Multi-variable adaptive observer based on Lyapunov stability theorem: application for sensorless ac drive

This paper introduced an adaptive flux observer with multi-variable and its application. The scheme was derived using Lyapunov stability theorem so that the control system is stable on theory. A sensorless stator flux oriented control of induction motor drive by estimated speed using proposal adaptive observer was presented later. The drive used observer for speed estimation and parameters of motor. Furthermore, it used mechanical model to improve the behavior during the speed transients. The new control strategy presented gave full play to the advantage of classical control schemes. The good steady static and dynamic performance of the proposed sensorless drive using experiment results is demonstrated.