Harmonic analysis and experimental validation of bistable vibration energy harvesters interfaced with rectifying electrical circuits
Harmonic analysis and experimental validation of bistable vibration energy harvesters interfaced with rectifying electrical circuits
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DOI：
10.1016/j.cnsns.2019.105069
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发表时间：
2020-03
期刊：
影响因子：
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通讯作者：
Chunlin Zhang;R. Harne;Bing Li;Kon-Well Wang
中科院分区：
文献类型：
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作者：
Chunlin Zhang;R. Harne;Bing Li;Kon-Well Wang
通常，高性能非线性振动能量收集器与简化的电阻电路（交流电路）集成时进行研究，而实际上在实际应用中电子设备和可充电电池需要直流电压。为了为实际能量收集系统开发提供一套准确有效的设计指南，提出了一种基于谐波平衡的分析方法来表征稳态性能并研究直流电路效应。在该分析方法的路线中，首先通过基于能量等价的平滑动态响应来近似感应的非线性分段压电电压，这使得随后的谐波平衡操作能够分析估计振动幅度。参数研究显示了耦合常数和阻性负载的优缺点。一方面，随着耦合常数或负载电阻在中等范围内的增加，可以提取更高的电功率。另一方面，较高的压电耦合和电阻负载会损害突跳振动的有益带宽。此外，还通过比较揭示了标准电路和交流电路的不同结构作用。研究发现，交流电路对采集系统表现出等效阻尼效应，而标准整流电路则表现出等效阻尼和等效刚度效应。这些不同的电路效应解释了理论预测和数值验证的现象，即在中等压电耦合常数和电阻负载下，标准整流电路提取的电功率比交流电路少，而当耦合常数或负载电阻相对较大时，标准整流电路的性能优于交流电路。
The high-performing, nonlinear vibration energy harvesters are conventionally investigated when integrated with simplified resistive electrical circuits (AC circuits), while in fact DC voltages are needed for electronics and rechargeable batteries in practical applications. To lead to an accurate and effective set of design guidelines for realistic energy harvesting system development, an analytical, harmonic balance based method is proposed to characterize the steady state performance and investigate the DC circuit effects. During the route of the analysis method, the induced nonlinear, piecewise piezovoltage is firstly approximated via smooth dynamic responses based on the energy equivalence, which enables the followed harmonic balance operation to analytically estimate the vibration amplitude. The parameter studies show the pros and cons of the coupling constant and resistive load. In one side, with increasing the coupling constant or load resistance during their moderate range, higher electric power is extracted. In the other side, higher piezoelectric coupling and resistive load compromise the beneficial bandwidth of snap-through vibrations. Moreover, comparisons are conducted to reveal the different structural roles of the standard electrical circuit and AC circuit. It is found that AC circuit exhibits equivalent damping effect while the standard rectifying electrical circuit exhibits both equivalent damping and stiffness effects to the harvester system. These different circuit effects explain the theoretically predicted and numerically validated phenomena that the standard rectifying electrical circuit extracts less electric power than AC circuit under moderate piezoelectric coupling constants and resistive loads, while outperforms AC circuit when the coupling constants or load resistances are relatively large.