A Series Compensated Buck-Boost Converter-Based Thermoelectric Energy Harvesting System with Sliding Mode Controller

A thermoelectric generator (TEG) is a semiconductor-based device that can exhibit a flow of electric current through the external circuit if the sides of the TEG are subjected to a temperature difference caused by a heat source. The terminal voltage and the TEG's internal resistance are altered depending on the temperature difference. Therefore, a suitable power electronic converter with a maximum power point tracking (MPPT) feature is required to harvest maximum power from the TEG and store the harvested energy in a battery-based energy storage system. This paper investigates a novel energy harvesting methodology from TEG using a series compensated buck-boost converter (SCBBC). MPPT has also been implemented using a sliding mode controller (SMC). A mathematical model of a TEG source has been developed in MATLAB-Simulink and tested with generic boost converter (GBC) and SCBBC for their dynamic performances during battery charging. The efficiency of conversion is found to be higher for SCBBC, at 97.87%. An experimental prototype has been developed with SCBBC and tested for two configurations, viz high voltage and low current configuration. The former configuration exhibits an efficiency of 86.3%, while the latter has an efficiency of 83%. The results indicate that SCBBC, along with SMC, opens up new efficient prospects for harvesting waste heat energy using TEGs.