1 Department of Energy Technology, The Faculty of Engineering and Science, Aalborg University, VBN2 Fluid Mechanics and Combustion, The Faculty of Engineering and Science, Aalborg University, VBN3 The Faculty of Engineering and Science, Aalborg University, VBN4 State Key Lab of Power Systems, Department of Electrical Engineering, Tsinghua University,5 Jiangsu Key Laboratory of New Energy Generation, Nanjing University of Aeronautics & Astronautics, Nanjing
To develop practical thermoelectric generator (TEG) systems, especially radioisotope thermoelectric power supplies for deep-space exploration, a power conditioning stage with high step-up gain is indispensable. This stage is used to step up the low output voltage of thermoelectric generators to the required high level. Furthermore, maximum power point tracking control for TEG modules needs to be implemented into the power electronics stages. In this paper, the temperature-dependent electrical characteristics of a thermoelectric generator are analyzed in depth. Three typical high step-up power converters suitable for TEG applications are discussed: an interleaved boost converter, a boost converter with a coupled inductor and an interleaved boost converter with an auxiliary transformer. A general comparison of the three high step-up converters is conducted to study the step-up gain, conversion efficiency and input current ripples. The interleaved boost converter with an auxiliary transformer is found to be the most suitable topology for TEG applications, which is verified by experiments.
Journal of Electronic Materials, 2013, Vol 42, Issue 7, p. 2157-2164
DC-DC converters; power electronics stage; Thermoelectric generator