Patent ID: 7583041

Claim:
An overheat preventing apparatus for preventing an electric motor for a vehicle from overheating, comprising: temperature transition estimating means for estimating a temperature transition of the electric motor caused by the passage of electric current through the electric motor; coolant supplying means for supplying a coolant to the electric motor; and coolant supply control means for controlling the amount of coolant supply from said coolant supplying means according to at least the estimated temperature transition of the electric motor, wherein the electric motor is controlled according to command values for torque to be produced by the electric motor; motor control means for performing d-q vector control of the electric motor according to the torque command values; and torque command correcting means for correcting the torque command values according to at least the rotational speed of the electric motor, wherein said temperature transition estimating means estimates the temperature transition of the electric motor using the corrected torque command values and an average value of the corrected torque command values.