A hybrid rectifier with dual-modes SECE method for piezoelectric energy harvesting

Due to the dynamic changes in vibration, energy harvesting using Piezoelectric Transducers (PZT) faces challenges with limited harvesting power. Hence, this paper presents a hybrid rectifier with dual-modes Synchronous Electric Charge Extraction (SECE) method for harvesting piezoelectric energy, aiming to achieve a higher output power. In situations where electric energy is insufficient, the rectifier operates in the passive SECE mode, enabling energy harvesting without a power supply and helping to self-start faster. When there is sufficient electric energy, it adaptively switches to the active SECE mode to enhance harvesting efficiency. Measurements indicate that the maximum power harvested in the passive SECE modes can be up to 2 times that achieved with the traditional full-bridge rectifier, and the peak conversion efficiency reaches 83% in the active SECE mode.