Improved Interface Circuit for Enhancing the Power Output of a Vibration-Threshold-Triggered Piezoelectric Energy Harvester

Jiqiang Liu,Qisheng He,Dacheng Xu,Xinxin Li,Ruofeng Han,Junjie Yang

doi:10.3390/en13153830

Abstract

The vibration-threshold-triggered piezoelectric energy harvester is a new type of piezoelectric energy harvester with a two-stage structure, which can generate electricity in a low frequency environment and recognize vibration intensity at the same time. In this study, a theoretical model of a vibration-threshold-triggered energy harvester was examined, and an equivalent circuit model of the energy harvester was obtained. Then, an interface circuit was proposed that can significantly improve the output power of the energy harvester. The interface circuit achieved impedance matching with the piezoelectric material to maximize the energy collected from the energy harvester. First, we calculated and analyzed the impedance characteristics of the energy harvester, based on the equivalent circuit model. It was found that because the piezoelectric material is in resonance as the energy harvester is in operation, the corresponding impedance is almost resistance. Therefore, a resistance-matching strategy was proposed. Last, we proposed an interface circuit with adjustable input impedance to achieve resistance matching. The experimental results show that the proposed interface circuit can increase the output power of the energy harvester by 48.1–55.7% over that achieved with the standard interface circuit.

Highlights

The study of wireless sensor nodes has made great progress in recent years, accompanied by the rapid development of Internet of Things technology
5.5set g, which ensured the energy harvester by the energy harvester, the vibration acceleration was to 5.5 g, which that ensured that the energy would be triggered all threeatfrequencies
To improve the interface circuit of the vibration-threshold-triggered piezoelectric energy harvester, we modeled and analyzed a vibration-threshold-triggered piezoelectric energy harvester, and established an equivalent circuit model

Summary

Introduction

The study of wireless sensor nodes has made great progress in recent years, accompanied by the rapid development of Internet of Things technology. The power supply problem remains a limiting factor in the development of wireless sensor nodes. It is effective to use energy from the environment to power wireless sensor nodes, so energy harvesters that convert energy that is present in the environment into electrical energy are attracting increased attention [1,2]. Converting vibration energy into electrical energy is a new research hotspot [3,4]. Vibration energy harvesters are classified as electrostatic [5], piezoelectric [6], triboelectric [7], and electromagnetic [8]. Piezoelectric vibration energy harvesters are increasingly being used to power sensor nodes, due to their simple operation and high energy density. Many recent reports focus on piezoelectric energy harvesters.

Methods

Results

Conclusion