Reconfigurable Buck-Boost Converter with Stacked Resonant Technology for Dual-Polarity Thermoelectric and Photovoltaic Energy Harvesting

This paper presents an energy harvesting interface for simultaneous extraction of dual-polarity thermoelectric generators (TEG) and photovoltaic cells (PV). The reconfigurable buck-boost converter topology is employed to convert positive or negative input voltages into positive output voltages. Compared to the single-source mode, the proposed double-stacking resonant mode (DSRM) increases the conversion efficiency by 5.6% with the same number of switch transitions for synchronous extraction of negative polarity TEG and PV. Utilizing adaptive impedance matching technology, the proposed adaptive maximum power point tracking controller achieves tracking efficiencies ${\gt}\mathbf{9 0 \%}$ in an ultra-wide range of source resistance (10-1500 $\Omega$). Implementation of the converter is carried out in the $0.18 \mu \mathrm{~m}$ process. As demonstrated by simulation results, the peak conversion efficiency of 88.3% is achieved in the DSRM.