Patent ID: 7638967

Claim:
A motor control unit, comprising: a power converter unit that energize a motor based on a commutating signal, the motor having a rotor provided with a permanent magnet and a stator having a coil wound thereto; a start-up controller that outputs a commutating signal to the power converter unit during a start-up operation, the commutating signal having a predetermined conductive pattern corresponding to a command rotational speed; a voltage calculator that calculates a voltage of the motor during the start-up operation by applying a parameter for the motor, the command rotational speed, and a current flown in the coil of the motor to a voltage-current equation of the motor; and a determiner that, during the start-up operation, compares a voltage calculated by the voltage calculator and an actual voltage of the motor and that determines occurrence of rotational abnormalities when the actual voltage is lower than the calculated voltage.