Design and Analysis of Switching Circuits for Energy Harvesting in Piezostrutures

Kim, Woon Kyung

Design and Analysis of Switching Circuits for Energy Harvesting in Piezostrutures

dc.contributor.author	Kim, Woon Kyung	en
dc.contributor.committeechair	Kurdila, Andrew J.	en
dc.contributor.committeemember	Inman, Daniel J.	en
dc.contributor.committeemember	Priya, Shashank	en
dc.contributor.committeemember	Burns, John A.	en
dc.contributor.committeemember	Erturk, Alper	en
dc.contributor.department	Mechanical Engineering	en
dc.date.accessioned	2014-03-14T20:15:11Z	en
dc.date.adate	2012-08-21	en
dc.date.available	2014-03-14T20:15:11Z	en
dc.date.issued	2012-08-06	en
dc.date.rdate	2012-08-21	en
dc.date.sdate	2012-08-13	en
dc.description.abstract	This study deals with a general method for the analysis of a semi-active control technique for a fast-shunt switching system. The benefit of the semi-active system is the reduction in power consumption, which is a significant disadvantage of a fully active system compared with a passive system. A semi-active system under consideration is a semi-actively shunted piezoelectric system, which converts the strain energy into electrical energy through strong electromechanical coupling achieved though the piezoelectric phenomenon. Our proposed semi-active approach combines a PZT-based energy harvesting with a fast switching system driven by a Pulse-Width Modulated (PWM) signal. The fast switching system enables continuous adaptation of vibration energy control/harvesting by varying the PWM duty cycle. This contrasts with a conventional capacitance switching system that can only change the capacitance at discrete values. The analysis of the current piezoelectric system combined with a fast-switching system poses a considerable challenge as it contains both continuous and discrete characteristics. The study proposes an enhanced averaging method for analyzing the piecewise linear system. The simulation of the averaged system is much faster than that of the time-varying system. Moreover, the analysis derives error bounds that characterize convergence in the time domain of the averaged system to the original system. The dissertation begins with the derivation of the equations governing the physics of a piezostructure combined with an electrical switching shunt network. The results of the averaging analysis and numerical simulation are presented in order to provide a basis for estimating the structural responses that range between open- and short-circuit conditions which constitutes two limiting conditions. An experimental study demonstrates that the capacitive shunt bimorph piezostructure coupled with a single switch can be adjusted continuously by varying the PWM duty cycle. And the behavior of such hybrid system can be well predicted by the averaging analysis.	en
dc.description.degree	Ph. D.	en
dc.identifier.other	etd-08132012-110953	en
dc.identifier.sourceurl	http://scholar.lib.vt.edu/theses/available/etd-08132012-110953/	en
dc.identifier.uri	http://hdl.handle.net/10919/28646	en
dc.publisher	Virginia Tech	en
dc.relation.haspart	Kim_WK_D_2012.pdf	en
dc.relation.haspart	fig1p1a_fairuse_results.pdf	en
dc.relation.haspart	fig1p1b_fairuse_results.pdf	en
dc.rights	In Copyright	en
dc.rights.uri	http://rightsstatements.org/vocab/InC/1.0/	en
dc.subject	PWM signal	en
dc.subject	averaging method	en
dc.subject	switching circuit systems	en
dc.subject	energy harvesting	en
dc.subject	piezoelectric material	en
dc.subject	hybrid continuous-discrete system	en
dc.title	Design and Analysis of Switching Circuits for Energy Harvesting in Piezostrutures	en
dc.type	Dissertation	en
thesis.degree.discipline	Mechanical Engineering	en
thesis.degree.grantor	Virginia Polytechnic Institute and State University	en
thesis.degree.level	doctoral	en
thesis.degree.name	Ph. D.	en