Sensorless control method and apparatus thereof

PURPOSE: A sensor-less controlling method and a device for the same are provided to sense an out-of phase of a rotator by comparing the angle of the rotator estimated based on a sensor-less algorithm and the angel of the rotator calculated with a voltage equation, thereby improving out-of phase sensing performance. CONSTITUTION: Speed instructions for a motor are outputted. If a voltage outputted according to the speed instruction is supplied to the motor, a current flowing in the motor is detected. The magnetic flux of the rotator is calculated based on the voltage outputted by the speed instructions and the detected current. The angle of the rotator is calculated based on the calculated magnetic flux. An out-of phase of the rotator is sensed depending on the result of comparing the calculated angle of the rotator and the angle of the rotator estimated by a sensor-less control algorithm.