Patent ID: 6249094
Filing Date: 2001-06-19
Classification: H02P

Abstract:
A method of determining the instantaneous rotary position of the rotor of a synchronous motor in relation to the rotating magnetic stator field comprising the steps of:measuring an induced voltage in at least one star connected stator winding, where each star point terminal is connected to oppositely located central tap-offs of a power bridge formed of two power transistors,through alternating pulse width modulated switching of said two power transistors quasi-continuously supplying said power transistors with a current, which is generally sinusoidal over a period of time,and during the zero passage of the current flow through the instantaneously currentless phase winding, the current induced from the rotating rotor at the terminal of this winding still produces a voltage, which is measured relative to the common terminal potential at the other windings which are transiently interconnected therewith for this purpose.