A voltage sensing approach for a maximum power tracking in integrated photovoltaic applications

The main aim of this paper is the analysis and experimental evaluation of the performance of a photovoltaic power plant controlled by a dedicated algorithm. This is devoted to the search of the maximum power point during the energy conversion of the photovoltaic panels. The proposed approach uses a control strategy that does not requires the current sensing, which is a main cause of noises, errors and delays during the step by step detection of the working point. Modeling of both the power source and the switching converter is a key step for the implementation of the voltage sensing tracking routine. The proposed algorithm has been implemented in a 8-bit microcontroller. A SEPIC converter topology is the core of the experimental workbench that has been realized with 100 W as rated power. The experimental analyses show a very low noise in the signal sensing and a very fast response of the whole system. This is able to reach suitable working points in less than 100 ms after the a perturbation occurred. The achieved results led to consider this set-up appropriate for a system that is composed by a PV module and an integrated DC-DC converter.