Feedback linearization control with sliding mode speed observer for three-phase induction machines

This paper addresses the problem of controlling a three-phase induction motor without speed measurements. A nonlinear feedback linearization control was designed for a fifth order induction motor model including electrical and mechanical dynamics. The proposed control scheme, which is an indirect field oriented control technique (IFOC) based on feedback linearization control (FLC), is made up of flux-speed controllers. It is inserted on these controllers additional terms designed according discrete time Lyapunov functions to ensure the flux alignment. In order to provide an estimated rotor speed for the control system, it is used a slide mode observer algorithm. Some experimental results with TMS 320F2812 DSP are provided to verify the proposed system performance in a low speed conditions.