Robust sensor fault detection and isolation for a doubly-fed induction generator

The problem of multiplicative fault detection and isolation (FDI) in the current sensors of a doubly-fed induction generator (DFIG) is considered in the presence of model uncertainty. A residual generator based on the DFIG model is proposed using the structure of the classical generalized observer scheme (GOS). However, each observer in this scheme is replaced by a robust H_-/H_∞ fault detection filter followed by a Kalman-like observer. It turns out that the fault detection/isolation problem then amounts to detecting the appearance of sine waves superimposed to specific components of a white noise vector. A Generalized Likelihood Ratio Test (GLRT) is developed to solve the problem. The complete FDI system is validated through simulations on a controlled DFIG.