Robust direct voltage control of stand-alone DFIG wind systems using a fractional-order fuzzy logic approach

This paper proposes a novel control strategy for stand-alone doubly fed induction generator (DFIG)-based wind energy systems by integrating fractional-order operators into a fuzzy logic control (FLC) framework. Conventional FLC approaches typically use integer-order operators, which may restrict the system's adaptability and dynamic performance. In this work, the standard integral and derivative components are replaced with fractional-order counterparts, resulting in a fractional-order fuzzy logic (FOFL) controller with a more flexible and tunable control architecture. This enhancement enables finer adjustment of the system response and improved robustness against external disturbances. The FOFL controller is applied within a direct voltage control (DVC) scheme to control the stator voltage and frequency. The performance of the proposed FOFL-DVC strategy is validated through simulation in MATLAB/Simulink and real-time experimental testing using a dSPACE-1104 platform. Results demonstrate that the FOFL-DVC strategy achieves high performance under both steady-state and transient conditions, ensuring stable operation under various wind speed and load disturbance.