Study of the effect of different configurations of bypass diodes on the performance of a PV string

Abstract

In this paper, the impact of different configurations; overlapped and non-overlapped, of bypass diodes on the performance of a photovoltaic (PV) module under varying levels of shading, are investigated using a simulation approach alleviating the need for complex modelling using numerical techniques. MATLAB/Simulink models have been developed for 18 series-connected solar cells in the commercially available KC200GT PV module. Simulation results show that the non-overlapped configuration of bypass diodes outperforms the overlapped scheme in terms of the energy yield and the number of local maximum power points in the power-voltage characteristic of a PV module. The overlapped scheme can lead to an increased number of local maximum power points placing onerous demands on the design of the maximum power point tracker required to track the global maximum power point.