A Self-Powered SICE Circuit for Piezoelectric Energy Harvesting With a Complete Charge Extraction Electronic Breaker

In piezoelectric transducer (PZT) energy harvesting, the synchronized electric charge extraction (SECE) technique is recognized for its desirable load-independent performance, while a self-powered SECE system remains a significant area of research. The electronic breaker is favored for its simplicity and reliability for achieving self-powering. However, current electronic breakers used in SECE tend to have a switch conduction time longer than one-fourth of the oscillation period T-LC, which results in charge backflow and compromises its load-independence feature. In this article, a complete charge extraction electronic breaker (CEB) is introduced. The CEB controls the switch-off action of the transistor via an envelope detector, ensuring the complete extraction of the accumulated charge from the PZT. Building upon the proposed CEB, a self-powered synchronous inversion and charge extraction (SP-SICE) circuit is proposed. Simulations and experimental results validate the effectiveness of both the CEB and the SP-SICE circuit. The measurements show that the SP-SICE circuit achieves a peak power output of 333.9 μW and a significantly enhanced load-independence range up to 1000 kΩ, which surpasses other existing techniques. The circuit has a stable output power without the need of a complex maximum power point tracking module, which makes it unprecedented among all relevant papers.