US 6,856,114 B2 · System for measuring motor rotor position

Abstract

The present invention relates to a method for the sensorless electric measurement of the position of a rotor of a permanently excited synchronous machine that is fed by a converter, by means of measuring signals which are sent to an evaluation device that 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 varies in approximation in sinusoidal manner with twice the value of the electric rotor position angle sought. The method of the invention which can be used in particular in stationary or blocked machines is characterized in that the distribution of absolute values is produced from respectively two successive measurements for an almost inversed magnetization, in such a way that the superposition of the impressed stator flux and permanently excited rotor flux enables, due to saturation, a 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°.

Claims19

Dependent claims

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.

Circuit configuration for the sensor-free electric rotor position measurement of a permanently excited synchronous machine, comprising:

a control-signal generating device,
a converter for feeding the synchronous machine, and
an evaluation device for evaluating measuring signals generated by a current measuring device, wherein the control-signal generating device includes a pattern generator for generating a stator flux pattern and a sampling signal generator providing control signals for the evaluation device, wherein the converter includes a flux model of the synchronous machine and the current measuring device which determines an energization pattern currently present, and wherein the evaluation device calculates from the energization pattern the distribution of absolute values of the differential current space vector and determines therefrom the electric rotor position angle sought unambiguously over 360° of rotor rotation.

Dependencies are inferred from the claim text.

System for measuring motor rotor position

Life of this patent

System for measuring motor rotor position

Life of this patent

Abstract

Claims19