MPP tracking of PV based low voltage DC microgrid system with adaptive droop algorithm

Several control methods are available in the literature for maximum power point (MPP) tracking, load sharing etc. in a photovoltaic (PV) based microgrid system. This paper proposes an adaptive droop based MPP tracking and load sharing of PV based dc microgrid. For this, proportional droop index (PDI) algorithm is introduced, which is a function of normalized current sharing difference and losses in the output side of the converters. This proposed control method calculates adaptive virtual resistance Rdroop, and allows the converter to operate at MPP. By fine tuning Rdroop values, the proposed method also eliminates poor voltage regulation issues of the conventional droop method. The detailed analysis and design procedure are explained and the effectiveness of proposed method is verified by detailed simulation analysis.