Submodule based MPPT with synchronous buck converter under dynamic partial shading conditions

Abstract

In order to obtain more power from photovoltaic (PV) modules under mismatching operating conditions, the submodule-based MPPT technique is an important solution. In this technique, since the power-voltage (P-V) curve of a submodule cannot be multi-peaked, the maximum power point (MPP) tracking (MPPT) is easily achieved through a DC-DC converter connected to each submodule. Since the P-V curve cannot be in a multi-peaked form, the maximum power can be obtained with a simple MPPT algorithm. For this reason, perturb & observe (P&O) algorithm can be chosen. In this study, the behaviour of a submodule-based MPPT with synchronous buck converter (SBC) is investigated for dynamic shading conditions. In addition, submodule-based MPPT and module-based MPPT technique were compared and the comparison was confirmed by simulation studies that submodule-based MPPT performed better. In this context, simulation studies were carried out for different shading conditions. According to the simulation results, the submodule-based MPPT approach achieves greater efficiencies to the module-based MPPT. In some simulations, when the module-based MPPT technique is used, the operation at the local MPP has been realized. In such cases, more advanced algorithms are needed. However, a simple algorithm is sufficient in submodule-based MPPT. The only disadvantage of this MPPT is the high hardware cost. However, the increase in efficiency obtained is at a level that can easily tolerate this cost.