A robust discrete-time observer for induction motors

This paper proposes a convex approach to the design of robust discrete-time observers to the state estimation of induction machines subject to rotor resistance variation and load disturbance. The observer gain is designed in order to minimize these effects on the state estimation in an ℋ_∞ sense, while guaranteeing the error dynamics stability. The proposed conditions are cast in terms of state-dependent linear matrix inequalities. Simulation results demonstrates the performance of the approach.