Self-Powered Multi-Input Serial SSHI Interface Circuit With Arbitrary Phase Difference for Piezoelectric Energy Harvesting

A self-powered multi-input serial synchronized switch harvesting on inductor (MIS-SSHI) interface circuit with arbitrary phase difference for piezoelectric energy harvesting is proposed in this article. The proposed MIS-SSHI can extract energy from multiple PZTs based on S-SSHI technique and handle inductor access conflict to avoid mutual influence between the PZTs, without using extra inductor access controlling circuit. Four cases of different phases between PZTs are discussed to explain how to handle the inductor access conflict. Besides, the diodes in traditional S-SSHI circuit are removed to improve the conversion efficiency. An experimental platform is built for testing the power generation performance of the proposed circuit. The experimental results show that the proposed MIS-SSHI circuit can harvest energy from two PZTs with arbitrary phase difference (0-2π) based on single inductor. The maximum harvested power of the proposed MIS-SSHI circuit for single PZT can reach 3.7 times that of the standard energy harvesting circuit.