Characterization of a Two-Coil Channel Considering Misalignment Scenarios

Publisher Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland.WPT system performances highly depend on the misalignment scenarios of the transmitter or the receiver coil. In this contribution, the authors analyze the effect of the misalignment influencing factors of the integrated WPT-PLC system receiving coil on the system performances. The simulations and experimental analysis are based on power efficiency and channel capacity metrics. The simulations are performed using finite element calculations in COMSOL Multiphysics and Advanced Design System (ADS) from Keysight technology. By analyzing the results, maximum transferred power is reached under resonance conditions. For instance, the calculated efficiencies versus the misalignment cases of the WPT-PLC system varies (η = 86% to 60%) when d = [3 cm to 7 cm], s = [3 cm to 9 cm], and for a tilt angle θ ≤ 20 deg, while the optimal data rate C(bps) is achieved while appealing different data access points and under reasonable SNR value.publishersversionpublishe

Wireless Charging Of Batteries On Military Vehicles

Recent developments, in the field of wireless charging, have led to increasing use of this technology across different areas of research. The search for improvement in Soldier Combat Systems has seen major investments in recent years, to find a standard architecture that can enhance military capabilities, such as in power management systems. This work is part of the C4I program of the Portuguese army, having had the primary objective of studying an alternative power supply option based on wireless technology, capable of charging man-portable devices in military vehicles. On this dissertation, it was conducted a study on the behavior of the components of a wireless power transfer, focusing on different configurations and geometries of the charging coils, as well as the optimization of key parameters in a wireless power module. For this, key operating principles and charging methods were approached. Using distance as a variable parameter, it was possible to study the variation in signal amplitude and compare the performances of each coil, reaching promising conclusions on which coil geometry is best suited in terms of shape, reach, and intensity of the generated magnetic field of the power transfer. Also, the matching outcomes from the theoretical deductions and the experimental work done in a controlled environment led to a strengthening of the obtained results. After fabricating and testing prototype 3D structures for the coils, a proposal for a wireless charging system was conceived. This proposal includes architecture, protocols, and its implementation taking into account the characteristics of the charging environment

Wireless Power System Design for Maximum Efficiency

With the potential of cutting the last cord, wireless power transfer (WPT) using magnetic resonant coupling is gaining increasing popularity. Evolved from the inductive WPT techniques used in commercial products today, resonant WPT can transfer power over a longer distance with higher spatial freedom. Experimental prototypes have shown power transfer across a 2 m air gap [1], proving the viability of resonant WPT. Industrial consortia such as the AirFuel Alliance have standard specifications that enable wide application in consumer electronics.Despite the promises of high efficiency and long transfer distance, resonant WPT has significant challenges to overcome before the broad adoption will occur. One of the critical challenges is the how to design the complicated system. A WPT system consists of multiple parts: the transmitter coil and the compensation capacitor, the receiver coil and the compensation capacitor, and the power stages which consists of the inverter in the transmitter side and rectifier in the receiver side. This thesis investigates the WPT system design for maximum efficiency. It explores modeling and design of individual stages as well as the entire system design method. From the careful literature review, it is found that current design method of coils is insufficient for consumer electronics applications due to the strict sensitivity of size. The current power stage design method is insufficient or inaccurate for WPT applications where wide loading situations need to be considered. The system-level design method is based on assumptions that are not generally true due to the neglect of ZVS requirement and diode rectifier reactance. Instead, previously established techniques in coil design are applied to invent a new coil structure for reduced ESR while achieving a compact size. Previous ZVS inverter and diode rectifier topology are combined with waveform and circuit analysis to develop new accurate modeling and design method for a wide load range. From the resulting coil and converter models, an entire WPT system model and design methodology are proposed which highlights the design parameters selection and the design sequence. These techniques together contribute to a WPT system in terms of both high efficiency and compact size

Wireless Power Transmission With Brook's Coil Adaptation and Class E Power Amplifier

Wireless Power Transmission (WPT) via Magnetic Resonance Coupling will be the future method in transmitting electrical power. The vision of transferring power wirelessly will provide a solution to power equipments in unreachable areas. Success of WPT depends on distance of power transmission which requires great improvement. This project propose a multilayer Brook's coil design and class E power amplifier to increase transmission distance. The use of zero voltage switching MOSFET operation in a 375kHz class E power amplifier, serves to reduce power loss and increase current supplied to transmitter coil. A DC voltage of 13.34V was obtained at 30cm with 3.068mW power output at receiver end. This resulted to 15 times increased in transmission distance from previous project. Maximum output power achievable for this project was 418mW at 10cm transmission distance

Novel Conformal Strongly Coupled Magnetic Resonance Systems

Wireless Power Transfer (WPT) is an emerging technology in today’s society. Recently, many advancements to WPT systems have been implemented, such as, the introduction of the Strongly Coupled Magnetic Resonance (SCMR) and Conformal SCMR (CSCMR) methods. These methods allow WPT systems to operate at increased distances with smaller dimensional footprints. However, their range is still limited and needs to be expanded, and their footprint is sometimes large and needs to be miniaturized. Therefore, the goal of this research is to develop new designs and methodologies that can achieve the range extension and miniaturization of CSCMR systems. Furthermore, many wireless devices are used today in the proximity of the human body (e.g., wearable and implantable applications). Therefore, WPT systems should be safe to use when placed on or inside the human body. To address this need, the secondary goal of this research is to study the effects of WPT systems when placed on or inside the human body

Improved Design of Wireless Electrical Energy Transfer System for Various Power Applications

This thesis introduces a state-of-the-art review of existing wireless power transfer (WPT) technologies with a detailed comparison and presents the limitations of the inductive power transfer system through simulation and practical analyses. This thesis also presents the expanded use of the high-frequency analysis tool, known as FEKO, and the novel application of frequency response analyser (FRA) with various simulations and practical demonstrations for enhancing the design and maintenance of WPT systems

A metamaterial-coupled wireless power transfer system based on cubic high-dielectric resonators

In this paper, a metamaterial-coupled, highly efficient, miniaturized, and long-range wireless power transfer (WPT) system based on a cubic high-dielectric resonator (CHDR) is explored. The proposed WPT system consists of two CHDR metamaterials separated by a distance and excited by two rectangular coils. Initially, this WPT system is analyzed by considering the cube dielectric permittivity, ε,. = 1000, and loss tangent, tanδ = 0.00001. From the Ansoft HFSS simulation, it is observed that the system operates in the hybrid resonance mode resonating as a horizontal magnetic dipole providing more than 90% power transfer efficiency at a distance of 0.1λ. In addition, parametric studies regarding the transmitter and receiver sizes, loss tangent, receiver misorientation, cube periodicity, etc., are carried out. One of the significant findings of this parametric study reveals that the suggested WPT system is less sensitive to the displacement of the receiver coil, and the WPT efficiency due to misorientation of the receiver can be increased by changing the CHDR cube rotation. Due to inaccessibility of the very high ε,. = 1000, 18 microwave ceramic samples of EXXELIA TEMEX E5080 (Oxide composition: Ba Sm Ti), which has a permittivity, ε,. = 78, permeability, μ,. = 1, and a loss tangent, tanδ = 0.0004, was made for experimental verification. These cubes are surrounded by Teflon to make the CHDR resonators. From simulations and measurements, it is found that the proposed system outperforms the most recent high-dielectric or copper-based WPT systems in terms of efficiency, range, size, and specific absorption rate

Inductive Wireless Power Transfer Charging for Electric vehicles - A Review

Considering a future scenario in which a driverless Electric Vehicle (EV) needs an automatic charging system without human intervention. In this regard, there is a requirement for a fully automatable, fast, safe, cost-effective, and reliable charging infrastructure that provides a profitable business model and fast adoption in the electrified transportation systems. These qualities can be comprehended through wireless charging systems. Wireless Power Transfer (WPT) is a futuristic technology with the advantage of flexibility, convenience, safety, and the capability of becoming fully automated. In WPT methods resonant inductive wireless charging has to gain more attention compared to other wireless power transfer methods due to high efficiency and easy maintenance. This literature presents a review of the status of Resonant Inductive Wireless Power Transfer Charging technology also highlighting the present status and its future of the wireless EV market. First, the paper delivers a brief history throw lights on wireless charging methods, highlighting the pros and cons. Then, the paper aids a comparative review of different type’s inductive pads, rails, and compensations technologies done so far. The static and dynamic charging techniques and their characteristics are also illustrated. The role and importance of power electronics and converter types used in various applications are discussed. The batteries and their management systems as well as various problems involved in WPT are also addressed. Different trades like cyber security economic effects, health and safety, foreign object detection, and the effect and impact on the distribution grid are explored. Prospects and challenges involved in wireless charging systems are also highlighting in this work. We believe that this work could help further the research and development of WPT systems.publishedVersio

A design technique for geometric optimisation of resonant coil sizes in low to mid frequency inductive power transmission systems.

Wireless power transfer (WPT) is a well-established method of energising electrically-powered devices. Among the different available WPT techniques, Resonant Inductive Power Transfer (RIPT) has been adapted for use in a wide range of applications. The primary reason is the relatively higher Power Transfer Efficiency (PTE) that RIPT can provide. RIPT systems operate on the principle of magnetic resonance coupling between a Transmitter (Tx) and a Receiver (Rx) coil. Maximising the PTE is a key driver for improving the performance of RIPT systems. In a RIPT link the PTE is influenced by three factors: (i) inductive linkage between the Tx and Rx, (ii) terminating circuitry of Tx and Rx sides and (iii) the Tx/Rx coil's geometrical size. In considering these impacting factors, different techniques to improve PTE have been extensively presented in the literature and are comprehensively reviewed in this thesis. The research work undertaken focuses on the geometrical optimisation of Tx/Rx coils to help maximise PTE in RIPT systems for operation over low- and mid-frequency bands (i.e. between few kHz to several MHz). Conventional methods for maximising PTE require defining various design parameters (i.e. figure-of-merits), which assist in finding the optimum Air-Cored Coil (ACC) geometry. However, traditional techniques for working with Figure-of-Merit (FoM) parameters are very time-consuming and process-demanding. In this thesis, the number of required FoMs have been reduced to one and incorporated into a process that will accelerate production of the optimum geometry design. A unique FoM parameter (i.e. Pscf) is developed by consolidating the PTE's impacting factors. Considering the RIPT application and its physical size constraints, a proper selection method for identifying the numerical value of Pscf is investigated. A novel iterative algorithm has been developed to assist in selection of the most favourable Pscf value, which provides the optimum ACC geometry. Theoretical design examples of two RIPT systems - operating at 10 kHz (low-frequency band) and 300 kHz (mid-frequency band) - are used to investigate the functionality of the ACC design approach, for which successful results are achieved. The novel iterative algorithm is also experimentally validated by developing four prototyped Tx/Rx ACC pairs, with real-world applications, which operate over low- and mid-frequency bands: 1:06 MHz, 100 kHz, 50 kHz, 15 kHz. For the designed ACC geometries, maximum PTEs of 85:63% at 1:06 MHz, 83:10% at 100 kHz, 72:85% at 50 kHz and 34:57% at 15 kHz are practically measured in bench top tests. The measured PTE values are in close correlation (within 14%) with the calculated PTEs at these frequency ranges, and thus validate the novel ACC design procedure. The RIPT system's maximum achievable PTE can be further increased by adding ferrite cores to the Tx/Rx ACC pair. In this thesis, an advanced iterative algorithm is also presented to support the design of geometrically optimised coil pairs employing ferrite cores. The advanced iterative algorithm is an extension of the initial work on optimising ACC geometries. Optimum Ferrite-Cored Coil (FCC) geometries, produced using the advanced iterative algorithm, for RIPT systems operating at 10 kHz and 300 kHz have been investigated. In comparing the FCC and ACC geometries designed for these frequencies, it is demonstrated that RIPT systems with ferrite cores reduce the ACC's geometrical size and additionally improve PTE. To validate the performance of the advanced FCC design algorithm over low- and mid-frequency bands, two RIPT systems are physically constructed for operation at 15 kHz (low-frequency) and 50 kHz (mid-frequency). For the prototyped RIPT systems, maximum PTEs of 45:16% at 50 kHz and 50:74% at 15 kHz are practically measured. The calculated and physically measured PTE values are within 2% difference; hence validating the advanced FCC design process