A Low-Power Thermoelectric Energy Harvesting System for High Internal Resistance Thermoelectric Generators

This paper presents an energy harvesting system targeted to harness energy from a high internal resistance thermoelectric generator (TEG) under low temperature difference condition. The system is based on a DC-DC boost converter with a maximum power point tracking scheme. An optimal current control scheme and zero current switching technique are applied for low power consumption and high efficiency. An analysis on power losses of the system is performed. A prototype system is built to show the performance and to verify the theoretical analysis. Experimental results show that the proposed system can harvest enough power to run a wireless sensor node at a transmission cycle of 30s with a minimum input power of 27 mu W and a low temperature difference of 1.9K across the TEG. The peak efficiency of the power conversion can reach 75.2% in the considered input voltage range.