Model reference adaptive sensorless control for surface permanent magnet synchronous machine under severe starting conditions

A closed-loop controlled torque start-up is proposed to obtain the rotor initial position using initial incremental motion, which allows the start-up with the optimal high torque in severe starting conditions with the least possible motor current. With the initial position, the sensorless control of a surface permanent magnet synchronous machine (SPMSM) is achieved by a new scheme of model reference adaptive system (MRAS). The H-norm of the transfer function is applied to assign the poles for achieving robust position and speed estimation. The experimental results show that the proposed method is very effective.