Patent ID: 8450981

Claim:
A power conversion apparatus, comprising: an AC/DC converter section for converting AC power from an AC power supply into DC power; a DC/DC converter section for converting an output from said AC/DC converter section into predetermined DC power for output; and a control section for performing switching control on switches provided at predetermined parts in accordance with detection signals input from a voltage detection circuit and a current detection circuit provided at predetermined parts of said AC/DC converter section and a voltage detection circuit and a current detection circuit provided at predetermined parts of said DC/DC converter section, wherein said AC/DC converter section includes: an inverter circuit in which at least one single-phase inverter having a DC voltage source and a plurality of semiconductor switching elements for charging and discharging the DC voltage source is connected in series; a rectifier element provided in a subsequent stage of said inverter circuit; a smoothing capacitor which is connected to said inverter circuit through said rectifier element, for smoothing an output from said inverter circuit for output; and a short-circuit switch for causing a current to bypass said smoothing capacitor, and wherein said control section controls a current input to said inverter circuit to cause a DC output voltage from said AC/DC converter section which is a voltage across said smoothing capacitor to follow a target voltage and to cause an input power factor from the AC power supply to approach one, to thereby maintain a DC voltage from the at least one single-phase inverter, and adjusts the target voltage for the DC output voltage from said AC/DC converter section in accordance with a voltage of the AC power supply.