A flexible power management strategy for grid-connected wind-PV hybrid energy systems

This study proposes a flexible power management strategy (FPMS) for a hybrid renewable energy system integrating a doubly fed induction generator-based wind turbine (DFIG-WT) and a photovoltaic generator (PVG). The system employs three power electronic converters to regulate power flows and interface the generators with the electrical grid. A key innovation of this work is the integration of the proposed FPMS with a direct connection of the PVG to the DC-link of the DFIG-WT, enabling a single grid-side converter (GSC) for grid coupling, thereby reducing switching losses and overall system costs. The FPMS dynamically manages power distribution, ensures uninterrupted supply to both DC and AC loads, and coordinates the rotor-side converter (RSC) and GSC according to sub- and super-synchronous DFIG operating modes. Five operational modes are defined to optimize DC/AC and AC/DC power flows, enhancing system flexibility and maximizing renewable energy utilization. Simulation results demonstrate that the implemented FPMS reduces grid dependency by up to 82.7% for DC loads and 4.76% for AC loads, increases energy injection into the grid, and maintains stable operation under variable wind, solar, and load conditions. These findings confirm that the suggested FPMS improves energy self-sufficiency and operational flexibility, providing an effective energy management framework for the integration of distributed renewable energy sources into the grid.