Backup Power System for Rack-Mounted Equipment

A power supply system comprising:

• an input from three-phase alternating current (AC) power grid lines;
• an output for supplying electrical power to rack-mounted computing equipment;
• a main power circuit including a power factor correction (PFC) module and a pair of PFC bulk capacitors in serial coupled to the output, wherein the main power circuit is configured to draw power from each of the three-phase power grid lines;
• and
• a bypass power circuit including a rectifier and a pair of shelf bulk capacitors in serial coupled in parallel to the pair of PFC bulk capacitors, wherein the bypass power circuit is configured to draw power from each of the power grid lines, and rectify the three-phase AC current from the power grid lines to produce a rectified output across the shelf bulk capacitor,
• wherein the main power circuit is configured to provide electrical power to the output during normal operation, and the bypass power circuit is configured to provide electrical power to the output during bypass operation upon failure of the PFC module.

A method comprising:

• receiving three-phase alternating current (AC) power at an input of a power system;
• during normal operation of the power system, operating a main power circuit to process the received AC power from one or more of the three phases of the received AC power using a power factor correction (PFC) module and outputting the processed AC power across a PFC bulk capacitor connected to an output of the power system;
• detecting a failure of the main power circuit;
• and
• responsive to detecting the failure of the main power circuit, operating a bypass power circuit to rectify the received AC power from each of the three phases of the received AC power to produce a rectified output across the output of the power system.