New Technologies for Efficient Wireless Power Transfer at Distance

点击翻译按钮获取中文摘要

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.