Increasing of Harvested Power in DMPPT-based PV Systems by a New Scan Method

In photovoltaics (PVs) applications, some limitations in power optimizers, such as voltage, current, and gain, would result in multiple maxima in the string's power-voltage (P-V) curve; therefore, constant DC-link voltage or centralized MPPT may lead to finding the wrong maxima in the P-V curve. On the other hand, power mismatches in submodules cause multiple maxima in the P-V curve of the PV panel, even if it is equipped with SPO. This paper focuses on a solution for multiple power-peak issue by presenting a P-V scan method. This method is added to the control system of both SPOs and central inverter. During this, the voltage is varied in a desired range until the most efficient operating voltage is recognized and adjusted, resulting in more harvested power by preventing the system's operation in local maximum power point. The main concepts of this paper are reemphasized through a set of simulations.