In this paper power electronics used in PV power generation systems have been reviewed and\nmodelled. PV systems need converters for maximum power point tracking, power conditioning,\nvoltage step-up/down as necessary, and for storage charge-controlling. Inverters are needed for\nAC loads and for utility grid interfacing. The four basic DC-DC converters commonly used with PV\nsystems have been reviewed and modelled. Different DC-AC inverter types and operational architectures\nhave also been reviewed with the two-stage DC-AC inverter, with the point of common\ncoupling (PCC) at the inverter input, suggested as the most cost-effective and efficient architecture\nfor PV-based communal grids. This is because only one inverter is used for the entire system as\nopposed to an inverter for every module string, resulting in higher efficiencies, low cost, and low\nharmonic distortions when compared to systems with PCC at AC terminal. The aim of power conversion/\ninversion is to extract maximum power possible from the PV system and where necessary,\nto invert it at close to 100% as possible. Highlight: 1) DC-DC converters are necessary for power\nconditioning in PV systems; 2) DC-AC inverters are necessary for AC loads and for utility grid interfacing;\n3) DC-AC inverters are also used to control the PV systems when grid connected; 4) Best\ninverter configuration cost-effectively and efficiently allows easy system modifications.
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