A Self-Powered S-SSHI and SECE Hybrid Rectifier for PE Energy Harvesters: Analysis and Experiment

A self-powered hybrid rectifier based on the association of series synchronized switch harvesting on inductor (S-SSHI) and synchronous electric charge extraction (SECE) is proposed for piezoelectric (PE) energy harvesters, aiming to achieve a good balance between the rectifier peak output power (RPOP) and optimal rectified voltage range (ORVR). The theory and simulation of the hybrid rectifier are presented with a good agreement. The measurements demonstrate that the prototyped hybrid rectifier can output the peak power of 0.28 mW and obtain the maximum end-to-end efficiency of 72.8% under PE open-circuit voltage of 6 V. It can achieve 1.55 times the RPOP of the SECE rectifier and 4.58 times the ORVR of the S-SSHI rectifier. The balance between the two indexes grasped in the hybrid rectifier is better than the others in the test. According to the estimation of FoM, BW0.9, and RoI0.9 factors, the overall performance of the hybrid rectifier is at the same level compared to state-of-the-art rectifiers. Additionally, the hybrid rectifier is easy to implement with some simple discrete components, which can be an alternative rectifier solution for PE harvesters.