Multi-Mode Operation and Seamless Transition for Grid-Interactive Wind, Solar, and Diesel Generation Based Hybrid AC/DC Microgrid

This paper presents the operational strategy and controller implementation of a grid-interactive hybrid AC/DC microgrid for remote areas, which possess favorable wind and solar generation capabilities but have unreliable grid connection. The AC/DC microgrid, operable in both gridinteractive and islanded conditions, employs wind generation through doubly-fed induction generator (DFIG), meanwhile, solar generation is facilitated by a solar photovoltaic (SPV) array. During islanded operation, the self-sufficiency of the microgrid to supply local AC/DC loads, is assisted by a diesel generator (DG) set. For economic benefits, the DFIG and SPV array are operated for peak power extraction, while the DG set is operated within an optimal fuel utilization zone. The microgrid structure is instilled with an uninterrupted supply feature at all possible operating modes, as well as with a seamless mode transition functionality. These features are administered through the controlled operation of three distinct solid-state transition switches. The overall microgrid control framework utilizes an arctangent least mean logarithmic square (ATLMLS) algorithm. The ATLMLS-based control framework is designed to enable smooth operation at mode transition scenarios, while ensuring uninterrupted supply for local loads. The AC/DC microgrid operation and control are verified using results from MATLAB/Simulink platform.