Robust control and stability analysis of linearized system with parameter variation application to induction motors

This paper discusses the synthesis and the analysis techniques applied to a nonlinear system subjected to parameter variations for which an exact feedback linearization is performed. The obtained linear system is described by a linear and a nonlinear dependant parameter parts. An H₂/H_∞ robust output feedback controller is designed on the linear part. The effect of the nonlinear part is attenuated by means of a reference model. A stability analysis method using parameter-dependant Lyapunov function is used to check the global stability in the presence of the nonlinearity which has been ignored in the synthesis step. The synthesis and the analysis results are then applied to an induction motor