When a command frequency to a rotating electric machine is included in an inverter lock frequency band, a frequency switching section switches the command frequency to a frequency outside the inverter lock frequency band by changing a slip frequency command value. In response to this, a torque command change section changes a torque command to a second rotating electric machine other than a first rotating electric machine of which the slip frequency is changed such that a torque fluctuation caused by the change of the slip frequency command value is canceled out.