Online stator and rotor fault diagnosis in induction machines by H∞ observer and sliding mode estimator

This paper proposes an innovative fault-diagnosis system for an Asynchronous machine. Stator and rotor faults are identified and analyzed such as inter turn faults resulting in the shorting of one or more circuits of stator phase winding, broken rotor bars. The model used is the one developed by [13]. The proposed strategy consists in developing an observer based on H_∞ Control theory followed by a sliding mode estimator. The performance index, the parameter that permit to differentiate between faults and disturbances or noise, for the H_∞ observer followed by the sliding mode estimator is the amplitude and the frequency. Simulations with a nonlinear Machine model were carried out which demonstrated the effectiveness of the proposed algorithm. Moreover, the robustness properties of the used H observer and the sliding estimator exhibited significant rejection of disturbances and noise-effects attenuation which make the proposed strategy adequately close to the conditions of the real physical system.