SMO-based fault tolerant control design for three phase induction motors

In present paper, an active fault tolerant control (FTC) system is proposed for three phase induction motor (IM) drives subjected to the mechanical faults caused by both stator and rotor failures. FTC design consists of two main parts. The first part is design of a nominal controller in the fault-free case to achieve control objectives. In this work, a feedback linearizing controller has been employed. The second one is the design of a sliding mode observer (SMO) in order to estimate additive faults which model mechanical faults and production of extra control inputs for compensating their undesirable effects on IM performance. SMO is also used for online estimation of axial fluxes in the both conditions. The simulations are performed using Matlab/Simulink software to illustrate the effectiveness of the proposed FTC scheme.