CONTROL APPARATUS FOR AC MOTOR AND ELECTRIC VEHICLE

An AC electric motor (M1), an inverter (14) and a controller (30) are mounted on an electric powered vehicle. The controller (30) includes a voltage deviation calculating unit (320), a modulation factor calculating unit (340), and a mode switching determination unit (360). The voltage deviation calculating unit (320) calculates a voltage deviation between a first voltage command when the rectangular wave voltage control is executed and a second voltage command when pulse width modulation control is executed, by inputting a current deviation to a voltage equation of the AC electric motor. Modulation factor calculating unit (340) calculates the modulation factor based on the first voltage command and the voltage deviation. The mode switching determination unit (360) determines whether or not control mode of the AC electric motor (M1) from the rectangular wave voltage control to the pulse width modulation control is necessary, based on the modulation factor.