An Active Approach to Model-based Fault Tolerant Control System Design for Three Phase Induction Motors

In this paper, a model-based active fault tolerant control system (FTCs) is proposed for three phase induction motor (IM) drives subjected to the mechanical faults caused by both stator and rotor failures. FTCs structure consists of two main parts. The first part is a nominal controller based on feedback linearization for fault-free case to achieve control objectives (rotor flux and speed control). The second part is a sliding mode observer (SMO) in order to estimate additive faults which model mechanical faults in the state space model of IM. This observer has been used not only for fault reconstruction and production of additional control inputs for compensating their undesirable influences on performance of IM, but also for online estimation of axial fluxes in any operating conditions. The simulations results are shown to illustrate the effectiveness of the proposed approach to compensate the mechanical faults in IM.