A Self-Powered FBRJT AC-DC Conversion Circuit for Piezoelectric Energy Harvesting Systems

Abstract

In this study, a complete model for a miniature excitation-powered piezoelectric generator (PG), analysis modes of operation and control of a full-bridge joule thief (FBRJT) circuit to identify the optimal points were investigated. The proposed model revealed the PG’s power dependency on mechanical excitation, acceleration, and frequency and defined the load behaviour for power optimisation. The proposed circuit, namely FBRJT, was integrated with the conventional full-bridge rectifier (FBR) in Stage 1 for AC-DC conversion and with the joule thief circuit in Stage 2 for DC-DC conversion. This integration acted as a boost converter without utilising the duty cycles and additional switching components. The electrical nature of the input of FBRJT with a simple structure, sensor-less control and auxiliary circuits showed a consistent agreement with the investigated testing scenarios using both ideal and impedance power sources. Additionally, the performance of the proposed circuit was also verified against the published results of power electronics circuits. The developed versatile circuit and control system can be utilised for many applications, such as mobile battery charging and energy harvesting.

Analysis of the Methods for Realization of Low-Power Piezoelectric Energy Harvesting Circuits for Wearable Battery-Free Power Supply Devices

“…In the last 2 years, various practical realizations of piezoelectric power conversion devices have been published [85,94,[99][100][101][102][103]. In this section, seven devices for piezoelectric energy harvesting are presented and compared.…”

“…The fourth selected work [102] was conducted by M. Kamran et al They proposed a topology called full-bridge joule thief (FBRJT). In this topology, the authors used a fullbridge rectifier with a buck/boost converter.…”

“…With this topology, the authors achieved an even higher output energy of 5.5 mW and a slightly higher efficiency of 72.3% in comparison to the FBRJT topology. The schematic consists of two stages, a classical full-bridge rectifier and a buck/boost converter, and conducts six modes of operation, as described in [102]. The authors claim that the simplicity of this schematic, e.g., the use of coil coupled feedback instead of logic control, reduces the self-consumption power and improves the efficiency of the device [95].…”

“…In the Table 3, a comparative representation of the investigated devices [85,94,[99][100][101][102][103]] is presented. The most important parameters such as the output power reached and/or the efficiency for each device are presented.…”

A Self-Powered VDJT AC–DC Conversion Circuit for Piezoelectric Energy Harvesting Systems

“…In practice, PGs are confined to low-power domains in the micro/milliwatt category caused by physically constrained features like internal capacitance and resistance [1][2][3][4]. They can withstand extremely high pressure but have minimal strain and make huge material quantities challenging to use [5][6][7][8][9]. In contrast, most anticipated excitations are generally in the range of 0.1 to 1 kHz and produce low voltage levels, whereas most electronic equipment requires 3 to 5 V dc.…”