AC and DC uninterruptible online power supplies

• US 8,203,235 B2
• Filed: 02/18/2009
• Issued: 06/19/2012
• Est. Priority Date: 04/11/2008
• Status: Active Grant

• Current Assignee: Vertiv Corporation (Vertiv Holdings Co.)
• Original Assignee: Liebert Corporation (Vertiv Holdings Co.)
• Inventors: Fox, Bret P., Taylor, Paul, Panfil, Peter A., Shelter, Russell E. Jr.
• Primary Examiner(s): Amrany, Adi
• Application Number:
  US12/388,078
• Publication Number:
  US 20090256422A1
• Time in Patent Office: 1,217 Days
• Field of Search: 307/64
• US Class Current: 307/64
• CPC Class Codes: H02J 9/062 for AC powered loads

Abstract

A power supply includes a rectifier that converts an alternating current input voltage to a first direct current voltage. An inverter that converts the first direct current voltage to an alternating current output voltage. A first set of output terminals that receives the alternating current output voltage. A second set of output terminals that receives the first direct current voltage. A charging circuit that charges a backup power source based on the first direct current voltage. The rectifier receives a second direct current voltage from the backup power source based on the power supply operating in a predetermined condition.

Claims

1. A power supply comprising:

a rectifier that converts an alternating current input voltage to a first direct current voltage;

an inverter that converts the first direct current voltage to an alternating current output voltage;

a first set of output terminals that receives the alternating current output voltage;

a second set of output terminals that receives the first direct current voltage; and

a control module that monitors at least one of voltage, current and power of each of (i) the first set of output terminals and (ii) the second set of output terminals,

wherein the rectifier receives a second direct current voltage from a backup power source based on the power supply operating in a predetermined condition, and

wherein the control module, based on the at least one of voltage, current and power of each of (i) the first set of output terminals and (ii) the second set of output terminals, signals

the rectifier to reduce a first maximum current output of the rectifier while maintaining supply of current out of the rectifier, and

the inverter to reduce a second maximum current output of the inverter while maintaining supply of current out of the inverter.

2. The power supply of claim 1 wherein the first set of output terminals supplies a first load with the alternating current output voltage, and

wherein the second set of output terminals supplies a second load with the first direct current voltage.

3. The power supply of claim 1 wherein the rectifier receives the second direct current voltage when amplitude of the alternating current input voltage is less than a predetermined amplitude.

4. The power supply of claim 1 wherein the rectifier receives the second direct current voltage instead of the alternating current input voltage.

5. The power supply of claim 1 wherein the rectifier receives the second direct current voltage when amplitude of the alternating current input voltage is greater than a predetermined amplitude.

6. The power supply of claim 1 further comprising a direct current bus that is connected between the rectifier and the inverter,

wherein the second set of output terminals is connected to the direct current bus.

7. The power supply of claim 6 further comprising an interrupter that is connected to the second set of output terminals and limits current to a direct current load.

8. The power supply of claim 1 further comprising a bypass circuit that is connected between inputs of the rectifier and outputs of the inverter and that couples the alternating current input voltage to the first set of output terminals when in a bypass condition.

9. The power supply of claim 8 wherein:

the first set of output terminals receives the alternating current input voltage from the inputs of the rectifier when the bypass circuit is in the bypass condition.

10. The power supply of claim 8 further comprising a switch that prevents the alternating current input voltage from being received by the rectifier when the bypass circuit is in the bypass condition coupling the alternating current input voltage to the first set of output terminals.

11. The power supply of claim 1 wherein the rectifier limits current supplied to the inverter.

12. The power supply of claim 1 wherein the rectifier limits current supplied to the second set of output terminals.

13. The power supply of claim 1 wherein the inverter limits current supplied to the first set of output terminals.

14. The power supply of claim 1 wherein at least one of the rectifier and the inverter are controlled to permit current to the second set of output terminals to increase when current to the first set of output terminals is less than a predetermined limit.

15. The power supply of claim 14 wherein at least one of the rectifier and the inverter are controlled to prevent current to the second set of output terminals from increasing when current to the first set of output terminals is greater than or equal to the predetermined limit.

16. The power supply of claim 1 wherein at least one of the rectifier and the inverter are controlled to limit current to the first set of output terminals when current supplied to the first set of output terminals is greater than or equal to a predetermined limit.

17. The power supply of claim 1 wherein at least one of the rectifier and the inverter are controlled to permit current to the first set of terminals to increase when current supplied to the second set of terminals is less than a predetermined limit.

18. The power supply of claim 17 wherein at least one of the rectifier and the inverter are controlled to prevent current to the first set of terminals from increasing when current supplied to the second set of terminals is greater than the predetermined limit.

19. The power supply of claim 1 wherein the rectifier is controlled to limit current to the second set of terminals when current supplied to the second set of terminals is greater than or equal to a predetermined limit.

20. The power supply of claim 1 wherein at least one of the rectifier and the inverter are controlled to limit current to the first set of output terminals and the rectifier is controlled to limit current to the second set of output terminals when a sum of current supplied to the first set of output terminals and current supplied to the second set of output terminals is greater than a predetermined limit.

21. The power supply of claim 20 wherein at least one of the rectifier and the inverter are controlled to not limit current to the first set of output terminals and the rectifier is controlled to not limit current to the second set of output terminals when a sum of current supplied to the first set of output terminals and current supplied to the second set of output terminals is less than or equal to the predetermined limit.

22. The power supply of claim 1 further comprising:

a first relay connected to the first set of output terminals; and

a second relay connected to the second set of output terminals,

wherein the control module selectively controls the first relay and the second relay to selectively provide current to at least one of the first set of output terminals and the second set of output terminals.

23. The power supply of claim 1 further comprising a charging circuit that charges the backup power source based on the first direct current voltage.

24. The power supply of claim 1 wherein:

the rectifier supplies current to the inverter and the second set of output terminals when the control module signals the rectifier to limit the current output of the rectifier; and

the inverter supplies current to the first set of output terminals when the control module signals the inverter to limit the current output of the inverter.

25. The power supply of claim 1 wherein:

the first set of output terminals provides the alternating current output voltage to a first load;

the second set of output terminals provides the first direct current voltage to a second load; and

the backup power source is separate from the second load.

26. The power supply of claim 1 wherein the rectifier limits the current of the rectifier while the inverter limits the current output of the inverter.

27. A power supply comprising:

a rectifier that converts an alternating current input voltage to a first direct current voltage;

an inverter that converts the first direct current voltage to an alternating current output voltage;

a first set of output terminals that receives the alternating current output voltage;

a second set of output terminals that receives the first direct current voltage;

wherein the rectifier receives a second direct current voltage from a backup power source based on the power supply operating in a predetermined condition, and

wherein the rectifier converts the alternating current input voltage to the first direct current voltage while converting the second direct current voltage to the first direct current voltage; and

a control module that determines a first current at the first set of output terminals, determines a second current at the second set of output terminals, calculates a sum of the first current and the second current, and limits current to at least one of the first set of output terminals and the second set of output terminals when the sum is greater than a predetermined limit while maintaining current to the at least one the first set of output terminals or the second set of output terminals.

28. The power supply of claim 27, wherein the first direct current voltage is different than the second direct current voltage.

29. The power supply of claim 27, wherein the control module does not limit current to the at least one of the first set of output terminals and the second set of output terminals when the sum is less than or equal to the predetermined limit.

30. A method of operating a power supply comprising:

converting an alternating current input voltage to a first direct current voltage via a rectifier;

converting the first direct current voltage to an alternating current output voltage via an inverter;

receiving the alternating current output voltage by a first set of output terminals;

receiving the first direct current voltage by a second set of output terminals;

supplying a second direct current voltage from a backup power source to the rectifier based on the power supply operating in a predetermined condition;

monitoring at least one of voltage, current and power of the first set of output terminals and the second set of output terminals;

based on the at least one of voltage, current and power of the first set of output terminals and the second set of output terminals, at least one of (i) signaling the rectifier to reduce a first maximum current output of the rectifier while maintaining supply of current out of the rectifier and (ii) signaling the inverter to reduce a second maximum current output of the inverter while maintaining supply of current out of the inverter;

limiting current to the first set of output terminals and the second set of output terminals when a sum of a first current supplied to the first set of output terminals and a second current supplied to the second set of output terminals is greater than a first predetermined limit; and

not limiting current to the first set of output terminals and the second set of output terminals when the sum is less than or equal to the first predetermined limit.

31. The method of claim 30 further comprising:

supplying a first load with the alternating current output voltage; and

supplying a second load with the first direct current voltage.

32. The method of claim 30 wherein the rectifier is supplied with the second direct current voltage when amplitude of the alternating current input voltage is less than a predetermined amplitude.

33. The method of claim 30 wherein the rectifier is supplied with the second direct current voltage instead of the alternating current input voltage.

34. The method of claim 30 wherein the rectifier is supplied with the second direct current voltage when amplitude of the alternating current input voltage is greater than a predetermined amplitude.

35. The method of claim 30 further comprising bypassing the rectifier and the inverter to supply the first set of output terminals with the alternating current input voltage.

36. The method of claim 35 further comprising preventing alternating current from being received by the rectifier when the first set of output terminals is supplied with the alternating current input voltage.

37. The method of claim 30 further comprising limiting current supplied to the inverter that converts the first direct current voltage to the alternating current output voltage.

38. The method of claim 30 further comprising limiting current supplied to the second set of output terminals.

39. The method of claim 30 further comprising limiting current supplied to the first set of output terminals.

40. The method of claim 30 further comprising permitting current to the second set of output terminals to increase when current to the first set of output terminals is less than a second predetermined limit.

41. The method of claim 30 further comprising limiting current to the first set of output terminals when current supplied to the first set of output terminals is greater than or equal to a second predetermined limit.

42. The method of claim 30 further comprising permitting current to the first set of terminals to increase when current supplied to the second set of terminals is less than a second predetermined limit.

43. The method of claim 30 further comprising limiting current to the second set of terminals when current supplied to the second set of terminals is greater than or equal to a second predetermined limit.

44. The method of claim 30 further comprising charging the backup power source based on the first direct current voltage.

45. A power supply comprising:

a rectifier that converts an alternating current input voltage to a first direct current voltage;

an inverter that converts the first direct current voltage to an alternating current output voltage;

a first set of output terminals that receives the alternating current output voltage;

a second set of output terminals that receives the first direct current voltage; and

a control module that monitors current of the first set of output terminals and current of the second set of output terminals,

wherein the rectifier receives a second direct current voltage from a backup power source based on the power supply operating in a predetermined condition, and

wherein the control module, based on the current of the first set of output terminals and the current of the second set of output terminals, at least one of

(i) permits the current of the first set of output terminals to increase when the current of the second set of output terminals is less than a first predetermined limit and prevents the current of the first set of output terminals from increasing when the current of the second set of output terminals is greater than or equal to the first predetermined limit, and

(ii) permits the current of the second set of output terminals to increase when the current of the first set of output terminals is less than a second predetermined limit and prevents the current of the second set of output terminals from increasing when current of the first set of output terminals is greater than or equal to the second predetermined limit.

46. The power supply of claim 45 further comprising a direct current interrupter that provides the direct current voltage from the rectifier to the second set of output terminals, wherein:

the first set of output terminals provides the alternating current output voltage to a first load;

the second set of output terminals provides the direct current voltage from the direct current interrupter to a second load; and

the backup power source is separate from the second load.

47. The power supply of claim 46 wherein the control module, based on the current of the first set of output terminals and the current of second set of output terminals, at least one of (i) signals the inverter to prevent the current of the first set of output terminals from increasing when the current of the second set of output terminals is greater than or equal to the first predetermined limit and (ii) signals the direct current interrupter to prevent the current of the second set of output terminals from increasing when the current of the first set of output terminals is greater than or equal to the second predetermined limit.

48. The power supply of claim 45 wherein the control module, based on the current of the first set of output terminals and the current of the second set of output terminals, at least one of (i) prevents the current of the first set of output terminals from increasing when the current of the second set of output terminals is greater than or equal to the first predetermined limit and (ii) prevents the current of the second set of output terminals from increasing when the current of the first set of output terminals is greater than or equal to the second predetermined limit.