Patent attributes
A sensorless controlling apparatus for controlling a brushless motor includes a speed calculator for calculating speed of a rotor ω, an angle calculator for calculating rotor angle θ at a predetermined time interval, and an angle controller for calculating correction angle Δθ based on the current value of a d-axis current (d-axis current value id), thereby controlling the rotor angle θ. The angle calculator uses the correction angle Δθ calculated by the angle controller, the speed ω calculated by the speed calculator, a predetermined time, and the rotor angle θ calculated by the angle calculator at a predetermined time to calculate the rotor angle at the predetermined time interval. Thus, the rotor angle θ calculated by the angle calculator is converged on the true angle of the rotor.
