Patent ID: 6847177
Filing Date: 2005-01-25
Classification: B62D,G01D,H02K

Abstract:
1. An apparatus comprising: an electric motor having a rotor that is rotatable relative to a stator, the rotor being formed from a series of laminations and having a plurality of rotor poles, the stator encircling the rotor and having a plurality of stator poles; each stator pole having a winding that is energizable to cause rotation of the rotor relative to the stator; a first sensor for sensing actual inductance in a respective stator winding and for providing a signal indicative of the actual inductance; a second sensor for sensing a position of the rotor relative to the stator and for providing a rotor position signal; and a controller for receiving the rotor position signal and for receiving the actual inductance signal, the controller determining a reference inductance for the respective stator winding based on the rotor position signal, determining a difference between the actual inductance and the reference inductance, and preventing further energization of the stator windings when the difference between the actual inductance and reference inductance exceeds a predetermined amount.