprising controlling the DC bus to have a first voltage range which indicates that one or more of the energy storage devices is being charged and a second voltage range of the DC bus which indicates that one or more of the energy storage devices is being discharged.

37. The method of claim 36, the method further comprising controlling the DC bus to have a third voltage range being between the first and the second voltage ranges which indicates that each energy storage device is neither being charged nor discharged.

38. The method of claim 36, the method further comprising controlling the DC bus to have a fourth voltage range being above the first and the second voltage ranges which indicates that the at least one energy storage devices are at a greater than capacity level.

39. A system for controlling multiple energy storage devices in an uninterruptible power supply (UPS) system, the system comprising:

a charger coupled to a direct current (DC) bus of the UPS system;

two or more energy storage circuits each comprising;

a power regulator coupled to the charger and coupled to the DC bus;

at least one energy storage device coupled to the power regulator; and

means for controlling a charge and a discharge of at least one energy storage device.

40. The system of claim 39, wherein each of the means for controlling the charge and the discharge of the at least one energy storage device communicate with each other.

41. The system of claim 39, further comprising means for communicating over the DC bus.