Patent ID: 7733674

Claim:
A power conversion apparatus for converting direct current from a power source to polyphase alternating current, the power conversion apparatus comprising: a plurality of carrier signal generators configured and arranged to independently generate and transmit a plurality of carrier signals, respectively, the carrier signals having mutually different frequencies, with the carrier signal generators configured and arranged to set a lowest frequency of each of the carrier signals above an audible band; a plurality of gate signal generators operatively coupled to the carrier signal generators, respectively, to receive the carrier signals, each of the gate signal generators being configured and arranged to generate an on/off signal by comparing a command value of each phase of the polyphase alternating current and corresponding one of the carrier signals; and a plurality of legs connected to the gate signal generators, each of the legs being operated based on the on/off signal transmitted from corresponding one of the gate signal generators to convert the direct current to each phase of the polyphase alternating current.