Patent ID: 7791309

Claim:
A motor controller to control a motor having a stator coil and a rotor, the motor controller comprising: an activating operator adapted to: receive an operation command with a predetermined target frequency while the motor remains stationary, activate the motor at a predetermined voltage and a voltage phase, and gradually increase, after activating, an operation frequency of the motor; an operation exchanger adapted to switch an activation operation into a normal operation when the operation frequency reaches a predetermined frequency, where the predetermined frequency is lower than the predetermined target frequency; an evaluator adapted to evaluate a location of the rotor included in the motor and the operation frequency based on a current or voltage detected from the motor; a normal operator adapted to operate the motor in a normal manner based on the evaluated rotor location; an error determiner adapted to determine, during operation of the motor, whether there is an error on the motor based on at least one of the detected current, the detected voltage, and the evaluated operation frequency; and an operation controller adapted to stop the motor upon a determination by the error determiner of an error on the motor.