Harmonics are generated when pulse width modulation is carried out with an asymmetrical triangular wave as a carrier signal in a power conversion device. In order to restrict these harmonics, a command value is corrected in advance so as to be distorted, a gate signal of a switching operation is determined lasing a post-correction command value and an asymmetrical carrier signal, and pulse width modulation is carried out, whereby an output voltage or output current with no distortion is obtained.