Experimental Analysis of a Piezoelectric Energy Harvesting System for Harmonic, Random, and Sine on Random Vibration

Abstract

Harvesting power with a piezoelectric vibration powered generator using a full-wave rectifier conditioning circuit is experimentally compared for varying sinusoidal, random, and sine on random (SOR) input vibration scenarios; the implications of source vibration characteristics on harvester design are discussed. The rise in popularity of harvesting energy from ambient vibrations has made compact, energy dense piezoelectric generators commercially available. Much of the available literature focuses on maximizing harvested power through nonlinear processing circuits that require accurate knowledge of generator internal mechanical and electrical characteristics and idealization of the input vibration source, which cannot be assumed in general application. Variations in source vibration and load resistance are explored for a commercially available piezoelectric generator. The results agree with numerical and theoretical predictions in the previous literature for optimal power harvesting in sinusoidal and flat broadband vibration scenarios. Going beyond idealized steady-state sinusoidal and flat random vibration input, experimental SOR testing allows for more accurate representation of real world ambient vibration. It is shown that characteristic interactions from more complex vibration sources significantly alter power generation and processing requirements by varying harvested power, shifting optimal conditioning impedance, inducing voltage fluctuations, and ultimately rendering idealized sinusoidal and random analyses incorrect.

Stochastic Thermodynamics of an Electromagnetic Energy Harvester

“…Both piezoelectric and electromagnetic vibration harvesters are typically operated in resonant structures and can efficiently operate only near resonance, even if electromagnetic harvesters are characterized by higher powers with respect to piezoelectric ones. In the literature, the study of vibration harvesters forced by non-sinusoidal or random vibrations has been deeply carried out in case of piezoelectric technology [ 25 , 26 , 27 ], and in case of hybrid electromagnetic-piezoelectric systems [ 28 , 29 ]. On the other hand, electromagnetic vibration harvesters are typically studied under purely sinusoidal vibrations tuned to their resonance frequency.…”

Stochastic Thermodynamics of a Piezoelectric Energy Harvester Model

“…In particular, the main focus is on their energetic performance, that is on the mechanical and power electronic architectures and on the control techniques leading to the maximization of the extracted power [40,41]. Less attention has been devoted to the case of resonant piezoelectric harvesters excited by non-sinusoidal vibrations or solicited by white noise vibrations [42][43][44][45]. In particular, the theoretical analysis of [42] provided a stochastic description of the output power from resonant energy harvesters driven by broadband vibrations and output power dependence on signal bandwidth was considered.…”

“…[44] proposed a methodology for the probabilistic analysis of a cantilever piezoelectric harvester under white Gaussian noise, without experimental validation. In [45], an experimental analysis on piezoelectric harvesters is carried out in the presence of harmonic, random and sine on random vibrations with particular reference to the electrical power extraction. However, in all previous studies on these energy harvesters no attention was devoted to the analysis of the fluctuations and distributions of relevant quantities such as the extracted power, in the general framework of stochastic thermodynamics of non-equilibrium systems.…”

Demonstrating the effects of elastic support on power generation and storage capability of piezoelectric energy harvesting devices

“…Furthermore, in addition to converting the mechanical vibrations to electrical current, the storage and delivery of this energy to a load is crucial and very challenging in practical conditions. In all realistic applications, the energy harvesting systems are connected to capacitance loads during instantaneous utilization or idle condition (Ali and Ibrahim, 2012; Cryns, 2013; Hagedorn et al, 2013; Morel et al, 2016). For example, a bridge or highway equipped with a PEH device exposed to continuous mechanical vibrations may produce energy more than its requirement at that moment.…”