Patent ID: 8222849

Claim:
A motor control method for an MDPS system, the method comprising: an OHP step that decreases electric current supplied to a motor to a second electric current reduction coefficient to prevent the motor from overheating; and a Pre-OHP step that gradually decreases the electric current supplied to the motor to a first electric current reduction coefficient smaller than the second electric current reduction coefficient, before the step of OHP; wherein the second electric current reduction coefficient is set five times or more larger than the first electric current reduction coefficient; and wherein in the step of Pre-OHP, the electric current supplied to the motor is decreased from the maximum motor electric current to the first electric current reduction coefficient until a predetermined first minimum motor electric current smaller than the maximum motor electric current that can be supplied to the motor, and then when the electric current supplied to the motor becomes smaller than the first minimum motor electric current, the electric current supplied to the motor is increased to a first electric current increase coefficient having the absolute value larger than the first electric current reduction coefficient.