POWER CONVERSION DEVICE

To provide a power conversion device configured to evenly pass current through phases and to achieve high power conversion efficiency in a wide current range. A power conversion device comprising conversion parts which are coupled in parallel to each other, which are capable of voltage conversion, and each of which includes a coil, wherein the power conversion device comprises M (M is a natural number of 2 or more) sets of conversion sets including the conversion parts of N phases (N is a natural number of 2 or more), and the coils of the conversion parts are capable of magnetic coupling to each other; wherein the power conversion device includes a controller configured to change a driving phase number X of the conversion parts according to a system requirement.