Optimization Strategies and Nonlinear Control for Hybrid Renewable Energy Conversion System

This paper focuses on controlling and optimizing a hybrid renewable energy system. The complex interactions and intermittent nature of renewable sources pose challenges to grid stability, necessitating sophisticated control strategies. The system includes a photovoltaic generator and a wind energy conversion system with a permanent magnet synchronous generator. Two key innovations are presented: i) connecting the photovoltaic generator to the grid in hybridization with the wind turbine without using a DC/DC converter, simplifying the structure, reducing losses, and ensuring grid stability and reliability; and ii) designing multi-objective controllers using the maximum power point tracking method based solely on electrical parameters, leading to fewer sensors and higher reliability compared to previous methods that required additional measurements like wind speed and irradiance. To address these challenges, a multiloop nonlinear controller is proposed, employing integral sliding mode and backstepping design techniques based on an accurate nonlinear system model. The stability of the multiloop control system is ensured using a suitable Lyapunov function.