Efficiency improvement of partially shaded photovoltaic panels

Layouts of domestic photovoltaic solar plants can be problematic due to obstacles that shade panels. This limits the total available area and, if not adequately considered, can deeply affect the efficiency of the plant. In this paper, a circuit that recovers generated power efficiency when a small number of cells of a panel are partially or totally shaded is proposed. This circuit is constituted by DC/DC converters that are connected in parallel to cells and that balance power generation. This solution is borrowed by architectures used to balance charge/discharge of lithium ion batteries. Simulation results and experimental measurements performed on a prototype version of the circuit are reported and described together with its advantages and drawbacks.