In a vehicle, a control apparatus controls a power converter supplying a rotary machine which can operate as a drive motor of the vehicle, and controls a cooling apparatus for circulating a coolant fluid through the rotary machine and the power converter. When a temporary condition occurs immediately after commencement of the circulation, whereby the temperatures of the coolant fluid and of switching elements in the power converter are judged to concurrently exceed respective specified temperature thresholds, the control apparatus limits the maximum power that can be supplied from the power converter to a lower value than is normally available. When the temperature of the coolant fluid is judged to no longer exceed the corresponding temperature threshold, the limiting is released.