Patent ID: 7304452

Claim:
A motor control device for controlling a permanent magnet motor including a rotor having a permanent magnet and a stator provided with three-phase windings, the motor control device comprising: a current detector detecting current flowing through the three-phase windings; an induced voltage computing unit obtaining voltage induced at each phase from the detected three-phase winding current based on a phase voltage equation, thereby delivering an induced voltage signal; a position detector detecting a rotational position of the rotor from the induced voltage of each phase computed by the induced current computing unit, the rotational position of the rotor having a 6n resolution where n is an integer which is equal to or larger than 1; an energization phase control unit determining a phase to be energized based on the rotational position of the rotor and a phase command; an energization signal forming unit forming a 6n-resolution three-phase energization signal based on the phase to be energized and a voltage command; and an energizing unit which carries out PWM modulation for the three-phase energization signal, thereby supplying voltage according to the modulated three-phase energization signal to each of the three-phase windings.