Synchronous Buck-Boost Converter for Energy Harvesting Application

High-temperature thermoelectric generators (TEGs) can be exploited for electrical energy harvesting in a variety of industrial processes that generate excess heat. In order to harvest the maximum amount of energy, a power converter in combination with a maximum power point tracking (MPPT) algorithm is required. This work presents a different approach of using a synchronous buck-boost converter in combination with the perturb and observe (P&O) MPPT algorithm, that uses a variable step size control for improved dynamics. The buck-boost converter is connected to a battery, that is being charged using the TEGs. Experimental results of the implemented MPPT algorithm are shown to prove that the converter reaches the maximum power point in a reasonable time interval. The measured efficiency of the converter is between 96-and 97 %.