Dynamic Analysis of a Transient-Motion Piezoelectric Energy Harvester Using Equivalent Circuit Modelling

This chapter presents a detailed investigation into the dynamics of transient-motion piezoelectric energy harvesters (TM-PEH), focusing on their optimization through equivalent circuit modeling. The study begins by addressing the limitations of traditional piezoelectric energy harvesters, which often struggle with narrow operational bandwidths and the need for high-frequency excitation. The chapter introduces a beam plucking mechanism that extends operational bandwidths and improves energy harvesting efficiency in random environmental vibrations. A key contribution is the development of an equivalent circuit model (ECM) for TM-PEH, which facilitates system-level simulations and integrates considerations for nonlinear power extraction circuits. The ECM is used to analyze the effects of initial position, stop position, and mover's speed on the harvester's performance. A notable finding is the identification of a 'decoupling velocity' threshold, above which the harvester's efficiency declines. Additionally, the chapter explores the Self-Powered Synchronous Electric Charge Extraction (SP-SECE) circuit, which enhances the TM-PEH's efficiency by leveraging improved electromechanical coupling. The parametric study reveals that the SP-SECE circuit significantly boosts energy harvesting capabilities, particularly at the decoupling velocity, where it captures nearly four times more energy than standard circuits. This chapter offers a comprehensive analysis and innovative solutions for optimizing piezoelectric energy harvesters in transient motion scenarios.