Natural field orientation sensorless induction motor drive with on-line stator resistance parameter update

Abstract

This article presents a new technique for on-line identification of an induction motor stator resistance parameter. The technique is designed as an upgrade of the natural field orientation system in a shaft-sensorless indirect field-oriented control induction motor drive. The proposed upgrade results in simultaneous rotor speed estimation and stator resistance parameter update, improving natural field orientation scheme robustness. The parameter update is based on information available in the d-axis back-emf component, investigated in detail using a steady-state model of potentially detuned natural field orientation scheme. The effectiveness of the parameter update technique is validated via practical experiments under a variety of conditions.