To prevent the composition of noises in a controller which executes the PWM control of the switching timings of a plurality of power converters.

A converter 12 is connected to an in-vehicle battery 10, and a first inverter 14 and a second inverter 16 are connected to the converter 12. A first MG (a motor generator) 18 is connected to the first inverter 14; a second MG (a motor generator) 20 is connected to the second inverter 16; and the switching elements of the converter 12, the first inverter 14, and the second inverter 16 are controlled by PWM signals from a PWM control circuit 22. The PWM control circuit 22 generates the PWM signals, by changing temporally a carrier signal frequency for each power converter. This prevents the composition of the noises by shifting the ON/OFF-timing of the switching elements.