Upon determining that the absolute value of an electrical angular speed of a motor-generator is smaller than or equal to a threshold value, a control apparatus compensates a current detected by a U-phase current sensor based on a temperature detected by a U-phase temperature sensor and compensates a current detected by a V-phase current sensor based on an estimated temperature of a V-phase current sensor. On the other hand, upon determining that the absolute value of the electrical angular speed is larger than the threshold value, the control apparatus compensates the currents detected by the U-phase and V-phase current sensors based on temperature detected by the U-phase temperature sensor.