Intelligent-based AT-SHAPF control for enhanced power quality in SOFC-driven hybrid system

Integrating Solid Oxide Fuel Cells (SOFCs) with the electrical grid and diesel generators at the point of common coupling forms a hybrid power system. However, power converters and nonlinear loads contribute to voltage drops and current distortions, especially under dynamic and imbalanced load conditions. Transient mismatches between supply and demand can lead to voltage instability, while the electrochemical response of SOFCs causes oxidant flow disturbances, accelerating H₂ starvation, O₂ imbalance, thermal stress, and efficiency loss. This study proposes a novel Adaptive Neuro-Fuzzy Inference System (ANFIS)-controlled Adaptive Tunable Shunt Active Power Filter (AT-SHAPF) to enhance power quality in Solid Oxide Fuel Cell (SOFC)-driven hybrid systems under unbalanced supply and nonlinear load conditions. The core contribution lies in employing ANFIS for intelligent real-time compensation of harmonics and reactive power, outperforming conventional Proportional-Integral (PI) and Fuzzy Logic Controllers (FLC). The system is evaluated using MATLAB/Simulink to analyze key performance metrics: Total Harmonic Distortion (THD), Current Distortion Factor (CDF), and true power factor. Without compensation, THD reaches 29.31% and 28.68% under steady and dynamic load conditions, respectively. With compensation, PI-based AT-SHAPF reduces THD to 5.88% and 5.46%, FLC-based to 3.22% and 4.03%, and ANFIS-based to 1.63% and 1.98%. Additionally, the Instantaneous Reactive Power Theory (IRPT) is applied for real-time reference current generation, enabling precise compensation. The proposed ANFIS-controlled AT-SHAPF demonstrates superior adaptability, power factor correction, and harmonic suppression compared to traditional methods.