Buck Converter for Low-Power PV Modules: A Comparative Study ^†

Autonomous sensors that harvest energy from the environment usually employ a dc/dc converter to regulate the operating voltage of the energy transducer around its maximum power point (MPP). In this context, this work evaluates the efficiency of a buck converter when regulating the operating point of two low-power photovoltaic (PV) modules subjected to different irradiance levels. The buck converter operates in burst mode (BM) and is able to transfer the energy from the PV module to a storage unit through an optimal value of the inductor current. Experimental results show that an irradiance increase can cause either an increase or a decrease of the converter efficiency. This is because the higher the irradiance, the higher both the MPP voltage and current of the PV module, which involve opposite effects in terms of the converter efficiency.