Power conversion device

A power conversion device comprising:

• a power conversion circuit for converting AC power from an AC power supply, to DC power, and outputting the DC power;
• and
• a control circuitry to perform output control for the power conversion circuit,
• wherein the power conversion circuit includes:
• a rectification bridge circuit connected to the AC power supply;
• a leg circuit including an upper leg and a lower leg, connected in series, each of which includes a plurality of semiconductor elements connected in series via connection points, the plurality of semiconductor elements of at least the lower leg being switching elements, the leg circuit connected between DC buses and connected to the AC power supply via the rectification bridge circuit;
• at least one DC capacitor connected between the connection point in the upper leg and the connection point in the lower leg;
• a reactor inserted in a current path between the AC power supply and the leg circuit;
• and
• a smoothing capacitor connected between the DC buses;
• and wherein the control circuitry performs PWM control of the leg circuit by generating a duty cycle so as to cause a voltage of the DC capacitor to follow a command value while controlling an input current from the AC power supply, such that a sum of duty cycles corresponding to each leg having the switching elements among the upper and the lower legs, is constant in one cycle.