Autonomous hybrid power system control integrating wind, solar PV, biomass, and battery storage

Recent advancements in decentralised renewable energy offer solutions for reliable grid-based power in remote Indian regions. This study introduces an AHDES (autonomous hybrid distributed energy system) for rural electrification, integrating solar, wind, biomass, and battery storage. A DFIG converts wind energy, with PV panels as the primary source, supported by a biomass generator and battery bank. An SPWM inverter ensures constant voltage and frequency at the PCC, replacing the conventional back-to-back converter for rotor power supply. Converter output current-based maximum power point tracking (COCB-MPPT) is anticipated. This process exploits the relationship between the converter output current and duty ratio to routinely fine-tune step fluctuations, thus maximising power output from the PV panel. In this study, a VFCL (voltage and frequency closed loop) controller combined with a harmonic filter is employed as a voltage controller to reduce the THD percentage. The AHDES topology is simulated in MATLAB and experimentally validated under various operating conditions. Test results presented indicate that the VFCL control strategy effectively maintains the stator voltage at 415 V and the frequency at 50 Hz under all conditions. Further, measured THD values remain below 3 % for voltage and below 6.5 % for current. This demonstrates that the hybrid Solar PV-wind-biomass AHDES maintains stability. Furthermore, the results confirm that the VFCL controller with a harmonic filter is an effective approach for mitigating voltage instability.