Desenvolvimento de um aparelho para caracterização de dispositivos termoelétricos

Abstract

Thermoelectric devices allow the generation of electricity from a temperature difference or the reverse process, i.e., produce a temperature difference by applying an electric potential. However, one of the limiting factors of this technology is its low energy conversion efficiency, which restricts its widespread use. This work aims to develop an equipment for conducting tests on thermoelectric devices of different technologies, with the purpose of understanding the fundamental electronic and thermoelectric mechanisms related to their operation. The equipment includes two sets of temperature controllers, which, through the PID controller composed of temperature sensor and heating and cooling elements, can adjust the temperature. Another important item in the project is the use of an external analog-to-digital converter, improving the reading resolution of the equipment, allowing reading of lower voltages with greater accuracy. This element is fundamental for reading the tests performed and transmitting to the microcontroller. Once the microcontroller obtains the test data, these data will be processed and displayed in a program developed in Python language. The program allow display graphs of internal resistence and Seebeck coefficient, according to the applied temperature difference. These parameters are some of the essential parameters for calculating the efficiency of the material, given by the dimensionless figure of merit. It is expected that, with the development of this equipment, it will be possible to conduct tests on commercial and laboratory-made thermoelectric devices, obtaining the electronic and thermoelectric parameters, thus allowing comparison between different topologies and technologies, to identify their limitations and propose solutions to increase their energy conversion efficiency.