Sensorless Dynamic Driving Method and System for Single Phase Alternating Current Permanent Magnet Motor

Abstract

A sensorless driving method for a single phase alternating current permanent magnet motor is described. The method comprises a starting drive mode and a stable drive mode. The starting drive mode comprises inputting a first current to drive a rotor to rotate to a stable position, the first current comprising a pulse current flowing in a first direction for a first predetermined starting time interval and a constant current flowing in a second direction contrary to the first direction for a second predetermined time interval, terminating the first current, determining generation of a back electromotive force, detecting a first zero crossing point of the back electromotive force, inputting a second current for a first charge time interval, waiting for a first post-charge time interval, detecting a second zero crossing point to define a previous half period between the first zero crossing point and the second crossing point, inputting the second current for a second charge time interval, waiting for a second post-charge time interval, and detecting speed of the rotor to compare the speed to a predetermined value. The second current flows in a direction in which the back electromotive force is generated.

Dependencies are inferred from the claim text.