AN INVESTIGATION OF THE POSSIBILITIES OF ROOM-SCALE WIRELESS POWER TRANSFER

Inspired by original work of Nikola Tesla in resonant inductive coupling, numerous investigations are going on making wireless power transfer (WPT) application an optimum choice for various fields. By implementing the concept of non-radiative magnetically-coupled resonant circuits, it has been found that wireless power transmission is achievable at room-scale. This thesis investigates various aspects of the possibilities of room-scale wireless power transfer. Firstly, following the background of WPT systems, MATLAB-coil design, calculation of mutual inductances and Excel-calculation of WPT system performance in multi-resonator systems design tools for WPT systems are discussed for estimating the performance of numerous WPT resonator networks at room-scale. Secondly, the WPT system with two transmitters and a load receiver was simulated for measuring resonator parameters and flux-coupling coefficients between inductors using MATLAB and excel computational tools. Also, the WPT network of four-transmitter coil system was proposed to overcome the shortcomings of two-transmitter coil system xiii incapable of transmitting power efficiently at the various orientation of receiver coil. The goal of this design was to permit greater flexibility in angular position, or attitude of the receiver coil at the room space. The simulated results were found to be promising for room-scale wireless power transmission. The chapter concludes with a design validation that is efficient for a room-scale wireless power transmission. Conclusions and suggestions for future work are provided

Smart Table Based on Metasurface for Wireless Power Transfer

Metasurfaces have been investigated and its numerous exotic functionalities and the potentials to arbitrarily control of the electromagnetic fields have been extensively explored. However, only limited types of metasurface have finally entered into real products. Here, we introduce a concept of a metasurface-based smart table for wirelessly charging portable devices and report its first prototype. The proposed metasurface can efficiently transform evanescent fields into propagating waves which significantly improves the near field coupling to charge a receiving device arbitrarily placed on its surface wirelessly through magnetic resonance coupling. In this way, power transfer efficiency of 80$\%$ is experimentally obtained when the receiver is placed at any distances from the transmitter. The proposed concept enables a variety of important applications in the fields of consumer electronics, electric automobiles, implanted medical devices, etc. The further developed metasurface-based smart table may serve as an ultimate 2-dimensional platform and support charging multiple receivers.Comment: 8 pages, 7 figure

Sensitivity Analysis of a Bidirectional Wireless Charger for EV

Bidirectional chargers are required to fully integrate Electric Vehicle (EV) into the smart grids. Additionally, wireless chargers ease the charge/discharge process of the EV batteries so that they are becoming more popular to fulfill a V2G scenario. When considering the load of wireless chargers, it is a requirement to know the real output power that these systems offer. The designed output power may differ from the real one as components suffer from tolerance. This paper defines six sensitivity factors to model the severity of the effects of tolerance into the output power. To do so, an electric circuit analysis is used and a mathematical formulation is derived. The six sensitivity factors are computed for a laboratory prototype.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Design and control of a bidirectional wireless charging system using GaN devices

Most of the existing wireless power transfer system works in unidirectional with one-direction control signals. This paper presents a bidirectional wireless charging system with duplex communication method, which is not only able to achieve the two-way wireless power transmission, but also transfer control signals bi-directionally. The power circuit operation mode is actively controlled by using the wireless transceiver module which can duplex communication to deliver measured signals remotely. The operational principle is analytically studied in details and is verified by simulation. Finally, a prototype of the bidirectional charging system using GaN devices has been successfully designed and tested. In addition, the measured feedback signals are effectively transmitted to validate the control algorithm