期刊
SENSORS
卷 21, 期 7, 页码 -出版社
MDPI
DOI: 10.3390/s21072388
关键词
piezoelectric; piezoelectric ceramic; lead zirconate titanate (PZT); polyvinylidene fluoride (PVDF); energy harvesting; efficiency; efficiency measurement; power conversion; power flow
资金
- Internal science fund of Brno University of Technology [FEKT-S-20-6205]
- European Union [857306]
- Ministry of Education, Youth and Sports under OP RDE grant [CZ.02.1.01/0.0/0.0/17_043/0010085]
Efficiency of piezo energy harvesters (PEHs) was measured using a new measurement system that can directly establish efficiency for different vibration parameters without the need for PEH parameters. The standard concept yielded higher values, especially in PVDFs, due to low device stiffness causing high displacement and reduced mechanical power. Main sources of loss were identified as damping from surrounding air and internal/interlayer friction causing thermal losses.
Measuring the efficiency of piezo energy harvesters (PEHs) according to the definition constitutes a challenging task. The power consumption is often established in a simplified manner, by ignoring the mechanical losses and focusing exclusively on the mechanical power of the PEH. Generally, the input power is calculated from the PEH's parameters. To improve the procedure, we have designed a method exploiting a measurement system that can directly establish the definition-based efficiency for different vibration amplitudes, frequencies, and resistance loads. Importantly, the parameters of the PEH need not be known. The input power is determined from the vibration source; therefore, the method is suitable for comparing different types of PEHs. The novel system exhibits a combined absolute uncertainty of less than 0.5% and allows quantifying the losses. The approach was tested with two commercially available PEHs, namely, a lead zirconate titanate (PZT) MIDE PPA-1011 and a polyvinylidene fluoride (PVDF) TE LDTM-028K. To facilitate comparison with the proposed efficiency, we calculated and measured the quantity also by using one of the standard options (simplified efficiency). The standard concept yields higher values, especially in PVDFs. The difference arises from the device's low stiffness, which produces high displacement that is proportional to the losses. Simultaneously, the insufficient stiffness markedly reduces the PEH's mechanical power. This effect cannot be detected via the standard techniques. We identified the main sources of loss in the damping of the movement by the surrounding air and thermal losses. The latter source is caused by internal and interlayer friction.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据