Reference Model and Lyapunov Analysis Approach : Application to an Induction Motor

This paper deals with a robust H_2/H_inf synthesis and an analysis technique applied to an induction motor. In order to robustify a linearizing decoupled feedback against parametric variations, H_2/Hinf controllers with a reference model are added. This mixed approach is necessary to have maximum performances (Hinf design) and the pursuit of the reference model (H_2 design). The main interests are performances and real decoupling between the rotor flux and the speed despite parameter variations. In order to make the synthesis and the analysis step the linearized system is modelized by a linear polytopic part and a nonlinear dependent parameters one. A stability analysis method using parameter-dependent Lyapunov function is also proposed to verify the global stability in presence of nonlinearities which have been neglected in the synthesis. Real time implementations are carried out.