Patent ID: 6583593
Filing Date: 2003-06-24
Classification: H02P

Abstract:
A position-sensorless motor control method comprising the steps of:(A) determining a target current vector of stator windings; (B) setting one of a rotor-position estimation current signal and a rotor-position estimation voltage signal, with varying the period thereof; (C) detecting currents flowing through said stator windings; (D) carrying out one of (a) superimposing said rotor-position estimation current signal on a component of said target current vector in a first direction based on an estimated position (&ggr;-axis direction, hereafter) of a rotor, thereby obtaining a target current vector with superimposed wave, and (b) superimposing said rotor-position estimation voltage signal on a component of a target voltage vector corresponding to said target current vector in said first direction, thereby obtaining a target voltage vector with superimposed wave; (E) supplying electric power to said stator windings through a motor driving device on the basis of one of said target current vector with superimposed wave and said target voltage vector with superimposed wave; (F) measuring a current response to one of said rotor-position estimation current signal and said rotor-position estimation voltage signal, from a component of a current vector in a second direction having a fixed relation with said first direction, said current vector representing said currents detected in said detecting step; and (G) correcting said &ggr;-axis direction on the basis of said current response.