1,494 research outputs found
Recharging of Flying Base Stations using Airborne RF Energy Sources
This paper presents a new method for recharging flying base stations, carried
by Unmanned Aerial Vehicles (UAVs), using wireless power transfer from
dedicated, airborne, Radio Frequency (RF) energy sources. In particular, we
study a system in which UAVs receive wireless power without being disrupted
from their regular trajectory. The optimal placement of the energy sources are
studied so as to maximize received power from the energy sources by the
receiver UAVs flying with a linear trajectory over a square area. We find that
for our studied scenario of two UAVs, if an even number of energy sources are
used, placing them in the optimal locations maximizes the total received power,
while achieving fairness among the UAVs. However, in the case of using an odd
number of energy sources, we can either maximize the total received power, or
achieve fairness, but not both at the same time. Numerical results show that
placing the energy sources at the suggested optimal locations results in
significant power gain compared to nonoptimal placements.Comment: 6 pages, 5 figures, conference pape
Review on Key Factors of Wireless Power Transfer Technology for Electric Vehicles
Electric vehicles (EVs) have become an alternative option for a clean energy society. A new charging technology which is wireless charging has been developed to satisfy the limitations of EVs which are the electric drive range and battery storage. Companies like Tesla, BMW, and Nissan have already started to develop wireless charging for EVs. This paper presents a literature review on wireless charging of EVs. The existing technologies for Wireless Power Transfer (WPT) system are summarized for different power applications. Coil design plays the most vital role in the WPT system so the different coil design with the transferred efficiency is reviewed. The other important parameters and technical components like significant factors of WPT system, track layout of dynamic wireless charging, foreign object detection method, and position alignment method that are affecting the efficiency of the wireless charging system are also discussed. Lastly, health and safety concerns for human beings and living things are investigated
Micro air vehicles energy transportation for a wireless power transfer system
The aim of this work is to demonstrate the feasibility use of an Micro air vehicles (MAV) in order to power wirelessly an electric system, for example, a sensor network, using low-cost and open-source elements. To achieve this objective, an inductive system has been modelled and validated to power wirelessly a sensor node using a Crazyflie 2.0 as MAV. The design of the inductive system must be small and light enough to fulfil the requirements of the Crazyflie. An inductive model based on two resonant coils is presented. Several coils are defined to be tested using the most suitable resonant configuration. Measurements are performed to validate the model and to select the most suitable coil. While attempting
to minimize the weight at transmitter’s side, on the receiver side it is intended to efficiently acquire and manage the power obtained from the transmitter. In order to prove its feasibility, a temperature sensor node is used as demonstrator.
The experiment results show successfully energy transportation by MAV, and wireless power transfer for the resonant configuration, being able to completely charge the node battery and to power the temperature sensor.Peer ReviewedPostprint (published version
Energy Cooperation in Battery-Free Wireless Communications with Radio Frequency Energy Harvesting
Radio frequency (RF) energy harvesting techniques are becoming a potential method to power battery-free wireless networks. In RF energy harvesting communications, energy cooperation enables shaping and optimization of the energy arrivals at the energy-receiving node to improve the overall system performance. In this paper, we proposed an energy cooperation scheme that enables energy cooperation in battery-free wireless networks with RF harvesting. We first study the battery-free wireless network with RF energy harvesting then state the problem that optimizing the system performance with limited harvesting energy through new energy cooperation protocol. Finally, from the extensive simulation results, our energy cooperation protocol performs better than the original battery-free wireless network solution.特
Smart wireless power transmission system for autonomous EV charging
This paper presents a novel localisation method for
electric vehicles (EVs) charging through wireless power transmission
(WPT). With the proposed technique, the wireless charging
system can self-determine the most efficient coil to transmit
power at the EV’s position based on the sensors activated by
its wheels. To ensure optimal charging, our approach involves
measurement of the transfer efficiency of individual transmission
coil to determine the most efficient one to be used. This not only
improves the charging performance, but also minimises energy
losses by autonomously activating only the coils with the highest
transfer efficiencies. The results show that with the proposed
system it is possible to detect the coil with maximum transmitting
efficiency without the use of actual power transmission and
comparison of the measured efficiency. This paper also proves
that with the proposed charger set-up, the position of the receiver
coil can be detected almost instantly, which indeed saves energy
and boosts the charging time
Technology development of electric vehicles: A review
To reduce the dependence on oil and environmental pollution, the development of electric vehicles has been accelerated in many countries. The implementation of EVs, especially battery electric vehicles, is considered a solution to the energy crisis and environmental issues. This paper provides a comprehensive review of the technical development of EVs and emerging technologies for their future application. Key technologies regarding batteries, charging technology, electric motors and control, and charging infrastructure of EVs are summarized. This paper also highlights the technical challenges and emerging technologies for the improvement of efficiency, reliability, and safety of EVs in the coming stages as another contribution
Wearable flexible lightweight modular RFID tag with integrated energy harvester
A novel wearable radio frequency identification (RFID) tag with sensing, processing, and decision-taking capability is presented for operation in the 2.45-GHz RFID superhigh frequency (SHF) band. The tag is powered by an integrated light harvester, with a flexible battery serving as an energy buffer. The proposed active tag features excellent wearability, very high read range, enhanced functionality, flexible interfacing with diverse low-power sensors, and extended system autonomy through an innovative holistic microwave system design paradigm that takes antenna design into consideration from the very early stages. Specifically, a dedicated textile shorted circular patch antenna with monopolar radiation pattern is designed and optimized for highly efficient and stable operation within the frequency band of operation. In this process, the textile antenna's functionality is augmented by reusing its surface as an integration platform for light-energy-harvesting, sensing, processing, and transceiver hardware, without sacrificing antenna performance or the wearer's comfort. The RFID tag is validated by measuring its stand-alone and on-body characteristics in free-space conditions. Moreover, measurements in a real-world scenario demonstrate an indoor read range up to 23 m in nonline-of-sight indoor propagation conditions, enabling interrogation by a reader situated in another room. In addition, the RFID platform only consumes 168.3 mu W, when sensing and processing are performed every 60 s
Massive Wireless Energy Transfer with Multiple Power Beacons for very large Internet of Things
The Internet of Things (IoT) comprises an increasing number of low-power and
low-cost devices that autonomously interact with the surrounding environment.
As a consequence of their popularity, future IoT deployments will be massive,
which demands energy-efficient systems to extend their lifetime and improve the
user experience. Radio frequency wireless energy transfer has the potential of
powering massive IoT networks, thus eliminating the need for frequent battery
replacement by using the so-called power beacons (PBs). In this paper, we
provide a framework for minimizing the sum transmit power of the PBs using
devices' positions information and their current battery state. Our strategy
aims to reduce the PBs' power consumption and to mitigate the possible impact
of the electromagnetic radiation on human health. We also present analytical
insights for the case of very distant clusters and evaluate their
applicability. Numerical results show that our proposed framework reduces the
outage probability as the number of PBs and/or the energy demands increase.Comment: 7 pages, 6 figures, Submitted to "The International Workshop on Very
Large Internet of Things (2021)
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