面向体域网的无线电能传输网络关键技术研究

For the sensor nodes in Body Area Network (BAN) implanted inside or nearby the human body, the volume of battery need to be reduced at the cost of the working life in order to ensure human comfort. Currently, much more energy consumed as the sensor nodes need to carry more functions and better performance, the thought that depending on saving energy and reducing energy loss to extend the life of the sensor nodes has limitations. The continuous energy supply can be realized to the sensors in BAN using wireless energy transfer based on magnetic resonant coupling by installing the resonators inside the sensor nodes. As the simulation and calculation methods according to specified topology are failed caused by limb swing or posture change, the high frequency electromagnetic model and numerical method suitable for sensor nodes in BAN under time-varying state are proposed. The resonators with micro-size and excellent transfer performance will be designed. The influence of spatial distribution, posture and energy transfer path of the sensor nodes on transfer performance under static and dynamic state will be studied respectively. The study will provide theoretical guidance and research foundation to solve the problems such as maximum energy transfer efficiency, transfer stability and the optimal path selection in the application of wireless energy transfer used in BAN.

体域网传感器节点因植入体内或放置在体域范围内，为保证人体舒适度需要缩小节点电池体积，牺牲工作寿命。因当前传感器节点逐渐向承载更多功能、更优性能的趋势发展，需要消耗更多的能量，传统的依靠节能和低功耗方式提高节点工作寿命的思路存在局限性。本项目拟采用磁谐振无线电能传输方式为体域网续供能量，将谐振器内置于传感器节点中组成体域无线电能传输网络。由于人体四肢摆动或姿势改变会导致按照特定拓扑结构进行模拟和计算的方法失效，本项目提出研究适用于体域网节点时变状态的无线电能传输网络高频电磁模型和数值计算方法，设计微尺寸、优传输性能节点用谐振器，考查无线电能传输网络节点处于静态和动态变化情况下空间分布、姿态以及能量传输链路的差异对传输性能的影响规律，为系统在体域环境获得最大传输能效、各节点稳定传能、随动最优链路选择等实际应用涉及的问题，提供实用化的理论指导，为无线电能传输在体域网供电的广泛应用提供研究基础。

本项目研究了适用于体域网节点时变状态的无线电能传输网络高频电磁模型和数值计算方法，采用耦合模模型和互感理论模型分析了磁谐振式输电技术的能量传播原理与特性。在硬件平台及实验研究方面，搭建了以E类功放作为系统电源的单源多用户无线电能传输系统，论证分析了系统各部件和总体的传输规律、特性。研究分析了在负载一定范围内变动的情况下，易受负载变动而影响输出特性的E类功放的输出情况和多用户输电系统的功率、效率与多个影响因素的关系。提出了对无线电能传输系统频率跟踪控制的方法。使用粒子群算法控制发射端信号源频率同步跟踪振荡电路固有谐振频率，并结合Matlab仿真验证了频率跟踪控制的有效性。经实验验证，频率跟踪控制系统对传输系统在过耦合处，存在频率分裂现象时的负载电压有明显提升。