MPPT Technique With Improved FOCV Control Applied to a Full Active Rectifier for Low-Voltage Piezoelectric Energy Harvesting

An improved ultra low power fractional open circuit voltage (FOCV) MPPT implementation for the inductorless full active rectifier (FAR) piezoelectric energy harvesting interface is presented in this brief. The proposed MPPT reduces the circuit’s disconnection time from the load by performing sampling of the optimal output regulation voltage in only half of a period. Additionally, the power consumption of this approach is remarkably low since it relies on a limited number of mainly passive components. The experimental results from the discrete circuit prototype revealed that the proposed MPPT strategy has 91% efficiency and a power conception of
$0.3mW$
. Furthermore, the system operates at very low open circuit voltages (VOC) in the order of
$0.5V$
with high efficiency thanks to the FAR interface.