Theoretical and behavioral analysis of power optimizers for grid-connected photovoltaic systems

Abstract

During the generation of electricity from a grid-connected photovoltaic (PV) system, non-uniform conditions are common. Such conditions occur when cells and/or PV modules of a PV system operate at different irradiances and/or temperatures. In this case, there is a limitation of operating power by the modules in the worst conditions. Thus, several PV architectures seek to mitigate losses under these conditions, such as power optimizers for PV systems (POPS). On that occasion, the paper presents theoretical aspects and experimental setup, filling a gap in the literature. For this, firstly, the theoretical curve of different converters is shown, and the temperature influence on the number of POPS in a string. Subsequently, the behavior of POPS in simulation and experimental is analyzed. As a result, a high-power extraction gain is seen compared to the conventional PV system in mismatch conditions, reaching 26.76% in relation to conventional architecture. Furthermore, the behavior of POPS works by compensating for input and output variables. With this behavior and the gain provided, POPS can be considered for scenarios with non-uniform conditions, especially if it is certified viability in simulations of PV software.

Keywords

• Power optimizer
• POPS
• Shading
• Mismatch
• Photovoltaic architectures