A Novel MPPT Technique Based on the Envelope Extraction Implemented With Passive Components for Piezoelectric Energy Harvesting

This article presents a rectifierless synchronized switch harvesting on inductor interface with a novel maximum power point tracking (MPPT) technique assistance for piezoelectric energy harvester (PEH). The proposed MPPT solution captures vibration states through an envelope extractor and then adjusts the rectified voltage to achieve the maximum power harvest. The MPPT method tracks the vibration amplitude through an envelope extractor, which no longer disconnects the PEH from the converter to measure its open-circuit voltage. Hence, energy harvesting and maximum power point finding can be achieved simultaneously. Besides, the MPPT solution was implemented through discrete passive analog components with ultralow power consumption, which can achieve the MPPT operation when the harvester was cold started. The experiment confirms the simplicity and efficiency of the proposed MPPT solution for the PEH, and the maximum MPPT efficiency can reach 99.5%.