Dual input buck-boost converter for hybrid piezoelectric energy harvester - Supercapacitor sources

Integration of energy sources provides superior flexibility and reliability in low power electronic system. A dual input positive buck-boost converter is proposed for integrating piezoelectric energy harvester (PEH) and supercapacitor sources. The converter circuit consists of three active power switches, a common inductor, and an output filter capacitor. The active switch connected with the PEH is operated at the optimum duty cycle for maximum power extraction through impedance matching. The voltage at the output can be regulated by adjusting the duty ratio of the active switch connected with the supercapacitor. The charging mechanism of supercapacitor from a piezoelectric energy harvester is also presented. The operational performance of the proposed system is verified through simulation and validated by experimental investigation. The output power is measured for the range of load resistance, and a maximum power of 4.48 mW with the efficiency of 59% is obtained for the load resistance of 22 k Omega. (C) 2019 Elsevier GmbH. All rights reserved.