Method And Apparatus For Sensorless Control Of Permanent-magnet Synchronous Motors

Abstract

A method of estimating and controlling rotor position and velocity for a multi-phase brushless permanent-magnet motor by measuring only the stator phase currents at a high sampling rate. Measurements of the stator phase currents are used to obtain estimates of rotor position and velocity. In turn, these estimates are used to determine an amount of voltage to apply to each stator phase so as to obtain a desired regulation of rotor position or velocity, or to command rotor position or velocity to follow a desired trajectory.