Method and a device for sensorless estimating the relative angular position between the stator and rotor of a three-phase synchronous motor.

摘要

A method for sensorless estimation of the relative position between the stator and the rotor of a three-phase synchronous motor during operation. The method comprises the steps of low-pass filtering of the terminal voltage, low-pass filtering of the terminal current, high-pass filtering of the terminal current and determining the rotor speed. Next the relative angular position is determined from the filtered magnitudes and corrected with an angular correction derived from the rotor speed.