Seamless Multimode Control and Operation of a DFIG-SPVA-BES-DG Based Hybrid Power Conversion System With Multiple Transition States

This study presents a hybrid power conversion system comprising a doubly fed induction generator (DFIG) based wind generator, solar photovoltaic array, and battery energy storage, and a diesel generator (DG) set, designed to shield DFIG from grid voltage abnormalities. Key contribution in this work is to ensure uninterrupted power delivery across six operating modes and ten transitions, enabling seamless dynamic performance. This work also ensures operating each renewable energy at maximum power point, regardless of operational modes or transitions. Sinusoidal currents are maintained for DG set, DFIG stator, and grid, even under nonlinear and unbalanced loads, meeting power quality standards. DG set operates within its optimal fuel utilization zone, enhancing efficiency, and reducing costs. Hardware validations in steady-state and dynamic conditions demonstrate stable operation, seamless transitions, and uninterrupted power supply in grid-tied and off-grid scenarios. Maximum utilization of wind and solar energy is achieved, with DG set ensuring adequacy during prolonged off-grid conditions. Results confirm compliance with power quality standards and seamless operation under various dynamic conditions.