Sensorless indirect field-oriented control of induction motors, based on high gain speed estimation

A novel speed sensorless control algorithm for IM with analytically proven local asymptotic stability properties is presented. It provides asymptotic speed tracking and flux regulation under condition of constant load torque. Conditions of persistency of excitation are defined; they coincide with the well-known nonzero excitation frequency of IM. Intensive experimental study demonstrates performance suitable for wide spectrum of technological applications.