Dynamic inductive power transfer lane design for e-bikes

This paper presents the concept and initial test results of an inductive lane design capable of dynamic and wirelessly transfer power to electric bicycles (e-bikes). On the lane side, a sequence of oblong primary coils embedded underneath ground surface, along the vehicle path, can be independently excited by high frequency alternating current. The oscillating magnetic field of each primary coil is individually enabled when a Radio Frequency Identification (RFID) tag on board of the e-bike is detected and authenticated by an auxiliary coil laying close to that primary coil. On the e-bike, energy for the powertrain is harvested from the lane by a secondary coil that is installed around its rear wheel. When the e-bike is moving over inter-coil gaps, or anywhere away from the inductive lane, on-board power is sustained with the excess energy stored during transits over energized coils. Preliminary results from a prototyped module demonstrate the feasibility of the system, which could also be used by similarly adapted lightweight electric vehicles, such as rickshaws, electric wheel chairs and other electric personal mobility devices, favoring a new, low cost, sustainable urban modal variant.Research partially supported by grant SFRH/BD/52349/2013 from FCT, the Portuguese funding agency supporting science, technology and innovation, under the scope of the MIT-Portugal Program. L. A. Lisboa Cardoso and J. L. Afonso are with the Centro ALGORITMI, Department of Industrial Electronics, University of Minho, Campus de Azurém, 4800-058 Guimarães, Portugal (tel. 351-253-510183; e-mails: [email protected], [email protected]). M. Comesaña Martinez and A. A. Nogueiras Meléndez, are with the Department of Electronics Technology, University of Vigo, Vigo, Pontevedra 36310, Spain (e-mail: [email protected])

Wireless communication and management system for E-Bike dynamic inductive power transfer lanes

This paper presents the design, implementation, and testing of a wireless communication system for automatic identification of e-bikes and management of their battery charging in the context of dynamic inductive wireless power transfer (DIWPT) lanes. The proposed system checks if an e-bike, uniquely identified by its RFID tag, is authorized to receive energy from the lane coils and acts accordingly. An authentication mechanism was developed based on the use of embedded Wi-Fi boards attached to the coils and communicating with a central HTTP server with a MySQL database. The developed management system also provides other features, such as the recording of the number of lane coils used by each e-bike for billing purposes. The results from experimental tests on a laboratory prototype were used to validate the developed functionalities and assess the quality of service provided by the proposed system.This work was supported by FCT national funds, under the national support to R&D units grant,through the reference project UIDB/04436/2020 and UIDP/04436/2020

Design of an intrinsically safe series-series compensation WPT system for automotive LiDAR

The earliest and simplest impedance compensation technique used in inductive wireless power transfer (WPT) design is the series-series (SS) compensation circuit, which uses capacitors in series with both primary and secondary coils of an air-gapped transformer. Despite of its simplicity at the resonant condition, this configuration exhibits a major sensitivity to variations of the load attached to the secondary, especially when higher coupling coefficients are used in the design. In the extreme situation that the secondary coil is left at open circuit, the current at the primary coil may increase above the safety limits for either the power converter driving the primary coil or the components in the primary circuit, including the coil itself. An approach often used to minimize this problem is detuning, but this also reduces the electrical efficiency of the power transfer. In low power, fixed-distance stationary WPT, a fair trade-off between efficiency and safety must be verified. This paper aims to consolidate a simple design procedure for such a SS-compensation, exemplifying its use in the prototype of a WPT system for automotive light detection and ranging (LiDAR) equipment. The guidelines herein provided should equally apply to other low power applications.This work has been supported by national funds through FCT—Fundação para a Ciência e Tecnologia within the Project Scope: UID/CEC/00319/2019, and also European Structural and Investment Funds in the FEDER component, through the Operational Competitiveness and Internationalization Programme (COMPETE 2020) [Project nº 037902; Funding Reference: POCI-01-0247-FEDER-037902]

Vehicle electrification: technologies, challenges and a global perspective for smart grids

Nowadays, due to economic and climate concerns, the private transportation sector is shifting for the vehicle electrification, mainly supported by electric and hybrid plug-in vehicles. For this new reality, new challenges about operation modes are emerging, demanding a cooperative and dynamic operation with the electrical power grid, guaranteeing a stable integration without omitting the power quality for the grid-side and for the vehicle-side. Besides the operation modes, new attractive and complementary technologies are offered by the vehicle electrification in the context of smart grids, which are valid for both on-board and off-board systems. In this perspective, this book chapter presents a global perspective and deals with challenges for the vehicle electrification, covering the key technologies toward a sustainable future. Among others, the flowing topics are covered: (1) Overview of power electronics structures for battery charging systems, including on-board and off-board systems; (2) State-of-the-art of communication technologies for application in the context of vehicular electrification, smart grids and smart homes; (3) Challenges and opportunities concerning wireless power transfer with bidirectional interface to the electrical grid; (4) Future perspectives about bidirectional power transfer between electric vehicles (vehicle-to-vehicle operation mode); (5) Unified technologies, allowing to combine functionalities of a bidirectional interface with the electrical grid and motor driver based on a single system; and (6) Smart grids and smart homes scenarios and accessible opportunities about operation modes.Fundação para a Ciência e Tecnologia (FCT

Detailed energy analysis of a sheet-metal-forming press from electrical measurements

This paper presents a methodology that allows for the detection of the state of a sheet-metal-forming press, the parts being produced, their cadence, and the energy demand for each unit produced. For this purpose, only electrical measurements are used. The proposed analysis is conducted at the level of the press subsystems: main motor, transfer module, cushion, and auxiliary systems, and is intended to count, classify, and monitor the production of pressed parts. The power data are collected every 20 ms and show cyclic behavior, which is the basis for the presented methodology. A neural network (NN) based on heuristic rules is developed to estimate the press states. Then, the production period is determined from the power data using a least squares method to obtain normalized harmonic coefficients. These are the basis for a second NN dedicated to identifying the parts in production. The global error in estimating the parts being produced is under 1%. The resulting information could be handy in determining relevant information regarding the press behavior, such as energy per part, which is necessary in order to evaluate the energy performance of the press under different production conditions.Xunta de Galicia | Ref. IN854A 2020/0

Efficiency comparison of different DC-DC converter architectures for a power supply of a LiDAR system

LiDAR (Light Detection And Ranging) is a technology used to meas-ure distances to objects. Internally, a LiDAR system is constituted by several components, including a power supply, which is responsible to provide the dis-tinct voltage levels necessary for all the components. In this context, this paper presents an efficiency comparison of three different DC-DC converter architec-tures for a LiDAR system, each one composed of three DC-DC converters: in parallel; in cascade; and hybrid (mix of parallel and cascade). The topology of the adopted integrated DC-DC converters is the synchronous buck Switched-Mode Power Supply (SMPS), which is a modified version of the basic buck SMPS topology. Three distinct SMPSs were considered: LM5146-Q1, LM5116, and TPS548A20RVER. These SMPSs were selected according to the require-ments of voltage levels, namely, 12 V, 5 V, and 3.3 V. Along the paper, the prin-ciple of operation of the SMPSs is presented, as well as the evaluation results obtained for different operating powers, allowing to establish a comprehensive efficiency comparison.This work has been supported by national funds through FCT—Fundação para a Ciência e Tecnologia within the Project Scope: UIDB/00319/2020, and also European Structural and Investment Funds in the FEDER component, through the Operational Competitiveness and Internationalization Programme (COMPETE 2020) [Project nº 037902; Funding Reference: POCI-01-0247-FEDER-037902]

Climate seasonality limits leaf carbon assimilation and wood productivity in tropical forests

The seasonal climate drivers of the carbon cycle in tropical forests remain poorly known, although these forests account for more carbon assimilation and storage than any other terrestrial ecosystem. Based on a unique combination of seasonal pan-tropical data sets from 89 experimental sites (68 include aboveground wood productivity measurements and 35 litter productivity measurements), their associated canopy photosynthetic capacity (enhanced vegetation index, EVI) and climate, we ask how carbon assimilation and aboveground allocation are related to climate seasonality in tropical forests and how they interact in the seasonal carbon cycle. We found that canopy photosynthetic capacity seasonality responds positively to precipitation when rainfall is  < 2000 mm yr⁻¹ (water-limited forests) and to radiation otherwise (light-limited forests). On the other hand, independent of climate limitations, wood productivity and litterfall are driven by seasonal variation in precipitation and evapotranspiration, respectively. Consequently, light-limited forests present an asynchronism between canopy photosynthetic capacity and wood productivity. First-order control by precipitation likely indicates a decrease in tropical forest productivity in a drier climate in water-limited forest, and in current light-limited forest with future rainfall  < 2000 mm yr⁻¹

Encefalopatia hepática: relatório da 1º reunião monotemática da Sociedade Brasileira de Hepatologia

Hepatic encephalopathy (HE) is a functional disorder of the central nervous system (CNS) associated with liver failure, either end-stage chronic liver disease or fulminant hepatic failure. Its pathogenesis remains complex and poorly understood. In view of recent advances in the management of HE, the Brazilian Society of Hepatology endorsed a monothematic meeting regarding HE in order to gather experts in the field to discuss related data and to draw evidence-based recommendations concerning: management of HE and intracranial hypertension in FHF, treatment of episodic HE in cirrhosis, controversies in the management of EH including difficult to treat cases and diagnostic and treatment challenges for minimal HE. The purpose of this review is to summarize the lectures and recommendations made by the panel of experts of the Brazilian Society of Hepatology.A encefalopatia hepática (EH) é um distúrbio funcional do sistema nervoso central (SNC) associado à insuficiência hepática, de fisiopatologia multifatorial e complexa. Devido aos avanços no conhecimento sobre o manejo da EH na cirrose e na insuficiência hepática aguda (IHA), a diretoria da Sociedade Brasileira de Hepatologia (SBH) promoveu uma reunião monotemática acerca da fisiopatologia, diagnóstico e tratamento da EH, abordando aspectos controversos relacionados ao tema. Com a utilização de sistemática da medicina baseada em evidências, foram abordados o manejo da EH e da hipertensão intracraniana na IHA, o manejo da EH episódica na cirrose, as controvérsias no manejo da EH e a abordagem da EH mínima. O objetivo desta revisão é resumir os principais tópicos discutidos na reunião monotemática e apresentar recomendações sobre o manejo da síndrome votadas pelo painel de expertos da SBH

Direct antiviral therapy for treatment of hepatitis C: A real-world study from Brazil

Introduction and objectives: Direct antiviral agents (DAAs) including sofosbuvir (SOF), daclatasvir (DCV), simeprevir (SIM) and ombitasvir, paritaprevir and dasabuvir were introduced 2015 in Brazil for treatment of hepatitis C virus (HCV) infection. The aims of this study were to assess effectiveness and safety of HCV treatment with DAA in real-life world in a highly admixed population from Brazil. Materials and methods: All Brazilian reference centers for HCV treatment were invited to take part in a web-based registry, prospectively conducted by the Brazilian Society of Hepatology, to assess outcomes of HCV treatment in Brazil with DAAs. Data to be collected included demographics, disease severity and comorbidities, genotype (GT), viral load, DAA regimens, treatment side effects and sustained virological response (SVR). Results: 3939 patients (60% males, mean age 58 ± 10 years) throughout the country were evaluated. Most had advanced fibrosis or cirrhosis, GT1 and were treated with SOF/DCV or SOF/SIM. Overall SVR rates were higher than 95%. Subjects with decompensated cirrhosis, GT2 and GT3 have lower SVR rates of 85%, 90% and 91%, respectively. Cirrhosis and decompensated cirrhosis in GT1 and male sex and decompensated cirrhosis in GT3 were significantly associated with no SVR. Adverse events (AD) and serious AD occurred in 18% and 5% of those subjects, respectively, but less than 1% of patients required treatment discontinuation. Conclusion: SOF-based DAA regimens are effective and safe in the heterogeneous highly admixed Brazilian population and could remain an option for HCV treatment at least in low-income countries