Doorsill effect and dependency factor between modules of solar PV array

Modules of solar photovoltaic (PV) array are normally connected in series-parallel pattern. This may causes dependence between PV modules. This dependency produces bad impacts at partial shading condition. To reduce these bad effects optimum configuration should be designed. This procedure needs to find a way to calculate the dependency. Furthermore, power reduction due to shadow is not directly proportional to shadow darkness. At shadow condition, the changes of irradiation intensity would not influence total maximum power point (MPP), as long as this shaded intensity was lower or larger doorsill value. Dependency factor and doorsill effect both could be analyzed by binary coding method which is the aim of this paper.