压电动能收集电路极限俘能性能研究

Harvesting mechanical vibration energy using piezoelectric materials can provides clean energy for powering distributed devices, such as wireless sensor nodes; in the meanwhile, by removing redundant vibration energy from a mechanical structure, the overall damping effect is increased, and structural safety is reinforced. Literature shows that the improvement of energy harvesting circuit leads to a significant increase on the harvesting capability of a piezoelectric energy harvesting system. New circuit topologies continuously refreshed the record of harvesting capability during the last decade; yet, the maximum energy harvesting capability, which can be achieved via circuit modification, is still vague. This project investigates the theoretical maximum of energy harvesting capability. Based on that, possible solution for further circuit improvement is explored. Under such a goal, the objective function corresponding to the energy harvesting capability is first derived. The theoretical maximum of harvesting capability is then solved out. The harvesting capabilities of existing circuit are uniformly described using the impedance model, so that the constraints introduced by difference practical circuit topologies, as well as the gaps between the harvesting capabilities of existing topologies and theoretical maximum, can be comparatively studied. With these theoretical knowledge, a multiple synchronized switching interface circuit, which can achieve higher harvesting capability, is designed and implemented. This study provides both theoretical and practical guidance for the design and optimization of piezoelectric energy harvester, in particular, future development of synchronized switching interface circuit.

使用压电材料收集环境中的机械振动能量可以在收获清洁能源为诸如无线传感器节点等分布式设备供电的同时增加系统阻尼以降低多余振动对机械结构安全的威胁。以往研究表明，能量收集电路的改进对压电能量收集系统俘能性能的提升具有显著作用。新的电路拓扑不断刷新俘能性能的纪录，然而通过电路手段所能达到的俘能性能极限至今仍不明晰。本项目深入分析该俘能性能的理论极限，并以此为依据探索能进一步提升俘能性能的可行电路方案。为了实现此研究目标，我们将首先推导对应俘能性能的目标函数；从理论上求解能量收集电路的俘能性能极限；使用阻抗模型对已有压电能量收集电路的俘能性能进行统一表述；进而研究不同实际电路拓扑所引入的约束，及其俘能性能与理论极限之间的差距；最后给出使用多次同步开关翻转实现更高俘能性能的电路方案与工程实现。该课题的探索将为压电能量收集器的设计与优化，尤其是能量收集开关界面电路的进一步发展，提供理论与实践的指引。

我们的日常环境中充斥着有害的机械振动，使用压电换能器以及相应的电力电子功率调理电路对这些机械振动能量进行收集利用，可以在收获清洁能源为诸如物联网传感器节点等分布式设备供电的同时增加系统阻尼以降低多余振动对机械结构安全的威胁。以往的压电动能收集电路设计缺乏清晰的设计思路与严谨的设计准则。有鉴于此，本研究着力在五个方面探讨压电动能收集电路的极限俘能性能。具体的研究内容包括：明确压电动能收集系统改进的根本目标；建立能抽象概括不同电路的电气特性的系统动态模型；对收集电路俘能性能极限的理论分析；探讨通过电路创新有目的地逼近极限俘能性能；以及新型压电能量收集电路的宽频性能研究。五部分的研究内容皆顺利按时执行。本项目最重要的贡献在于对机电动能收集电路的极限俘能效能进行数学抽象，进而实现理论优化和更深入的认识。这一理论是开展压电动能收集电路的研究数十年以来所未明确提出之根本认识。在该理论的指导下，我们按图索骥，迅速提出并实现了两款新型的压电能量收集电路，打破了保持了数年的已有电路俘能效能的纪录。在完成本项目各项研究目标的过程中，课题组成员先后开发了三款新型压电俘能电路原型机，在国际学术期刊与会议发表了近20篇相关的技术论文，提交了两项发明专利申请。在此科研成果的基础上，我们开始开展与相关企业的合作探索，务求将在本项目资助下所得到的科研成果转化为实际生产力。