符合人体安全标准的大功率模块化无线充电系统的研究

Wireless charging is the key technology for the popularization of electric vehicles. Yet human safety issue is the bottle neck of the commercialization of wireless charging techniques. International committees such as IEEE has published standards to define the safety limits for human exposure to electromagnetic fields. However, an effective and low-cost solution which can make a high-power wireless charging system compliant with the standards has not been reported. The project utilizes the mechanism of flux cancellation in a multi-winding structure and proposes modular design for high-power wireless charging systems to ensure compliance with the safety standards. First of all, winding optimization is a basic requirement for designing a wireless charging system, so the project proposes a fast winding optimization methodology based on magneto static field calculations. Then, the stray field distribution of multi-winding structures will be studied and more efforts will be put on the method to minimize the stay field by optimizing the shape, size or current ratios of the windings. Based on the multi-winding structure, modular design of a wireless charging system will be proposed. The circuit model of such a system will be provided to investigate the operation and control strategy of the system. Furthermore, the system performance with misalignment between primary and secondary windings will be analyzed and power control method will be proposed to ensure human safety under misalignment conditions. Finally, the ideas and analysis will be verified with a practical 50kW modular wireless charging system built for experiments.

无线充电是促进电动汽车普及的关键技术。无线充电对人体安全的影响问题是其工业化的瓶颈。电机电子工程师协会（IEEE）等国际组织已制定了人体暴露于电磁场的相关安全标准。但是使大功率无线充电系统符合安全标准的高效低成本的解决方案，尚未有报道。本项目利用线圈组合结构产生相互抵消的杂散磁场的机理，提出模块化的大功率无线充电系统，有望填补这一空白。首先，以快速的线圈优化理论为前提，研究线圈组合结构的杂散磁场的分布；然后，对基于线圈组合结构的模块化无线充电系统进行建模分析，并提出适用的控制方案；进一步探讨该系统对位置偏移的耐受，提出在产生位置偏移情况下确保系统符合安全标准的调控方法；最后搭建50kW的模块化无线充电系统，对其安全性、效率、控制以及偏移耐受等主要性能进行验证与评估。

无线充电是促进电动汽车普及的关键技术。无线充电对人体安全的影响问题是其工业化的瓶颈。电机电子工程师协会（IEEE）等国际组织已制定了人体暴露于电磁场的相关安全标准。但是使大功率无线充电系统符合安全标准的高效低成本的解决方案，尚未有报道。本项目提出和研究的模块化大功率无线充电技术，填补了这一空白。本项目取得的主要研究成果包括：提出了基于感量插值和求导的线圈损耗快速计算理论和优化方法，解决了目前基于有限元仿真和穷尽试错的设计方法低效的问题（超预期）；提出模块化无线充电系统在电流相位差和幅值的设计方法，以大幅地降低磁场辐射；提出了模块化无线充电系统的定电压相位差和定电压幅值比的联合控制方法，是模块化无线充电系统正常运行的基础。最终，搭建50kW三模块无线充电系统样机，与国际领先的研究结果对比，实测杂散磁场降低超过38%，远低于安全标准的规定。通过实验证明了本项目所提出的方法和理论的正确性和有效性。