Patent ID: 7078873

Claim:
A controller for controlling a three-phase brushless motor, the controller comprising: a three-phase/two-phase converter for converting values of three-phase current provided to the brushless motor to two-phase current values; a two-phase/three-phase converter for converting two-phase voltage command values in accordance with a difference between the two-phase current values and the two-phase current command values to generate three-phase voltage command values; a rotation angle detector for detecting rotation angle of the brushless motor; an angular velocity calculator for calculating angular velocity of the brushless motor; a conditional determination circuit for determining whether an absolute value of the calculated angular velocity is equal to or greater than a predetermined value; a phase advancing angle calculator for calculating a phase advancing angle corresponding to a delay angle of the phase of the phase current with respect to the phase of the phase voltage command resulting from influence of inductance of the motor based on a function of the angular velocity and the inductance; and a rotation angle corrector for adding the phase advancing angle to the rotation angle to generate a corrected rotation angle, wherein the two-phase/three-phase converter performs two-phase/three-phase conversion using the corrected rotation angle.