Cascaded simplified fuzzy logic-FOPID control of DSTATCOMs in electric vehicle-integrated microgrids

This paper proposes a cascaded simplified PD-like fuzzy logic controller and fractional-order PID (SFLC + FOPID) control strategy for DSTATCOMs in electric vehicle-integrated microgrids. The simplified fuzzy logic controller employs a reduced rule base, preserving effective nonlinear control characteristics while significantly lowering computational burden. The cascaded FOPID enhances tuning flexibility and robustness against system uncertainties, improving both transient and steady-state performance under voltage disturbances. A constrained optimization framework is formulated to tune the controller parameters to achieve fast voltage regulation and enhanced dynamic response. To validate the proposed approach, five recent metaheuristic algorithms, Starfish Optimization Algorithm (SFOA), Mountaineering Team-Based Optimization, Animated Oat Optimization Algorithm, Enzyme Action Optimizer, and Rapidly-Exploring Random Trees-based Optimizer, are employed for parameter tuning and performance comparison. Simulation results confirm that the proposed SFLC + FOPID-controlled DSTATCOM achieves superior voltage regulation and robustness compared to the PI and FOPI, the cascaded FOPI controller, the simplified fractional-order fuzzy logic controller (SFO-FLC), and the two-input FO-FLC. In addition, the results demonstrate the superiority of SFOA in tuning the SFLC + FOPID parameters relative to the other algorithms.