High-gain DC-DC converter with extremum seeking control for PV application

This chapter presents a novel approximation-based extremum-seeking control (AESC) method for the maximum power point tracking (MPPT) problem for the solar photovoltaic (PV) system. Generally, rapid solar radiation and temperature variations make the MPPT problem more challenging in the solar PV system. Besides solving the MPPT problem, the model-free nature of the suggested (AESC) method makes it easy to implement. This feature leads to more precise and faster tracking of maximum power point (MPP) in sudden changes of ambient temperature and solar irradiation as an important factor in MPPT. A high voltage-gain DC-DC converter is utilized in combination with the AESC approach to track the MPP which acts as a power interface between load and panels. The utilized structure has several advantages such as high gain step-up ability per used devices, continuous input current, simple structure, and common ground between source and load. Simulations were performed in MATLAB®-Simulink® and the proposed approach was studied for two scenarios that investigate the impacts of solar radiation and temperature on the solar system. Based on simulation results, the proposed method reduces the oscillations around the MPP of the PV system more significantly compared to the conventional P&O method and tracks MPP faster than the conventional P&O method.