Bidirectional Modeling of Thermoelectric Module Using MATLAB/Simulink for Circuit Simulations

This paper presents a complete model for thermoelectric modules (TEMs) for use in circuit simulations using MATLAB/Simulink software. The purpose of this study is to develop a single block similar to other circuit elements in the Simulink library by combining both the thermoelectric generator (TEG) and thermoelectric cooler (TEC) module parameters and their operations. Since TEG and TEC are both thermoelectric devices, mostly whose main material, such as Bi₂Te₃, is the same for similar temperature ranges, a TEG can be operated as TEC and vice versa a TEC can be operated as TEG. In some systems, such as PV-thermoelectric (TE), fuel cell-TE, and battery temperature management of electric vehicles, modules can be used in both modes. In addition, in some cases of these systems, the TEM may need to be operated as a generator and sometimes as a cooler. The bidirectional operation of a TEM is a cost-saving approach because the two types of TEMs do not need to be installed together. This study proposes a novel model, whereas the studies to date in the literature have not been fully compatible with the bidirectional usage of modules. The proposed model deals with the polarities of both the thermal and electrical ports of the TEM to determine the mode of operation, that is, TEG or TEC. The maximum and performance parameters for both the TEG and TEC operations are included in the module block to observe and control the device under the desired operating conditions. It can be seen that the simulations with temperature-dependent parameters gave very close results to the graphics of the datasheet. However, simulations in which Thomson heat is not ignored have more deviations compared to the datasheet. Moreover, the simulations with constant material properties provided better results than those with Thomson heat in the cases of higher $\Delta \text{T}$ levels. When $\Delta \text{T}$ is 10°K, $COP_{max}$ without Thomson heat was found to be 3.399, which is the same as the datasheet. Meanwhile, $COP_{max}$ with Thomson heat was found to be 3.7147 and $COP_{max}$ with constant properties was 3.8057. However, when $\Delta \text{T}$ is 50°K, $COP_{max}$ is 0.247 without Thomson heat, which is the same as the datasheet, but $COP_{max}$ is 0.341 with Thomson heat, and $COP_{max}$ is 0.268 with constant material properties. In addition, it is shown that under variable polarities of thermal and electrical ports, bidirectional operation of the TEM is successfully achieved, and the TEM is operated as both TEG and TEC in the same simulation.