Research on control methods of wind–solar hybrid power generation system

Wind–solar hybrid power generation systems effectively utilize the natural spatiotemporal complementarity of wind and solar resources to realize a continuous and stable off-grid power supply, which has become one of the important development directions of distributed renewable energy. The maximum power point tracking (MPPT) control and battery charging management are the core technologies that determine the energy conversion efficiency and operational reliability of the whole system. In this paper, the mathematical models of wind turbine, photovoltaic array, and lead–acid battery are established, and the energy conversion mechanism and dynamic output characteristics are analyzed in depth. An integrated coordinated control scheme combining the perturbation and observation MPPT algorithm and a three-stage charging strategy is proposed. A dedicated wind–solar hybrid controller is developed based on the PIC16F877A microcontroller, including dual buck DC/DC conversion circuits, voltage and current detection modules, MOSFET drive circuits, and modular software design. Simulation and experimental results show that the proposed control method can achieve fast and stable MPPT under variable illumination and random wind speed conditions, with the tracking efficiency reaching 92%–96%. The three-stage charging strategy effectively suppresses battery overcharge, thermal runaway, and irreversible sulfation and significantly prolongs the service life of the energy storage unit. The system has the advantages of high efficiency, strong robustness, low cost, and high engineering practicability, which can provide an important reference for the design and application of small- and medium-sized off-grid wind–solar hybrid power generation systems.