Patent ID: 6906491
Filing Date: 2005-06-14
Classification: H02P

Abstract:
1. A motor controller, comprising: a synchronous motor including stator windings and a rotor; a feed back detector that detects a position and a velocity of the rotor and produces an output signal; a magnetic pole position detector that determines a magnetic pole position of the rotor based, at least on part, on the output signal; a power control apparatus that controls electric power supplied to said synchronous motor according to said detected magnetic pole position; a magnetic pole position estimator that estimates the magnetic pole position of the rotor from an induced voltage of the stator windings; and a magnetic pole position abnormality detector that 1) compares said detected magnetic pole position and the estimated magnetic pole position and 2) determines that the said feed back detector is abnormal when an absolute value of the difference between said detected magnetic pole position and the estimated magnetic pole position is larger than a predetermined value: wherein, when an abnormality of said feed back detector is determined, said power control apparatus controls the electric power according to said estimated magnetic pole position.