Power Optimization of Systems for Direct Thermal to Electrical Energy Conversion

Thermoelectric generators (TEGs) offer the possibility of extracting electrical power from any heat source, including low-enthalpy heat. The operation of thermoelectric generators is closely related to not only thermal factors but also the electrical load conditions. Consequently, simulations of TEG-based thermoelectric systems require the adequate modeling of both thermal and electric phenomena. In this paper, the developed TEG model is presented and verified through the design of a complete thermoelectric system able to optimize the extraction of electrical power according to the thermal conditions. The system consisted of a TEG, a properly designed low-cost DC/DC converter, and an energy storage element. The DC/DC converter was controlled by a specific algorithm that optimized the electrical power extraction following the maximum power point. The choices adopted for the system design, the implementation of the DC/DC converter, and the algorithm development were verified with experimental measurements.