Thermoelectric Generator With Boost Converter as a Portable Power Source for Battery Charging

This research describes a portable power source that harvests energy from waste heat using a thermoelectric generator (TEG). The output voltage and power of TEG depend on the temperature gradient across it. This article describes an experimental investigation to keep the TEG’s cold end temperature low by using phase-changing material (PCM) in the heatsink. Using this setup for a 102 °C heat source results in a temperature gradient of 35 °C, allowing the energy harvesting device to generate 502 mW of power with a voltage of 410 mV. The output voltage of the energy harvesting device is made suitable for any electronics load or for battery charging by dc-dc boost converter. The proposed oscillator-driven self-start-up maximum power point tracking (MPPT) controlled dc-dc converter operates over a wide input voltage and power range of 210 mV (47 mW)–1.5 V (1.48 W). The circuit uses a unique technique for resampling of open circuit voltage which is determined by the change of duty cycle value from steady state. It eliminates the need for periodic sampling. The maximum efficiency of 76.5% at an input voltage of 300 mV and an input power of 242 mW demonstrates that the present work has the potential to become a future portable power bank.