Power conversion apparatus

A power conversion apparatus that converts power of a rotating electric machine including a three-phase winding set, the power conversion apparatus comprising:

• an inverter unit that comprises a plurality of switching elements provided in correspondence to the phases of the winding set;
• and
• a control unit that is configured to control currents of the winding set by controlling on-off operations of the switching elements by pulse width modulation control, the control unit comprising a modulation processing unit that is configured to perform a modulation process that is a down-shift process or an up-shift process, wherein in the down-shift process, a neutral-point voltage is shifted towards a low voltage side such that a smallest phase voltage command value is a lower fixed value that is a first lower limit value or a second lower limit value, and in the up-shift process, the neutral-point voltage is shifted towards a high voltage side such that a largest phase voltage command value is an upper fixed value that is a first upper limit value or a second upper limit value, wherein
• the modulation processing unit selects either of a first fixed value and a second fixed value based on a difference between the phase voltage command values, the first fixed value being the first lower limit value or the first upper limit value, the second fixed value being the second lower limit value or the second upper limit value, wherein in the modulation process, the first fixed value is switched to the second fixed value based on a first determination value, the second fixed value is switched to the first fixed value based on a second determination value, and the first determination value and the second determination value are differing values.