Reliability enhancement of thermoelectric power conversion and management using geothermal energy for stand-alone applications

摘要

A thermoelectric Generator (TEG) is one of the most interesting types of power supply for stand-alone applications by dint of its long lifetime and high reliability. In this paper, a TEG is used to harvest waste heat from geothermal energy. To develop a practical TEG power supply system, power conversion and management stages between the TEG module and the load are mandatory, the latter being employed to regulate the output voltage of the TEG module since the variation in the thermal gradient between the geothermal energy and the environment. Moreover, this power conversion stage should harvest the maximum of the available electrical power using Maximum Power Point Tracking (MPPT) algorithms. In the state-of-the-art, two DC-DC converters are usually used to perform the MPPT and the output voltage regulation. This paper proposes a novel approach, enhancing the reliability of the power source, by reducing the number of switches or by using functional redundancy. Both topologies we proposed can perform the MPPT and the output voltage control. They have been modelled and simulated in Matlab/Simulink; the obtained results confirm that the two proposed topologies have the same performances and allow enhancing the overall system's reliability and increasing its life time.