151 results found
Aldhaher S, Yates DC, Mitcheson PD, 2018, Load-Independent Class E/EF Inverters and Rectifiers for MHz-Switching Applications, IEEE TRANSACTIONS ON POWER ELECTRONICS, Vol: 33, Pages: 8270-8287, ISSN: 0885-8993
Arteaga JM, Aldhaher S, Kkelis G, et al., 2018, Dynamic Capabilities of Multi-MHz Inductive Power Transfer Systems Demonstrated with Batteryless Drones, IEEE Transactions on Power Electronics, ISSN: 0885-8993
CCBY This paper presents the design of a multi-MHz inductive power transfer (IPT) system showcasing lightweight and energy-efficient solutions for non-radiative wireless power transfer. A proof of concept is developed by powering a drone without a battery that can hover freely in proximity to an IPT transmitter. The most challenging aspect, addressed here for the first time, is the complete system level design to provide uninterrupted power-flow efficiently while allowing for variable power demand and highly variable coupling factor. The proposed solution includes the design of lightweight air-core coils that can achieve sufficient coupling without degrading the aerodynamics of the drone, and designing newly-developed resonant power converters at both ends of the system. At the transmittingend, a load-independent Class EF inverter, which can drive a transmitting-coil with constant current amplitude and achieves zero-voltage switching (ZVS) for the entire range of operation, was developed; and at the receiving-end, a hybrid Class E rectifier, which allows tuning for large changes in coupling and power demand, was used. For the demo, the range of motion of the drone was limited by a 7.5 cm nylon string tether, connected between the centre of the transmitting-coil and the bottom of the drone. The design of the IPT system, including all the power conversion stages and the IPT link, is explained in detail. The results on performance and specific practical considerations required for the physical implementation are provided. An average end-to-end efficiency of 60% was achieved for a coupling range of 23% to 5.8%. Relevant simulations concerning human exposure to electromagnetic fields are also included to assure that the demo is safe according to the relevant guidelines. This paper is accompanied by a video featuring the proposed IPT system.
Mitcheson PD, Kkelis G, Aldhaher S, et al., 2018, Power Electronics for Wireless Power Delivery in Synthetic Sensor Networks, 17th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS), Publisher: IOP PUBLISHING LTD, ISSN: 1742-6588
Arteaga JM, Kkelis G, Aldhaher S, et al., 2018, Probability-based Optimisation for a Multi-MHz IPT System with Variable Coupling, IEEE PELS Workshop on Emerging Technologies - Wireless Power Transfer (Wow), Publisher: IEEE
Aldhaher S, Mitcheson PD, 2018, Sate-Space Modelling and Design of a 10MHz 180W Class E DC/DC Converter using WBG Devices, 33nd Annual IEEE Applied Power Electronics Conference and Exposition (APEC), Publisher: IEEE, Pages: 2918-2921, ISSN: 1048-2334
© 2017 IEEE. This paper describes the system concept and initial results for end-to-end energy-autonomous sensor systems using unmanned aerial vehicles (drones) as agents for power delivery to and data gathering from sensing devices. Such systems may be particularly useful for delay tolerant monitoring scenarios, where sensing devices may be deployed in remote, harsh conditions, often with sparse connectivity, long life and high reliability requirements. This paper discusses the latest advances in wireless power delivery that makes this it possible to fly wireless power delivery systems on drones that have little payload capability.
Pacini A, Costanzo A, Aldhaher S, et al., 2017, Load- and Position-Independent Moving MHz WPT System Based on GaN-Distributed Current Sources, IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, Vol: 65, Pages: 5367-5376, ISSN: 0018-9480
Douthwaite M, Koutsos E, Yates DC, et al., 2017, A Thermally Powered ISFET Array for On-Body pH Measurement, IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS, Vol: 11, Pages: 1324-1334, ISSN: 1932-4545
Kkelis G, Yates DC, Mitcheson PD, 2017, Class-E Half-Wave Zero dv/dt Rectifiers for Inductive Power Transfer, IEEE TRANSACTIONS ON POWER ELECTRONICS, Vol: 32, Pages: 8322-8337, ISSN: 0885-8993
Lawson J, 2017, High frequency electromagnetic links for wireless power transfer
This thesis investigates inductive links used in wireless power transfer systems. Inductive power transfer can be used as a power delivery method for a variety of portable devices, from medical implants to electric vehicles and is gaining increased interest. The focus is on high quality factor coils and MHz operation, where accurate measurements are difficult to achieve. Fast models of all pertinent aspects of inductive power transfer systems for constant cross section coils are developed. These models are used to optimise a new coil winding pattern that aims to increase efficiency in volume constrained scenarios. Measurement systems are developed to measure coil Q factors in excess of 1,000. The prototype measurement systems are verified against models of that system, as well as finite element simulations of the coil under test. Shielding of inductive power transfer systems is then investigated. A structure typically used at GHz frequencies, the artificial magnetic conductor, is miniaturised as an alternative to conventional ferrite backed ground plane shielding. Finite element simulation shows this structure significantly improves link efficiency. The artificial magnetic conductor prototype does not result in a gain in efficiency expected, however it does display the properties expected of an artificial magnetic conductor, including increased coupling factor. Finally, an unconventional inductive power transfer system is presented where transmitter and receiver are up to 6m away from each other and of radically different size. This system provides mW level power to remote devices in a room, for example thermostats or e-ink displays. Conventional approaches to design do not consider the distortion of the magnetic field caused by metallic objects in the room. It was found that treating the system as a decoupled receiver and transmitter provides a better prediction of received power in real world environments.
Allmen LV, Bailleul G, Becker T, et al., 2017, Aircraft Strain WSN Powered by Heat Storage Harvesting, IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, Vol: 64, Pages: 7284-7292, ISSN: 0278-0046
Pacini A, Costanzo A, Aldhaher S, et al., 2017, Design of a Position-Independent End-to-End Inductive WPT link for Industrial Dynamic Systems, IEEE-Microwave-Theory-and-Techniques-Society International Microwave Symposium (IMS) / Session on Women in Microwaves (WIM), Publisher: IEEE, Pages: 1049-1052, ISSN: 0149-645X
Mitcheson PD, Boyle D, Kkelis G, et al., 2017, Energy-Autonomous Sensing Systems Using Drones, 16th IEEE SENSORS CONFERENCE, Publisher: IEEE, Pages: 648-650, ISSN: 1930-0395
Aldhaher S, Mitcheson PD, Arteaga JM, et al., 2017, Light-Weight Wireless Power Transfer for Mid-Air Charging of Drones, 11th European Conference on Antennas and Propagation (EUCAP), Publisher: IEEE, Pages: 336-340, ISSN: 2164-3342
Kim J, Clerckx B, Mitcheson PD, 2017, Prototyping and Experimentation of a Closed-Loop Wireless Power Transmission with Channel Acquisition and Waveform Optimization, 2017 IEEE WIRELESS POWER TRANSFER CONFERENCE (WPTC 2017), ISSN: 2474-0225
Kkelis G, Aldhaher S, Arteaga JM, et al., 2017, Hybrid Class-E Synchronous Rectifier for Wireless Powering of Quadcopters, IEEE Wireless Power Transfer Conference (WPTC), Publisher: IEEE, ISSN: 2474-0225
Douthwaite M, Koutsos E, Yates DC, et al., 2017, A Thermally Powered ISFET Array for On-Body pH Measurement., IEEE Trans. Biomed. Circuits and Systems, Vol: 11, Pages: 1324-1334
Aldhaher S, Yates DC, Mitcheson PD, 2016, Design and Development of a Class EF2 Inverter and Rectifier for Multimegahertz Wireless Power Transfer Systems, IEEE TRANSACTIONS ON POWER ELECTRONICS, Vol: 31, Pages: 8138-8150, ISSN: 0885-8993
Boyle DE, Kiziroglou ME, Mitcheson PD, et al., 2016, Energy Provision and Storage for Pervasive Computing, IEEE PERVASIVE COMPUTING, Vol: 15, Pages: 28-35, ISSN: 1536-1268
Kiziroglou ME, Elefsiniotis A, Kokorakis N, et al., 2016, Scaling and super-cooling in heat storage harvesting devices, MICROSYSTEM TECHNOLOGIES-MICRO-AND NANOSYSTEMS-INFORMATION STORAGE AND PROCESSING SYSTEMS, Vol: 22, Pages: 1905-1914, ISSN: 0946-7076
Mitcheson PD, Lucyszyn S, Pinuela M, et al., 2016, RF energy harvester, US9837865B2
Disclosed herein is an antenna apparatus for use in harvesting ambient radio frequency, RF, energy. The apparatus comprises one or more RF antenna components arranged to receive RF energy for producing electricity. The one or more RF antenna components comprise a plurality of frequency filtering components, each frequency filtering component being arranged to filter a respective frequency band of the received RF energy. Also disclosed herein is an apparatus comprising a rectifying circuit arranged to convert a variable electrical signal received at an input from an associated antenna into a direct current electrical signal for supplying to an electrical energy storage unit, the antenna for use in harvesting ambient radio frequency, RF, energy. The apparatus also comprises a power management module having an input arranged to receive the direct current and control supply of the direct current to the electrical energy storage unit. The rectifying circuit comprises a plurality of transmission lines, wherein the input of the rectifying circuit and the input of the power management module are connected via the plurality of transmission lines. The power management module is arranged at least partially within a boundary defined by the plurality of transmission lines.
Miller LM, Elliott ADT, Mitcheson PD, et al., 2016, Maximum Performance of Piezoelectric Energy Harvesters When Coupled to Interface Circuits, IEEE SENSORS JOURNAL, Vol: 16, Pages: 4803-4815, ISSN: 1530-437X
Kwan CH, Pinuela M, Mitcheson P, et al., 2016, Inductive power transfer system, WO2016050633 A3
There is provided a near-field inductive power transfer system (10), comprising a power transmission device (100) arranged to transmit power wirelessly at a first frequency, f0, and a power reception device (200) arranged to receive power transmitted by the power transmission device (100). The power reception device (200) is moveable relative to the power transmission device (100) and comprises a receiver circuit (210) configured to receive power for powering a variable load (230) when the power reception device (200) is in a near-field region of the power transmission device (100), the receiver circuit being a resonant circuit with a resonant frequency, fR, such that 0.2 < f0/fR < 3. The power reception device (200) also includes an impedance emulator (220) for providing the received power to the variable load (230), the impedance emulator being arranged to suppress a variation in an impedance presented to the receiver circuit (210) by the load when the load varies during use of the near-field inductive power transfer system (10).
Aldhaher S, Yates DC, Mitcheson PD, 2016, Modeling and Analysis of Class EF and Class E/F Inverters With Series-Tuned Resonant Networks, IEEE TRANSACTIONS ON POWER ELECTRONICS, Vol: 31, Pages: 3415-3430, ISSN: 0885-8993
Arteaga JM, Aldhaher S, Kkelis G, et al., 2016, Design of a 13.56 MHz IPT System Optimised for Dynamic Wireless Charging Environments, 2nd IEEE Annual Southern Power Electronics Conference (SPEC), Publisher: IEEE
Yates DC, Aldhaher S, Mitcheson PD, 2016, A 100-W 94% Efficient 6-MHz SiC Class E Inverter with a Sub 2-W GaN Resonant Gate Drive for IPT, IEEE Wireless Power Transfer Conference (WPTC), Publisher: IEEE, ISSN: 2474-0225
Elliott ADT, Caccia A, Thomas A, et al., 2016, Shared inductor hybrid topology for weight constrained piezoelectric actuators, 16th International Conference on Micro- and Nano-Technology for Power Generation and Energy Conversion Applications (PowerMEMS), Publisher: IOP PUBLISHING LTD, ISSN: 1742-6588
Yates DC, Aldhaher S, Mitcheson PD, 2016, Design of 3 MHz DC/AC Inverter with Resonant Gate Drive for a 3.3 kW EV WPT System, 2nd IEEE Annual Southern Power Electronics Conference (SPEC), Publisher: IEEE
Douthwaite M, Moser N, Koutsos E, et al., 2016, A CMOS ISFET Array for Wearable Thermoelectrically Powered Perspiration Analysis, 12th IEEE Biomedical Circuits and Systems Conference (BioCAS), Publisher: IEEE, Pages: 54-57, ISSN: 2163-4025
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