Multiphase resonant converter with output current multiplier for battery charger applications

This paper presents the analysis and design of a multiphase resonant converter suitable for high-current low-voltage battery charger applications. In order to reduce the conduction losses, the inverter stage of the converter is obtained from the parallel connection of N class D LCp resonant inverters. In the same way, the output stage is based on a current multiplier, obtained through the parallel connection of two current-doubler rectifiers. The regulation of the charging current is implemented at constant frequency, modifying the phase displacement of the drive signals. The battery charger is designed for a high-performance Absorbent Glass Mat (AGM) battery; at present, widely used in micro-hybrid vehicles.This work was funded by the Spanish Ministry of Economy and Competitiveness, the Principality of Asturias Government and the European Union (ERFD), under Research Grants FC- 15-GRUPTNI4-073 and DPI2013-46541-R and the Spanish Ministry of Science and the EU through the project TEC2014-52316-R: 'Estimation and Optimal Control for Energy Conversion with Digital Devices' ECOTRENDD

Design and validation of a tool for prognosis of the energy consumption and performance in electric vehicles

This work develops a software tool to calculate and predict the energy consumption of an electric vehicle (EV) for any desired route. The software tool is based on a mathematical model of an electric vehicle, which relates the energy consumption of the vehicle with factors such as the speed and the terrain slope. In addition, factors such as driving style, weather conditions and traffic congestion can be taken into account. The model has been validated with real data from an electric vehicle. On the other hand, this work proposes a methodology to use this tool with any other EV, as long as its basic characteristics are known. The results obtained in this work are applied in automated testing systems, specific for EV storage systems at laboratory level. The main advantage lies in the use of more realistic power profiles than those commonly used and proposed in the specialized literature (eg, FUDS). In addition, the proposed methodology can be applied to any EV, in different scenarios of orography, traffic, climatology, etc.This work was supported by the Science of Innovation Spanish Ministry and FEDER funds under the Project TEC2016-80700-R (AEI/FEDER, UE), by the Principality of Asturias Government under project FC-15GRUPIN14-073 and the University Institute of Industrial Technology of Asturias (IUTA) under project SV-15GIJON-1.13

High power li-Ion battery performance: a mechanistic analysis of aging

Tesis con mención internacionalNowadays, lithium ion batteries (LIBs) are omnipresent on a worldwide level. As a result of their high energy density, high power density and increasing cycling life, LIBs are a well-founded technology for its use on portable electronic devices, electric vehicles (EVs) and electrical energy storage (EES) systems. The extensive use of LIBs accentuates the fact that these power sources are currently playing a crucial role in the commercial and industrial applications. As a result of the rapid growth and substantial interest devoted to LIBs, an increasing number of opportunities in the industrial and research LIB fields are emerging. Fast charging is gaining momentum in order to meet the demands of high power LIB systems. The ability of a LIB to perform fast charging depends on various factors, including cell active materials, and the design of a reliable fast charging protocol. To date, efficient fast charging protocol and procedures to achieve rapid charges remain lacking. In addition, fast charging/high power duty cycling may affect the battery¿s performance due to accelerated aging. The effects of battery aging are detrimental to LIB systems, reducing its performance and even causing safety issues. In fact, the aging phenomenon is a key issue in durable applications such as EVs and EES, where long-term cycling and long service life are demanded. Hence, it becomes essential to evaluate the performance and the aging mechanisms ongoing on battery systems. This thesis is focused towards the key field of high power applications of commercial LIBs and the study of the performance and identification of battery aging mechanisms through in situ techniques. A broad analysis of the performance and the degradation mechanisms that various cycling schemes (i.e. standard, fast charging and dynamic stress) cause on commercial high power LiFePO 4 batteries is reported in this work. In addition, an efficient, multistage fast charging protocol is developed and analyzed. In order to identify both qualitatively and quantitatively the aging mechanisms ongoing on the tested batteries, we use in situ analyses, including incremental capacity (IC), peak area (PA), and mechanistic model simulations using the `Alawa toolbox. An innovative approach to attain accurate simulation results is carried out by feeding the toolbox with harvested half-cell data from the actual cells. The results show that the developed fast-charge protocol is efficient, completes full charges within ~22 min and does not cause additional degradation in comparison with standard cycling. The end-of-life both for standard and fast charge cycling schemes surpassed 4500 cycles. The quantitative degradation measured for both cycling schemes is equal, caused by a linear loss of lithium inventory (LLI), coupled with a less degree of linear loss of active material (LAM) on the negative electrode (NE). The dynamic stress cycling caused rapid cell degradation, reaching 1100 cycles at end-of-life. The degradation is caused by large LAM on the NE, and in less degree, LLI. Moreover, the cell exhibited Li plating, which was identified and quantitatively measured using the in situtechniques. To finish the study, prognosis analyses on the fast charging scheme are carried out and we found that the use of fast charging protocol does not risk Li plating after all. In total, this thesis investigates the performance and aging mechanisms in commercial high power LiFePO4 batteries. The in situ, online techniques used in this work provide a systematic methodology to attain battery degradation identification, both qualitatively and quantitatively. The use of these techniques could be quite enlightening for the development of diagnosis and prognosis models for battery management system (BMS) applications to effectively manage and control LIB systems. Finally, the combination of proper cell chemistry and architecture, coupled with the use of an efficient fast charging protocol is key to achieving optimal fast charging in high power LIB applications

Health assessment of automotive batteries through computational intelligence-based soft sensors: An empirical study

International Joint Conference SOCO’17-CISIS’17-ICEUTE’17 (2017. León

Distal learning of the incremental capacity curve of a LiFePO4 battery

Abstract An intelligent model of the incremental capacity (IC) curve of an automotive lithium-ferrophosphate battery is presented. The relative heights of the two major peaks of the IC curve can be acquired from high-current discharges, thus enabling the state of health estimation of the battery while the vehicle is being operated and in certain cases, aging mechanisms can be suggested. Our model has been validated using a large dataset (number of batteries) representing different degradation scenarios, obtained from a recently available open-source database

Redesigning European Public Transport: Impact of New Battery Technologies in the Design of Electric Bus Fleets

Conference on Transport Engineering, CIT2018 (13th, 2018, Gijón, Asturias, Spain

Main Trends and Challenges in Road Transportation Electrification

Conference on Transport Engineering, CIT2018 (13th, 2018, Gijón, Asturias, Spain