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Characterization and Modeling of Electrochemical Energy Conversion Systems by Impedance Techniques

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Book Series: Schriften des Instituts für Werkstoffe der Elektrotechnik, Karlsruher Institut für Technologie / Institut für Werkstoffe der Elektrotechnik ISSN: 18681603 ISBN: 9783866449039 Year: Volume: 23 Pages: IX, 166 p. DOI: 10.5445/KSP/1000029318 Language: ENGLISH
Publisher: KIT Scientific Publishing
Subject: Technology (General)
Added to DOAB on : 2019-07-30 20:01:58

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This thesis introduces (i) amendments to basic electrochemical measurement techniques in the time and frequency domain suitable for electrochemical energy conversion systems like fuel cells and batteries, which enable shorter measurement times and improved precision in both measurement and parameter identification, and (ii) a modeling approach that is able to simulate a technically relevant system just by information gained through static and impedance measurements of laboratory size cells.

SOFC modelling and parameter identification by means of impedance spectroscopy

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Book Series: Schriften des Instituts für Werkstoffe der Elektrotechnik, Karlsruher Institut für Technologie / Institut für Werkstoffe der Elektrotechnik ISSN: 18681603 ISBN: 9783866445383 Year: Volume: 18 Pages: VIII, 147 p. DOI: 10.5445/KSP/1000019173 Language: ENGLISH
Publisher: KIT Scientific Publishing
Subject: Technology (General)
Added to DOAB on : 2019-07-30 20:02:01
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A high resolution electrochemical impedance spectroscopy study on anode supported single cells (ASC) is presented. The cells were characterised over a broad range of operating conditions, including different temperatures, current densities and various cathode and anode gas compositions.The analysis of the distribution of relaxation times combined with the numeric accuracy of a CNLS fit enabled the identification of five different processes contributing to the total polarisation loss of an ASC.

Grain-size effects in nanoscaled electrolyte and cathode thin films for solid oxide fuel cells (SOFC)

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Book Series: Schriften des Instituts für Werkstoffe der Elektrotechnik, Universität Karlsruhe (TH) / Institut für Werkstoffe der Elektrotechnik ISSN: 18681603 ISBN: 9783866443365 Year: Volume: 15 Pages: VIII, 155 p. DOI: 10.5445/KSP/1000010126 Language: ENGLISH
Publisher: KIT Scientific Publishing
Subject: Technology (General)
Added to DOAB on : 2019-07-30 20:02:01
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Due to their high energy conversion efficiencies and low emissions, Solid Oxide Fuel Cells (SOFCs) show promise as a replacement for combustion-based electrical generators at all sizes. Further increase of SOFC efficiency can be achieved by microstructural optimization of the oxygen-ion conducting electrolyte and the mixed ionic-electronic conducting cathode. By application of nanoscaled thin films, the exceptionally high efficiency allows the realization of mobile SOFCs.

Microstructural Characterisation, Modelling and Simulation of Solid Oxide Fuel Cell Cathodes

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Book Series: Schriften des Instituts für Angewandte Materialien - Werkstoffe der Elektrotechnik, Karlsruher Institut für Technologie / Institut für Angewandte Materialien - Werkstoffe der Elektrotechnik ISSN: 23658029 ISBN: 9783731506256 Year: Volume: 30 Pages: XI, 217 p. DOI: 10.5445/KSP/1000064791 Language: ENGLISH
Publisher: KIT Scientific Publishing
Subject: Technology (General)
Added to DOAB on : 2019-07-30 20:01:57
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This work deals with microstructural characterisation, modelling and simulation of SOFC electrodes with the goal of optimizing the electrode microstructures. Methods for a detailed electrode analysis based on focused ion beam (FIB) tomography are presented. A 3D FEM model able to perform simulations of LSCF cathodes based on 3D tomography data is shown. A model generating realistic, yet synthetic microstructures is presented that enables the optimization of microstructural characteristics.

Charakterisierung und Modellentwicklung von Natur und Funktionalität der Kathoden/Elektrolyt-Grenzfläche von Hochtemperatur-Brennstoffzellen (SOFC)

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Book Series: Schriften des Instituts für Angewandte Materialien - Werkstoffe der Elektrotechnik, Karlsruher Institut für Technologie / Institut für Angewandte Materialien - Werkstoffe der Elektrotechnik ISSN: 23658029 ISBN: 9783731508618 Year: Volume: 35 Pages: II, 246 p. DOI: 10.5445/KSP/1000087336 Language: GERMAN
Publisher: KIT Scientific Publishing
Subject: Technology (General)
Added to DOAB on : 2019-07-30 20:02:01
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Solid oxide fuel cells (SOFC) achieve high efficiencies, the lower the internal electrochemical losses are. This work investigates insulating secondary phases at the cathode/electrolyte interface that are formed during fabrication. Full cells and model systems are electrochemically characterized, analyzed by electron microscopy and reconstructed by tomography. A FEM model reveals performance limiting factors. As a result, an optimized production routine is proposed.

Finite Element Method (FEM) Model and Performance Analysis of Solid Oxide Fuel Cells

Author:
Book Series: Schriften des Instituts für Angewandte Materialien - Werkstoffe der Elektrotechnik, Karlsruher Institut für Technologie / Institut für Angewandte Materialien - Werkstoffe der Elektrotechnik ISSN: 23658029 ISBN: 9783731508953 Year: Volume: 36 Pages: XIII, 259 p. DOI: 10.5445/KSP/1000090508 Language: ENGLISH
Publisher: KIT Scientific Publishing
Subject: Technology (General)
Added to DOAB on : 2019-07-30 20:01:57
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This work presents a numerical FEM framework, capable of predicting SOFC performance under technically relevant, planar stack contacting conditions. A high level of confidence in the model predictions is supplied by using exclusively experimentally determined material/kinetic parameters and by a comprehensive validation. The presented model aids SOFC stack development by pre-evaluating possible material choices and design combinations for cells/interconnectors without any experimental effort.

Energy and Technical Building Systems - Scientific and Technological Advances

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ISBN: 9783039281787 9783039281794 Year: Pages: 220 DOI: 10.3390/books978-3-03928-179-4 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Science (General) --- Physics (General)
Added to DOAB on : 2020-04-07 23:07:09
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Future buildings require not only energy efficiency but also proper building automation and control system functionalities in order to respond to the needs of occupants and energy grids. These development paths require a focus on occupant needs such as good indoor climate, easy operability, and monitoring. Another area to be tackled is energy flexibility, which is needed to make buildings responsive to the price signals of electricity grids with increasing amounts of fluctuating renewable energy generation installed both in central grids and at building sites. This Special Issue is dedicated to HVAC systems, load shifting, indoor climate, and energy and ventilation performance analyses in buildings. All these topics are important for improving the energy performance of new and renovated buildings within the roadmap of low energy and nearly zero energy buildings. To improve energy performance and, at the same time, occupant comfort and wellbeing, new technical solutions are required. Occupancy patterns and recognition, intelligent building management, demand response and performance of heating, cooling and ventilation systems are some common keywords in the articles of this Special Issue contributing to future highly performing buildings with reliable operation.

Keywords

ice rinks --- air distribution solutions --- indoor air temperature gradient --- air handling unit configuration --- building energy efficiency --- building performance simulation --- energy and HVAC-systems in buildings --- energy piles --- validation --- floor slab heat loss --- energy --- computer simulations --- predictive rule-based control --- hourly CO2eq. intensity --- demand response --- energy flexibility --- n/a --- indoor environment quality --- thermal comfort --- personalized ventilation --- fuzzy logic --- environmental impact --- device efficiency --- air pollutant --- multi-households --- solid oxide fuel cell cogeneration system --- end-use energy consumption --- heating --- ventilation and air conditioning (HVAC) --- intelligent system management --- lighting electrical energy --- national electricity grid --- office building --- Photovoltaic system --- simulation --- Simulink® --- deep renovation --- energy retrofit --- detached house --- multi-objective optimization --- greenhouse gas emissions --- heat pump --- genetic algorithm --- occupancy density --- moisture conditions --- energy use --- indoor air quality --- ventilation rate --- KNX --- Neural Network (NN) --- Multilayer Perceptron (MLP) --- Random Tree (RT) --- Linear Regression (LR) --- Cloud Computing (CC) --- Internet of Things (IoT) --- LMS (Least Mean Squares) Adaptive filter (AF) --- gateway --- monitoring --- occupancy --- prediction --- IBM SPSS --- Intelligent Buildings (IB) --- energy savings

Microgrids

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ISBN: 9783039218684 9783039218691 Year: Pages: 108 DOI: 10.3390/books978-3-03921-869-1 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: General and Civil Engineering --- Technology (General)
Added to DOAB on : 2020-01-30 16:39:46
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Electrical power systems are evolving at the generation, transmission, and distribution levels. At distribution level, small generating and storage units—the so-called distributed energy sources (DERs)—are being installed close to consumption sites. The expansion of DERs is empowering renewable energy source integration and, as a consequence, new actors are appearing in electrical systems. Among them, the prosumer is a game-changer; the fruit of the behavior transformation of the consumer who has not only the ability to consume power but also to produce it. Microgrids can be understood as DER installations that have the capability of both grid-connected and grid-isolated operation. During the last decades, there has been a significant deployment of microgrids (e.g., in countries like the United States, Switzerland, and Denmark) and a consequent increase in renewable energy generation. This is contributing to the decarbonization of electrical power systems. However, the variability and intermittency of renewable sources introduce uncertainty, which implies a more complex operation and control. Taking into account that existing and future planned microgrids are being/going to be interconnected to the current electrical network, challenges in terms of design, operation, and control at power system level need to be addressed, considering existing regulations.

Keywords

demand-side management --- optimization --- deterministic optimization --- stochastic optimization --- residential users --- devices scheduling --- renewable sources --- storage systems --- electric energy market --- power quality --- chaos synchronization detection --- extension theory --- direct search method (DSM) --- microgrid (MG) --- distributed energy resources (DERs) --- distributed generation (DG) --- optimal dispatch --- microgrids --- multi-agent --- coordinated control --- IEC 61850 Standard --- generic object oriented substation event (GOOSE) communication --- power quality disturbances --- S-transform --- multiresolution --- particle swarm optimization --- decision tree --- reliability evaluation --- microgrid --- distributed generation --- battery storage --- vehicle-to-grid --- ruleless EV --- regular EV --- combined power generation system --- microgrid --- coordinative optimization of energy --- predictive control --- genetic algorithm --- distributed generation (DG) --- microgrid --- microgrid stability controller (MSC) --- total sliding-mode control --- hierarchical control scheme --- maximum electrical efficiency --- nonlinear programming --- solid oxide fuel cell --- electric vehicle (EV) --- vehicle-to-grid (V2G) --- isolated grid --- load frequency control (LFC) --- multivariable generalized predictive control (MGPC) --- current harmonic reduction --- active filter --- power quality --- buck-boost converter --- renewable energy source --- optimal capacity --- reliability --- renewable --- energy storage --- genetic algorithm --- DC microgrid --- communication delay --- droop control --- load power sharing --- mesh configuration --- radial configuration --- electric vehicle --- energy management system --- peak-shift --- peak-cut --- vehicle information system --- photovoltaic feasibility --- flexible generation --- distributed energy resources --- power quality --- DC distribution --- DC microgrid --- inrush current --- grounding --- DC architectures --- datacenter --- residential power systems --- telecommunication power management --- smart grids --- microgrid --- network planning --- power distribution --- grid independence --- distributed energy resources --- micro-grid --- IEC 61850 --- plug and play --- operation --- small-scale standalone microgrid --- HESS --- ESS effective rate --- coordinated control strategy --- cost and life --- technical and economic optimization --- microgrid --- flywheel energy storage (FES) --- doubly fed induction machine --- frequency control --- smoothing wind power --- distributed generation --- congestion problems --- medium-voltage networks --- curtailment --- flexibility --- microgrid test facility --- distributed generation --- integrated electrical and thermal grids --- flexible and configurable architecture --- energy efficiency --- distributed optimization --- optimal power flow --- microgrids --- embedded system --- smart grid --- smart inverter --- distributed energy resource --- power quality

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