APPARATUS AND METHOD FOR ESTIMATING ROTOR POSITION OF BRUSHLESS DC MOTOR

摘要

A rotor position estimating device of a BLDC motor comprises;a counter electromotive force measuring unit which measures a counter electromotive force signal induced to a stator of a BLDC motor; and a control unit which detects the position of the rotor of the BLDC motor by determining zero crossing of the counter electromotive force signal based on a standard voltage. The control unit calculates a counter electromotive force error rate based on the predetermined standard voltage and the change amount of the counter electromotive force signal after detecting the position of the rotor with the zero crossing. The control unit corrects the detected position of the rotor by calculating a rotor position error amount from the counter electromotive force error rate. Therefore, the accuracy of the motor control can be improved by grasping the position of the rotor accurately after compensating for a position error of the rotor using the counter electromotive force and also, the malfunction, deterioration, and system instability of a motor can be prevented.