提升磁谐振无线电能传输水平的有源中继技术研究

For the issues that magnetically coupled resonant wireless power transfer (MCR-WPT) system pursues to enhance the transmission distance, transmission power and transmission efficiency and is heavily affected by the variations of surrounding environment and self parameters, resulting in low reliability, this application will propose the active relay method. The design method of convenient, high-efficiency, and light active relay is studied and a plan of connecting the relay source like active power filter is proposed to avoid the use of wires. The schemes of magnetic-filed-orientation concentration and current shifting are studied to reveal the mechanism of enhancing the MCR-WPT transmission level under the use of active relay. The cooperating control method of transmission source and relay source is studied to guarantee the stability of power transmission with maximum efficiency and the finite-control-set model predictive control is used to improve the dynamic response. The features of this application is that, via analyzing the scheme, the proposed systems take the active relay as the active relay station for magnetic energy transmission, by changing the relay coil currents, effectively concentrate the magnetic field, enlarge the magnetic field intensity around the receiving coils, increase the equivalent power factor, reduce the losses of transmitting coils and transmitting source, and then make a further step to enhance the transmission distance, transmission power and transmission efficiency. On the other hand, the proposed system increase the control freedom of degree and then guarantee the stability of power transmission and optimize the system efficiency.

针对磁谐振无线电能传输系统亟待提高传输距离、传输功率和传输效率，且受周围环境和自身参数变化影响大，可靠性低，提出有源中继方案。研究有源中继机构便捷、高效、轻型化设计，并提出类似有源电力滤波器方式的中继电源接入方法，避免导线连接；研究磁场取向集中和电流转移原理，在此基础上揭示有源中继作用下传输距离、传输功率和传输效率提升机理；研究发射电源和中继电源协同控制方法，保障最大效率下功率平稳传输，并基于有限控制集模型预测控制技术，改善系统动态响应。本申请特色在于，以有源中继作为磁场能量传递的主动接力站，通过人为改变中继线圈电流，从原理上分析，能够有效实现磁场取向集中，增强接收线圈附近磁场强度，提高等效功率因数，减少发射线圈和发射电源损耗，使传输距离、传输功率和传输效率得到进一步提升，并增加控制自由度，有利于保障功率传输平稳性和实现系统效率优化。

无线电能传输能否像有线输电一样成为一种通用技术，其传输水平是人们共同关心的问题。传输结构是决定磁谐振无线电能传输水平的关键。目前，主要有两线圈、四线圈和无源中继三种传输结构。相比之下，加入无源中继单元，可以有效增加传输距离，并有可能提高传输效率，但还存在传输水平存在提高空间、传输平稳性难以保障和效率优化难以实现等问题。为此，本课题提出有源中继方案，通过主动改变中继线圈电流，增加控制自由度，进一步提升传输水平，并有利于保障功率传输平稳性和实现效率优化，从而丰富中继技术的内涵与形式。.本课题围绕“有源中继”，分别从设计、机理和控制方面寻找提升磁耦合无线电能传输水平方法。设计方面，提出了基于开关型控制可变电容的有源中继线圈，实现中继电源便捷独立接入和轻型化；提出了一种通用精确的线圈参数理论计算方法，为研究有源中继线圈高效轻型化设计提供重要支持；拓展至多接收系统，提出了多频谐振补偿网络的一般性设计方法，该方法适用于任意数量、任意谐振频率接收装置。机理方面，建立系统损耗模型，从减少总体损耗方面揭示了有源中继技术提升磁谐振无线电能传输效率机理；建立系统电磁仿真模型，从磁场取向集中作用方面揭示了有源中继技术提升磁谐振无线电能传输功率机理。控制方面，首次提出了无线电能传输系统有限控制集模型预测控制方法，极大地提高了系统动态响应速度；拓展至多接收系统，提出了多频调制与控制方法，该方法仅依靠发射侧单一逆变器可以实现多接收输出电压独立、连续和准确调节，无需额外硬件电路，有效降低开关频率，计算负担小，易于拓展。