Quadratic observers for estimation and control in induction motors

We prove that a (quadratic) bounded observer can be always designed for an asynchronous motor. Furthermore, when considering an incrementally bounded state feedback control law, a separation principle holds for this class of observers. In order to usefully design the observer, we propose a process based on convex optimization using linear matrix inequality constraints. To this purpose, the asynchronous motor is modeled as a time varying system. A numerical application illustrates the theoretical results