功率匹配型高效无线电能传输系统结构与控制技术研究

Low transmission efficiency and electromagnetic radiation pollution are the two challenges of the Electric Vehicle Wireless Power Transfer (WPT) technology. In order to simplify the system, improve the work reliability and transmission efficiency, this project studies the power matching structure and advanced control technology of the magnetic induction WPT, which has lower electromagnetic radiation pollution. The improvement of the system structural, topology and the magnetic design of the transformer are discussed to overcome the low transmission efficiency of the WPT. The system efficiency and reliability are improved by advanced control technology. The main research contents are as follows. The power automatic matching three-stage structural and topology without dead-time of the magnetic induction WPT system are researched to avoid the wireless communication of electrical signals. The system is simplified and the reliability is improved. The dead-time is eliminated and the loss of the power devices is reduced. The DC voltage utilization is improved. The magnetic core, winding design method and compensation strategy of the non-contact DC Transformer is analyzed combining with the topology. The transmission efficiency is improved and the volume can be reduced. The advanced topology and control technology which can realize the energy interaction between the batteries and the power grid is discussed. The high efficiency and reliability in the process of energy transfer are ensured. The implementation of these techniques will provide new ideas for the multilevel power matching, topology and transformer integration and islanding detection.

低传输效率和电磁辐射污染是目前电动汽车无线电能传输技术面临的两大难题。本项目以简化系统、提高工作可靠性和传输效率为目标，研究电磁辐射污染较小的磁感应式电动汽车无线电能传输系统的功率匹配结构与先进控制技术，从结构拓扑的改进和变压器的磁设计两个方面克服磁感应式无线电能传输效率低的问题，并通过先进控制技术提高系统效率和可靠性。主要研究内容有：研究高效磁感应无线电能传输系统的变换器自动功率匹配三级式结构与无死区拓扑，省去电气信号的无线通信，简化系统并提高工作可靠性，消除死区，减小功率器件损耗并提高直流电压利用率。研究与拓扑集成的非接触式直流变压器磁芯、绕组设计方法和补偿策略，提高传输效率、减小体积。研究实现动力电池与电网能量交互的先进拓扑与控制技术，保证能量传输的高效与高可靠性。这些技术的实现将为多级式功率匹配、拓扑和变压器集成以及无畸变抗孤岛效应检测等研究方向提供新思路。

本项目针对三级式无线电能传输系统，研究其AC/DC、DCT和DC/DC级的拓扑和关键控制技术，提出了可以实现能量双向流动的无死区AC/DC变流器拓扑和绕组耦合型DC/DC变换器拓扑，针对AC/DC拓扑，通过无锁相、半周期等双向控制技术降低了系统工作时对电网的污染，通过无功功率闭环被动孤岛检测技术实现了系统的双向V2G可靠并网，针对DC/DC拓扑，通过容错控制技术提高了系统工作可靠性，并结合拓扑，提出了磁耦合机构的EMC抑制方案，提高了系统效率。最终AC/DC级效率达到99.1%，DCT和DC/DC级效率达到96%，系统级联效率为95.1%，达到了预期目标。上述技术的实现为无线电能传输系统的高效、可靠性充电机并网的研究方向提供理论支撑，在现有研究成果的基础上，进行了多端口扩展研究，为系统进一步的整车集成提供了新思路。