According to one embodiment, there is provided a power conversion device, including a control unit configured to control ON/OFF of a switching element of a neutral-point-clamped power conversion device unit, wherein the control unit drives the power conversion device unit by a one-pulse control, controls a phase difference of an output voltage of the power conversion device unit with respect to a reference phase of to control an active current component of an output current of the power conversion device unit, and controls ON/OFF based on: (a) a phase angle for eliminating a predetermined odd-order harmonic component of the output voltage; and (b) a sum of the reference phase and the phase difference.