Patent ID: 7324361

Claim:
A bi-directional power supply adapted to supply AC power to a utility grid or stand-alone load, comprising: a DC power source; a bi-directional inverter that provides output power through a single power stage of DC-AC conversion; an output filtering grid interface that filters and supplies the output power from the bi-directional inverter into the utility grid; and a system controller for regulating the voltage of the DC power source at its maximum power voltage, controlling the waveform of the inverter output current to be sinusoidal, and reducing the output power when the utility grid voltage exceeds a predetermined threshold; wherein the output power: tracks the maximum power output of the DC power source; and is sinusoidal AC current that is controlled to be other in phase with or optimally phase-shifted with the utility grid voltage; wherein the bi-directional inverter comprises a cascade connection of an input bulk capacitor for sufficient energy storage to limit voltage ripple across the DC power source to a predetermined level, a line-filter for filtering the inverter input current to suppress the conducted and radiated switching noise produced by the inverter, and the bi-directional inverter power stage; and wherein the output filtering grid interface comprises an output filter, a fuse, and an output relay switching network for transferring power to either the utility grid or the stand-alone load.