Direct-coupled IT load

• US 8,080,900 B2
• Filed: 07/18/2007
• Issued: 12/20/2011
• Est. Priority Date: 07/18/2007
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Exaflop LLC (Alphabet Inc.)
• Inventors: Corhodzic, Selver, Carlson, Andrew B., Whitted, William H., Sykora, Montgomery, Krieger, Ken, Hamburgen, William, Beaty, Donald L., Aigner, Gerald, Clidaras, Jimmy
• Primary Examiner(s): Barnie, Rexford
• Assistant Examiner(s): Fauth, Justen
• Application Number:
  US11/779,606
• Publication Number:
  US 20090021078A1
• Time in Patent Office: 1,616 Days
• Field of Search: None
• US Class Current: 307/66
• CPC Class Codes: G06F 1/263 Arrangements for using multiple switchable power supplies, e.g. battery and AC G06F1/30 takes precedence
• CPC Class Codes: G06F 1/30 Means for acting in the event of power-supply failure or interruption, e.g. power-supply fluctuations for resetting only G06F1/24
• CPC Class Codes: H02J 1/001 Hot plugging or unplugging of load or power modules to or from power distribution networks
• CPC Class Codes: H02J 1/14 Balancing the load in a network
• CPC Class Codes: H02J 9/062 for AC powered loads
• CPC Class Codes: H02M 3/335 using semiconductor devices only
• CPC Class Codes: Y02B 10/70 Hybrid systems, e.g. uninterruptible or back-up power supplies integrating renewable energies

Abstract

Apparatus and associated method and computer program products involve a highly efficient uninterruptible power distribution architecture to support modular processing units. As an illustrative example, a modular processing unit includes an integrated uninterruptible power system in which a PFC-boost AC-to-DC conversion occurs between the utility AC grid and the processing circuit (e.g., microprocessor) loads. In an illustrative data center facility, a power distribution architecture includes a modular array of rack-mountable processing units, each of which has processing circuitry to handle network-related processing tasks. Associated with each modular processing unit is an integrated uninterruptible power supply (UPS) to supply operating power to the network processing circuitry. Each UPS includes a battery selectively connectable across a DC bus, and a AC-to-DC rectifier that converts an AC input voltage to a single output voltage on the DC bus. The regulated DC bus voltage may be close to the battery'"'"'s fully charged voltage.

Claims

1. A power distribution system for a data center, the system comprising:

a power source configured to provide AC power received from an electric utility grid;

multiple rack mountable processing units, wherein each rack mountable processing unit is mounted in a position in a rack and is coupled to the power source to receive the provided AC power from the power source without any intermediary AC/DC conversion or conditioning of the AC power, each of the rack mountable processing units comprising;

a DC load comprising at least one digital processor operative to process data received over a network;

a DC bus configured to deliver operating power to the DC load; and

an uninterruptible power supply (UPS), the UPS comprising;

a battery circuit configured to operatively connect a battery across the DC bus during a fault condition in which the AC power falls outside of a normal operating range, wherein the AC input voltage signal originates at a rotating AC generator;

an AC-to-DC rectification stage comprising an AC-to-DC conversion circuit configured to filter noise and harmonic components from the received AC power, correct a power factor of the received AC power to a power factor closer to unity, and to convert the filtered and corrected AC power to a single DC output voltage signal across the DC bus when the received AC power is within the normal operating range, wherein the AC-to-DC conversion circuit is configured to regulate the DC output voltage signal to a voltage level above and substantially near a maximum nominal charge voltage of the battery; and

a controller configured to selectively activate the battery circuit and the AC-to-DC conversion circuit such that the battery is operatively connected across the DC bus during the fault condition instead of the DC output voltage signal, and the AC-to-DC conversion circuit resumes supplying the DC output voltage signal across the DC bus when the AC power has returned to the normal operating range.

2. The system of claim 1, wherein the controller is configured to control a switch to selectively connect the battery across the DC bus.

3. The system of claim 1, wherein the battery comprises one or more cells electrically connected in series.

4. The system of claim 1, wherein the battery comprises one or more cells electrically connected in parallel.

5. The system of claim 1, wherein the AC power received from the electric utility grid comprises a phase voltage signal and a neutral signal from a three phase AC system.

6. The system of claim 1, wherein the AC power received from the electric utility grid has an r.m.s. value of about 208 Volts to about 277 Volts.

7. The system of claim 1, wherein the AC power received from the electric utility grid has an r.m.s. value between about 85 Volts and at least about 480 Volts.

8. The system of claim 1, wherein the AC power received from an electric utility grid substantially comprises a sinusoidal waveform at frequency of between about 45 Hz and at least about 500 Hertz.

9. The system of claim 1, wherein a cell in the battery comprises a battery chemistry selected from the group consisting of:

lead acid;

nickel metal hydride;

nickel cadmium;

alkaline; and

, lithium ion.

10. The system of claim 1, further comprising a charger configured to charge the battery through a path connected across the DC bus.

11. The system of claim 1, wherein the single DC output voltage signal is less than about 26 Volts.

12. The system of claim 1, wherein the single DC output voltage signal is between about 10 Volts and about 15 Volts.

13. The system of claim 1, wherein the single DC output voltage signal is about 13.65 Volts.

14. The system of claim 1, wherein the AC-to-DC conversion circuit regulates the DC output voltage signal to approximately 1 Volt above the maximum nominal charge voltage of the battery.

15. The system of claim 1, wherein the DC output voltage signal provides sufficient voltage for a linear regulator connected in series with the battery across the DC bus to trickle charge the battery to a fully charged state.

16. The system of claim 1, wherein the DC bus comprises a first electrical path at a first voltage, and further comprises a second electrical path at a second voltage.

17. The system of claim 16, wherein one of the first or second voltages is substantially at a ground reference potential.

18. The system of claim 1, wherein a first terminal of the battery is connected directly to a first rail of the DC bus, and the second terminal of the battery is selectively connected to a second rail of the DC bus.

19. The system of claim 1, wherein each rack mountable processing unit further comprises a data store storing a delay time parameter, wherein the controller is configured to selectively activate the AC-to-DC conversion circuit to resume supplying operating power to the DC load a delay time after the controller receives the signal indicative of the removal of the fault in the AC voltage input signal, said delay time corresponding to the delay time parameter in the data store, wherein delay times associated with at least some of the rack mountable processing units are different from one another such that inrush currents into the data center are mitigated.

20. The system of claim 19, wherein the controller is configured to determine the stored delay time parameter.

21. The system of claim 19, wherein the stored delay time parameter comprises a pseudo-randomly generated value.

22. The system of claim 1, wherein the DC load comprises at least one member of the group consisting of:

a central processing unit;

a data storage device;

a math coprocessor; and

, a digital signal processor.

23. The system of claim 22, further comprising at least one DC-DC converter configured to convert a voltage supplied on the DC bus to at least one further DC voltage.

24. The system of claim 23, wherein one or more of the at least one further DC voltage is approximately the voltage of a member of the group consisting of:

−

5;

1;

3;

3.3;

5;

7.5;

10;

about 18-20; and

, about 20-26 Volts.

25. The system of claim 23, wherein the one or more of the at least one DC-DC converters is configured to filter noise from the voltage supplied on the DC bus.

26. The system of claim 1, wherein the DC load further comprises one or more information-containing signals transmitted to a load external to the DC load.

27. The system of claim 1, wherein the controller is configured to selectively activate the battery circuit and the AC-to-DC conversion circuit such that the AC-to-DC conversion circuit resumes supplying the DC output voltage signal across the DC bus in response to a signal that indicates that the received AC power has returned to the normal operating range.

28. A system comprising:

multiple rack mountable processing units, wherein each rack mountable processing unit is mounted in a position in a rack and is coupled to a power source configured to receive AC power from an electric utility grid and to provide the received AC power to the rack mountable processing units without any intermediary AC/DC conversion or conditioning of the AC power, each of the rack mountable processing units comprising;

a motherboard including at least one digital processor operative to process data received over a network;

a DC bus configured to deliver operating power to the motherboard; and

an uninterruptible power supply (UPS), the UPS comprising;

a battery circuit configured to operatively connect a battery across the DC bus during a fault condition in which the AC power falls outside of a normal operating range;

an AC-to-DC rectification stage comprising an AC-to-DC conversion circuit configured to filter noise and harmonic components from the received AC power, correct a power factor of the received AC power to a power factor closer to unity, and to convert the filtered and corrected AC power to a single DC output voltage signal across the DC bus when the received AC power is within the normal operating range, wherein the AC-to-DC conversion circuit is configured to regulate the DC output voltage signal to a voltage level above and substantially near a maximum nominal charge voltage of the battery; and

a controller configured to selectively activate the battery circuit and the AC-to-DC conversion circuit such that the battery is operatively connected across the DC bus during the fault condition instead of the DC output voltage signal, and the AC-to-DC conversion circuit resumes supplying the DC output voltage signal across the DC bus when the AC input voltage signal has returned to the normal operating range.

29. The DC load of claim 28, further comprising at least one point-of-load DC-DC converter on the motherboard, configured to receive DC voltage from the DC bus and provide conditioned DC voltage to an operating circuit on the motherboard.

30. The DC load of claim 28 wherein the AC-to-DC conversion circuit is of a continuous conduction mode (CCM) type including average current mode control (ACMC).

31. The DC load of claim 28 wherein the AC-to-DC conversion circuit is of a critical conduction mode (CRM) type.

32. The system of claim 28, wherein the controller is configured to control a switch to selectively connect the battery across the DC bus.

33. The system of claim 28, wherein the single DC output voltage signal is less than about 26 Volts.

34. The system of claim 28, wherein the single DC output voltage signal is between about 10 Volts and about 15 Volts.

35. The system of claim 28, wherein the single DC output voltage signal is about 13.65 Volts.

36. The system of claim 28, wherein the AC-to-DC conversion circuit regulates the DC output voltage signal to approximately 1 Volt above the maximum nominal charge voltage of the battery.

37. The system of claim 28, wherein the DC output voltage signal provides sufficient voltage for a linear regulator connected in series with the battery across the DC bus to trickle charge the battery to a fully charged state.

38. The system of claim 28, wherein the DC bus comprises a first electrical path at a first voltage, and further comprises a second electrical path at a second voltage.

39. The system of claim 38, wherein one of the first and second voltages is substantially at a ground reference potential.

40. The system of claim 28, wherein each rack mountable processing unit further comprises a data store storing a delay time parameter, wherein the controller is configured to selectively activate the AC-to-DC conversion circuit to resume supplying operating power to the DC load a delay time after the controller receives the signal indicative of the removal of the fault in the AC voltage input signal, said delay time corresponding to the delay time parameter in the data store wherein delay times associated with at least some of the rack mountable processing units are different from one another such that inrush currents into the data center are mitigated.

41. The system of claim 40, wherein the controller is configured to determine the stored delay time parameter.

42. The system of claim 40, wherein the stored delay time parameter comprises a pseudo-randomly generated value.

43. The system of claim 28, wherein the controller is configured to selectively activate the battery circuit and the AC-to-DC conversion circuit such that the AC-to-DC conversion circuit resumes supplying the DC output voltage signal across the DC bus in response to a signal that indicates that the received AC power has returned to the normal operating range.