Robust Power Electronic Converter Fault Detection and Isolation Technique for DFIG Wind Turbines

This work proposes a robust fault detection and isolation (FDI) technique for power electronic converters (PECs) operating doubly fed induction generators in wind turbines. More precisely, a diagnosis system able to detect and isolate open-switch faults is developed. It combines fault indicators based on the Clarke transformation of the converter currents and a statistical change detection algorithm, namely a cumulative sum (CUSUM) algorithm, that detects significant changes in the variance of the stator reactive power. This allows a reduction of the false alarm rate compared to an approach relying exclusively on the current analysis. The performance of the FDI technique is verified by both simulation and
experimental studies.