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1
Cakici, Murat. "Highly flexible carbon fibre fabric based nanostructured hybrids for high performance energy storage systems." Thesis, The University of Sydney, 2017. http://hdl.handle.net/2123/18123.
Full textAbstract:
Electrochemical supercapacitors (ES), or ultracapacitors, store energy using either reversible adsorption of electrolyte ions (electrochemical double layer capacitors) or fast surface redox reactions on its electrodes (pseuodocapacitors). Currently, they are used together with batteries or fuel cells when high-power delivery or uptake is required. They have exceptional features such as high power density, high cycle efficiency, fast charging-discharging rate, long lifecycle, and safe operation. Therefore, they have attracted tremendous interest as next generation energy conversion and storage systems, ranging from portable wearable electronics to hybrid electric vehicles. However, low energy density is the main drawback to use ES as a stand-alone energy storage system. Thus, their performance should be improved to fulfil the requirements of ever-growing energy demands of progressing global economy and industry. In addition, most of the ES electrodes are fabricated from powders which makes them unsuitable for their potential use as wearable lightweight flexible devices in the future. Considering the requirements of future industrial applications of ES, this thesis focuses on synthesizing high performance, flexible, mechanically stable, lightweight, eco-friendly, and low cost ES electrodes using green, scalable, and inexpensive fabrication methods. To develop highly efficient electrode materials suitable for practical applications in a flexible design, novel synthesis procedures were explored to incorporate pseudocapacitive materials (metal oxides and electrically conductive polymers) into three-dimensional and flexible conductive carbon materials to obtain multicomponent hybrid materials. Therefore, hybrid materials reported in this thesis are binder-/conductive agent-free and also have enhanced three-dimensional nanostructures which promote energy storage. Simplicity of the fabrication methods also enable large scale and economical production of flexible and mechanically stable materials which can be directly used as ES electrodes. First, electrode materials with a unique nanostructure was developed for supercapacitor applications based on carbon fibre fabric (CFF) / MnO2 hybrid materials, in which MnO2 was uniformly coated on the surface of CFF. A green hydrothermal method was used to functionalize CFF with coral-like MnO2 nanostructures to improve the electrochemical performance of the hybrid composites. The morphological, structural, and crystalline properties of composites were analysed by using various techniques to confirm the deposition of coral-like MnO2 on CFF. The electrochemical performance was examined in a three-electrode system and cyclic voltammetry results reveal the superior specific capacitance of 467 F g-1 at a scan rate of 5 mV s-1. The cycling performance test revealed that the capacitance retention was 99.7% and the coulombic efficiency remained as high as 99.3% after 5000 cycles, demonstrating an outstanding electrochemical stability of the coral-like MnO2/CFF composite electrode. Second, synthesis method used in the first study was optimised to obtain three novel nanostructured MnO2 layers on flexible CFF substrates. It was observed that different morphologies of MnO2 could be grown on carbon fibres by adjusting the concentration of precursor solution. The morphological, structural, and crystalline properties of the composites were analysed by using various techniques to confirm that MnO2 nanostructures were successfully anchored on CFF. The electrochemical performances of the nanostructured MnO2/CFF composites were examined in two-electrode symmetric cell configuration in 1 M Na2SO4 electrolyte. Among three different morphologies, nanoplate type MnO2/CFF electrode had the best electrochemical performance (528 F g-1 at 0.5 A g-1 current density). In addition, binder and conductive agent free, flexible MnO2/CFF composite electrode had excellent cycling stability and coulombic efficiency. Finally, activated CFF (ACFF) / reduced graphene oxide (RGO)/polyaniline (PANI) composite flexible electrodes were prepared by in-situ polymerization method. Polymerization of aniline was optimized by adjusting aniline concentration to obtain PANI nanowire arrays on the three-dimensional flexible carbon based substrate. Electrochemical performance of ACFF/RGO/PANI composite was compared with ACFF and ACFF/RGO electrodes in two-electrode symmetrical cell configuration in 1 M H2SO4 electrolyte. The results indicated that ACFF/RGO/PANI exhibited outstanding area normalized capacitance due to synergistic effect between ACFF, RGO, and PANI. The facile synthesis method of the composite electrode using textile based substrate enables the possibility for fabrication of high-performance flexible energy storage devices.
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Chandrasekaran, Rajeswari. "Modeling of electrochemical energy storage and energy conversion devices." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/37292.
Full textAbstract:
With increasing interest in energy storage and conversion devices for automobile applications, the necessity to understand and predict life behavior of rechargeable batteries, PEM fuel cells and super capacitors is paramount. These electrochemical devices are most beneficial when used in hybrid configurations rather than as individual components because no single device can meet both range and power requirements to effectively replace internal combustion engines for automobile applications. A system model helps us to understand the interactions between components and enables us to determine the response of the system as a whole. However, system models that are available predict just the performance and neglect degradation. In the first part of the thesis, a framework is provided to account for the durability phenomena that are prevalent in fuel cells and batteries in a hybrid system. Toward this end, the methodology for development of surrogate models is provided, and Pt catalyst dissolution in PEMFCs is used as an example to demonstrate the approach. Surrogate models are more easily integrated into higher level system models than the detailed physics-based models. As an illustration, the effects of changes in control strategies and power management approaches in mitigating platinum instability in fuel cells are reported. A system model that includes a fuel cell stack, a storage battery, power-sharing algorithm, and dc/dc converter has been developed; and preliminary results have been presented. These results show that platinum stability can be improved with only a small impact on system efficiency. Thus, this research will elucidate the importance of degradation issues in system design and optimization as opposed to just initial performance metrics.
In the second part of the thesis, modeling of silicon negative electrodes for lithium ion batteries is done at both particle level and cell level. The dependence of the open-circuit potential curve on the state of charge in lithium insertion electrodes is usually measured at equilibrium conditions. Firstly, for modeling of lithium-silicon electrodes at room temperature, the use of a pseudo-thermodynamic potential vs. composition curve based on metastable amorphous phase transitions with path dependence is proposed. Volume changes during lithium insertion/de-insertion in single silicon electrode particle under potentiodynamic control are modeled and compared with experimental data to provide justification for the same. This work stresses the need for experiments for accurate determination of transfer coefficients and the exchange current density before reasoning kinetic hysteresis for the potential gap in Li-Si system. The silicon electrode particle model enables one to analyze the influence of diffusion in the solid phase, particle size, and kinetic parameters without interference from other components in a practical porous electrode. Concentration profiles within the silicon electrode particle under galvanostatic control are investigated. Sluggish kinetics is established from cyclic voltammograms at different scan rates. Need for accurate determination of exchange current density for lithium insertion in silicon nanoparticles is discussed. This model and knowledge thereof can be used in cell-sandwich model for the design of practical lithium ion cells with composite silicon negative electrodes. Secondly, galvanostatic charge and discharge of a silicon composite electrode/separator/ lithium foil is modeled using porous electrode theory and concentrated solution theory. Porosity changes arising due to large volume changes in the silicon electrode with lithium insertion and de-insertion are included and analyzed. The concept of reservoir is introduced for lithium ion cells to accommodate the displaced electrolyte. Influence of initial porosity and thickness of the electrode on utilization at different rates is quantitatively discussed. Knowledge from these studies will guide design of better silicon negative electrodes to be used in dual lithium insertion cells for practical applications.
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CASTIGLIA, VINCENZO JUNIOR. "Hybrid Energy Storage Modeling And Innovative Solutions For Energy Storage Management Systems." Doctoral thesis, Università degli Studi di Palermo, 2022. https://hdl.handle.net/10447/533479.
Full textAbstract:
La presente tesi riguarda la modellazione di diverse fonti di accumulo di energia elettrica, in particolare batterie e supercondensatori (SC), e di nuove configurazioni di metodi di gestione di sistemi di accumulo di energia ibridi . Il crescente bisogno di domanda di energia e il desiderio di raggiungere uno sviluppo sostenibile, si riflettono nell'uso di Generatori Distribuiti (DG) basati sulle Fonti energetiche Rinnovabili (FER). L'uso di un controllo di supervisione intelligente e il raggruppamento locale della domanda e della generazione possono portare a notevoli miglioramenti nell'efficienza, affidabilità e resilienza del sistema elettrico. Il problema principale della DG basata sulle FER è la variazione naturale di alcune fonti rinnovabili, come il vento e il sole. Per ridurre l'impatto della generazione intermittente delle FER, la soluzione più efficace e pratica è l'impiego di sistemi di stoccaggio dell'energia.<br>The present dissertation concerns about the modeling of different electrical energy storage sources, in particular batteries and supercapacitors (SCs), and of novel configurations of Hybrid Energy Storage Management Systems (HESMS). The growing need for energy demand and the desire to achieve sustainable development, are reflected in the use of Renewable Energy Sources (RESs)-based Distributed Generators (DG). The use of smart supervisory control and local clustering of demand and generation can lead to marked improvements in the efficiency, reliability, and resilience of the electrical system. The main problem of RESs-based DG is the natural variation of some renewable sources, such as wind and solar. To reduce the impact of intermittent RES generation, the most effective and practical solution is the employment of Energy Storage Systems (ESSs).
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Smith, Ian C. S. M. (Ian Charles) Massachusetts Institute of Technology. "Benefits of battery-uItracapacitor hybrid energy storage systems." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/75685.
Full textAbstract:
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2012.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (p. 85-88).<br>This thesis explores the benefits of battery and battery-ultracapacitor hybrid energy storage systems (ESSs) in pulsed-load applications. It investigates and quantifies the benefits of the hybrid ESS over its battery-only counterparts. The metric for quantifying the benefits is charge efficiency - the amount of energy delivered to the load per unit charge supplied by the battery. The efficiency gain is defined as the difference in charge efficiency between the hybrid and the battery-only ESS. A custom experimental apparatus is designed and built to supply the current control for charging and discharging the batteries, as well as the data acquisition for measuring energy and current output. Experiments are performed on both ESSs under four different pulsed load profiles: 1. 436 ms pulse period, 10% duty cycle, 8 A pulse amplitude 2. 436 ms pulse period, 25% duty cycle, 8 A pulse amplitude 3. 436 ms pulse period, 10% duty cycle, 16 A pulse amplitude 4. 436 ms pulse period, 25% duty cycle, 16 A pulse amplitude Circuit models are created to accurately represent the battery and ultracapacitors. These models are used in simulations of the same test cases from the physical experiments, and efficiency gains are compared. The circuit models differed from the experimentation by less than 1%. Both experimental and simulated data demonstrate significantly increased charge efficiencies of hybrid ESSs over battery-only ESSs, with demonstrated gains between 10% and 36%. These benefits were greatest for the 16 A, 10% duty cycle test case because it combined the highest pulse amplitude and the shortest duty cycle. It is concluded that high-amplitude, low duty cycle, and low period pulsedload profiles yield the highest efficiency gains.<br>by .Ian C. Smith<br>S.M.
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Eriksson, Emma. "Hybrid Renewable Energy Systems with Battery and Hydrogen Storage." Thesis, Griffith University, 2017. http://hdl.handle.net/10072/378157.
Full textAbstract:
As population numbers and people's standards of living increase, so does the global
energy demand and carbon dioxide emissions and it is imperative that new sustainable and
renewable energy sources are sought, as the world's natural resources are depleting. Electricity
generation presents the biggest opportunity to lower CO2 emissions and in an emerging world
where the demand for alternative renewable energy systems is growing it is expected that one
of the technologies in conjunction with conventional storage which will play a key role in
reducing emissions is hydrogen fuel cell technology with hydrogen storage.
Many attempts have been made to realise optimisation algorithms of renewable energy
system using multiple techniques in literature. These attempts have consisted of using
mathematical models combined with rules and object oriented modelling in order to assist in
the design of renewable applications. The integration methods described in previous papers up
to date seems to offer mainly technical and/or economical optimisation parameters. None of the
presented methods seems to be based on a unified model where multi objectives and/constraints
are taken into account above technical and economic considerations. There are also few
practical examples of analysis and optimisation of hybrid renewable energy systems in a
complete optimisation model where the behaviour of renewable energy sources, battery banks,
electrolysers, fuel cells and hydrogen storage tanks are reviewed throughout the simulation in
detail. For a successful transition to a renewable energy economy, optimisation of renewable
energy systems must evolve to take into account metrics additional to technical performance
and cost. A Normalised Weighted Constrained Multi-Objective (NWCMO) meta-heuristic
optimisation algorithm has been proposed in conjunction with optional constraints for
achieving a compromise between mutually conflicting objectives in multiple simultaneous
categories; technical, economic, environmental and socio-political objectives, to simulate and
optimise a renewable energy system with balanced outcomes. The socio political objective is represented by a proposed socio acceptance matrix which outputs a weighted measured social
acceptance indicator towards proposed renewable energy systems. The methodology was
implemented using an adjusted Particle Swarm Optimisation algorithm and tested against data
and other studies from the literature. In each case the original results could be reproduced, but
the newly-implemented algorithm was further able to find a more optimal design solution under
the same constraints. In addition, the influence of additional quantified socio-political inputs
was explored.
This thesis presents a review of issues for integration of hydrogen energy technology into
energy systems, emphasising electricity generation using fuel cell hydrogen technology.
Integration of energy storage, sizing methodologies, energy flow management and their
associated optimization algorithms and software implementation are addressed. The model
presented in this thesis offers a streamlined integration of design rules, optimization techniques
and constraints merged into one planning system. The outcome is a model offering an end user
the possibility to carry out a proper feasibility study prior to embarking on implementing a
renewable system. An optimisation methodology based on four classes of objective (technical,
economic, environmental, socio-political) is presented, benchmarked and tested against various
hybrid renewable energy systems with conventional and hydrogen storage.<br>Thesis (PhD Doctorate)<br>Doctor of Philosophy (PhD)<br>School of Environment and Sc<br>Science, Environment, Engineering and Technology<br>Full Text
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He, Yiou. "The assessment of battery-ultracapacitor hybrid energy storage systems." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/91088.
Full textAbstract:
Thesis: S.M., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2014.<br>55<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (pages 154-157).<br>Battery-ultracapacitors hybrid energy storage systems (ESS) could combine the high power density and high life cycle of ultracapacitors with the high energy density of batteries, which forms a promising energy storage system. In this thesis, an assessment of the benefits of the hybrid ESS relative to its battery-only counterpart in pulse-load applications is investigated for both Nickel-Metal Hydride (NiMH) batteries and Lithium-ion (Li-ion) batteries, and under different load profiles. Specifically, the hybrid ESS in this assessment is of the simplest type - paralleling the ultracapacitors across the batteries without any power electronics interface between them. To quantify this assessment, Discharge Capacity(0) is defined as the amount of energy one can draw out of an ESS per unit charge supplied by this ESS. The metric for quantifying the benefits is energy efficiency gain, defined as the percentage increase in the discharge capability of the hybrid ESS over its battery-only counterpart. The investigation proves that the hybrid system is more beneficial over the battery-only system in terms of how much energy it can output at a specific state-of-charge level. Among the test cases covered by this thesis, the increase in the output energy of Li-ion battery systems by incorporating ultracapacitors can reach to 17% and that of Ni-MH battery systems can reach to 33%. This thesis also shows that the benefits of paralleling ultracapactors across batteries depended upon the discharge profile of the load, the battery type and the capacitance. The benefits increase quadratically with the pulse amplitude, decreases linearly with the duty cycle and inverse with the pulse period. Moreover, capacitors with higher capacitance and lower ESR yield to larger benefits. And for batteries with a higher ESR, the ultracapacitors will show more benefits than for batteries with low ESR.<br>by Yiou He.<br>S.M.
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Martino, Drew J. "Evaluation of Electrochemical Storage Systems for Higher Efficiency and Energy Density." Digital WPI, 2017. https://digitalcommons.wpi.edu/etd-dissertations/470.
Full textAbstract:
Lack of energy storage is a key issue in the development of renewable energy sources. Most renewables, especially solar and wind, when used alone, cannot sustain a reliably constant power output over an extended period of time. These sources generally generate variable amounts of power intermittently, therefore, an efficient electrical energy storage (EES) method is required to better temporally balance power generation to power consumption. One of the more promising methods of electrical energy storage is the unitized regenerative fuel cell (UFRC.) UFRCs are fuel cells that can operate in a charge-discharge cycle, similar to a battery, to store and then to subsequently release power. Power is stored by means of electrolysis while the products of this electrolysis reaction can be recombined as in a normal fuel cell to release the stored power. A major advantage of UFRCs over batteries is that storage capacity can be decoupled from cell power, thus reducing the potential cost and weight of the cell unit. Here we investigate UFRCs based on hydrogen-halogen systems, specifically hydrogen-bromine, which has potential for improved electrode reaction kinetics and hence cheaper catalysts and higher efficiency and energy density. A mathematical model has been developed to analyze this system and determine cell behavior and cycle efficiency under various conditions. The conventional H2-Br2 URFCs, however also so far have utilized Pt catalysts and Nafion membranes. Consequently, a goal of this work was to explore alternate schemes and materials for the H2-Br2 URFC. Thus, three generations of test cells have been created. The first two cells were designed to use a molten bromide salt, ionic liquid or anion exchange membrane as the ion exchange electrolyte with the liquids supported on a porous membrane. This type of system provides the potential to reduce the amount of precious metal catalyst required, or possibly eliminate it altogether. Each cell showed improvement over the previous generation, although the results are preliminary. The final set of results are promising for anion exchange membranes on a cost basis compared Nafion. Another promising energy storage solution involves liquid methanol as an intermediate or as a hydrogen carrier. An alternative to storing high-pressure hydrogen is to produce it on-board/on-site on demand via a methanol electrocatalytic reformer (eCRef), a PEM electrolyzer in which methanol-water coelectrolysis takes place. Methanol handling, storage, and transportation is much easier than that for hydrogen. The hydrogen produced via methanol eCref may then be used in any number of applications, including for energy storage and generation in a standard H2-O2 PEM fuel cell. The mathematical modeling and analysis for an eCref is very similar to that of the HBr URFC. In this work, a comprehensive model for the coelectrolysis of methanol and water into hydrogen is created and compared with experimental data. The performance of the methanol electrolyzer coupled with a H2-O2 fuel cell is then compared for efficiency to that of a direct methanol fuel cell data and was found to be superior. The results suggest that an efficient and small paired eCRef-fuel cell system is potentially be a cheaper and more viable alternative to the standard direct methanol fuel cell. Both the H2-Br2 URFC and the methanol eCref in combination with a H2-O2 fuel cell have significant potential to provide higher energy efficiency and energy density for EES purposes.
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SUN, C. "Electrical energy storage by electrochemical vanadium redox flow battery methods." Doctoral thesis, Università degli studi di Padova, 2018. http://hdl.handle.net/11577/3424975.
Full textAbstract:
Redox flow batteries (RFBs) are electrochemical cells that are able to reversibly convert the chemical energy stored into the redox couples into electrical power. Vanadium redox flow batteries (VRFBs) exploit redox couples both based on vanadium species. To make VRFB technology commercially viable, technical and economic barriers including high capital cost and rapid capacity decay need to be addressed. The primary objective of this thesis is to achieve high performance VRFB with long durability, mainly by reducing the vanadium permeability through the membrane. Nowadays perfluorosulfonic acid membranes are widely used in VRFB, such as Nafion. Nafion has high chemical and mechanical stability, and it exhibits good proton conductivity. Nevertheless, the VRFB cell with Nafion membrane has fast capacity decay due to the high vanadium crossover.
In an effort to overcome the limitations of Nafion, this thesis reports the synthesis and characterization of hybrid inorganic-organic proton-conducting membrane alternatives to classic perfluorinated ionomers. Two families of hybrid membranes were synthesized:
1) Nafion membrane doped with WO3 nanofiller, in order to reduce its vanadium crossover while maintaining the high proton conductivity;
2) synthesis of sulfonated poly (ether ether ketone) (SPEEK) membrane with optimized degree of sulfonation as an alternative low-cost membrane. Then further dope the SPEEK membrane with WO3 to reduce vanadium crossover.
For all the hybrid membranes prepared by a solvent-casting procedure, the introduction of WO3 nanoparticles does not alter significantly the thermal degradation events of the polymer host and the hybrid membranes maintain the good thermal stability. MDSC reveals that in hybrid membranes the endothermic events are slightly shifted attributed to the formation of “dynamic crosslinks” between the WO3 nanoparticles and the polymer host, that stabilize the hybrid membrane. The hydrophilic domains of the polymer host are reduced in size as the content of WO3 is raised. The water uptake of hybrid membranes decreases with the increasing loading of WO3 nanofillers; as a consequence, the pathways of charge migration become more tortuous. While the higher charge migration tortuosity would correspond to a dramatically lower permeability to vanadium species. The tortuosity for protons is likely much less than that for vanadium, as the vanadium ions are only passing through the bulk water, while the protons are also delocalized at the polymer-nanofiller interfaces in the presence of interface water. The vanadium permeability of hybrid membranes decreases significantly and the ion selectivity is much improved in comparison with Nafion. The hybrid membranes with highest ion selectivity are chosen for VRFB single cell test. They exhibits a higher coulombic efficiency in comparison with the Nafion 212 reference. The reduced permeation of vanadium species is also revealed by the lower discharge capacity decay and longer self-discharge times for the hybrid membranes. Therefore, the new family of hybrid membranes may be promising candidates for application in VRFBs.
The final chapter describes the study by Raman spectroscopy of the species present in the positive feed of a VRFB as a function of the state of charge (SOC). Changes in complexation due to presence of stable oxygenated coordination complexes of vanadium, also interacting strongly with HSO4- and SO42- ligands, are put in evidence. In particular, it is demonstrated that the positive feed includes additional species beyond VO2+ and VO2+, with a particular reference to dimers such as HV2O5- and H3V2O7-. Such species may be accounted to understand in detail the charge-discharge processes taking place at the electrodes of a VRFB. Indeed, on these bases, the processes are expected to involve a broad distribution of V(IV) and V(V) species, that may end up affecting significantly crucial macroscopic features of the overall VRFB.<br>Le batterie Redox a Flusso (RFB) sono celle elettrochimiche capaci di convertire reversibilmente l'energia chimica immagazzinata in coppie redox in energia elettrica. Le batterie a flusso al vanadio (VRFB) sfruttano coppie redox entrambe basate su specie di vanadio. Per far sì che la tecnologia VRFB sia commercialmente valida, occorre superare barriere tecniche ed economiche che includono elevati costi di capitale ed un rapido decadimento della capacità. L'obiettivo principale di questa tesi è di ottenere VRFB ad alte prestazioni e di lunga durata, principalmente riducendo la permeabilità del vanadio attraverso la membrana. Al giorno d'oggi nelle VRFB vengono utilizzate membrane a base di acido perfluorosolfonico, come il Nafion. Il Nafion ha un'elevata stabilità chimica e meccanica, e presenta una buona conducibilità protonica. La VRFB con membrana al Nafion hanno un rapido decadimento della capacità a causa dell'alto crossover del vanadio.
Per superare i limiti del Nafion, questa tesi riporta la sintesi e la caratterizzazione di membrane ibride inorganico-organiche conduttrici di protoni alternative agli ionomeri perfluorurati. Due famiglie di membrane ibride sono state ottenute:
1) membrana di Nafion drogata con nanofiller WO3, per ridurre il crossover del vanadio mantenendo un’elevata conducibilità protonica;
2) sintesi di una membrana a base di poli(etere-etere-chetone) solfonato (SPEEK), con grado di solfonazione ottimizzato. Anche la membrana a base di SPEEK viene poi drogata con WO3 per ridurre il crossover del vanadio.
Nelle membrane ibride preparate mediante una procedura di solvent-casting, l'introduzione di nanoparticelle di WO3 non altera in modo significativo gli eventi di degradazione termica della matrice polimerica, mantenendo così una buona stabilità termica. Misure MDSC rivelano che nelle membrane ibride gli eventi termici sono leggermente spostati a causa della formazione di "crosslink dinamici" tra le nanoparticelle di WO3 e la matrice polimerica, che stabilizzano la membrana. La dimensione dei domini idrofili e l’assorbimento d’acqua della mambrana si riducono all’aumentare del contenuto di WO3. Di conseguenza, i percorsi di migrazione di carica diventano più tortuosi. Questa maggiore tortuosità alla migrazione di carica corrisponde ad una permeabilità inferiore delle specie vanadio. Al contrario del vanadio, la tortuosità ha probabilmente un effetto inferiore per i protoni, poiché gli ioni di vanadio attraversano solo i domini massivi di acqua, mentre i protoni vengono scambiati anche alle interfacce polimero-nanofiller. Così, la permeabilità al vanadio delle membrane ibride diminuisce significativamente e la selettività degli ioni è molto migliorata rispetto al Nafion. Le migliori membrane ibride sono scelte per il test in cella VRFB. Esse esibiscono una maggiore efficienza coulombica rispetto al riferimento Nafion 212. La ridotta permeazione delle specie di vanadio è rivelata anche dal minore decadimento della capacità di scarica e dai tempi di autoscarica più lunghi per le membrane ibride. Pertanto, la nuova famiglia di membrane ibride è un promettente candidato per l'applicazione in VRFB.
Il capitolo finale descrive lo studio, attraverso la spettroscopia Raman, delle specie presenti nella soluzione positiva (catolita) di una VRFB in funzione dello stato di carica (SOC). Gli equilibri dovuti alla presenza di complessi di coordinazione del vanadio, che interagiscono fortemente con i leganti HSO4- e SO42-, vengono evidenziati. In particolare, viene dimostrato come il catolita includa specie addizionali oltre a VO2+ e VO2+, quali HV2O5- e H3V2O7-. La presenza di tali specie deve essere considerata per comprendere in dettaglio i processi di scarica e carica che avvengono agli elettrodi di una VRFB. Infatti, su queste basi, ci si aspetta il coinvolgimento di un'ampia distribuzione di specie V(IV) e V(V), che potrebbero influenzare le caratteristiche macroscopiche significativamente cruciali di una VRFB.
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Austin, Kurumi Ria, Krishna Muralidharan, Kurumi Ria Austin, and Krishna Muralidharan. "Synthesis and Characterization of Lithiated C60 Systems: Applications in Electrochemical Energy Storage." Thesis, The University of Arizona, 2017. http://hdl.handle.net/10150/624906.
Full textAbstract:
Mixed ionic and electronic conduction makes alkali-metal intercalated fullerides a material of interest for solid-state battery applications. Alkali-metal intercalation introduces an electron into the fulleride lattice, allowing alkali-metal ions to occupy the respective octahedral or tetrahedral sites within a monoclinic polymerized structure. The presence of the alkali metal ions within the lattice allows for easy activation of these carbon-based nanomaterial by creating continuous channels for facile ionic conduction, while the presence of the mobile electrons, donated by the alkali metal atoms, also promotes electronic conductivity. A comparison was made between literature analysis of Li4C60 and experimentally synthesized Li3C60. Raman spectroscopy, X-ray diffraction, and Li-NMR were used to characterize the Li3C60 polymeric structure. XRD was used to confirm the crystal structure as a monoclinic polymerized crystal structure. Raman spectroscopy revealed a 6 cm-1 shift in the Ag(2) pentagonal-pinch mode between Li3C60 and pristine C60, compared to a shift of around 25 cm-1 for Li4C60. Li-NMR verified occupation of the octahedral and tetrahedral sites of the C60 lattice. Analysis of lithium intercalated fulleride systems was done to fully characterize and understand materials that have the potential to be safer, and more efficient alternative to current electrolyte technologies.
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Abdin, Zainul. "Components models for solar hydrogen hybrid energy systems based on metal hydride energy storage." Thesis, Griffith University, 2017. http://hdl.handle.net/10072/370890.
Full textAbstract:
Modelling and simulation are essential tools for concept evaluation and for predicting
the performance of a hybrid energy system, since prototyping and testing each candidate
design for such a complex system would almost always be prohibitively cumbersome,
expensive and time consuming. To meet the modelling and simulation objectives, the various
components of the system (sources, storage, loads, and converters) need to be characterised
and modelled in a tractable way. The tuning of the models to reflect the actual system
components is a key milestone in this process and requires reliable and comprehensive
experimental data. Furthermore, environmental conditions such as ambient temperature may
have a significant impact on the performance, which has to be taken into account.
The complexity of hybrid energy systems and their dependence on embedded control
software increases the difficulty in predicting interactions among the various components and
subsystems. A modelling environment that can model not only the components but also
control algorithms (such as Matlab/Simulink, Homer etc.) is therefore advantageous.
Effective diagnosis of faults in an installed system also presents a challenge, because of the
interactions between the components and the control system. Modelling may play an
important role in diagnosis of the operating components. For example, running an electrolyser
model and comparing actual electrolyser operating variables with those obtained from the
model may help to diagnose a fault in the real electrolyser.
This thesis focuses on modelling the principal components of hybrid solar energy
systems that include energy storage in the form of hydrogen: a large photovoltaic array
subject to manufacturer’s variability and temperature inhomogeneity; two types of
electrolyser as commonly found in hydrogen energy systems; a metal-hydride hydrogen
storage tank; a fuel cell. Attention is given here to building physics-based component models with minimum empiricism and to critically analysing the state of the art in modelling such
components. The models have been realised in Simulink, so that they are mutually compatible
and can be linked into a whole of system model. All the models were validated against
experimental data and performed at least as well as models found in the literature. The thesis
is based on six papers, four already published and two submitted.<br>Thesis (PhD Doctorate)<br>Doctor of Philosophy (PhD)<br>School of Natural Sciences<br>Science, Environment, Engineering and Technology<br>Full Text
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Vieira, Giovani Giulio Tristão Thibes. "Hybrid powertrains analysis for ship propulsion using energy storage." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/3/3143/tde-17122018-090614/.
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The ship emission already occupy the eighth position in the world biggest emitters ranking. This happens because the ship operations have a huge demand variation therefore in order to reduce the ship emissions is required an efficient operation of the generators. This work aims at integrating advanced storage systems into the operation of diesel generators. The variation of the operation point has a direct interference on the emissions and on the diesel consumption, this variation is allowed through the frequency and voltage control. The use of lithium batteries for various operation points of the generators is analyzed. The use of an energy storage system allowed the operation of the generators in a better operation point therefore there was a reduction in diesel consumption and in CO2 emissions when the diesel generators. The main result of this work could also shed light in the operation of isolated power systems equipped with advanced storage systems and diesel generators.<br>As emissões dos navios já ocupam a oitava posição entre os países com maior emissão no mundo. Isso pode ser explicado pelo fato de que as operações dos navios têm uma grande variação de demanda de potência, com isso a operação inteligente dos geradores a diesel é fundamental para a redução das emissões. A abordagem desenvolvida nesse trabalho integra o uso de sistemas de armazenamento avançados na operação dos geradores a diesel. A variação do ponto de operação dos geradores a diesel interfere diretamente no consumo e nas emissões, essa variação só é possível por meio do controle de frequência e tensão providos pelo sistema de armazenamento de energia. Nesse trabalho foram analisados o uso de baterias de lítio para diferentes pontos de operação do gerador a diesel. O uso das baterias possibilitou a operação dos geradores num melhor ponto de carga com isso houve uma redução das emissões e do consumo de combustível. Os resultados encontrados nesse trabalho podem ser extrapolados qualitativamente para outros sistemas de potência offshore, como plataformas de petróleo e de perfuração, que operem com sistemas de baterias avançadas e geradores a diesel.
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Samuel, Durair Raj Kingsly Jebakumar. "Modeling, Control and Prototyping of Alternative Energy Storage Systems for Hybrid Vehicles." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1331140529.
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Muller, Jan. "Do hybrid compressed air energy storage (HCAES) systems offer a viable alternative solution to energy storage requirements for small to medium size renewable energy systems?" Thesis, Muller, Jan (2009) Do hybrid compressed air energy storage (HCAES) systems offer a viable alternative solution to energy storage requirements for small to medium size renewable energy systems? Masters by Coursework thesis, Murdoch University, 2009. https://researchrepository.murdoch.edu.au/id/eprint/2087/.
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With the increased international pressure to make use of more renewable energy technologies, the intermittent nature of renewable resources requires some kind of energy storage in order to ensure energy is available when needed. Most conventional storage solutions for small to medium size applications are based on chemical batteries which are hazardous, not easily recycled and can have a negative environmental effect. Thus renewed interest is being given to clean and environmentally friendly storage technologies such as compressed air, a technology more than a century old, and still being used in flammable and explosive industrial environments.
New, improved compressors, air motors and advanced technologies and materials that can withstand large fluctuations in temperature have become available, and have been used by some innovative manufacturers to produce Hybrid Compressed Air Energy Storage (HCAES) Systems, which claim to have high turn around efficiencies. In this research, the available literature on compressed air systems, and new HCAES systems are evaluated in order to compare them to conventional storage technologies. Furthermore, an evaluation was conducted to determine if it would be possible to design a HCAES system with off the shelf air equipment and if this HCAES system could possibly be a viable alternative to conventional or new chemical battery storage technologies.
During the research it was found that there is very little literature on the subject of HCEAS systems, and that the manufacturers do not give much information or proof on actual efficiencies of their systems. What was found is that there are several academic institutions working on combining compressed air with technologies such as diesel engines, oil pneumatics, wind, water, super capacitors and flywheels in order to improve current hybrid systems’ effectiveness and efficiency in energy storage and supply applications and to reduce the environmental footprint of such systems.
From literature, research and manufacturer specifications it was found that although theoretical efficiencies of close to 100% can be realised, available HCAES systems do
not offer such an effective or efficient solution as chemical battery systems. In addition off the shelf compressors and motors that can be used to design a HCAES system have been manufactured to give high performance and torque with low efficiencies. The efficiency is further drastically reduced as the storage pressure is increased, which is necessary to decrease storage vessel requirements.
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Pinto, Jonathan Hunder Dutra Gherard. "Conversor modular multinível aplicado a sistema híbrido de armazenamento de energia." Universidade Federal de Juiz de Fora (UFJF), 2018. https://repositorio.ufjf.br/jspui/handle/ufjf/6501.
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Previous issue date: 2018-02-19<br>Este trabalho tem como contribuição o desenvolvimento de uma estratégia de equa-lização das tensões em um conversor multinível modular, como parte integrante de um sistema híbrido de armazenamento de energia. O conversor modular multinível realiza a conexão em série de módulos supercapacitores, o que possibilita aumentar a ten-são sem prejudicar a transferência rápida de energia. Em relação à outras topologias, este trabalho permite reduzir a quantidade, volume e massa do elemento magnético da estrutura do conversor. Um banco de baterias de íons de lítio também integra o sistema por intermédio de um conversor estático. Como é a fonte de maior densidade de energia, fornece a potência média requerida pelo carga. A associação com uma fonte de transferência rápida de energia permite aumentar o desempenho dinâmico, a eficiência energética e a vida útil da bateria. Com efeito, tem-se um sistema híbrido de armazenamento de energia que requer estratégias de gestão para múltiplas fontes de suprimento. Os resultados simulados considerando a estimativa da demanda de po-tência de um protótipo de veículo elétrico, são adequados e propiciam os fundamentos necessários para a construção de um protótipo.<br>This work is a contribution to develop a strategy equalization of tensions in a mo-dular multilevel converter as part of a hybrid system energy storage. The multilevel modular converter realizes the series connection of supercapacitor modules, which al-lows to increase the voltage without cause damages to the quick energy transfer. In relation to other topologies, it allows reduction of the quantity, volume and mass of the magnetic element of the converter structure. A lithium-ion battery bank also integrates the system via a voltage boost converter. This battery is the source of high energy density, which provides the average power required by the load. The association with a fast transfer power source allows for increased dynamic performance, energy efficiency and service life. In fact, there is a hybrid energy storage system that requires mana-gement strategies for multiple sources of supply. The simulated results were obtained considering the power demand estimation of an electric vehicle prototype.
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Zhang, Boya. "Modeling and Analysis of Hydraulic Energy Storage System for Hybrid Locomotives." University of Toledo / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1288815815.
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Alawhali, Nasser. "CONTRIBUTIONS TO HYBRID POWER SYSTEMS INCORPORATING RENEWABLES FOR DESALINATION SYSTEMS." UKnowledge, 2018. https://uknowledge.uky.edu/ece_etds/115.
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Renewable energy is one of the most reliable resource that can be used to generate the electricity. It is expected to be the most highly used resource for electricity generation in many countries in the world in the next few decades. Renewable energy resources can be used in several purposes. It can be used for electricity generation, water desalination and mining. Using renewable resources to desalinate the water has several advantages such as reduce the emission, save money and improve the public health. The research described in the thesis focuses on the analysis of using the renewable resources such as solar and wind turbines for desalination plant. The output power from wind turbine is connected through converter and the excess power will be transfer back to the main grid. The photo-voltaic system (PV) is divided into several sections, each section has its own DC-DC converter for maximum power point tracking and a two-level grid connected inverter with different control strategies. The functions of the battery are explored by connecting it to the system in order to prevent possible voltage fluctuations and as a bu er storage in order to eliminate the power mismatch between PV array generation and load demand. Computer models of the system are developed and implemented using the PSCADTM / EMTDCTM software.
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Pardo, García Nicolás. "Energy efficiency improvement of hybrid ground coupled HVAC systems from thermal energy generation and storage management." Doctoral thesis, Universitat Politècnica de València, 2009. http://hdl.handle.net/10251/6065.
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Nowadays, the increasing of the energy consumption is producing serious
changes in the natural environment as the global warming. Around the 40%
of all greenhouse gas emissions in developed countries come from the building
equipments, where approximately 60% are produced by the air conditioning
systems. In this context, ground coupled heat pumps are an attractive solution
as air conditioning systems in commercial buildings due to their higher
efficiency compared with the conventional air to water heat pump. In fact,
the American Environmental Protection Agency recognizes ground coupled
heat pump systems among the most efficient and comfortable systems available
today. Nevertheless, the energy efficiency of the ground coupled heat
pumps could be improve by means a properly management of the di erent
equipments which form them.
The objective of the research of this PhD thesis will be the development
of management strategies in the air conditioning system based on the ground
coupled heat pumps to improve its energy efficiency at the same time that we
keep the thermal comfort in the conditioned areas. The energy management
strategies will be oriented in the three ways: combining of several generation
systems (ground coupled heat pump and air to water heat pump), decoupling
thermal generation from thermal distribution (by means a thermal storage
device) and strategies based on the management of the devices of the system
(by means of continuous regulation of them).
From the results of this research we can obtain two main conclusions.
The rst one is that a properly management of a system composed by a
thermal storage, an air to water heat pump and a ground coupled heat pump
produce an improvement of the energy efficiency around a 40% respect to a
conventional system and around a 18% respect to a geothermal system. The
second main conclusion of this thesis is that a properly management strategy
in continuous regulation of the devices which are part of a ground coupled ..<br>Pardo García, N. (2009). Energy efficiency improvement of hybrid ground coupled HVAC systems from thermal energy generation and storage management [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/6065<br>Palancia
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Broday, Gabriel Renan. "Bidirectional DC-DC converters for hybrid energy storage systems in electric vehicle applications." Universidade Tecnológica Federal do Paraná, 2016. http://repositorio.utfpr.edu.br/jspui/handle/1/2411.
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Em um momento em que questões ambientais e a segurança energética estão numa posição de destaque, Veículos Elétricos (VEs) estão no centro das atenções. Entretanto, ainda é difícil para eles substituir os tradicionais veículos de combustão interna e a razão principal para isso é o seu sistema de energia. Normalmente, devido a suas características, baterias são usadas como banco de energia para VEs. No entanto, baterias também apresentam algumas limitações para essa aplicação e o problema no sistema de energia é relacionado a essas limitações. Uma das soluções propostas é se colocar baterias e supercapacitores (SC) em paralelo, resultando em um Sistema Híbrido de Armazenamento de Energia (SHAE). Para fazer essa configuração possível e o fluxo de potência controlável em um SHAE, um conversor CC-CC bidirecional interfaceando a bateria e o SC é necessário. Levando isso em consideração, o estudo de topologias CC-CC bidirecionais é apresentado nessa Dissertação de Mestrado. Primeiro, o estudo de um conversor CC-CC bidirecional com indutor dividido, envolvendo sua análise teórica em regime permanente, análise dinâmica e uma metodologia de projeto com resultados de simulação, é apresentado, resultando na construção de um protótipo experimental com as seguintes especificações de projeto: Fonte de tensão 1 de 300 V, fonte de tensão 2 de 96 V, frequência de comutação de 20 kHz e potência nominal de 1000 W. Então, o estudo de uma segunda topologia, um conversor CC-CC Buck-Boost ZVS bidirecional, envolvendo sua análise em regime permanente e uma metodologia de projeto com resultados de simulação, também é apresentado.<br>In an era where environmental issues and the energetic safety are in an outstanding position, Electric Vehicles (EVs) are in the spotlight. However, it is difficult for them to replace the ICE vehicles and the main reason for that it is their energy system. Normally, due to some of their characteristics, batteries are used as energy bank in Electric Vehicles. Nevertheless, batteries also present some limitations for this application and the energy system problem is related to these limitations. One of the proposed solutions is to place batteries and Supercapacitors (SC) in parallel, resulting in a Hybrid Energy Storage System (HESS). To make this configuration possible and the power flow controllable in the HESS, a bidirectional DC-DC converter interfacing the battery and the SC is necessary. Taking this into account, the study of bidirectional DC-DC topologies is presented in this Master’s Thesis. First, a study of a bidirectional DC-DC converter with tapped inductor, involving its theoretical steady state analysis, dynamic analysis and design methodology with simulation results, is presented, resulting in the design of an experimental prototype with the following design specifications: Voltage source 1 of 300 V, voltage source 2 of 96 V, switching frequency of 20 kHz and rated power of 1000 W. Then, the study of a second topology, a bidirectional ZVS Buck-Boost DC-DC converter, involving he steady state analysis and a design methodology with simulation results, is also presented.
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Tolosa, Aura [Verfasser], and Volker [Akademischer Betreuer] Presser. "Electrospun carbon hybrid fibers as binder-free electrodes for electrochemical energy storage / Aura Tolosa ; Betreuer: Volker Presser." Saarbrücken : Saarländische Universitäts- und Landesbibliothek, 2018. http://d-nb.info/1174876948/34.
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Tolosa, Rodriguez Aura Monserrat [Verfasser], and Volker [Akademischer Betreuer] Presser. "Electrospun carbon hybrid fibers as binder-free electrodes for electrochemical energy storage / Aura Tolosa ; Betreuer: Volker Presser." Saarbrücken : Saarländische Universitäts- und Landesbibliothek, 2018. http://d-nb.info/1174876948/34.
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Walter, Oliver [Verfasser], Stefan [Akademischer Betreuer] Becker, Stefan [Gutachter] Becker, and Jürgen [Gutachter] Karl. "Hybrid Energy Storage in Future Energy Systems / Oliver Walter ; Gutachter: Stefan Becker, Jürgen Karl ; Betreuer: Stefan Becker." Erlangen : Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 2021. http://d-nb.info/1238899056/34.
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Gan, Leong Kit. "Improving the performance of hybrid wind-diesel-battery systems." Thesis, University of Edinburgh, 2017. http://hdl.handle.net/1842/31482.
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Off-grid hybrid renewable energy systems are known as an attractive and sustainable solution for supplying clean electricity to autonomous consumers. Typically, this applies to the communities that are located in remote or islanded areas where it is not cost-effective to extend the grid facilities to these regions. In addition, the use of diesel generators for electricity supply in these remote locations are proven to be uneconomical due to the difficult terrain which translates into high fuel transportation costs. The use of renewable energy sources, coupling with the diesel generator allows for the diesel fuel to be offset. However, to date, a common design standard for the off-grid system has yet to be found and some challenges still exist while attempting to design a reliable system. These include the sizing of hybrid systems, coordination between the operation of dissimilar power generators and the fluctuating load demands, optimal utilisation of the renewable energy resources and identifying the underlying principles which reduce the reliability of the off-grid systems. In order to address these challenges, this research has first endeavoured into developing a sizing algorithm which particularly seeks the optimal size of the batteries and the diesel generator usage. The batteries and diesel generator function in filling the gap between the power generated from the renewable energy resources and the load demand. Thus, the load requirement is also an important factor in determining the cost-effectiveness of the overall system in the long run. A sensitivity analysis is carried out to provide a better understanding of the relationship between the assessed renewable energy resources, the load demand, the storage capacity and the diesel generator fuel usage. The thesis also presents the modelling, simulation and experimental work on the proposed hybrid wind-diesel-battery system. These are being implemented with a full-scale system and they are based on the off-the-shelf components. A novel algorithm to optimise the operation of a diesel generator is also proposed. The steady-state and dynamic analysis of the proposed system are presented, from both simulation and an experimental perspective. Three single-phase grid-forming inverters and a fixed speed wind turbine are used as a platform for case studies. The grid-forming inverters adopt droop control method which allows parallel operation of several grid-forming sources. Droop control-based inverters are known as independent and autonomous due to the elimination of intercommunication links among distributed converters. Moreover, the adopted fixed speed wind turbine employs a squirrel cage induction generator which is well known for its robustness, high reliability, simple operation and low maintenance. The results show a good correlation between the modelling, the experimental measurements, and the field tested results. The final stage of this research explores the effect of tower shadow on off-grid systems. Common tower designs for small wind turbine applications, which are the tubular and the lattice configurations, are considered in this work. They generate dissimilar tower shadow profiles due to the difference in structure. In this research, they are analytically modelled for a wind turbine which is being constructed as a downwind configuration. It is proven that tower shadow indeed brings negative consequence to the system, particularly its influence on battery lifetime within an off-grid system. This detrimental effect occurs when power generation closely matches the load demand. In this situation, small frequent charging and discharging cycles or the so called microcycles, take place. The battery lifetime reduction due to these microcycles has been quantified and it is proven that they are not negligible and should be taken into consideration while designing an off-grid hybrid system.
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Fleischmann, Simon [Verfasser], and Volker [Akademischer Betreuer] Presser. "Hybridization of electrochemical energy storage : nanohybrid materials and hybrid cell architectures for high energy, power and stability / Simon Fleischmann ; Betreuer: Volker Presser." Saarbrücken : Saarländische Universitäts- und Landesbibliothek, 2018. http://d-nb.info/1175950122/34.
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Fleischmann, Simon Verfasser], and Volker [Akademischer Betreuer] [Presser. "Hybridization of electrochemical energy storage : nanohybrid materials and hybrid cell architectures for high energy, power and stability / Simon Fleischmann ; Betreuer: Volker Presser." Saarbrücken : Saarländische Universitäts- und Landesbibliothek, 2018. http://nbn-resolving.de/urn:nbn:de:bsz:291--ds-275606.
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Haeri, Seyedehzahra. "Enhancing energy efficiency in solar thermal systems: The role of hybrid nanofluids in sustainable energy harvesting and storage." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2025. https://ro.ecu.edu.au/theses/2933.
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Global energy demand continues to grow, making the reliance on fossil fuels increasingly unsustainable due to dwindling reserves and environmental impacts. Among these, solar thermal systems have emerged as a practical and environmentally friendly solution, with applications ranging from industrial heating and solar water heating to concentrated solar power (CSP) plants and solar desalination units. Solar-based thermal systems offer a promising alternative, with nanofluids (NFs) emerging as a transformative solution. Engineered by dispersing nanoparticles into base fluids, NFs enhance thermal conductivity, heat absorption, and efficiency. Notably, nanoparticles such as titanium nitride also act as nano-catalysts, improving chemical reactions and reducing waste in solar-driven processes like hydrogen production and photocatalysis. NFs significantly boost the performance of solar collectors, concentrated solar power plants, and desalination systems, representing a critical step towards cleaner, more sustainable energy solutions.
Metal-Organic Frameworks (MOFs), a class of highly porous materials, are gaining recognition for their exceptional energy adsorption, storage, and transfer properties. MOFs have been extensively studied for solar energy harvesting due to their ability to absorb specific wavelengths of light, making them ideal for applications such as solar thermal storage systems and photocatalysis. With tunable porosity and surface chemistry, MOFs enhance light absorption, thermal stability, and energy conversion efficiency, providing a cutting-edge pathway for solar energy utilization.
The performance of MOF-based NFs can be further improved by incorporating advanced nanoparticles such as Titanium nitride (TiN) and MXenes. Titanium nitride nanoparticles are particularly promising due to their superior photothermal conversion efficiency, high thermal stability, and unique plasmonic properties, which significantly enhance the heat absorption, energy conversion, and thermal conductivity of MOF-based NFs. Similarly, MXenes, with their layered structure, high electrical conductivity, and outstanding thermal characteristics, synergize effectively with MOFs to optimize solar energy capture and transfer. The integration of TiN and MXenes into MOF-based NFs creates hybrid materials with enhanced solar absorption, improved energy storage, and superior heat transfer properties.
This thesis introduces innovative strategies for incorporating advanced nanocomposites into base fluids such as water and ethylene glycol, aiming to improve their optical properties, stability, and photothermal performance for solar energy harvesting. These nanofluids not only facilitate more efficient solar-to-thermal energy conversion but also reduce heat losses and improve overall system efficiency, even at lower nanoparticle concentrations. By integrating novel nanocomposites into solar thermal systems, this study aims to support the development of cost-effective, scalable, and high-performance renewable energy technologies, thereby contributing to the broader transition toward sustainable and low-carbon energy solutions. A range of nanoparticles and nanocomposites, including NH2-MIL125 (Ti), titanium nitride, NH2-UiO-66 (Zr), TiN/NH2-MIL125 (Ti), MIL-88B (Fe), MXene/NH2-UiO-66 (Zr), MXene/MIL-88B (Fe), and MXene/NH2-MIL125 (Ti), were synthesized and characterized using advanced techniques. These included X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDXS), and Brunauer-Emmett-Teller (BET) analysis. The synthesized materials were incorporated into base fluids, and their photothermal and stability properties were evaluated using a range of parameters, including thermal conductivity, transmittance variations, zeta potential, spectral irradiance, solar energy absorption fraction, temperature distribution, surface and bulk temperature profiles, and photothermal conversion efficiency. This research offers valuable insights into the development of advanced hybrid NFs, making a significant step forward in improving the efficiency and adaptability of solar energy systems. By integrating novel materials and employing advanced characterization techniques, this work establishes a strong foundation for future innovations in sustainable energy harvesting.
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Octaviano, Villasana Claudia Alejandra. "The value of electricity storage under large-scale penetration of renewable energy : a hybrid modeling approach." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/99824.
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Thesis: Ph. D., Massachusetts Institute of Technology, Engineering Systems Division, 2015.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (pages 219-234).<br>Due to the physics of electricity, and the current high costs of storage technologies, electricity generation and demand need to be instantaneously balanced at all times. The large-scale deployment of intermittent renewables requires increased operational flexibility to accommodate fluctuating and unpredictable power supply while maintaining this balance. This dissertation investigates the value of electricity storage for the economy. Specifically, what is the value of storage under large-scale penetration of renewable energy in the context of climate policy? To answer this question, I develop a new hybrid modeling approach that couples an electricity sector model to the MIT EPPA model, a general equilibrium model for climate change policy analysis. The electricity sector model includes the main constraints for reliable and secure operation; electricity demand; wind, solar and hydro resources on the hourly time-scale; and utility-scale storage technologies. The hybrid modeling approach reconciles the very short-term dynamics required for renewables and storage technologies assessment, and the long-term time-scale required for the analysis of economic and environmental outcomes under climate policy. Using Mexico as a case study, this dissertation analyses policies currently under discussion in the country. The experimental design explores increasing shares of renewables with varying levels of storage capacity. Under scenarios with increasing shares of renewables in the power grid, the value of storage increases sharply. By 2050, with 50% renewables penetration, the present value of storage capacity per MW installed in Mexico is estimated at $1500/MW and $200/MWh. Energy management services resulted in the highest value component (58%), followed by operational reserves provision (22%) and capacity payments (18%). Storage capacity in the system changes both investments and operational decisions, allowing larger penetration of wind technologies and displacing gas technologies. Storage capacity in the system reduces price volatility and the occurrence of negative prices that would otherwise result as renewables scale up. The general equilibrium analysis shows that the availability of competitive storage technologies under an economy-wide climate policy reduces the overall policy costs. Simulating a 50% emissions reduction by 2050, the model demonstrated that storage could decrease total welfare losses by 0.7% when compared to the case without storage. Despite the sharp increase in the value of storage driven by renewables penetration, the findings suggest that the current cost of most storage technologies will still have to drastically be reduced for them to be economical.<br>by Claudia Alejandra Octaviano Villasana.<br>Ph. D.
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Gee, Anthony. "Design and assessment of a battery-supercapacitor hybrid energy storage system for remote area wind power systems." Thesis, University of Bath, 2012. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.577732.
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Recent advances in innovative energy storage devices such as supercapacitors have made battery-supercapacitor hybrid energy storage systems technically attractive. However the field of hybrid energy storage system control is relatively new, involving the major challenge of developing control techniques optimised for improved battery-life or other performance metrics. This thesis presents the design and analysis of an actively controlled hybrid energy storage system. Detailed information is given regarding the system implementation and dynamic controls developed as a part of the research. Novel use of the sliding-mode or hysteretic current-controlled DC/DC converter is shown to provide a versatile and robust power electronic building block for the power-control hardware implementation. Current state of the art in the field has converged around a frequency-domain approach to the overall power sharing strategy within hybrid energy storage systems employing batteries and high-power, low-energy density storage such as supercapacitors, with benefits in terms of reduced battery current maxima and an (un-quantified) increase in battery life having been reported. This research extends previous studies by considering the frequency-domain approach in further detail and providing quantitative simulation results confirming how an estimated increase in battery cycle-life of ~18% can be achieved. A systematic simulation framework used for the development and assessment of novel hybrid energy storage system control strategies is described and demonstrated in the context of a remote wind power application. The hardware design of all systems considered is described in detail and demonstrated by experiment.
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Hegazi, Mohamed. "The assessment of on-board clean hybrid energy storage systems for railway locomotives and multiple units." Thesis, University of British Columbia, 2016. http://hdl.handle.net/2429/59595.
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Batteries, supercapacitors, and hydrogen fuel cells are energy storage devices that have no emissions at the point of use. The idea of powering railway locomotives using these devices is one that could, theoretically, eliminate emissions from the railway sector. The motivation behind the research work presented in this thesis is to assess the technical feasibility of employing batteries, supercapacitors, and hydrogen fuel cells in a railway vehicle. This is meant to serve as reference to future work regarding the cost-benefit analysis, well-to-wheel emissions analysis, and life-cycle assessment of railway vehicles that employ these power sources. In this thesis, the application of on-board clean energy storage systems to railway vehicles were studied. Simulation models for battery/supercapacitor and hydrogen fuel cell/battery hybrid powertrains were developed in Simulink. These models were then used to conduct simulations for two train trips. The first trip selected was the 14 km Trehafod to Treherbert route, on which the British Class 150 diesel motive unit operates. The second trip was the 432
km London to Newcastle trip, on which the Intercity 125 train operates. Since no data regarding freight trains on freight tracks could be obtained, only passenger trains were simulated. The conclusions made at the end of this thesis could potentially apply to freight trains as well. Based on the case studies considered, it was found out that railway systems are very well suited to run on on-board clean energy storage systems from an energy consumption point of view. Although being slower responding power sources, hydrogen fuel cells proved to be capable of handling dynamic load changes in railway systems to a great extent but still required the assistance of a faster acting power source. Despite having a significantly lower electrochemical efficiency, employing hydrogen fuel cells resulted in increasing the range of travel without refueling/recharging due to the high energy density of hydrogen. Lithium ion batteries proved to be very capable in handling all the required transient power demand. In regeneration, supercapacitors outperformed lithium-ion batteries and reduced the need for frictional brakes.<br>Applied Science, Faculty of<br>Engineering, School of (Okanagan)<br>Graduate
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Sergent, Aaronn. "Optimal Sizing and Control of Battery Energy Storage Systems for Hybrid-Electric, Distributed-Propulsion Regional Aircraft." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1595519141013663.
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Blechynden, Bruce. "Super-capacitor/lead acid battery hybrid energy storage suitable for remote area power supply (raps) systems." Thesis, Blechynden, Bruce (2010) Super-capacitor/lead acid battery hybrid energy storage suitable for remote area power supply (raps) systems. Other thesis, Murdoch University, 2010. https://researchrepository.murdoch.edu.au/id/eprint/4121/.
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Abstract
This paper presents the results of simulations based on real load data collected from a RAPS system in the south west of Western Australia. The load data was collected at a rate of one sample per second to capture the transient changes. The data had features of a base load suited to lead-acid batteries and transient spikes in load suited to super-capacitors.
A model of a RAPS energy storage system including batteries and super-capacitors was built in Simulink. This model was designed to capture the major influences on battery life and performance: battery current, state of charge and battery temperature.
Simulations were run under standard conditions of no diesel generation (solar generation only), fixed ambient temperature (25°C), fixed total energy storage of 875Ah and equal hours of daylight and darkness.
An optimum super-capacitor size of 65Ah capacity was identified for the conditions of the simulation. Battery temperature was found to be dominated by ambient temperature and little improvement was achieved by including super-capacitors.
Battery life was improved by seven months from nine years and fourteen weeks to nine years and forty one weeks.
With the use of a 65Ah super-capacitor equivalent performance to the battery only base case can be achieved with a battery of 460Ah, approximately half the capacity of the existing batteries.
A 450Ah battery bank costs by $3520 less than the 875Ah battery bank used in the RAPS system that was monitored. A 65Ah super-capacitor costs between $115 500 and $147 500 indicating that a reduction in price in the order of forty times is necessary before super-capacitors could be justified in a battery super-capacitor hybrid energy store.
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Karlsson, Christoffer. "Conducting Redox Polymers for Electrical Energy Storage : Backbone - Substituent Interactions in Quinone Polypyrrole Model Systems." Doctoral thesis, Uppsala universitet, Nanoteknologi och funktionella material, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-230647.
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Organic electrical energy storage (EES) is a growing field of research that is expected to play an important role in the future, as the need for sustainable EES increases. Conducting redox polymers (CRPs), i.e. conducting polymers with incorporated redox active moieties e.g. as pendant groups (PGs), are proposed as a promising class of compounds for this purpose. Redox cycling of the PGs can be utilized for high charge storage capacity, while the conducting polymer backbone provides fast charge transport through the material. Some of the major challenges with small-molecule systems for EES could be solved by using CRPs, e.g. capacity fading due to dissolution of the active compound, and high resistance due to slow charge transport between molecules. The latter issue is often solved by adding large amounts of conducting additives to the active material, drastically lowering the specific capacity. In this project, CRPs are shown to be able to function in battery cells without any additives, making both high capacity and high power possible. Although several CRPs have been reported in the literature, very few detailed studies have been conducted on the electrochemical processes of the two systems (i.e. the conducting polymer backbone and the redox active PGs). An important factor to consider in CRP design is the possibility for interaction between the two redox systems, which could be either beneficial or detrimental to the function as EES material. In this thesis, CRP model systems composed of hydroquinone functionalized polypyrrole have been studied, and they exhibit separate redox reactions for the PGs and the backbone, overlapping in potential. Significant interaction between them was observed, as oxidation of the PGs has severe impact on the backbone: When the oxidized and hydrophobic p-benzoquinone PGs are formed, they pack and force the polymer backbone to twist, localizing the bipolarons, and decreasing the conductivity. This is accompanied by a contraction of the polymer film and expulsion of electrolyte. Overall, the interaction in these polymers is destructive for their EES function, and it could be eliminated by introduction of a long linker unit between the PGs and the backbone.
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Lashway, Christopher R. "Resilient and Real-time Control for the Optimum Management of Hybrid Energy Storage Systems with Distributed Dynamic Demands." FIU Digital Commons, 2017. https://digitalcommons.fiu.edu/etd/3515.
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A continuous increase in demands from the utility grid and traction applications have steered public attention toward the integration of energy storage (ES) and hybrid ES (HESS) solutions. Modern technologies are no longer limited to batteries, but can include supercapacitors (SC) and flywheel electromechanical ES well. However, insufficient control and algorithms to monitor these devices can result in a wide range of operational issues. A modern day control platform must have a deep understanding of the source. In this dissertation, specialized modular Energy Storage Management Controllers (ESMC) were developed to interface with a variety of ES devices. The EMSC provides the capability to individually monitor and control a wide range of different ES, enabling the extraction of an ES module within a series array to charge or conduct maintenance, while remaining storage can still function to serve a demand. Enhancements and testing of the ESMC are explored in not only interfacing of multiple ES and HESS, but also as a platform to improve management algorithms. There is an imperative need to provide a bridge between the depth of the electrochemical physics of the battery and the power engineering sector, a feat which was accomplished over the course of this work. First, the ESMC was tested on a lead acid battery array to verify its capabilities. Next, physics-based models of lead acid and lithium ion batteries lead to the improvement of both online battery management and established multiple metrics to assess their lifetime, or state of health. Three unique HESS were then tested and evaluated for different applications and purposes. First, a hybrid battery and SC HESS was designed and tested for shipboard power systems. Next, a lithium ion battery and SC HESS was utilized for an electric vehicle application, with the goal to reduce cycling on the battery. Finally, a lead acid battery and flywheel ES HESS was analyzed for how the inclusion of a battery can provide a dramatic improvement in the power quality versus flywheel ES alone.
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Aldubyan, Mohammad Hasan. "Thermo-Economic Study of Hybrid Photovoltaic-Thermal (PVT) Solar Collectors Combined with Borehole Thermal Energy Storage Systems." University of Dayton / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1493243575479443.
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Bolletta, Alberto. "Design of alternative energy storage systems for hybrid vehicles based on statistical processing of driving cycles information." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2011. http://amslaurea.unibo.it/2092/.
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Hybrid vehicles represent the future for automakers, since they allow to improve the fuel economy and to reduce the pollutant emissions. A key component of the hybrid powertrain is the Energy Storage System, that determines the ability of the vehicle to store and reuse energy. Though electrified Energy Storage Systems (ESS), based on batteries and ultracapacitors, are a proven technology, Alternative Energy Storage Systems (AESS), based on mechanical, hydraulic and pneumatic devices, are gaining interest because they give the possibility of realizing low-cost mild-hybrid vehicles. Currently, most literature of design methodologies focuses on electric ESS, which are not suitable for AESS design. In this contest, The Ohio State University has developed an Alternative Energy Storage System design methodology.
This work focuses on the development of driving cycle analysis methodology that is a key component of Alternative Energy Storage System design procedure. The proposed methodology is based on a statistical approach to analyzing driving schedules that represent the vehicle typical use. Driving data are broken up into power events sequence, namely traction and braking events, and for each of them, energy-related and dynamic metrics are calculated. By means of a clustering process and statistical synthesis methods, statistically-relevant metrics are determined. These metrics define cycle representative braking events. By using these events as inputs for the Alternative Energy Storage System design methodology, different system designs are obtained. Each of them is characterized by attributes, namely system volume and weight. In the last part the work, the designs are evaluated in simulation by introducing and calculating a metric related to the energy conversion efficiency. Finally, the designs are compared accounting for attributes and efficiency values. In order to automate the driving data extraction and synthesis process, a specific script Matlab based has been developed.
Results show that the driving cycle analysis methodology, based on the statistical approach, allows to extract and synthesize cycle representative data. The designs based on cycle statistically-relevant metrics are properly sized and have satisfying efficiency values with respect to the expectations. An exception is the design based on the cycle worst-case scenario, corresponding to same approach adopted by the conventional electric ESS design methodologies. In this case, a heavy system with poor efficiency is produced. The proposed new methodology seems to be a valid and consistent support for Alternative Energy Storage System design.
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Barnawi, Abdulwasa. "Hybrid PV/Wind Power Systems Incorporating Battery Storage and Considering the Stochastic Nature of Renewable Resources." University of Toledo / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1470357709.
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Zhang, Shengqi. "Investigating the impacts of renewable energy generators and energy storage systems on power system frequency response." Thesis, Queensland University of Technology, 2016. https://eprints.qut.edu.au/94463/1/Shengqi_Zhang_Thesis.pdf.
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High level of intermittent renewable generation such as PV plants and wind farms will require distributed storage systems to meet the power system frequency operation standards. This thesis proposes a rule-based controller to co-ordinate the renewables and distributed energy storage system for improving frequency response.
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McDonough, Joshua. "System Dynamics Modeling and Development of a Design Procedure for Short-term Alternative Energy Storage Systems." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1308287500.
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Baumann, Lars. "Improved system models for building-integrated hybrid renewable energy systems with advanced storage : a combined experimental and simulation approach." Thesis, De Montfort University, 2015. http://hdl.handle.net/2086/11103.
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The domestic sector will play an important role in the decarbonisation and decentralisation of the energy sector in the future. Installation numbers of building-integrated small-scale energy systems such as photovoltaics (PV), wind turbines and micro-combined heat and power (CHP) have significantly increased. However, the power output of PV and wind turbines is inherently linked to weather conditions; thus, the injected power into the public grid can be highly intermittent. With the increasing share of renewable energy at all voltage levels challenges arise in terms of power stability and quality. To overcome the volatility of such energy sources, storage technologies can be applied to temporarily decouple power generation from power consumption. Two emerging storage technologies which can be applied at residential level are hydrogen systems and vanadium-redox-flow-batteries (VRFB). In addition, the building-integrated energy sources and storage system can be combined to form a hybrid renewable energy system (HRES) to manage the energy flow more efficiently. The main focus of this thesis is to investigate the dynamic performance of two emerging energy storage technologies, a hydrogen loop composed of alkaline electrolyser, gas storage and proton exchange membrane (PEM) fuel cell, and a VRFB. In addition, the application of building-integrated HRES at customer level to increase the self-consumption of the onsite generated electricity and to lower the grid interaction of the building has been analysed. The first part deals with the development of a research test-bed known as the Hybrid Renewable Energy Park (HREP). The HREP is a residential-scale distributed energy system that comprises photovoltaic, wind turbine, CHP, lead acid batteries, PEM fuel cell, alkaline electrolyser and VRFB. In addition, it is equipped with programmable electronic loads to emulate different energy consumption patterns and a charging point for electric vehicles. Because of its modular structure different combinations of energy systems can be investigated and it can be easily extended. A unified communication channel based on the local operating network (LON) has been established to coordinate and control the HREP. Information from the energy systems is gathered with a temporal resolution of one second. Integration issues encountered during the integration process have been addressed. The second part presents an experimental methodology to assess the steady state and dynamic performance of the electrolyser, the fuel cell and the VRFB. Operational constrains such as minimum input/output power or start-up times were extracted from the experiments. The response of the energy systems to single and multiple dynamic events was analysed, too. The results show that there are temporal limits for each energy system, which affect its response to a sudden load change or the ability to follow a load profile. Obstacles arise in terms of temporal delays mainly caused by the distributed communication system and should be considered when operating or simulating a HRES at system level. The third part shows how improved system models of each component can be developed using the findings from the experiments. System models presented in the literature have the shortcoming that operational aspects are not adequately addressed. For example, it is commonly assumed that energy systems at system level can respond to load variations almost instantaneously. Thus, component models were developed in an integrated manner to combine theoretical and operational aspects. A generic model layout was defined containing several subsystems, which enables an easy implementation into an overall simulation model in MATLAB®/Simulink®. Experimental methods were explained to extract the new parameters of the semi-empirical models and discrete operational aspects were modelled using Stateflow®, a graphical tool to formulate statechart diagrams. All system models were validated using measured data from the experimental analysis. The results show a low mean-absolute-percentage-error (<3%). Furthermore, an advanced energy management strategy has been developed to coordinate and to control the energy systems by combining three mechanisms; statechart diagrams, double exponential smoothing and frequency decoupling. The last part deals with the evaluation, operation and control of HRES in the light of the improved system models and the energy management strategy. Various simulated case studies were defined to assess a building-integrated HRES on an annual basis. Results show that the overall performance of the hydrogen loop can be improved by limiting the operational window and by reducing the dynamic operation. The capability to capture the waste heat from the electrolyser to supply hot water to the residence as a means of increasing the overall system efficiency was also determined. Finally, the energy management strategy was demonstrated by real-time experiments with the HREP and the dynamic performance of the combined operation has been evaluated. The presented results of the detailed experimental study to characterise the hydrogen loop and the VRFB as well as the developed system models revealed valuable information about their dynamic operation at system level. These findings have relevance to the future application and for simulation studies of building-integrated HRES. There are still integration aspects which need to be addressed in the future to overcome the proprietary problem of the control systems. The innovations in the HREP provide an advanced platform for future investigations such as electric-vehicles as decentralised mobile storage and the development of more advanced control approaches.
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K, C. Bibek. "Impact of a Hybrid Storage Framework Containing Battery and Supercapacitor on Uncertain Output of Wind and Solar Power Systems." OpenSIUC, 2019. https://opensiuc.lib.siu.edu/theses/2618.
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Renewable energy resources (RES) are becoming more popular for electricity generation due to their easy installation, flexibility, low cost, environmental compatibility, etc. However, their fluctuating nature is a major drawback, which decreases the power quality and makes them less trusty in the power system. To mitigate this problem, battery energy storage (BES) has been widely used with renewable energy sources. Because batteries are designed to handle “steady fluctuations” of power, the “sudden and peak” fluctuating power levels of renewable energy sources may cause shorter life spans for them, which may cause dramatic economic loss or negatively impact the power quality. Also, even though batteries have been used as a backup for RES, high power quality cannot be guaranteed when there is a rapid and peak fluctuations on source/load.
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Elsayed, Ahmed T. "Optimum Distribution System Architectures for Efficient Operation of Hybrid AC/DC Power Systems Involving Energy Storage and Pulsed Loads." FIU Digital Commons, 2016. http://digitalcommons.fiu.edu/etd/3005.
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After more than a century of the ultimate dominance of AC in distribution systems, DC distribution is being re-considered. However, the advantages of AC systems cannot be omitted. This is mainly due to the cheap and efficient means of generation provided by the synchronous AC machines and voltage stepping up/down allowed by the AC transformers. As an intermediate solution, hybrid AC/DC distribution systems or microgrids are proposed. This hybridization of distribution systems, incorporation of heterogeneous mix of energy sources, and introducing Pulsed Power Loads (PPL) together add more complications and challenges to the design problem of distribution systems. In this dissertation, a comprehensive multi-objective optimization approach is presented to determine the optimal design of the AC/DC distribution system architecture. The mathematical formulation of a multi-objective optimal power flow problem based on the sequential power flow method and the Pareto concept is developed and discussed. The outcome of this approach is to answer the following questions: 1) the optimal size and location of energy storage (ES) in the AC/DC distribution system, 2) optimal location of the PPLs, 3) optimal point of common coupling (PCC) between the AC and DC sides of the network, and 4) optimal network connectivity. These parameters are to be optimized to design a distribution architecture that supplies the PPLs, while fulfilling the safe operation constraints and the related standard limitations. The optimization problem is NP-hard, mixed integer and combinatorial with nonlinear constraints. Four objectives are involved in the problem: minimizing the voltage deviation (ΔV), minimizing frequency deviation (Δf), minimizing the active power losses in the distribution system and minimizing the energy storage weight. The last objective is considered in the context of ship power systems, where the equipment’s weight and size are restricted.
The utilization of Hybrid Energy Storage Systems (HESS) in PPL applications is investigated. The design, hardware implementation and performance evaluation of an advanced – low cost Modular Energy Storage regulator (MESR) to efficiently integrate ES to the DC bus are depicted. MESR provides a set of unique features: 1) It is capable of controlling each individual unit within a series/parallel array (i.e. each single unit can be treated, controlled and monitored separately from the others), 2) It is able to charge some units within an ES array while other units continue to serve the load, 3) Balance the SoC without the need for power electronic converters, and 4) It is able to electrically disconnect a unit and allow the operator to perform the required maintenance or replacement without affecting the performance of the whole array.
A low speed flywheel Energy Storage System (FESS) is designed and implemented to be used as an energy reservoir in PPL applications. The system was based on a separately excited DC machine and a bi-directional Buck-Boost converter as the driver to control the charging/discharging of the flywheel. Stable control loops were designed to charge the FESS off the pulse and discharge on the pulse. All the developments in this dissertation were experimentally verified at the Smart Grid Testbed.
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Lundquist, Philip. "Operation strategies of using energy storage for improving cost efficiency of wind farms. : Examining emergency power supply and support services." Thesis, Uppsala universitet, Elektricitetslära, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-447078.
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With the increase in the world energy demand and environmental incentives, renewable energy sources (RES) need to determine their place as some of the primary power sources in future power systems. However, due to uncertain energy production, renewable energy sources cause unbalance in the power system due to the unsynchronized supply and electricity demand. The intermittent power production causes undesired power fluctuation, affecting the power quality and reliability of the power source. Energy storage is one solution that is debated to increase the reliability of renewable energy production. This thesis aims to model and simulate hybrid energy storage system (HESS), constructed of hydrogen and ultracapacitor energy storage, to investigate different operation strategies for everyday use and crises. The two different energy storage technologies complement each other, where hydrogen fuel cells can produce power for long periods of time while the ultracapacitor can quickly maintain the balance of production and consumption of electricity for a short instance. The HESS showed promising results for emergency power supply and supported service operation strategies. In case of a power shortage, the HESS could cover for the disconnected production. The ultracapacitor proved to be a suitable component due to its ability to support the shortcomings of a hydrogen energy storage system. Moreover, the HESS could meet the requirements to deliver support services. However, further studies have to be done to investigate how the HESS can deliver multiple support services to increase profit and help maintain the power system's balance and security.
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Guo, Yuhua. "IMPROVING THE PERFORMANCE AND ENERGY EFFICIENCY OF EMERGING MEMORY SYSTEMS." VCU Scholars Compass, 2018. https://scholarscompass.vcu.edu/etd/5317.
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Modern main memory is primarily built using dynamic random access memory (DRAM) chips. As DRAM chip scales to higher density, there are mainly three problems that impede DRAM scalability and performance improvement. First, DRAM refresh overhead grows from negligible to severe, which limits DRAM scalability and causes performance degradation. Second, although memory capacity has increased dramatically in past decade, memory bandwidth has not kept pace with CPU performance scaling, which has led to the memory wall problem. Third, DRAM dissipates considerable power and has been reported to account for as much as 40% of the total system energy and this problem exacerbates as DRAM scales up.
To address these problems, 1) we propose Rank-level Piggyback Caching (RPC) to alleviate DRAM refresh overhead by servicing memory requests and refresh operations in parallel; 2) we propose a high performance and bandwidth efficient approach, called SELF, to breaking the memory bandwidth wall by exploiting die-stacked DRAM as a part of memory; 3) we propose a cost-effective and energy-efficient architecture for hybrid memory systems composed of high bandwidth memory (HBM) and phase change memory (PCM), called Dual Role HBM (DR-HBM). In DR-HBM, hot pages are tracked at a cost-effective way and migrated to the HBM to improve performance, while cold pages are stored at the PCM to save energy.
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Gazey, Ross Neville. "Sizing hybrid green hydrogen energy generation and storage systems (HGHES) to enable an increase in renewable penetration for stabilising the grid." Thesis, Robert Gordon University, 2014. http://hdl.handle.net/10059/947.
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A problem that has become apparently growing in the deployment of renewable energy systems is the power grids inability to accept the forecasted growth in renewable energy generation integration. To support forecasted growth in renewable generation integration, it is now recognised that Energy Storage Technologies (EST) must be utilised. Recent advances in Hydrogen Energy Storage Technologies (HEST) have unlocked their potential for use with constrained renewable generation. HEST combines Hydrogen production, storage and end use technologies with renewable generation in either a directly connected configuration, or indirectly via existing power networks. A levelised cost (LC) model has been developed within this thesis to identify the financial competitiveness of the different HEST application scenarios when used with grid constrained renewable energy. Five HEST scenarios have been investigated to demonstrate the most financially competitive configuration and the benefit that the by-product oxygen from renewable electrolysis can have on financial competitiveness. Furthermore, to address the lack in commercial software tools available to size an energy system incorporating HEST with limited data, a deterministic modelling approach has been developed to enable the initial automatic sizing of a hybrid renewable hydrogen energy system (HRHES) for a specified consumer demand. Within this approach, a worst-case scenario from the financial competitiveness analysis has been used to demonstrate that initial sizing of a HRHES can be achieved with only two input data, namely – the available renewable resource and the load profile. The effect of the electrolyser thermal transients at start-up on the overall quantity of hydrogen produced (and accordingly the energy stored), when operated in conjunction with an intermittent renewable generation source, has also been modelled. Finally, a mass-transfer simulation model has been developed to investigate the suitability of constrained renewable generation in creating hydrogen for a hydrogen refuelling station.
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Wilson, Jason Clifford. "A techno-economic environmental approach to improving the performance of PV, battery, grid-connected, diesel hybrid energy systems : A case study in Kenya." Thesis, Högskolan Dalarna, Energiteknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:du-28542.
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Backup diesel generator (DG) systems continue to be a heavily polluting and costly solution for institutions with unreliable grid connections. These systems slow economic growth and accelerate climate change. Photovoltaic (PV), energy storage (ES), grid connected, DG – Hybrid Energy Systems (HESs) or, PV-HESs, can alleviate overwhelming costs and harmful emissions incurred from traditional back-up DG systems and improve the reliability of power supply. However, from project conception to end of lifetime, PV-HESs face significant barriers of uncertainty and variable operating conditions. The fit-and-forget solution previously applied to backup DG systems should not be adopted for PV-HESs. To maximize cost and emission reductions, PV-HESs must be adapted to their boundary conditions for example, irradiance, temperature, and demand. These conditions can be defined and monitored using measurement equipment. From this, an opportunity for performance optimization can be established. The method demonstrated in this study is a techno-economic and environmental approach to improving the performance of PV-HESs. The method has been applied to a case study of an existing PV-HES in Kenya. A combination of both analytical and numerical analyses has been conducted. The analytical analysis has been carried out in Microsoft Excel with the intent of being easily repeatable and practical in a business environment. Simulation analysis has been conducted in improved Hybrid Optimization by Genetic Algorithms (iHOGA), which is a commercially available software for simulating HESs. Using six months of measurement data, the method presented identifies performance inefficiencies and explores corrective interventions. The proposed interventions are evaluated, by simulation analyses, using a set of techno-economic and environment key performance indicators, namely: Net Present Cost (NPC), generator runtime, fuel consumption, total system emissions, and renewable fraction. Five corrective interventions are proposed, and predictions indicate that if these are implemented fuel consumption can be reduced by 70 % and battery lifetime can be extended by 28 %, net present cost can be reduced by 30 % and emissions fall by 42 %. This method has only been applied to a single PV-HES; however, the impact this method could have on sub-Saharan Africa as well as similar regions with unreliable grid connections is found to be significant. In the future, in sub-Saharan Africa alone, over $500 million dollars (USD) and 1.7 billion kgCO2 emissions could be saved annually if only 25 % of the fuel savings identified in this study were realized. The method proposed here could be improved with additional measurement data and refined simulation models. Furthermore, this method could potentially be fully automated, which could allow it to be implemented more frequently and at lower cost.
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Linzen, Dirk [Verfasser]. "Impedance-Based Loss Calculation and Thermal Modeling of Electrochemical Energy Storage Devices for Design Considerations of Automotive Power Systems / Dirk Linzen." Aachen : Shaker, 2006. http://d-nb.info/1166515028/34.
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Chotia, Imran. "Electrical performance and economic feasibility analyses of hybrid and battery storage devices used in remote area islanded renewable energy systems." Master's thesis, University of Cape Town, 2016. http://hdl.handle.net/11427/22933.
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South Africa has the fifth largest coal based utility grid in the world, unfortunately many regions in the country are simply too remote for connection with this grid thus have no electricity access [1]. Many remote areas possess high wind speeds and solar irradiance exposure, which makes them ideal for Renewable Energy Systems (RES) but the electrical and economic viability of this deployment, is still in question. Based on these observations, an electrical performance analysis and economic feasibility study based on islanded RES deployment in remote areas of SA is conducted. RES growth is restricted to the effectiveness of its energy management strategy. Pumped Hydro Storage (PHS) is the cheapest islanded large scale storage option but its assignment is restricted to applicable an landscape and terrain [2], [3]. After conducting a critical review, the Lead Acid Battery Storage System (BSS) and Hybrid Battery Supercapacitor Storage (HBS) were over the PHS. A theory development study on established generations systems and storage models was used to compare software designs which resulted in the selection of Matlab software for electric performance analysis and HOMER for the economic feasibility study. The electric performance analysis was divided into three case studies based on the input power supply, viz. ideal voltage source, Solar Photo Voltaic (PV) and Wind Energy Conversion System (WECS), with each case being connected to a BSS and HBS. A load profile and solar and wind resource investigation was conducted using the NASA, Wind Atlas of South Africa (WASA) and Solar GIS database. Electrical cases were modelled in Matlab and evaluated in terms of power security, load matching, power response and charge algorithm accuracy. The results showed that deploying an islanded RES in South Africa is indeed electrically feasible based on the high power security, load matching accuracy, and disturbance response seen in the solar-RES cases. The wind-RES maintained an uninterruptable power supply but failed to match the load as accurately. Cases which used the HBS showed improvements in power stability; load fluctuation response and an extension of storage device lifespan when compared to the BSS connected cases. This was due to the supercapacitor high power density which made it ideal for the compensation of RES and load fluctuations. Three new cases were established for the economic study as follows; solar, wind and hybrid solar-wind generation all tested under BSS and HBS conditions once again. A socio economic study established the region of deployment, natural resources, terrain, landscape as well as the price of WECS, PV, storage, and converter components. These findings were used in HOMER to construct an optimised combination of components required for the supply of a 5MWh/d average load. This was followed by a sensitivity analysis which conducted 14 different optimisations at loads ranging from 1-10MWh/d. Economic benefits of the supercapacitor power density was uncovered through a reduction of the required RES Peak Operating Reserve (POR) capacity. This is especially significant in islanded RES, as they demand large POR in order to maintain autonomous power supply. This amounted to substantial NPC savings ranging from $1 - $7.5 million for the 25 year project. What was more interesting was the hybrid wind-solar generation results of the last case which extended total NPC savings, by up to $10 million. The hybrid-HBS does show some POR reductions which brought the COE to 0.3$/kWh on average, with the hybrid-BSS at 0.35$/kWh. The hybrid-BSS is slightly more expensive but has a reduced complexity which can be more inviting to project engineers therefore both hybrid cases are exceptionally feasible for local RES deployment. Single source RES is indeed electrically and economically feasible and shows extended sizing and performance benefits when implementing HBS. However, the cost reductions and performance benefits of hybrid generation make it the most practical solution to islanded RES in South Africa.
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Nassabeh, Seyedmohammadmehdi. "Applications of reservoir simulation and machine learning in subsurface energy systems for decarbonization." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2025. https://ro.ecu.edu.au/theses/2939.
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The transition to a low-carbon future necessitates innovative approaches to carbon management and hydrogen storage, particularly in the context of enhanced oil recovery (EOR) from hydrocarbon reservoirs. This study employs advanced analytics and machine learning techniques to optimize carbon management strategies. One key focus of this research is to evaluate the effectiveness of flue gas and CO2 in Water Alternating Gas (WAG) injection within a homogeneous fractured carbonate reservoir characterized by low porosity and permeability. A computational model was developed to depict the flow regime in the reservoir and simulate reservoir fluid behavior using Eclipse (E300) software, various hybrid EOR methods were evaluated, revealing that natural production accounted for only 29% of the total output. The optimized Hybrid EOR method achieved an impressive oil recovery factor of approximately 85%, demonstrating the critical need for EOR techniques to enhance overall production. In parallel, to mitigate greenhouse gas emissions caused by reliance on hydrocarbon resources, the integration simulation study of CO2 storage with EOR in fractured carbonate reservoirs is implemented to meet this pressing requirement. Utilizing the Eclipse simulator, various gas injection scenarios were modeled to assess the effectiveness of CO2 and flue gas geo-sequestration and EOR. Key findings revealed that flue gas demonstrated superior storage capacity (150 MMSCF) compared to CO2 (85 MMSCF) and maintained better reservoir pressure, while CO2 injection resulted in a higher oil recovery factor of 52% versus 36% for flue gas. Sensitivity analyses indicated that increased reservoir porosity, permeability, and injection rates enhanced gas storage capacity, although CO2 showed a normal distribution trend in permeability. In addition, further reservoir simulation study explores the synergistic relationship between flue gas compositions, reservoir characteristics, and injection rates, highlighting that flue gases with higher concentrations of CO2 and O2 significantly improve recovery factors. Key findings indicate that reservoir temperature, porosity, and permeability are vital factors influencing oil recovery, with CO2 injection consistently yielding the highest recovery rates. Notably, the study established that flue gas injection demonstrated greater sensitivity to increased injection rates, with specific flue gas compositions enhancing recovery efficiency.
On another facet of advanced analytical techniques, a data-driven framework for site screening of offshore CO2 storage is introduced, which integrates diverse geospatial data with expert-weighted criteria to identify optimal locations for Carbon Capture, Utilization, and Storage (CCUS) projects. Machine learning algorithms, particularly Deep Neural Networks (DNN), were employed to enhance predictive accuracy in site selection, achieving an Average Absolute Percentage Difference (AAPD) of 1.486% and a Variance Accounted For (VAF) of 0.9937, thus bridging the gap between scientific inquiry and practical application. This approach not only enhances the precision of site selection but also exemplifies the transformative potential of machine learning in advancing carbon management strategies. The Deep Neural Network (DNN) algorithm proved to be the most effective tool for predicting site suitability, achieving accuracy rates exceeding 90% across various performance metrics.
In response to the escalating global energy demands and the transition to a low-carbon future, this study presents an advanced analytics framework aimed at hydrogen storage potential through machine learning methodologies. Hydrogen is emerging as a vital clean energy vector, and efficient underground storage in geological formations is essential for maintaining energy security. However, challenges remain in understanding the interactions between gas and rock. To tackle these challenges, a comprehensive dataset of 1,045 entries and over 5,200 data points was utilized to develop predictive models for contact angles in water-hydrogen-rock systems. Various machine learning algorithms including Support Vector Machine (SVM), k-Nearest Neighbors (KNN), Feedforward Deep Neural Network (FNN), and Recurrent Deep Neural Network (RNN) were evaluated, with the FNN achieving the highest predictive accuracy. This capability is crucial for assessing hydrogen flow through porous media during underground storage.
Overall, this thesis highlights the potential of advanced analytics and machine learning in refining carbon management practices and optimizing hydrogen storage capabilities. It provides essential insights for the energy sector's sustainable transition, demonstrating that integrating CO2 storage with EOR is a viable strategy for reducing greenhouse gas emissions while enhancing oil recovery metrics. The findings underscore the importance of advanced analytics in addressing key challenges in the energy sector and promoting sustainable practices for a low-carbon future, paving the way for future research in these critical areas.
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Kailas, Aravind. "Toward perpetual wireless networks: opportunistic large arrays with transmission thresholds and energy harvesting." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/34720.
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Solving the key issue of sustainability of battery-powered sensors continues to attract significant research attention. The prevailing theme of this research is to address this concern using energy-efficient protocols based on a form of simple cooperative transmission (CT) called the opportunistic large arrays (OLAs), and intelligent exploitation of energy harvesting and hybrid energy storage systems (HESSs). The two key contributions of this research, namely, OLA with transmission threshold (OLA-T) and alternating OLA-T (A-OLA-T), offer an signal-to-noise ratio (SNR) advantage (i.e., benefits of diversity and array (power) gains) in a multi-path fading environment, thereby reducing transmit powers or extending range. Because these protocols do not address nodes individually, the network overhead remains constant for high density networks or nodes with mobility. During broadcasting across energy-constrained networks, while OLA-T saves energy by limiting node participation within a single broadcast, A-OLA-T optimizes over multiple broadcasts and drains the the nodes in an equitable fashion. Another important contribution of this research is the design and analysis of a novel routing metric called communications using HESS (CHESS), which extends the rechargeable battery (RB)-life by relaying exclusively with supercapacitor (SC) energy, and is asymptotically optimal with respect to the number of nodes in the network.
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PUGLIA, GLORIA. "Study and development of a web-based software for hybrid energy system design and solar prediction analysis." Doctoral thesis, Università Politecnica delle Marche, 2017. http://hdl.handle.net/11566/245401.
Full textAbstract:
La sfida di integrare la potenza intermittente proveniente da fonti energetiche rinnovabili nella rete elettrica non può essere considerata come un problema isolato, ma deve essere visto come uno strumento per integrare e mettere in primo piano i sistemi energetici rinnovabili.
Questo progetto di tesi di dottorato presenta l'analisi, lo studio e lo sviluppo di un software ad interfaccia web in grado di progettare sistemi energetici ibridi in qualsiasi luogo del mondo, in grado di migliorare l'affidabilità, la disponibilità e la sostenibilità sia di sistemi connessi alla rete che di sistemi isolati.
Il software EHS (Energy Hybrid System) è stato sviluppato per ottenere la configurazione ottimale per varie tipologie di sistemi energetici ibridi. Lo studio della configurazione ottimale del sistema ibrido si basa sul valore del LCC (Life Cycle Cost) calcolato sulla durata potenziale dell'intero sistema considerando tutti i costi presenti e futuri.
La tesi presenta un caso di studio di progettazione, effettuata tramite software EHS, di un sistema energetico ibrido situato in Uganda. I risultati rivelano che la configurazione ottimale del sistema ibrido (generatori FV-baterie-diesel), nonostante il suo elevato costo di investimento, presenta un beneficio economico del 25,5 e del 22,2% rispetto all'utilizzo di solo FV e generatori diesel e solo generatori diesel e una riduzione del consumo di carburante pari rispettivamente al 74,7 e al 77%. Al fine di migliorare l'efficienza del sistema energetico ibrido, il progetto di tesi propone anche uno sviluppo di uno strumento in grado di fare una previsione affidabile della produzione fotovoltaica attraverso uno strumento sperimentale chiamato "predittore solare". In questo studio è stato utilizzato un sistema di acquisizione di immagini, basato su una fotocamera digitale commerciale, utilizzate per ottenere l'elaborazione delle immagini, rilevamento dei corpi nuvolosi, previsione del loro movimento e predizione dell’irraggiamento.<br>The challenge of integrating fluctuating power from renewable energy sources in the electricity grid cannot be looked upon as an isolated issue but should be seen as one out of various means and challenges of approaching sustainable energy systems.
The presented PhD thesis project illustrates the analysis, study and development of a web-based software able to design hybrid energy systems in any location of the world, able improve the reliability, availability and sustainability of both grid-connected and isolated energy systems.
The software EHS (Energy Hybrid System) is programmed to evaluate the optimal design for various configuration of energy hybrid systems. The evaluation of the optimal hybrid system configuration is based on the value of the LCC (Life Cycle Cost) calculated along the potential lifetime of the entire system, considering all the future costs.
The thesis presents a design case study, carried out through EHS software, of a hybrid power system located in Uganda. The results of the simulation through the software EHS show that the usage of battery storage is economically crucial. Results disclose that the optimal configuration of the hybrid system (PV-storage-diesel generators), despite its high investment cost, presents an economic benefit of 25.5 and 22.2% compared to the usage of only PV array and diesel generators and only diesel generators and a reduction of fuel consumption equal to 74.7 and 77%, respectively. In order to improve the hybrid energy system efficiency, the thesis project also proposes a development of an instrument able to make a reliable prediction of PV production and a solar irradiance forecast methodology to predict the photovoltaic production through an experimental instrument called "solar predictor". Within this study a sky image system, based on a commercial digital camera, has been used and characterised with respect to get image elaboration, cloudy shape detection, motion estimation and tracking.
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Ali, Sadaqat. "Energy management of multi-source DC microgrid systems for residential applications." Electronic Thesis or Diss., Université de Lorraine, 2023. http://www.theses.fr/2023LORR0159.
Full textAbstract:
Comparé au réseau électrique alternatif (AC), le réseau électrique en courant continu (DC) a démontré de nombreux avantages tels que son interface naturelle avec les RES, les systèmes de stockage d'énergie et les charges en courant continu, une efficacité supérieure avec moins d'étapes de conversion, et un contrôle plus simple sans effet de peau et sans considérations sur le flux de puissance réactive. Le micro-réseaux DC reste une technologie relativement nouvelle, et ses architectures de réseau, stratégies de contrôle, techniques de stabilisation méritent d'énormes efforts de recherche. Dans ce contexte, cette thèse porte sur les problèmes de gestion de l'énergie d'un réseau électrique en courant continu (DC) multi-source dédié aux applications résidentielles. Le réseau électrique en courant continu (DC) est composé de générateurs distribués (panneaux solaires), d'un système de stockage d'énergie hybride (HESS) avec des batteries et un supercondensateur (SC), et de charges en courant continu, interconnectées via des convertisseurs de puissance DC/DC. L'objectif principal de cette recherche est de développer une stratégie avancée de gestion de l'énergie (EMS) d'améliorer l'efficacité opérationnelle du système tout en renforçant sa fiabilité et sa durabilité. Une plateforme de simulation hiérarchique de réseau électrique DC a été développée sous MATLAB/Simulink. Elle est composée de deux couches avec des échelles de temps différentes : une couche de contrôle de niveau local (échelle de temps de quelques secondes à quelques minutes en raison des comportements de commutation des convertisseurs) pour les contrôles des composants locaux, et une couche de contrôle de niveau système (avec une échelle de temps de quelques jours à quelques mois avec un test accéléré) pour la validation à long terme de l'EMS et son évaluation de performance. Dans la couche de contrôle de niveau local, les panneaux solaires, les batteries et le supercondensateur ont été modélisés et contrôlés séparément. Différents modes de contrôle tels que le contrôle de courant, le contrôle de tension et le contrôle du point de puissance maximale (MPPT) ont été mis en œuvre. Un filtre passe-bas (LPF) a été appliqué pour diviser la puissance totale du HESS : basse et haute fréquence pour les batteries et le supercondensateur. Différentes fréquences de coupure du LPF pour le partage de puissance a également été étudiée. Un EMS hybride bi-niveau combiné et un dimensionnement automatique ont été proposés et validés. Il couvre principalement cinq scénarios d'exploitation, notamment la réduction de la production des panneaux solaires, la réduction de la charge et trois scénarios via le contrôle du HESS associé à la rétention du contrôle de l'état de charge (SOC) du supercondensateur. Une fonction objective prenant en compte à la fois le coût en capital (CAPEX) et les coûts d'exploitation (OPEX) a été conçue pour l'évaluation des performances de l'EMS. L'interaction entre l'HESS et l'EMS a été étudiée conjointement sur la base d'un ensemble de données ouvertes de profils de consommation électrique résidentielle couvrant à la fois l'été et l'hiver. Finalement, une plateforme expérimentale de réseau électrique à courant continu (DC) multi-source a été développée pour valider en temps réel l'EMS. Elle est composée de quatre batteries lithium-ion, d'un supercondensateur, d'une alimentation électrique à courant continu programmable, d'une charge à courant continu programmable, de convertisseurs DC/DC correspondants et d'un contrôleur en temps réel (dSPACE/Microlabbox). Des tests accélérés ont été réalisés pour vérifier l'EMS proposé dans différents scénarios d'exploitation en intégrant des panneaux solaires réels et les profils de consommation de charge. Les plateformes de simulation hiérarchique de réseau électrique en courant continu (DC) et expérimentale, peuvent être utilisées de manière générale pour vérifier et évaluer divers EMS<br>Compared to the alternating current (AC) electrical grid, the direct current (DC) electrical grid has demonstrated numerous advantages, such as its natural interface with renewable energy sources (RES), energy storage systems, and DC loads. It offers superior efficiency with fewer conversion steps, simpler control without skin effect or reactive power considerations. DC microgrids remain a relatively new technology, and their network architectures, control strategies, and stabilization techniques require significant research efforts. In this context, this thesis focuses on energy management issues in a multi-source DC electrical grid dedicated to residential applications. The DC electrical grid consists of distributed generators (solar panels), a hybrid energy storage system (HESS) with batteries and a supercapacitor (SC), and DC loads interconnected via DC/DC power converters. The primary objective of this research is to develop an advanced energy management strategy (EMS) to enhance the operational efficiency of the system while improving its reliability and sustainability. A hierarchical simulation platform of the DC electrical grid has been developed using MATLAB/Simulink. It comprises two layers with different time scales: a local control layer (time scale of a few seconds to minutes due to converter switching behavior) for controlling local components, and a system-level control layer (time scale of a few days to months with accelerated testing) for long-term validation and performance evaluation of the EMS. In the local control layer, solar panels, batteries, and the supercapacitor have been modeled and controlled separately. Various control modes, such as current control, voltage control, and maximum power point tracking (MPPT), have been implemented. A low-pass filter (LPF) has been applied to divide the total HESS power into low and high frequencies for the batteries and supercapacitor. Different LPF cutoff frequencies for power sharing have also been studied. A combined hybrid bi-level EMS and automatic sizing have been proposed and validated. It mainly covers five operational scenarios, including solar panel production reduction, load reduction, and three scenarios involving HESS control combined with supercapacitor state of charge (SOC) control retention. An objective function that considers both capital expenditure (CAPEX) and operating costs (OPEX) has been designed for EMS performance evaluation. The interaction between the HESS and EMS has been jointly studied based on an open dataset of residential electrical consumption profiles covering both summer and winter seasons. Finally, an experimental platform of a multi-source DC electrical grid has been developed to validate the EMS in real-time. It comprises four lithium-ion batteries, a supercapacitor, a programmable DC power supply, a programmable DC load, corresponding DC/DC converters, and a real-time controller (dSPACE/Microlabbox). Accelerated tests have been conducted to verify the proposed EMS in different operational scenarios by integrating real solar panels and load consumption profiles. The hierarchical simulation and experimental DC electrical grid platforms can be generally used to verify and evaluate various EMS