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

This paper proposes a robust fault detection and isolation (FDI) technique for the power electronic converter (PEC) of doubly-fed induction generator (DFIG) wind turbines (WTs), and in particular for open-circuit faults herein. It combines fault indicators based on the processing of 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 reactive power. This allows for a reduction of the false alarm rate compared to an approach relying exclusively on the current analysis. The proposed FDI technique is validated by means of both simulation and experimental results.