New Technologies for Efficient Wireless Power Transfer at Distance

远距离无线传输高功率的能力是一个潜在的游戏规则改变者。在这个项目中，我们雄心勃勃地研究中功率（200w）中距离（25m）微波无线传输（WPT）领域。目前微波WPT的研究趋向于功率水平< 1mW的低功率“清除”技术。这对于低功率传感器等应用很有用，但对于需要更高功率的常用无线设备（如智能手机甚至电动汽车）不太可能造成破坏。使用低频电感耦合技术可以实现更高功率的WPT，尽管范围非常短（<20厘米）。因此，我们认为微波WPT是打破更远距离和更高功率障碍的唯一途径。我们打算将商用无人机（Drones）作为一个要求高、附加值高、尚未解决的应用实例。目前的无人机技术是电池驱动的，飞行时间只有20分钟左右。无人机连续飞行的能力将具有高度的颠覆性，使该技术能够获得许多目前无法获得的新应用，例如紧急医疗用品交付等第一反应情况。中等（<25米）范围无线电力传输（WPT）的新策略的发展，允许高效率的端到端能量传输，提供高达200W的直流功率，将改变游戏规则，因为它将在很大程度上抵消目前对可充电电池技术的严重依赖。该提案将提供微波WPT技术的一个步骤变化，以便以一种能源有效的方式允许任意位置的移动电气系统以完全无线的方式连续供电。据我们所知，目前还没有其他研究项目研究过任意方向的移动平台的高效端到端WPT，这些平台能够同时提供近场和远场电力，确保24/7的续航能力。我们打算解决微波WPT中关于发射和接收整流天线（整流天线）技术的复杂研究挑战。我们提出了一种创新的微波WPT系统；(i)可以将功率传输到一个或多个物体，其相对于无线电源的位置是先验未知的；（ii）可以在视线和非视线情况下以任意方向位于彼此的近场或远场；（iii）可以使用小的，任意间隔的发射子阵列来人为地提高发射孔径，因为使用单个传统天线的WPT需要大孔径才能产生合理的效率。这将需要目前超出技术水平的重大创新。(a)近场/远场自动聚焦跟踪天线阵列技术，具有来自分布式阵列发射器的高度聚焦，允许极低的自由空间路径损耗(b)功率放大器，可以在一定功率水平范围内保持极高的效率(c)共形，方向不可知整流天线（整流天线）系统。除此之外，我们意识到，如果无人机仍然能够高效稳定地飞行，那么在无人机周围应用保形整流天线将是极具挑战性的。因此，昆士兰大学机械和航空航天工程学院的工作人员也参与了该项目，以建立新的保形整流天线飞行解决方案。作为研究计划的压轴之作，我们建议展示两个高影响力的实际演示。我们打算展示高效微波WPT的实验室测量，但是，为了将这个研究项目推向世界舞台，我们计划通过完全由微波无线电源供电的无人机连续飞行来展示长时间垂直起降（VTOL）飞行。

The ability to transmit high power wirelessly over long distances is a potential game changer. In this project we are ambitiously investigating the area of medium power (200 W) medium distance (25 m) microwave wireless power transmission (WPT). Current research on microwave WPT tends to focus on low power "scavenging" techniques, with power levels of < 1mW. This can be useful for applications such as low power sensors, but is unlikely to be disruptive for commonly used wireless devices requiring higher power such as smartphones, or even electric vehicles. Higher powered WPT can be carried out using low frequency inductive coupling techniques, although range is very short (<20 cm). Therefore we see microwave WPT, as the only way of breaking the barrier of longer distance and higher power.We intend to take commercial Unmanned Aerial Vehicles (Drones) as a demanding, high added value, and un-resolved application example. Current drone technology is battery powered with a flight time of around only 20 minutes. The ability for continuous drone flight would be highly disruptive allowing many new applications for the technology that currently cannot be accessed e.g. first response situations such as delivery of emergency medical supplies. The development of new strategies for medium (<25m) range wireless power transmission (WPT) that permit high efficiency end to end energy transfer delivering up to 200W d.c. power will be a game changer, as it will largely offset the current critical dependence on rechargeable battery technology. This proposal will provide a step change in microwave WPT technology in order to allow continuous powering of arbitrarily located mobile electrical systems entirely wirelessly over distance in an energy effective way. We are not aware of any other research programme that has studied efficient end to end WPT to moving platforms with arbitrary orientation that are capable of both near and far field power delivery ensuring 24/7 endurance.We intend to address complex research challenges in microwave WPT regarding both transmit and receive rectifying antenna (rectenna) technology. We propose an innovative microwave WPT system that; (i) can transfer power to an object or objects whose position relative to the wireless power source is/are unknown a-priori, (ii) can lie in either the near or the far-field of each other with arbitrary orientation in both line of sight and non-line sight situations (iii) can operate using small, arbitrarily spaced, transmit sub-arrays, to artificially enhance the transmit aperture, since WPT with a single, conventional antenna, requires a massive aperture to produce reasonable efficiency. This will require major innovations that currently lie beyond state of the art. (a) Near/far field auto focusing tracking antenna array technology, with a high degree of focusing from a distributed array transmitter, allowing for extremely low free space path loss (b) Power amplifiers that can maintain extremely high efficiency over a range of power levels (c) Conformal, orientation agnostic rectifying antenna (rectenna) systems.In addition to the above we are aware that applying a conformal rectenna around a drone will be highly challenging, if the drone is still to be capable of efficient and stable flight. Therefore staff from the QUB school of Mechanical and Aerospace engineering are also involved in the project to establish novel conformal rectenna flight-ready solutions. As a grand finale to the research programme we propose to show two high impact practical demonstrations. We intend to show a laboratory measurement of high efficiency microwave WPT, but, to put this research project on the world stage, we plan to show a long duration vertical take-off and landing (VTOL) flight, by flying a drone continuously, powered entirely by microwave wireless power.