To easily make a switching frequency changeable, this power conversion device (13) is provided with the following: a rectifying circuit (2) that is disposed between an AC power supply (1) and a load (12) and rectifies the voltage from said AC power supply (1); a smoothing unit (25) that smoothes the DC voltage on the load (12) side of the rectifying circuit (2); a short-circuiting unit (24) that is disposed on the AC-power-supply (1) side of the smoothing unit (25) and short-circuits the AC power supply (1); a voltage-increasing inductor (4) disposed on the AC-power-supply (1) side of the short-circuiting unit (24); an inductor-current detection unit (8) that detects the amount of current flowing through the voltage-increasing inductor (4) and/or a bus-conductor-voltage detection unit (9) that detects the output voltage of the smoothing unit (25); a reverse-current prevention element (6) that prevents current from flowing from the smoothing unit (25) back towards the AC power supply (1); a switching control unit (10) that generates drive pulses from an output signal from the inductor-current detection unit (8) or the bus-conductor-voltage detection unit (9) and outputs a control signal for the short-circuiting unit (24); and a switching-frequency changing unit (11) that is disposed between the switching control unit (10) and the short-circuiting unit (24) and can change the frequency of the control signal via logical operations.
