A robust Luenberger-like observer for induction machines

A Luenberger-like observer is proposed 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 performance in an H/spl infin/ sense, where the stability of the error dynamics is guaranteed. The proposed conditions are cast in terms of state-dependent linear matrix inequalities that are solved efficiently using standard software packages. Simulation results demonstrates the performance of the approach.