Compatibility assessment of TEGs arrangement coupled with DC/DC converter to harvest electricity from low-temperature heat sources

Abstract

Expanding intelligent control systems based on the Internet of Things (IoT) requires powering sensors, actuators, and wireless data transfer, which may be located off-grid or difficult to access. Energy harvesting from industrial excess heat by thermoelectric generators (TEGs) can help to overcome challenges ahead. A fully integrated TEG system, however, remains an obstacle to the effective conversion of heat into electricity for IoT applications. The purpose of this paper is to investigate experimentally the electrical arrangement of TEGs and the design of a DC-DC boost converter in order to optimize the harvesting of electrical power from low-temperature sources of heat in TEG systems. The results of this study provide a guide for selecting a suitable arrangement in a system with several TEGs as well as for the design of matched DC-DC converters with desired electrical generators and consumers. This study shows the impact of specialized arrangement of TEGs in a power generation system to optimize the output power of a DC-DC converter. Accordingly, the most suitable electrical combination of four TEG modules among series, parallel-series, and parallel connections is discussed with heat source temperatures lower than 55 °C, between 55 and 75 °C, and higher than 75 °C. Based on the results of the studied TEG system, it is determined that using inductors and capacitors lower than 0.33 µH and 0.47 µF, respectively in the converter’s circuit decreases the output power dramatically, and delays the startup point to higher heat source temperatures.