Design and Power Quality Improvement of Photovoltaic Power System

This book presents a case study on a new approach for optimum design of rooftop grid-connected Photovoltaic system installation. The study presented in this book includes two scenarios using different brands of commercially available PV modules and inverters. Many different configurations of rooftop grid-connected PV systems have been investigated and a comparative study between these configurations has been carried out taking into account PV modules and inverters specifications. Energy production capabilities, Cost of Energy (COE), simple payback time (SPBT) and Greenhouse Gas (GHG) emissions have been estimated for each configuration using proposed MATLAB computer program. A detailed dynamic MATLAB/Simulink model of proposed rooftop grid-connected PV system is also investigated in this thesis. The system structure (i.e. dual-stage, three-phase grid-connected PV system) comprises a PV array, DC-DC converter, Voltage Source Inverter (VSI), and a low-pass filter. The proposed PV system is tested against different circumstances, which in real facilities can be caused by solar radiation variations. Also, a comparative study between Two-Level VSI (2L-VSI) and Three-Level VSI (3L-VSI) topologies are carried out. The comparison is based on estimation of Total Harmonic Distortion (THD) content in voltage and current waveforms at the Point of Common Coupling (PCC). Also, this book presents a comprehensive small signal MATLAB/Simulink model for the DC-DC converter operated under Continuous Conduction Mode (CCM). Initially, the buck converter is modeled using state-space average model and dynamic equations, depicting the converter, are derived. Then, a detailed MATLAB/Simulink model utilizing SimElectronics ® Toolbox is developed. Finally, the robustness of the converter model is verified against input voltage variations and step load changes.