High-efficiency self-resonant transmitters and receivers for wireless power transfer

无线功率传输具有新兴的和潜在的应用，例如为个人电子设备和电动车辆充电，以及为无线传感器供电。 然而，目前，在距离和效率方面的能力是有限的。这项工作将开发一种新的自谐振结构，以取代现在使用的发射和接收线圈，并能够提高距离和效率。 该结构可以使用低成本无毒可回收材料制造，并且可以扩展到各种功率水平，频率和尺寸。这种新方法的效率提高可以允许从传统的有线连接迁移到无线电力传输，而效率损失最小，同时无线电力的扩展使用可以促进有益的新技术，如低成本传感器网络和电动汽车。用于发射和接收无线功率的谐振电路的品质因数Q是决定可实现的距离和效率的基本品质因数。 在这项工作中开发的新的谐振结构有望实现更高的Q值，从而使更长的距离和更高效率的电力传输成为可能。 除了无线电力传输的应用，在这项工作中开发的方法可能会导致更有效的谐振结构适用于更传统的电力和能源的applications.Two几何形状的谐振结构将开发。 平面版本使用由薄聚合物电介质层分隔的薄箔导体的堆叠。 每个箔比趋肤深度薄得多，从而克服趋肤效应损失。 箔层之间的电容在操作频率下与电流回路的电感谐振，使得主高电流路径完全在线圈内，消除了对离开线圈的高电流连接的需要，以及消除了对外部谐振电容器的需要。 由层形成的电容器还充当镇流器阻抗，以便实现层之间的相等电流共享，这在更传统的分层箔绕组中是一个关键且困难的挑战。平面技术与磁芯结合使用效果最佳，磁芯可形成磁场，以实现发射器和接收器之间最有效的耦合，并通过使磁场平行于箔层来最大限度地减少损耗。 对于软磁材料性能不太好的较高频率应用，将使用在环形衬底上以多个步骤沉积的类似结构来实现相同的优点，而不需要磁芯。

Wireless power transfer has emerging and potential applications such as charging personal electronics and electric vehicles, and powering wireless sensors. However, at present, the capabilities in terms of distance and efficiency are limited. This work will develop a new self-resonant structure to replace the transmit and receive coils now used, and enable improvements in distance and efficiency. The structure can be fabricated using low-cost non-toxic recyclable materials, and is scalable for a wide range of power levels, frequencies and sizes. The increased efficiency of this new approach can allow migration from conventional wired connections to wireless power transfer with minimal loss of efficiency, while expanded use of wireless power can facilitate beneficial new technologies such as low-cost sensor networks and electric vehicles. The quality factor Q of the resonant circuits used for transmitting and receiving wireless power is an essential figure of merit that determines the achievable distance and efficiency. The new resonant structures developed in this work are expected to achieve higher Q and therefore make longer distance and higher efficiency power transfer feasible. Beyond the application to wireless power transfer, the approach developed in this work may lead to more efficient resonant structures applicable to more conventional power and energy applications.Two geometries of the resonant structure will be developed. A planar version uses a stack of thin foil conductors separated by thin polymer dielectric layers. Each foil is much thinner than a skin depth, thereby overcoming skin-effect losses. The capacitance between the foil layers resonates with the inductance of the current loop at the frequency of operation, such that the main high-current path is completely within the coil, eliminating the need for high-current connections exiting the coil, as well as eliminating the need for external resonant capacitors. The capacitors formed by the layers also act as ballast impedance in order to achieve equal current sharing between layers, a critical and difficult challenge in more conventional layered-foil windings. The planar technology works best in conjunction with a magnetic core that shapes the field to achieve the most effective coupling between the transmitter and receiver, and to minimize losses by making the field parallel to the foil layers. For higher frequency applications, where soft magnetic material performance is not as good, similar structures deposited in multiple steps on a toroidal substrate will be used to effect the same advantages without the need for a magnetic core.