A power converting device is disclosed that can reduce switching loss occurring in a voltage source inverter that drives an AC motor. It is possible to supply DC power to the voltage source inverter from both a voltage source rectifier, which converts AC power from an AC generator into DC power, and a battery. A first switching circuit is inserted between the voltage source rectifier and the AC generator, and the battery is connected to the output side of the voltage source rectifier. A second switching circuit is inserted between the battery and the voltage source inverter. A third switching circuit and a reactor are inserted in series between the input side of the voltage source inverter and the input side of the voltage source rectifier. At least one of an upper arm and a lower arm of the voltage source rectifier can be chopper controlled.