Novel principle for characterizing the material-level parameters of a thermoelectric generator module

Accurate characterization of all the three material-level parameters, i.e., thermal conductivity, Seebeck coefficient and electrical resistivity, is a premise for performance evaluation or degradation analysis of both the lab-made and commercial thermoelectric generator (TEG) modules. The recently reported quasi-steady-state (QSS) method can directly derive all the three temperature-dependent parameters through in situ TEG module characterization but shows a poor efficiency. This paper presents a modified QSS method based on stepped temperature rise for a high implementation efficiency. Both the optimal ‘width’ and ‘height’ of each step are elaborately specified. Its feasibility is then validated using a high-fidelity transient TEG model, which considers all the related effects and key irreversible factors. According to the simulations, the modified method has a 108 times higher efficiency than that of the original QSS method. Finally, the practicality of this modified method is explored by tests, which shows a consistent accuracy compared to the original method. Therefore, the modified QSS method is more practical, because it can greatly improve the efficiency on the premise of ensuring the accuracy with its similarity to the original QSS method. All the principle, method and conclusions can assist TEG performance estimation and guide the design of large-scale power systems.