Modeling, control, and analysis of a three-phase hexagonal voltage source converter for grid-connected photovoltaic systems

This paper investigates the operation principle, modeling, and control of a hexagonal converter for grid connected photovoltaic (PV) systems. The hexagonal converter is composed of six conventional two-level voltage source converters (VSCs) in which each VSC module are connected to a string of PV modules. The equivalent circuit model of the proposed topology is first detailed in the abc reference frame and then transformed into the orthogonal dq0 reference frame. To extract the maximum power from the PV arrays, a control scheme for maximum power point tracking, including PWM technique, is developed. The usefulness of the proposed control scheme is verified through simulation under different solar radiation conditions.