Patent ID: 8080900

Claim:
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.