This article proposes a novel wireless power transfer (WPT) system, which achieves high misalignment tolerance in all directions by using antiparallel windings. The transmitter coil is composed of two parts of wires wound in opposite directions; thus, the magnetic flux with different directions would counteract partly. With the properly designed parameters, the mutual inductance between transmitter and receiver coils could remain constant when misalignment occurs. Therefore, the output power and the efficiency of the system can remain unchanged. Moreover, this article proposes a novel analytical calculation method for mutual inductance based on the truncated region eigenfunction expansion method, which greatly promotes and simplifies the design process of a magnetic coupler. This method solves the problem of mutual inductance calculation with a finite ferrite substrate. Factors that influence the mutual inductance of circular coils are systematically studied based on the method. Finally, an experimental prototype is built to verify the validity of the system. The mutual inductance can remain 97% of the well-aligned value within a 0.1-m misalignment, and the overall efficiency is consistently higher than 90.2%, while the fluctuation of the output power is within 3%.

中文翻译：

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一种基于截断区域特征函数展开法设计的新型全方位抗错位无线电力传输系统

本文提出了一种新颖的无线电力传输 (WPT) 系统，该系统通过使用反平行绕组在所有方向上实现高错位容限。发射线圈由两部分反向缠绕的导线组成；因此，不同方向的磁通量会部分抵消。使用正确设计的参数，发射器和接收器线圈之间的互感可以在发生未对准时保持恒定。因此，系统的输出功率和效率可以保持不变。此外，本文提出了一种新的基于截断区域特征函数展开法的互感解析计算方法，极大地促进和简化了磁耦合器的设计过程。该方法解决了有限铁氧体衬底的互感计算问题。基于该方法系统地研究了影响圆形线圈互感的因素。最后，搭建了一个实验原型来验证系统的有效性。互感可在0.1-m错位内保持97%的良好对齐值，整体效率始终高于90.2%，而输出功率的波动在3%以内。