This article proposes a modular stacked multiport wireless energy interconnection (WEI) system with a virtual ac bus for multisource and multiload wireless power transfer (WPT) applications, which has the following advantages. 1) It can serve as an interface for WPT among multiple sources and loads. 2) Bipolar coils are adopted to eliminate the undesired cross-coupling among multiple coils, which simplifies the complexity of system modeling and power flow control. 3) The relay coil with constant current characteristics is introduced as a virtual ac bus, from which the derived multicoil structure provides the bidirectional channel for power transfer between any two ports. 4) System applicability and scalability are greatly enhanced due to the modularization of coils, power converters, and compensation circuits. For power flow control, the hybrid phase-shifted control method matched with the WEI system is applied, in which the power flow direction is determined by the external phase-shifted angles between ports, whereas the power values are regulated by the internal phase-shifted angles. Furthermore, the peak value of the current of the virtual ac bus, as an intermediate control variable, is controlled to be constant; thus, distributed control can be further realized. Finally, a four-port experimental prototype was built and experiments were carried out under different operating conditions. The efficiency curves and loss distribution, as well as the tolerance analysis of coil misalignments, are given. From the experimental results, the effectiveness of the proposed system architecture and its power flow control strategy is verified.

中文翻译：

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具有虚拟交流总线的模块化堆叠多端口无线能源互联系统及其潮流控制策略

本文提出了一种用于多源和多负载无线功率传输 (WPT) 应用的具有虚拟交流总线的模块化堆叠多端口无线能量互连 (WEI) 系统，该系统具有以下优点。1）它可以作为WPT在多个源和负载之间的接口。2）采用双极线圈，消除了多个线圈之间不希望的交叉耦合，简化了系统建模和潮流控制的复杂性。3) 将具有恒流特性的继电器线圈作为虚拟交流总线引入，由此衍生的多线圈结构为任意两个端口之间的功率传输提供双向通道。4）由于线圈、功率变换器和补偿电路的模块化，大大增强了系统的适用性和可扩展性。对于潮流控制，采用与WEI系统相匹配的混合相移控制方法，其中功率流向由端口之间的外部相移角决定，而功率值由内部相移角调节。进一步，将虚拟交流母线的电流峰值作为中间控制变量控制为恒定；从而可以进一步实现分布式控制。最后，搭建了一个四端口实验样机，并在不同的运行条件下进行了实验。给出了效率曲线和损耗分布，以及线圈错位的容差分析。从实验结果来看，验证了所提出的系统架构及其潮流控制策略的有效性。