High Gain Non Isolated DC Converter Employed in Single-Phase Grid-Tied Solar Photovoltaic Supply System

This article presents a high gain non isolated dc converter (HGNIDC) employed in single-phase grid-tied solar photovoltaic supply system (SPSS). In the proposed power optimized architecture based SPSS, each photovoltaic (PV) module is connected through HGNIDC to the common dc bus. The HGNIDC boosts up the low PV voltage as well as facilitates to harvest the maximum solar energy. For maximum power harvesting, fuzzy logic control (FLC) is used. The FLC enables high conversion efficiency at different weather conditions, fast dynamic response, reduced PV voltage oscillation, and does not require system specifications. For delivering the power to the ac grid from the common dc bus, an H-bridge voltage source converter (VSC) is used. The synchronization of VSC with the utility grid is carried out using an enhanced third-order generalized integrator (ETOGI). The ETOGI is able to extract fundamental grid voltage even under grid polluted conditions such as voltage sag, swell, higher dc-offsets, and harmonics. The performance of the proposed control approaches is validated using MATLAB/Simulink platform. The real time implementation is obtained using DSP board TMS320F28379D on the developed laboratory prototype.