Data Center Uninterruptible Power Distribution Architecture

• US 20090206670A1
• Filed: 04/29/2009
• Published: 08/20/2009
• Est. Priority Date: 06/01/2006
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Exaflop LLC (Alphabet Inc.)
• Inventors: Krieger, Ken, Hamburgen, William, Clidaras, Jimmy, Sykora, Montgomery, Jai, Benchiao, Whitted, William, Beaty, Donald L., Aigner, Gerald
• Granted Patent: US 8,624,433 B2
• Time in Patent Office: Days
• US Class Current: 307/64
• 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 9/061 for DC powered loads
• 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 corresponding uninterruptible power system in which only one AC-to-DC rectification 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 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 modular base configured to be supported in one of a plurality of positions on a rack mounting structure, the base 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, the power being received from a power source connected across the DC bus; and

an uninterruptible power supply (UPS) supported by the base, the UPS comprising;

a battery circuit configured to operatively connect a battery across the DC bus during a fault condition in which an AC input voltage signal from an AC generator falls outside of a normal operating range;

an AC-to-DC rectification stage comprising an AC-to-DC conversion circuit configured to convert the AC input voltage signal to a single DC output voltage signal across the DC bus when the AC input voltage signal 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 AC-to-DC conversion circuit to resume supplying operating power to the DC load in response to a signal that indicates that the AC input voltage signal has returned to the normal operating range.

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

3. The system of claim 1, wherein the AC input voltage signal comprises a phase voltage signal and a neutral signal from a three phase AC system.

4. The system of claim 1, wherein the AC input voltage has an r.m.s. value between about 85 Volts and at least about 480 Volts.

5. The system of claim 1, wherein the AC input voltage substantially comprises a sinusoidal waveform at frequency of between about 45 Hz and at least about 500 Hertz.

6. The system of claim 1, wherein the AC input voltage is connected to WYE-connected voltage source.

7. The system of claim 1, wherein the AC input voltage is connected to a DELTA-connected voltage source.

8. 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.

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

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

11. The system of claim 1, wherein the single DC bus voltage is about 13.65 Volts.

12. 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.

13. The system of claim 1, wherein the DC bus voltage 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 according to battery specifications.

14. The system of claim 1, wherein the system has only one rectification circuit configured to convert a sinusoidal AC waveform to a DC waveform.

15. The system of claim 1, wherein a first terminal of the battery is configured to connect 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.

16. The system of claim 1, further comprising a data store, wherein the AC-to-DC converter resumes regulating the DC output voltage signal a delay time after the at least one processor receives a signal indicative of the removal of the fault in the AC voltage input signal, said delay time corresponding to a delay time parameter in the data store.

17. The system of claim 15, wherein one of the at least one digital processors determines the stored delay time parameter.

18. The system of claim 15, wherein the stored delay time parameter comprises a pseudo-randomly generated value.

19. 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.

20. The system of claim 19, 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.