Detection and isolation of faults on the rotor side converter of doubly fed induction generators

Abstract

This article presents a fault diagnosis strategy for open switch faults in the rotor side converter of doubly fed induction generators. The proposed strategy uses state observers based on dynamic models obtained from an approach based on differential geometry. These observers allow the generation of residue signals that are sensitive to each fault and insensitive to disturbances. From these signals a residual vector is constructed with information that can be used for the detection and isolation of the fault. The detection strategy consists of evaluating the envelope of the module of the residual vector. Isolation requires evaluating the region of the plane described by the residual vector and comparing that region with the one associated with each fault scenario. Finally, results are presented where it is demonstrated that the proposal allows to detect, isolate and identify open switch faults, both single and multiple, even against parametric errors and other disturbances.