Patent ID: 8324851

Claim:
A method for determining the absolute position of a rotor in a PMSM motor having a rotor which includes at least one north pole, at least one south pole, and a stator having windings arranged about a core, wherein each winding is arranged such that when a current passes through the winding, the current generates flux in the core, the method comprising the steps of: (a) applying a short duration voltage pulse of to the stator windings at each of a plurality of successively spaced electrical angle sample points; (b) sampling a current at the end of each voltage pulse; (c) identifying an electrical angle segment between a first and a second successive electrical angle sample point that includes a maximum current; (d) evaluating a magnitude of the current in the identified electrical angle segment to locate the peak current; and (e) determining an angle of the peak current, wherein the angle of the peak current correlates to a rotor position.