FORFARANDE OCH ANORDNING FOR BESTAMNING AV BEGYNNELSEVERDET AV ROTORVINKELN I EN FREKVENSOMFORMARE-MATAD, SERSKILT SJELVSTYRD VEXELSTROMSMASKIN

摘要

A method and apparatus for determining the initial rotor angle in a rotating field machine in which a voltage step is applied to the excitation winding of the machine and to a simulated network and the measured stator voltage vector and simulated voltage vector, after transformation through an assumed rotor angle, used to determine an angular difference which is used to correct the assumed rotor angle until it agrees with the actual rotor angle.