Effective fault tolerant control design for nonlinear systems: application to a class of motor control system

An effective fault tolerant control design for nonlinear systems is described. The proposed approach detects the occurrence of a fault in the closed loop system and switches itself between a control strategy designed for nominal operations and a robust control strategy designed for faulty conditions. It achieves a compromise between the need for high performance and robustness by integrating the most advantageous features of each control strategy. The proposed control design is applied to a class of motor control characterised by its highly nonlinear and multivariable dynamic system, induction motor (IM) drives. Simulation experiments in terms of speed and flux responses show the applicability of the proposed approach to IMs subject to faulty conditions caused by a combination of thermal and mechanical stresses for good performance.