This paper presents an analytical method for the design and power optimization of vacuum-packaged piezoelectric energy harvesters. It is shown that the maximum power point of a vacuum-packaged energy harvester is different from the conventional one which occurs when the electrical damping ratio equals to its mechanical counterpart. Also, it is shown that the captured power by a vacuum-packaged energy harvester is highly sensitive to the vibration frequency due to very low-mechanical damping ratio, e.g., up to 50% power drops corresponding to 2% deviations in the frequency. The analysis and design are performed in the context of an ac-line magnetic field energy harvester in which the line frequency is also fixed and this energy harvester is useful for developing the self-powered wireless monitoring devices. Furthermore, the vacuum-packaged devices are inherently robust against dust storm and icing phenomenon, which occur for overhead power lines. The proposed analytical method is established based on simplified assumptions and then an accurate method is developed for the analysis of vacuum-packaged devices. Obtained theoretical results are verified in the laboratory through a prototype of the vacuum-packaged piezoelectric device, which captures up to 90 μW from a 10-A line current.

中文翻译：

---

用于为智能电网监控设备供电的真空封装压电能量采集器


本文提出了真空封装压电能量收集器的设计和功率优化的分析方法。结果表明，真空封装能量收集器的最大功率点与传统能量收集器的最大功率点不同，该最大功率点出现在电阻尼比等于其机械阻尼比时。此外，结果表明，由于机械阻尼比非常低，真空封装能量采集器捕获的功率对振动频率高度敏感，例如，频率偏差 2% 时功率下降高达 50%。分析和设计是在交流线磁场能量收集器的背景下进行的，其中线频率也是固定的，并且该能量收集器对于开发自供电无线监控设备非常有用。此外，真空封装的器件本身就能够抵抗架空电力线发生的沙尘暴和结冰现象。所提出的分析方法是基于简化的假设建立的，然后开发了一种用于分析真空封装器件的准确方法。所获得的理论结果在实验室中通过真空封装压电器件原型进行了验证，该器件可从 10A 线路电流中捕获高达 90μW 的功率。