A switch device is brought into conduction in a case where a carrier takes a value zero to drt, a switch device is brought into conduction in a case where the carrier takes a value the drt to one, and one cycle of the carrier is divided into a period in which the carrier has a command value or more and a period in which the carrier has the command value or less. The periods are calculated by dst·T and drt·T, respectively. The same one as the carrier of a converter is employed in a carrier of an inverter, and based on the value drt set as a reference value, a command value of the inverter is provided in each of a side with a value larger than the reference value and a side with a value smaller than the reference value. The period in which the carrier takes the value or more is divided at a ratio among d0, d4 and d6, and the period in which the carrier takes the value drt or less is divided at the ratio among d0, d4 and d6.