Power-Extraction Circuits for Piezoelectric Energy Harvesters in Miniature and Low-Power Applications
Power-Extraction Circuits for Piezoelectric Energy Harvesters in Miniature and Low-Power Applications
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DOI：
10.1109/tpel.2012.2192291
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发表时间：
2012-11-01
影响因子：
6.7
通讯作者：
Yeatman, Eric M.
中科院分区：
文献类型：
--
作者：
Dicken, James;Mitcheson, Paul D.;Yeatman, Eric M.
当压电能量采集器连接到简单的负载电路时，压电元件能够产生的阻尼力通常低于最大化发电的最佳值。旨在增加压电能量采集器的功率输出的电路通过修改压电电流源驱动其电荷的电压来实现。本文提出了一个系统的分析和比较的所有主要类型的功率提取电路，允许这种阻尼力增加，在理想和现实的约束。特别强调的是低幅度操作。一个电路称为单电源预偏置显示收获更多的权力比以前的方法。大多数分析的电路能够增加功率输出这样做，通过电感器同步反相或充电的压电电容。对于电感Q值仅大于2的情况，单电源预偏置电路的功率密度最高。在传导路径中不存在二极管，可以用最少数量的同步整流器实现，这意味着输入激励幅度在可以提取功率之前不需要克服最小值，使得其特别适合于微尺度应用或幅度变化较大的应用。
When a piezoelectric energy harvester is connected to a simple load circuit, the damping force which the piezoelectric element is able to generate is often below the optimal value to maximize electrical power generation. Circuits that aim to increase the power output of a piezoelectric energy harvester do so by modifying the voltage onto which the piezoelectric current source drives its charge. This paper presents a systematic analysis and comparison of all the principal types of power extraction circuit that allow this damping force to be increased, under both ideal and realistic constraints. Particular emphasis is placed on low-amplitude operation. A circuit called single-supply prebiasing is shown to harvest more power than previous approaches. Most of the analyzed circuits able to increase the power output do so by synchronously inverting or charging the piezoelectric capacitance through an inductor. For inductor Q factors greater than around only 2, the single-supply prebiasing circuit has the highest power density of the analyzed circuits. The absence of diodes in conduction paths, achievable with a minimum number of synchronous rectifiers, means that the input excitation amplitude is not required to overcome a minimum value before power can be extracted, making it particularly suitable for microscale applications or those with a wide variation in amplitude.