Individual solar cells balance for maximum power extraction in series arrays

Ladder converter architectures offer substantial improvements compared to traditional solutions since each converter only needs to process the power difference between series connected photovoltaic (PV) devices (module, substring, cells). A strategy for balancing the current produced by each cell is studied in this work, using a group of DC-DC buck-boost converters. A controller capable of profiting from the distributed structure and tracking the maximum power point (MPP) is proposed. Simulation results show that the control strategy effectively drives the system to the optimum operating point even when there are changes on the cell illumination.