A high effectiveness impact-optimized piezoelectric energy harvesting interface system

Abstract

This paper presents a novel high-performance impact-optimized interface system for an impact-driven piezoelectric energy harvester (PEH) which utilizes two independent parallel harvesting plans, that is, low-efficiency self-powered passive path and high-efficiency active maximum power point tracking (MPPT)-based path, for different situations based on the characteristics of the input excitation and stored energy content which are evaluated by the mode detection unit. It uses a synchronous electrical charge extraction-based self-powered passive circuit as a primary energy extraction strategy. Thus, the proposed structure is self-sustained with cold start capability. When the determined prerequisites are met, the system switches to the secondary energy extraction strategy, that is, high-efficiency MPPT-based path, in which during the maximum power point sensing phase, the PEH is sensed without disconnecting it from the interface and during the maximum power point setting phase, a bidirectional DC/DC converter performs a fully bidirectional energy transfer, increasing the extraction efficiency. The proposed system is designed and simulated using standard 180 nm complementary metal-oxide semiconductor (CMOS) technology. Post-layout simulation results show that when the input energy content is around 50 µJ, the FoMMOPIR, periodic harvesting efficiency, shock harvesting efficiency, MPPT efficiency, and effectiveness of the proposed system are 505%, 65%, 80%, 70%, and 56%, respectively.