Patent ID: 7245104
Filing Date: 2007-07-17
Classification: H02P

Abstract:
1. A position-sensorless motor control device for controlling a motor, wherein let an axis parallel to a magnetic flux produced by a permanent magnet forming a rotor of the motor be called a d axis, let an axis estimated, for a purpose of control, to correspond to the d axis be called a γ axis, and let an axis estimated to lead the γ axis by an electrical angle of 90 degrees be called a δ axis, then the position-sensorless motor control device controls the motor such that an axis error between the d- and γ-axes is reduced, the position-sensorless motor control device comprising: a superposer that superposes, on a drive current with which the motor is driven, a superposed current having a different frequency than the drive current; a superposed component extractor that extracts, from a motor current fed to the motor, γ-axis and δ-axis components of the superposed current; and a controller that reduces the axis error by controlling the motor based on an arithmetic product of the γ-axis and δ-axis components of the superposed current.