Validation of an interconnected high-gain observer for a sensorless induction motor against a low frequency benchmark: application to an experimental setup

An interconnected high-gain observer and a flux estimator are presented for the elucidation of the angular speed and load torque of an induction motor. Because of observation difficulties at low frequencies, both the observer and the estimator are tested and validated against reference trajectories derived using a proposed benchmark. This is true even in the case where the motor state is unobservable. Experimental results to validate the proposed benchmark criteria are presented.