H∞ design of a robust speed controller for induction motors

A speed controller for an induction motor is developed in the framework of H_∞ theory design criteria. The proposed control law achieves convergence to zero of both speed and flux norm tracking errors and ensures robustness with respect to load torque disturbances and imperfect system modeling. Implementation of the controller requires full state measurement; this is exploited both to decouple the rotor speed and the flux norm dynamics via feedback linearization, and to close a static state-feedback loop at the new control inputs of the decoupled system. A simulation case study is finally reported to show the effectiveness of the proposed control scheme