To remove switching ripples and accurately detect the fundamental component of current when a power converter is operated in 180-degree conduction mode, so-called, one-pulse mode.

A power conversion device includes: a phase generating means that determines the fundamental wave phase of alternating-current voltage applied to a three-phase alternating-current load; and a controller that inverts the state of conduction of a power converter every 180 degrees of phase based on the fundamental wave phase outputted by the phase generating means. The controller includes: a means for sampling three-phase alternating current outputted by a current detecting means; a coordinate transforming means that converts the sampled three-phase alternating current into orthogonal two-phase direct current based on the fundamental wave phase outputted by the phase generating means; and a filter for removing higher harmonics contained in the orthogonal two-phase direct current after coordinate transformation. The power conversion device is operated at a sampling frequency equal to an integral multiple (however, not less than 12) of 6 of the frequency outputted by a frequency generating means.