Patent ID: 8842452

Claim:
A method of providing AC output power from a UPS, the UPS comprising a multiphase AC input, a plurality of DC buses including a first positive DC bus, a second positive DC bus, a first negative DC bus and a second negative DC bus, power converter circuitry including a first power converter and a second power converter each coupled to the AC input and at least one of the plurality of DC buses, the method comprising acts of: supplying power from the multiphase AC input to an input of the first power converter and providing power to the plurality of DC buses from an output of the first power converter during a first positive region of a sinusoidal waveform provided from the multiphase AC input and during a first negative region of the sinusoidal waveform; supplying power from the multiphase AC input to an input of the second power converter and providing power to at least some of the plurality of DC buses from an output of the second power converter during a second positive region of the sinusoidal waveform and during a second negative region of the sinusoidal waveform; and converting power supplied from the plurality of DC buses to AC output power provided at an AC output of the UPS.