Patent ID: 6856114

Claim:
Method for measuring the position of a rotor of a permanently excited synchronous machine that is fed by a converter, comprising the stops of: measuring signals which are sent to an evaluation device wherein said evaluation device calculates the electric position of the rotor from the angular dependence of the current space vector at an impressed stator flux pattern, wherein the distribution of absolute values of the differential current space vector changes in approximation in sinusoidal manner with twice the value of the electric rotor position angle sought, producing a distribution of absolute values of said differential current space vector from respectively two successive measurements using inversed magnetization, in such a way that the superposition of the impressed stator flux and permanently excited rotor flux enables, due to saturation, an distribution of absolute values of the current space vector with two different maximum values, from which the electric rotor position angle sought is determined directly and unambiguously over 360° of rotor rotation.