Abstract

CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior O objetivo deste trabalho consiste em analisar o comportamento de um sistema de transferência de potência sem fios para aplicações em veículos elétricos, utilizando o princípio do acoplamento magnético. E, para alcança-lo, foi necessário construir um circuito inversor para que a bobina emissora opere em ressonância magnética com a bobina receptora. Foi elaborado uma rotina computacional para calcular o rendimento de um circuito ressonante, a partir dos parâmetros físicos e elétricos das bobinas. O protótipo consiste em energizar uma bobina plana primária e realizar a transferência indutiva para a bobina secundária, podendo ser de mesmo tamanho ou não. Resultados experimentais foram coletados, tais como, curvas de rendimento em função da distância, transferência através de barreiras metálicas e não metálicas, rendimentos em função do desalinhamento entre bobinas, carga em bateria automotiva, distâncias máximas de transferência; dentre outros. Um sistema desse tipo pode trazer muitos benefícios para aplicação no carregamento de baterias em veículos elétricos de forma prática, segura e com rendimentos satisfatórios quando realizado a transferência indutiva sem fios. The objective of this work is to analyze the behavior of a wireless power transfer system for applications in electric vehicles, using the principle of magnetic coupling. And in order to reach it, it was necessary to construct an inverter circuit so that the sending coil operates in magnetic resonance with the receiving coil. A computational routine was developed to calculate the efficiency of a resonant circuit, based on the physical and electrical parameters of the coils. The prototype consists of energizing a primary flat coil and performing the inductive transfer to the secondary coil, which may be the same size or not. Experimental results were collected, such as yield curves as a function of distance, transfer through metallic and non-metallic barriers, yields due to misalignment between coils, automotive battery charge, maximum transfer distances; and others. Such a system can bring many benefits for application in battery charging in electric vehicles in a practical way and with satisfactory yields when conducting wireless inductive transfer. Dissertação (Mestrado)

Abstract

LTIN, Necmi/0000-0003-3294-9782; ALTIN, Necmi/0000-0003-3294-9782; WOS: 000406726000035 In this study, a 15 kW wireless power transfer system with high frequency and large air gap for electrical vehicle battery charge systems is designed and co-simulations with ANSYS-Maxwell and Simplorer software are performed. The air gap between the primary and the secondary windings are determined as 20 cm for the 15 kW wireless power transfer system. Operation of the designed system for different operation conditions such as completely aligned windings (ideal condition) and windings with alignment errors, which can occur because of user error or another reason, are analyzed and obtained results are reported. The resonant frequency of the designed system which has a 60 x 60 cm secondary winding and a 60 x 100 cm primary winding is 17.702 kHz, and the maximum efficiency of the system is obtained as 75.38% for completely aligned windings. The distribution and density of the electromagnetic flux, and variation of efficiency versus load level of the system and responses of the system in case of different alignment errors are also investigated and reported for both ideal operation conditions and in case of alignment errors. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Abstract

International audience; The present paper focuses on wireless energy transfer mechanisms applied to urban electric vehicles. It describes the using conditions of a particular transformer without ferromagnetic core, supplied by a resonant inverter and loaded by mobile sources (catenaries with magnetic induction to power electric vehicles). The system consists of unconventional transformers with large air-gaps and a generator who supplies the transformer. The paper describes the theoretical model used for the numerical simulation (magnetic circuit, power converter, loads), and the measurements provided by our experimental platform (Tesla lab.). The transformer is supplied by a half-bridge series resonant converter. The transformer secondary coil is mobile compared to the primary, which is fixed on the road. This system is found in many industrial applications such as light automatic vehicles, tramways, etc. In this work we will show that the performance of a transformer without magnetic circuit can be equivalent to a standard transformer.

Abstract

Wireless power transfer (WPT) is an emerging technology that is used in ad hoc networks of battery-powered devices, to deliver energy and keep the network functional. Existing state-of-the-art studies have mainly focused on applying this technology, but the potential risk of electromagnetic radiation (EMR) exposure is really overlooked by them. This still holds for the general case of the RF Wireless Communication networks. Hence, we consider The Minimum Radiation Path Problem of finding the lowest radiation trajectory of an agent moving from a source to a destination point in a network plane. Different from previous works, we attempt to study (for the first time in the state-of-the-art) path radiation under a more realistic WPT model than the usual one-dimensional models, that have been used in the past and cannot capture interesting superadditive and cancellation effects between distinct electromagnetic sources. In the light of the above, we design and evaluate both an algorithm and a heuristic that achieve different trade-offs between radiation and trajectory length of a moving agent. Document type: Conference object

Abstract

Wireless power transfer for electric and plug-in hybrid vehicles has been developed to facilitate battery charging. In a wireless power transfer system, because the magnetic field leaks to the surroundings of the vehicle, it is important to evaluate the quantitative human exposure. The International Commission on Non-Ionizing Radiation Protection provides guidelines for human exposure assessment. In this study, we evaluate the magnetic field leakage under two parking configurations and current phase differences for two vehicles being simultaneously charged (3.7 kW at 85 kHz per vehicle). The results of the analysis show that the magnetic field leakage is lower than the reference level of the guidelines for all cases and that the leakage could be reduced by controlling the phase difference between the two wireless power transfer systems equally distributed from the single high-frequency power source for each parking configuration. Document type: Article

Abstract

This paper presents a thermal investigation of lightweight on-board receiver modules of wireless power transfer systems for electric vehicles. The studied modules are capable of receiving up to 11 kW at a resonance frequency of 85 kHz over a distance of 110–160 mm. The receiver modules were built as sandwich and space–frame concept to design stiff and lightweight structures. The high transmission power of automotive wireless power transfer systems combined with the multi-part assembly of receiver modules led to challenges in heat management. To address this, the physical behaviour of the proposed lightweight concepts were studied on component and system level using a hardware-in-the-loop testing facility for wireless power transfer systems. Special emphasis was laid on the validation of a thermal simulation model, which uses analytical calculated power losses taking into account their temperature dependency. The proposed simulation model is consistent with the experimental validation of the critical active components. The performed systematic studies build the basis for a more sophisticated thermal dimensioning of various constructions for wireless power transfer modules. Document type: Article

Abstract

The goal of the study presented in this article is to provide a general overview of the various aspects related to electric vehicles (EVs), along with all associated emerging challenges and perspectives. In this context, the basic types of EVs and the corresponding charging technologies are analyzed. Since EVs are expected to be a key component of future smart electrical grids (SEG), connection to the grid issues, along with advanced charging techniques (i.e., wireless power transfer), are analyzed as well. To this end, the main features, the requirements of vehicle to grid (V2G) communications, as well as future developments and scenarios of electrification, are also presented and analyzed. Moreover, integration issues with currently deployed fifth generation (5G) mobile wireless networks are also outlined, in order to ensure optimum transmission and reception quality in V2G communications and improved user experience. This integration is also expanded in autonomous vehicles (AVs) technology (self-driving objects), since optimized information processing from various diverse sources is required in order to ensure advanced traffic management aspects. Document type: Article