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Dissertations / Theses on the topic 'Microgrid model'

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Published: 4 June 2025
Last updated: 23 June 2025

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1

Carbone, Marc A. "HIERARCHICAL DECENTRALIZED CONTROL TECHNIQUES OF A MODEL DC MICROGRID." Case Western Reserve University School of Graduate Studies / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=case1464259866.

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2

Omara, Ahmed Mohamed Elsayed. "Predictive Operational Strategies for Smart Microgrid Networks." Thesis, Université d'Ottawa / University of Ottawa, 2020. http://hdl.handle.net/10393/40101.

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There have been significant advances in communication technologies over the last decade, such as cellular networks, Wi-Fi, and optical communication. Not only does the technology impact peoples’ everyday lives, but it also helps cities prepare for power outages by collecting and exchanging data that facilitates real-time status monitoring of transmission and distribution lines. Smart grids, contrary to the traditional utility grids, allow bi-directional flow of electricity and information, such as grid status and customer requirements, among different parties in the grid. Thus, smart grids reduce the power losses and increase the efficiency of electricity generation and distribution, as they allow for the exchange of information between subsystems. However, smart grids is not resilient under extreme conditions, particularly when the utility grid is unavailable. With the increasing penetration of the renewable energy sources (RES) in smart grids, the uncertainty of the generated power from the distributed generators (DGs) has brought new challenges to smart grids in general and smart microgrids in particular. The rapid change of the weather conditions can directly affect the amount of the generated power from RES such as wind turbine and solar panels, and thus degrading the reliability and resiliency of the smart microgrids. Therefore, new strategies and technologies to improve power reliability,sustainability, and resiliency have emerged. To this end, in this thesis, we propose a novel framework to improve the smart microgrids reliability and resiliency under severe conditions. We study the transition to the grid-connected operational mode in smart microgrids,in the absence of the utility grid, as an example of emergency case that requires fast and accurate response. We perform a comparative study to accurately predict upcoming grid-connected events using machine learning techniques. We show that decision tree models achieve the best average prediction performance. The packets that carry the occurrence time of the next grid-connected transition are considered urgent packets. Hence, we per-form an extensive study of a smart data aggregation approach that considers the priority of the data. The received smart microgrids data is clustered based on the delay-sensitivity into three groups using k-means algorithm. Our delay-aware technique successfully reduces the queuing delay by 93% for the packets of delay-sensitive (urgent) messages and the Packet Loss Rate (PLR) by 7% when compared to the benchmark where no aggregation mechanism exists prior to the small-cell base stations. As a mitigation action of the utility grid unavailability, we use the electrical vehicles (EVs) batteries as mobile storage units to cover smart microgrids power needs until the utility grid recovery. We formulate a Mixed Integer Linear Programming (MILP) model to find the best set of electrical vehicles with the objective of minimum cost. The EVs participating in the emergency power supply process are selected based on the distance and throughput performance between the base station and the EVs
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3

deSa, Michael E. "An Original Microgrid Business Model Determines an Imminent New Asset Market." Case Western Reserve University Doctor of Management / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=casedm1568628001000343.

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4

Forel, Alexandre. "Distributed Model Predictive Operation Control of Interconnected Microgrids." Thesis, KTH, Reglerteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-206145.

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The upward trends in renewable energy deployment in recent years brings new challengesto the development of electrical networks. Interconnected microgrids appear as a novelbottom-up approach to the production and integration of renewable energy.Using model predictive control (MPC), the energy management of several interconnectedmicrogrids is investigated. An optimisation problem is formulated and distributed ontothe individual units using the alternating direction method of multipliers (ADMM). Themicrogrids cooperate to reach a global optimum using neighbour-to-neighbour communications.The benefits of using distributed operation control for microgrids are analysed and a controlarchitecture is proposed. Two algorithms are implemented to solve the optimisationproblem and their advantages or differences are confronted.<br>Förnybara energikällor har ökat under senaste åren. Det innebär nya utmaningar förevolutionen av elektriska nät. Microgrids är en bottom-up ansats för produktion ochintegrering av förnybar energi.Energiförsörjning av flera sammankoppladeMicrogrids studeras in detta arbete genommodellbaserad prediktiv kontroll (MPC). Ett optimeringsproblem formuleras på de enskildaenheterna med Alternating DirectionMethod ofMultipliers (ADMM) och parallellberäkningar härledas.Microgrids samarbetar för att nå en global lösning av neighbourto-neighbour kommunikation.Distribuerad energiförsörjning av microgrids analyseras och två kontroll algorithmerutformas.
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5

Rasouli, Disfani Vahid. "Optimization and Control for Microgrid and Power Electronic Converters." Scholar Commons, 2015. http://scholarcommons.usf.edu/etd/5764.

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The proposed dissertation research investigates Optimization and Control for Microgrid and Power Electronic Converters. The research has two major parts: i- Microgrid Operation and Control, ii- Power Electronic Converter Control and Optimization. In the first part, three focuses are investigated. First, a completely distributed algorithm is developed for dc optimal power flow problem for power distribution systems as one of the necessary functions considered in unit-commitment problem in day-ahead markets. This method is derived based upon the partial primal-dual representation of the economic dispatch problem, which is finally translated to DC-OPF problem. Second, the optimal interaction between the utility and communities will be studied, due to its improtance in real-time markets. The objective of this section will be to develop an iterative agent-based algorithm for optimal utility-community control. The algorithm will consider the AC power system constraints to maintain power system stability. In this algorithm, a simplified model of microgrid is considered. In the third focus, a comprehensive model of microgrid is taken into account. The optimal operation of the microgrid considering energy storage systems and renewable energy resources is investigated. The interaction of such microgrids with the main grid to define the optimal operation of the entire embedded system is studied through two iterative methods. In the microgrid's internal problem, a moving-horizon algorithm is considered to define the optimal dispatch of all distributed energy resources while considering the time-correlated constraints of energy storage systems. A thorough analysis of the effects of the size of storage systems on energy and reserve market parameters are also performed. In the second part, the focus of research is to develop optimal control strategies for Power Electronic Converters. A Model Predictive Control (MPC) switching method is proposed for Modular Multilevel Converters (MMC). The optimal solution of MPC problem is then represented as an optimization problem. Due to lack of efficient algorithms to seek the optimal solution, a fast algorithm will be proposed in this research. The method proposed reduces the number of possible solutions and computation efforts dramatically.
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6

Osama, Hassan Eltayeb Khalid. "Development of the Simulation Model for the CoSES Laboratory Test Microgrid in Modelica." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021.

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Evolution of the traditional consumer in a power system to a prosumer has posed many problems in the traditional uni-directional grid. This evolution in the grid model has made it important to study the behaviour of microgrids. This thesis deals with the laboratory microgrid setup at the Munich School of Engineering, built to assist researchers in studying microgrids. The model is built in Dymola which is a tool for the OpenModelica language. Models for the different components were derived, suiting the purpose of this study. The equivalent parameters were derived from data sheets and other simulation programs such as PSCAD. The parameters were entered into the model grid and tested at steady state, firstly. This yielded satisfactory results that were similar to the reference results from MATPOWER power flow. Furthermore, fault conditions at several buses were simulated to observe the behaviour of the grid under these conditions. Recommendations for further developing this model to include more detailed models for components, such as power electronic converters, were made at the end of the thesis.
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Гузов, Анатолій Геннадійович. "Модифікована система управління мережею MicroGrid на основі Інтернету Речей". Master's thesis, КПІ ім. Ігоря Сікорського, 2020. https://ela.kpi.ua/handle/123456789/39339.

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Робота містить 69 сторінки, 20 рисунків та 25 таблиць. Було використано 32 джерела. Мета роботи: Покращити ефективність системи управління мережею MicroGrid за рахунок її модифікації при застосуванні Інтернету речей. Проаналізовано різні існуючі типи структур інтелектуальних мереж. Зокрема Smart Grid, Smart Power Grid, SCADA системи та MicroGrid. Підсумовано і підтверджено актуальність розробки концепції контролю Інтернету речей над MicroGrid. Розглянуті проблематики, які виникають при впровадженні і експлуатації даної концепції системи. Поставлено за завдання модифікувати створену імітаційну модель управління ІоТ над MicroGrid. Для вирішення поставленного завдання запропонована аналітична модель, заснована на принципах існуючих конецепцій інтелектуальних мереж Smart Grid та Microgrid з урахуванням Інтернету речей з використанням хмарних технологій. У рамках даної імітаційної моделі визначено правила взаємодій елементів системи. Застосування запропонованого рішення дозволяє мати певне представлення системи при її проектуванні, яке відповідає заданій предметній області. Метод мусить передбачати відсутність участі людини, але при формуванні на стільки великої системи не дозволяє ліквідувати її контроль над не контрольованими елементами мережі. Отримані результати доводять на основі імітаційної моделі, що запропонована модифікація є енергоефективною та відмовостійкою.<br>The work contains 69 pages, 20 figures and 25 tables. 32 sources were used. Purpose: To improve the efficiency of the MicroGrid network management system by modifying it when using the Internet of Things. Various existing types of intelligent network structures are analyzed. In particular Smart Grid, Smart Power Grid, SCADA systems and MicroGrid. The relevance of developing the concept of Internet of Things control over MicroGrid is summarized and confirmed. The problems that arise during the implementation and operation of this system concept are considered. The task is to modify the created simulation model of IoT control over MicroGrid. To solve this problem, an analytical model based on the principles of existing concepts of intelligent networks Smart Grid and Micro Grid, taking into account the Internet of Things using useless technologies. Within the framework of this simulation model the rules of interactions of system elements are defined. The application of the proposed solution allows you to have a certain representation of the system in its design, which corresponds to a given subject area. The method must provide for the absence of human participation, but when forming such a large system does not allow to eliminate its control over uncontrolled elements of the network. The obtained results prove on the basis of the simulation model that the proposed modification is energy efficient and fault tolerant.
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8

Chettiyar, Thanigasalam. "Examination of Power Quality Control within a Cost-based Microgrid Architecture." University of Dayton / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1385545865.

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9

Sampaio, Junior Adalberto Ribeiro. "Controle de microgrids dirigido por modelos." Universidade Federal de Goiás, 2014. http://repositorio.bc.ufg.br/tede/handle/tede/3859.

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Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2015-01-13T10:58:35Z No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertação - Adalberto Ribeiro Sampaio Junior - 2014.pdf: 1618396 bytes, checksum: bd9ccea5178781ea6e1d2e0b346d9787 (MD5)<br>Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2015-01-13T10:58:56Z (GMT) No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertação - Adalberto Ribeiro Sampaio Junior - 2014.pdf: 1618396 bytes, checksum: bd9ccea5178781ea6e1d2e0b346d9787 (MD5)<br>Made available in DSpace on 2015-01-13T10:58:56Z (GMT). No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertação - Adalberto Ribeiro Sampaio Junior - 2014.pdf: 1618396 bytes, checksum: bd9ccea5178781ea6e1d2e0b346d9787 (MD5) Previous issue date: 2014-03-31<br>Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG<br>The use of model driven engineering (MDE) and models at runtime represent an important tools for the development and management of complex systems. We show how a model driven approach can be used to create a manager able to control the various components of a microgrid, besides adding autonomic behavior in this kind of system. Applying an architecture that respects the hierarchy of controllers present in microgrids, we show how devices can be controlled through calls and events that are targeted to a manager and defined in its model. This model-driven approach facilitates the control of devices and allows customization of the bahavior of a microgrid by the end user in charge of managing it.<br>O uso de engenharia de software dirigida por modelos (MDE) e de modelos em tempo de execução constitui uma ferramenta importante para desenvolver e controlar sistemas complexos. Neste trabalho utilizamos uma abordagem dirigida por modelos para controlar sistemas de distribuição de energia elétrica conhecidos como microgrids. Mostramos como uma abordagem dirigida por modelos pode ser utilizada para criar um gerente capaz de controlar os diversos componentes de uma microgrid, além de adicionar comportamento autonômico neste tipo de sistema. Aplicando uma arquitetura que respeita a hierarquia dos controladores presentes em microgrids, mostramos como os dispositivos podem ser controlados por meio de chamadas e eventos direcionados ao gerente de recursos e definidos em seu modelo. Essa forma de controle dirigido por modelos facilita a definição do controle dos dispositivos de uma microgrid por parte do usuário, além de permitir uma personalização do comportamento global de uma microgrid.
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Hijjo, Mohammed M. A. [Verfasser], and Georg [Akademischer Betreuer] Frey. "Model-based development and design of microgrid power systems / Mohammed M. A. Hijjo ; Betreuer: Georg Frey." Saarbrücken : Saarländische Universitäts- und Landesbibliothek, 2018. http://d-nb.info/1183673043/34.

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11

Guo, Qihao. "On control strategies of switched reluctance generator-based DC microgrid." Electronic Thesis or Diss., université Paris-Saclay, 2024. http://www.theses.fr/2024UPAST002.

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Les microréseaux (MG) à courant continu (DC) sont une solution prometteuse pour l’intégration massive des énergies renouvelables dans la production durable et décentralisée d’énergie électrique pour s’inscrire dans la transition énergétique. En tant que sous-système du micro-réseau, la machine à réluctance variable (MRV) est une solution sans terres rares pour des systèmes de conversion de l’énergie éolienne (SCEE) à petite échelle. Cependant, la commande de la Génératrice à Réluctance Variable (GRV) dans les applications MG est un défi en raison de la forte non-linéarité de son modèle. L’objectif de cette thèse est donc de développer des stratégies de contrôle de la GRV et des convertisseurs statiques pour répondre aux différentes exigences d’un microréseau à courant continu. Le modèle analytique de la GRV est fortement non linéaire du fait du principe de génération du couple et de la saturation du matériau ferromagnétique. De ce fait, la relation entre les courants dans les enroulements de la machine et le courant du bus continu est complexe. Cette relation a été identifiée par des essais expérimentaux et approchée par une relation analytique. L’insertion de cette relation sous forme de tabulation a permis de linéariser le modèle de la boucle de tension du bus continu. Les essais expérimentaux ont permis de valider l’approche grâce aux meilleures performances dynamiques en comparaison de l’approche classique qui ignore cette relation. Dans les microréseaux à courant continu, les convertisseurs statiques dc-dc sont incontournables aux interfaces entre les sources et le bus continu. Dans nos travaux, nous nous sommes intéressés à la modélisation et la commande du convertisseur boost. Des techniques de commande linéaire (correcteur proportionnel-intégral) et non linéaire (contrôle prédictif) ont été évaluées et comparées du point de vue des performances et de leur complexité de mise en oeuvre pour le contrôle de la tension du bus continu. La commande prédictive a été développée en raison de son concept intuitif, de sa nature discrète adaptée aux convertisseurs statiques et sa forte pénétration dans le monde industriel, pour contrôler le courant et la tension. De plus, elle est flexible puisqu’elle permet de contrôler le convertisseur en modes continu et discontinu de fonctionnement. Son principe consiste à l’optimisation d’une fonction objectif définie comme un compromis entre la minimisation de l’erreur de poursuite et la réduction des contraintes sur les signaux de commande. Un horizon de prédiction minimal a été adopté pour garantir les performances temps réel du système. L’étude comparative expérimentale réalisée sur un banc d’essai du laboratoire GeePs a permis de dégager des lignes directrices pour le choix de la technique de commande la plus appropriée. Pour évaluer les performances de la GRV dans des conditions proches d’une exploitation réelle, il faudrait disposer d’une éolienne. Dans les conditions de laboratoire, il faut passer par un émulateur temps réel. La complexité du système complet (émulateur + GRV + bus continu) nous a conduit à adopter la représentation énergétique macroscopique (REM) pour la modélisation et la déduction du schéma de contrôle. Une stratégie de contrôle hiérarchique avec trois modes de fonctionnement (Poursuite du Point de Puissance Maximale (MPPT), contrôle direct de la puissance (DPC), contrôle de la tension (VC)) a été développée. La transition entre ces modes dépend des conditions du vent, de l’état de charge des batteries et de la configuration du micro-réseau (isolé ou connecté). L’efficacité des trois modes de fonctionnement a été validée expérimentalement<br>DC microgrids (MGs) are a promising solution for the massive integration of distributed renewable generation, promoting the energy transition to a more digital, sustainable, and decentralized future. As an essential subsystem of, DC MG, the distributed small-scale wind energy conversion systems (WECSs) generally use Permanent Magnet Synchronous Machines (PMSMs) with rare-earth materials, which are expensive and potentially environmentally damaging. The Switched Reluctance Generator (SRG) is a rare-earth free and lowcost electrical generator solution, which may potentially replace PMSM in WECS. However, developing the control strategy for SRG in DC MG application is challenging due to the operating principles and nonlinearity of SRG. The research objective of this thesis is to develop a multi-stage and multi-time scale control strategy for SRG-based DC MG. To design the output voltage controller of SRG, the physical modelling of SRG is first studied, showing the differences between SRG and classical machines. Starting from the basic electromechanical energy conversion principle, the averaged torque expression of SRG is obtained, dependent on the square of the phase current amplitude. Besides, due to the saturation of ferromagnetic material, SRG’s electromagnetic characteristics, e.g., the inductance profile, exhibit intrinsic spatial and magnetic nonlinearities. Usual output voltage control solutions ignore these nonlinearities, resulting in degraded performance. An enhanced output voltage controller is proposed to improve the output voltage control of SRG by integrating a linearization block into the control loop. The proposed controller improves the system’s dynamic performance, i.e., voltage tracking and robustness to disturbances. Then, this research turns to the modelling and control of the DC-DC boost converters since they are fundamental blocks in DC MGs for power flow control and voltage matching. Although there are several control methods for the boost converter, how to select and design appropriate controllers is still challenging. Model Predictive Control (MPC) is selected as a promising candidate for power electronic converters for its intuitive concept and intrinsic discrete time nature. To evaluate the performance of the MPC strategies, the classical linear strategies are also discussed in detail. A comprehensive experimental comparative study is carried out based on a self-established test bench at the Paris Electrical Engineering Laboratory (GeePs). This study provides a design guideline for DC MG designers in selecting suitable control strategies. To test the performance of SRG under different wind conditions in the laboratory, the modelling and control of a real-time Wind Turbine Emulator (WTE) is studied. Energetic Macroscopic Representation (EMR), a graphical formalism based on physical causality and interaction, is adopted for system organization and control scheme deduction. Thanks to EMR, the entire design process, from system modelling to experimental validation, is organized in a clear and systematic way. A conceptual hierarchical DC MG control strategy with three possible operating modes of SRG, namely, maximum power point tracking, direct power control, and output voltage control, is deduced by considering the DC MG’s physical constraints. Based on the established WTE, the effectiveness of these operating modes is validated experimentally
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García, Elvira David. "Contributions on DC microgrid supervision and control strategies for efficiency optimization through battery modeling, management, and balancing techniques." Doctoral thesis, Universitat Rovira i Virgili, 2021. http://hdl.handle.net/10803/672010.

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Aquesta tesi presenta equips, models i estratègies de control que han estat desenvolupats amb l'objectiu final de millorar el funcionament d'una microxarxa CC. Es proposen dues estratègies de control per a millorar l'eficiència dels convertidors CC-CC que interconnecten les unitats de potència de la microxarxa amb el bus CC. La primera estratègia, Control d'Optimització de Tensió de Bus centralitzat, administra la potència del Sistema d'Emmagatzematge d'Energia en Bateries de la microxarxa per aconseguir que la tensió del bus segueixi la referència dinàmica de tensió òptima que minimitza les pèrdues dels convertidors. La segona, Optimització en Temps Real de la Freqüència de Commutació, consisteix a operar localment cada convertidor a la seva freqüència de commutació òptima, minimitzant les seves pèrdues. A més, es proposa una nova topologia d'equilibrador actiu de bateries mitjançant un únic convertidor CC-CC i s'ha dissenyat la seva estratègia de control. El convertidor CC-CC transfereix càrrega cel·la a cel·la, emprant encaminament de potència a través d'un sistema d'interruptors controlats. L'estratègia de control de l'equalitzador aconsegueix un ràpid equilibrat del SOC evitant sobrecompensar el desequilibri. Finalment, es proposa un model simple de degradació d'una cel·la NMC amb elèctrode negatiu de grafit. El model combina la simplicitat d'un model de circuit equivalent, que explica la dinàmica ràpida de la cel·la, amb un model físic del creixement de la capa Interfase Sòlid-Electròlit (SEI), que prediu la pèrdua de capacitat i l'augment de la resistència interna a llarg termini. El model proposat quantifica la incorporació de liti al rang de liti ciclable necessària per a aconseguir els límits de OCV després de la pèrdua de liti ciclable en la reacció secundària. El model de degradació SEI pot emprar-se per a realitzar un control predictiu de bateries orientat a estendre la seva vida útil.<br>Aquesta tesi presenta equips, models i estratègies de control que han estat desenvolupats amb l'objectiu final de millorar el funcionament d'una microxarxa CC. Es proposen dues estratègies de control per a millorar l'eficiència dels convertidors CC-CC que interconnecten les unitats de potència de la microxarxa amb el bus CC. La primera estratègia, Control d'Optimització de Tensió de Bus centralitzat, administra la potència del Sistema d'Emmagatzematge d'Energia en Bateries de la microxarxa per aconseguir que la tensió del bus segueixi la referència dinàmica de tensió òptima que minimitza les pèrdues dels convertidors. La segona, Optimització en Temps Real de la Freqüència de Commutació, consisteix a operar localment cada convertidor a la seva freqüència de commutació òptima, minimitzant les seves pèrdues. A més, es proposa una nova topologia d'equilibrador actiu de bateries mitjançant un únic convertidor CC-CC i s'ha dissenyat la seva estratègia de control. El convertidor CC-CC transfereix càrrega cel·la a cel·la, emprant encaminament de potència a través d'un sistema d'interruptors controlats. L'estratègia de control de l'equalitzador aconsegueix un ràpid equilibrat del SOC evitant sobrecompensar el desequilibri. Finalment, es proposa un model simple de degradació d'una cel·la NMC amb elèctrode negatiu de grafit. El model combina la simplicitat d'un model de circuit equivalent, que explica la dinàmica ràpida de la cel·la, amb un model físic del creixement de la capa Interfase Sòlid-Electròlit (SEI), que prediu la pèrdua de capacitat i l'augment de la resistència interna a llarg termini. El model proposat quantifica la incorporació de liti al rang de liti ciclable necessària per a aconseguir els límits de OCV després de la pèrdua de liti ciclable en la reacció secundària. El model de degradació SEI pot emprar-se per a realitzar un control predictiu de bateries orientat a estendre la seva vida útil.<br>This dissertation presents a set of equipment, models and control strategies, that have been developed with the final goal of improving the operation of a DC microgrid. Two control strategies are proposed to improve the efficiency of the DC-DC converters that interface the microgrid’s power units with the DC bus. The first strategy is centralized Bus Voltage Optimization Control, which manages the power of the microgrid’s Battery Energy Storage System to make the bus voltage follow the optimum voltage dynamic reference that minimizes the converters’ losses. The second control strategy is Online Optimization of Switching Frequency, which consists in locally operating each converter at its optimum switching frequency, again minimizing power losses. The two proposed optimization strategies have been validated in simulations. Moreover, a new converter-based active balancing topology has been proposed and its control strategy has been designed. This equalizer topology consists of a single DC-DC converter that performs cell-to-cell charge transfer employing power routing via controlled switches. The control strategy of the equalizer has been designed to achieve rapid SOC balancing while avoiding imbalance overcompensation. Its performance has been validated in simulation. Finally, a simple degradation model of an NMC battery cell with graphite negative electrode is proposed. The model combines the simplicity of an equivalent circuit model, which explains the fast dynamics of the cell, with a physical model of the Solid-Electrolyte Interphase (SEI) layer growth process, which predicts the capacity loss and the internal resistance rise in the long term. The proposed model fine-tunes the capacity loss prediction by accounting for the incorporation of unused lithium reserves of both electrodes into the cyclable lithium range to reach the OCV limits after the side reaction has consumed cyclable lithium. The SEI degradation model can be used to perform predictive control of batteries oriented toward extending their lifetime.
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Halás, Andrej. "Model mikro sítě s akumulací." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2015. http://www.nusl.cz/ntk/nusl-221197.

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This thesis describes the operation , characteristics and operating conditions of microgrid with energy storage , provides insight into the benefits of using listed concepts . The first part deals with the description of microgrid systems, distribution and shows examples of its use. The second part describes individual elements of the storage systems, energy production and energy transformation used in microgrids . The third part describes the work with PSCAD software. The main goal is to design a micro grid model in PSCAD and validate its function.
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14

LABELLA, ALESSANDRO GIUSEPPE. "Advanced Primary Controllers for Inverter Based Power Sources: Microgrids and Wind Power Plants." Doctoral thesis, Università degli studi di Genova, 2020. http://hdl.handle.net/11567/1009797.

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The aim of this doctoral thesis is to present the research activity fulfilled during the Ph.D. studies. The research project of the candidate was focused on two main cores. The first core is centred in the microgrid area; in particular in islanded microgrid modelling and control. Firstly, the model was compared with experimental results collected in some facilities available at University of Genoa. Then traditional controllers for islanded microgrid are analysed and explored, proposing a new stability estimation procedure for droop controlled microgrid. Finally, a new control strategy based on Model Predictive Control (MPC) is proposed in order to collect many functionalities in just one control layer. MPC is widely used in MG environment, but just for power and energy management at tertiary level; instead here it is here proposed with an inedited use. Some experimental validations about this new methodology are obtained during a research period in Serbia and Denmark. The second core is related with synthetic inertia for wind turbine connected to the main grid, i.e. frequency support during under-frequency transients. This aspect is very important today because it represents a way to increase grid stability in low inertia power systems. The importance of this feature is shared by all the most important Transmitter System Operators (TSO) all over the world.
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15

Piyasinghe, Lakshan Prageeth. "Dynamic Phasor Based Analysis and Control in Renewable Energy Integration." Scholar Commons, 2015. http://scholarcommons.usf.edu/etd/6015.

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The objective of this dissertation is to carry out dynamic modeling, analysis and control of power systems with Renewable Energy Sources (RES) such as: Photovoltaic (PV) power sources and wind farms. The dissertation work is mainly focused on microgrid since it plays a major role in modern power systems and tend to have higher renewable power penetration. Two main theoretical concepts, dynamic phasor and impedance modeling have been adopted to model and analyze the power systems/mocrogrids with RES. The initial state calculation which is essential for small signal analysis of a system is carried out as the first step of the dissertation work. Dynamic phasor and impedance modeling techniques have been utilized to model and analyze power systems/micogrids as the second phase of the work. This part consists of two main studies. First case investigates the impedance modeling of Thyristor Controller Series Capacitor (TCSC) for sub-synchronous resonance (SSR) analysis where a wind farm is connected to a power system through series compensated line. Second case utilizes the dynamic phasor concept to model a microgrid in unbalanced condition. Here the unbalance is caused by a single phase PV connected to the microgrid. Third Phase of the dissertation work includes upper level control of the microgrid. Here prediction and optimization control for a microgrid with a wind farm, a PV system, an energy storage system and loads is evaluated. The last part of the dissertation work focuses on real time modeling and hardware in loop simulation test bed for microgrid applications. This dissertation has led to four journal papers (three accepted, one submitted) and five conference papers.
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Tulpule, Pinak J. "Control and optimization of energy flow in hybrid large scale systems - A microgrid for photovoltaic based PEV charging station." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1313522717.

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17

Aldaouab, Ibrahim. "Optimization and Control of Smart Renewable Energy Systems." University of Dayton / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1567770026080553.

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18

Pham, Thanh Hung. "Commande optimale sous contraintes pour micro-réseaux en courant continu." Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAT086/document.

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Cette thèse aborde les problèmes de la modélisation et de la commande d'un micro-réseau courant continu (CC) en vue de la gestion énergétique optimale, sous contraintes et incertitudes. Le micro-réseau étudie contient des dispositifs de stockage électrique (batteries ou super-capacités), des sources renouvelables (panneaux photovoltaïques) et des charges (un système d'ascenseur motorise par une machine synchrone a aimant permanent réversible). Ces composants, ainsi que le réseau triphasé, sont relies a un bus commun en courant continu, par des convertisseurs dédies. Le problème de gestion énergétique est formule comme un problème de commande optimale qui prend en compte la dynamique du système, des contraintes sur les variables, des prédictions sur les prix, la consommation ou la production et des profils de référence.Le micro-réseau considère est un système complexe, de par l'hétérogénéité de ses composants, sa nature distribuée, la non-linéarité de certaines dynamiques, son caractère multi-physiques (électromécanique, électrochimique, électromagnétique), ainsi que la présence de contraintes et d'incertitudes. La représentation consistante des puissances échangées et des énergies stockées, dissipées ou fournies au sein de ce système est nécessaire pour assurer son opération optimale et fiable.Le problème pose est abordé via l'usage combine de la formulation hamiltonienne a port, de la platitude et de la commande prédictive économique base sur le modelé. Le formalisme hamiltonien a port permet de décrire les conservations de la puissance et de l'énergie au sein du micro-réseau explicitement et de relier les composants hétérogènes dans un même cadre théorique. Les non linéarités sont gérées par l'introduction de la notion de platitude démentielle et la sélection de sorties plates associées au modèle hamiltonien a ports. Les profils de référence sont génères a l'aide d'une para métrisation des sorties plates de telle sorte que l'énergie dissipée soit minimisée et les contraintes physiques satisfaites. Les systèmes hamiltoniens sur graphes sont ensuite introduits pour permettre la formulation et la résolution du problème de commande prédictive _économique a l'échelle de l'ensemble du micro-réseau CC. Les stratégies de commande proposées sont validées par des résultats de simulation pour un système d'ascenseur multi-sources utilisant des données réelles, identifiées sur base de mesures effectuées sur une machine synchrone<br>The goals of this thesis is to propose modelling and control solutions for the optimal energy management of a DC microgrid under constraints. The studied microgrid system includes electrical storage units (e.g., batteries, supercapacitors), renewable sources (e.g., solar panels) and loads (e.g., an electro-mechanical elevator system). These interconnected components are linked to a three phase electrical grid through a DC bus and associated DC/AC converters. The optimal energy management is usually formulated as an optimal control problem which takes into account the system dynamics, cost, constraints and reference profiles.An optimal energy management for the microgrid is challenging with respect to classical control theories. Needless to say, a DC microgrid is a complex system due to its heterogeneity, distributed nature (both spatial and in sampling time), nonlinearity of dynamics, multi-physic characteristics, the presence of constraints and uncertainties. Moreover, the power-preserving structure and the energy conservation of a microgrid are essential for ensuring a reliable operation.This challenges are tackled through the combined use of port-Hamiltonian formulations, differential flatness, and economic Model Predictive Control.The Port-Hamiltonian formalism allows to explicitly describe the power-preserving structure and the energy conservation of the microgrid and to connect different components of different physical natures through the same formalism. The strongly non-linear system is then translated into a flat representation. Taking into account differential flatness properties, reference profiles are generated such that the dissipated energy and various physical constraints are taken into account. Lastly, we minimize the purchasing/selling electricity cost within the microgrid using the economic Model Predictive Control with the Port-Hamiltonian formalism on graphs.The proposed control designs are validated through simulation results
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19

Yassuda, Yamashita Damiela. "Hierarchical Control for Building Microgrids." Thesis, Poitiers, 2021. http://www.theses.fr/2021POIT2267.

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Représentant plus d'un tiers de la consommation mondiale d'électricité, les bâtiments sont le secteur énergétique majeur pour promouvoir l’usage des énergies renouvelables. L'installation à la fois de sources d’énergie rénouvelable et d'un système de stockage d'énergie électrique dans les bâtiments peut favoriser la transition énergétique vers un système électrique à faible émission de carbone, tout en permettant aux consommateurs d'énergie finaux de bénéficier d'une énergie propre. Malgré tous ces avantages, cette topologie innovante et distribuée d’un Micro-réseau dédié au Bâtiment (MB)nécessite des changements importants dans le réseau actuel, qui dépend des politiques énergétiques et d’avancement technologiques.La conception d'un Système de Gestion de l'Energie (EMS) capable de gérer efficacement les composants électriques du micro-réseau sans menacer la stabilité du réseau principal est un obstacle au développement des MB. Pour atténuer les effets néfastes introduits par des acteurs d’énergie imprévisibles, le concept d'autoconsommation est de plus en plus adopté. Néanmoins, une analyse technico-économique plus approfondie est nécessaire pour piloter d’une manière optimaledes systèmes de stockage d'énergie afin d’atteindre des indices d'autoconsommation plus élevés.Face à ces enjeux, le but de ce doctorat est de proposer un EMS pour les micro-réseaux installés dans les bâtiments afin de maximiser leur taux d’autoconsommation à un coût d’exploitation minimum. Parmi les architectures de contrôle, la structure hiérarchique s'est avérée efficace pour gérer des objectifs contradictoires qui ne sont pas dans la même échelle de temps. Ainsi, une structure de contrôle Hiérarchique à Modèle Prédictif (HMPC) a été adoptée pour remédier aux incertitudes liées aux déséquilibres de puissance ainsi qu’établir un compromis entre la réduction du coût de fonctionnement et le respect du code de l’énergie français.Considérant que les bâtiments ne sont pas homogènes et nécessitent des solutions adaptées à leur besoin, le contrôleur proposé a été couplé à deux modules fonctionnant à base d’analyse de données. Le premier algorithme consiste à gérer les inexactitudes dans les modèles internes de l’HMPC. Sans avoir besoin de régler aucun paramètre, cet algorithme améliore la précision du modèle de batteries jusqu'à trois fois et augmente jusqu'à dix fois la précision du modèle de stockage d'hydrogène, réduisant ainsi la dépendance de l’EMS aux étapes de modélisation. Le deuxième algorithme détermine de manière autonome les paramètres de l’HMPC et facilite le compromis entre les aspects économiques et énergétiques. S'appuyant uniquement sur l'analyse des données de déséquilibre de puissance et des mesures, le contrôleur hiérarchique spécifie quel dispositif de stockage d'énergie doit fonctionner quotidiennement en fonction de l'estimation du taux d'autoconsommation et du coût de fonctionnement du micro-réseau. Ces estimations diminuent les dépenses annuelles du micro-réseau en évitant la pénalisation en ce qui concerne les exigences d'autoconsommation et en réduisant la dégradation et l'entretien des systèmes de stockage d'énergie.L’EMS proposé s'est également révélé capable de charger de préférence les batteries des véhicules électriques en période de surplus d’énergie et les décharger pendant les périodes de déficit pour réduire les échanges d’énergie avec le réseau principal. Les résultats ont aussi montré que la contribution des batteries de véhicules électriques dépend de la taille du parc de véhicules, de leur temps de connexion et du profil de déséquilibre de puissance. En conclusion, à travers les simulations utilisant le dimensionnement réel d'un bâtiment public et résidentiel, l’EMS hiérarchique s'est avéré efficace pour gérer de nombreux dispositifs de stockage d'énergie et contribuer à l’essor de micro-réseaux dédiés aux bâtiments à l’avenir<br>Representing more than one-third of global electricity consumption, buildings undergo the most important sector capable of reducing greenhouse gas emissions and promote the share of Renewable Energy Sources (RES). The integrated RES and electric energy storage system in buildings can assist the energy transition toward a low-carbon electricity system while allowing end-energy consumers to benefit from clean energy. Despite its valuable advantages, this innovative distributed Building Microgrids (BM) topology requires significant changes in the current electric grid, which is highly dependent on grid energy policies and technology breakthroughs.The complexity of designing a robust Energy Management System (EMS) capable of managing all electric components inside the microgrid efficiently without harming the main grid stability is one of the greatest challenge in the development of BM. To mitigate the harmful effects of unpredictable grid actors, the concept of self-consumption has been increasingly adopted. Nonetheless, further technical-economic analysis is needed to optimally manage the energy storage systems to attain higher marks of self-consumption.Faceing these issues, the purpose of this doctoral thesis is to propose a complete framework for designing a building EMS for microgrids installed in buildings capable of maximising the self-consumption rate at minimum operating cost. Among all possible control architectures, the hierarchical structure has proved effective to handle conflicting goals that are not in the same timeframe. Hence, a Hierarchical Model Predictive (HMPC) control structure was adopted to address the uncertainties in the power imbalance as well as the trade-off between costs and compliance with the French grid code.Considering that buildings are not homogeneous and require solutions tailored to their specific conditions, the proposed controller was enhanced by two data-driven modules. The first data-driven algorithm is to handle inaccuracies in HMPC internal models. Without needing to tune any parameter, this algorithm can enhance the accuracy of the battery model up to three times and improve up to ten times the precision of the hydrogen storage model. This makes the building EMS more flexible and less dependent on pre-modelling steps.The second data-oriented algorithm determines autonomously adequate parameters to HMPC to relieve the trade-off between economic and energy aspects. Relying only on power imbalance data analysis and local measurements, the proposed hierarchical controller determines which energy storage device must run daily based on the estimation of the annual self-consumption rate and the annual microgrid operating cost. These estimations decrease microgrid expenditure because it avoids grid penalties regarding the requirements of annual self-consumption and reduces the degradation and maintenance of energy storage devices.The proposed EMS also demonstrated being capable of exploiting the potentials of shifting in time the charging of batteries of plug-in electric vehicles. The simulation confirmed that the proposed controller preferably charges electric vehicles’ batteries at periods of energy surplus and discharges them during periods of energy deficit, leading the building microgrid to reduce grid energy exchange. The results also showed that electric vehicle batteries' contribution depends on the size of the vehicle parking, their arrival and departure time, and the building’s net power imbalance profile. In conclusion, through simulations using the dataset of both public and residential buildings, the proposed hierarchical building EMS proved its effectiveness to handle different kinds of energy storage devices and foster the development of forthcoming building microgrids
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20

Alqahtani, Ayedh H. A. S. "Modeling and Control of Photovoltaic Systems for Microgrids." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1381786869.

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21

Hartono, Aryudha. "Microgrid Safety and Protection Strategies." Thesis, KTH, Elektroteknisk teori och konstruktion, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-226593.

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One of the challenging issues with the Microgrid is that the bidirectional power flow providedby the distributed generator (DG) which modify the fault current level. Furthermore, theinverter based-renewable energy source (IB-RES) limits the total fault current contributionto the grid due to its thermal capability. Since Microgrid should be able to operate in gridconnectedand islanded mode, protection strategies are needed to solve this challenging issue.By only having IB-RES and battery storage system, the fault condition and normaloperation cannot be distinguished. Apart from fault clearing issue, there is a consideration tostudy the fault isolation in the Microgrid under the limited fault current provided by IB-RES.To have fault isolation capability, the intelligent electrical device (IED) is needed. The firststep is to find a method that can detect a fault under the fault level modification constraint.This thesis presents a zero and negative sequence current protection to detect a fault.However, to make it selective, this protection will be applied directionally. It is common thatthe distribution grid has unbalanced load operation, thus providing zero and negativesequence component in the grid. To apply the directional zero and negative sequence currentprotection, the unbalanced load flow is simulated to distinguish the fault and normaloperation under unbalanced load condition.Safety and regulation are discussed briefly in this thesis. It is important that each of theIB-RES has fault ride-through (FRT) capability that follows a regulation. However, thisregulation is expected to have a coordination with the proposed protection in the Microgridso the reliability, selectivity, and sensitivity can be achieved in grid-connected and islandedmode. This thesis shows the coordination between fuses, IED, and inverter FRT capability.After providing a protection strategy, the adaptability of the proposed protection isassessed regarding of Microgrid expansion. The result shows that by applying the schemeand following the grading margin requirement that is presented in this thesis, the Microgridexpansion will not disrupt the proposed protection coordination. Since it is known that thedistribution grid is expanding its load capacity and microgeneration in continuous basis, it isconvenient that the proposed protection in the IED is expected to be adaptable, means that ithas a fixed IED setting when the grid is expanded. The analysis is performed by electrical transient analysis program (ETAP) and MatlabSimulink. The short circuit analysis, sequence-of-operation, and unbalanced load flow aresimulated by ETAP, while the protection stability is simulated by Matlab Simulink.<br>Ett problem som finns med microgrid är att de distribuerade produktionsgeneratorerna harett dubbelriktat effektflöde som modifierar felströmmen. Dessutom, inverterbaseradeförnyelsebara energikällor (IB-RES) begränsar det totala felströmsbidraget på grund av desstermiska kapacitet. Eftersom microgrids ska vara operativ vid både anslutning till externt nätsamt önätsdrift behövs skyddsstrategier för att kunna hantera fel, speciellt vid önätsdrift.Om endast IB-RES och batterilager används kan feldrift och normal drift inte särskiljas.Bortsätt från felhantering är det viktigt att studera felbortkoppling för microgrid underbegränsad felström som fås av IB-RES. För att kunna åstadkomma felbortkoppling behöveren IED (från engelskans Intelligent Electronic Device). Det första steget är att finna en metodför att kunna detektera fel under fel nivå modifiering. Denna avhandling tittar på att användanoll- och minusföljds ström sekvensskydd för att detektera fel. För att göra skyddet selektivtkommer det att titta på riktningen av effektflödet. I distributionsnät är det vanligt att haobalanserade laster vilket medför noll- och negativa sekvenskomponenter i nätet. För atttillämpa riktningsskydd för noll och negativ sekvens ström simuleras ett obalanserateffektflöde för att särskilja på feldrift och normal drift vid obalanserad last.Säkerhet och förordningar diskuteras kortfattat i denna avhandling. Det är viktigt att varjeIB-RES har en feltålighet som följer vissa förordningar. Denna förordning förväntassamordna det föreslagna skyddet i micronåt så att pålitlighet, selektivitet och känslighet kanåstadkommas vid nätanslutning och önätsdrift. Denna avhandling visar samordningen mellansäkringar, IED och feltåligheten för växelomriktare.Anpassningsförmågan för det föreslagna skyddet bedöms med avseende på expansion avmicrogrid. Resultatet visar att en expansion av ett microgrid inte kommer att störa denföreslagna samordningen om skyddsmetoden och tidsfördröjningskravet som presenteras idenna avhandling följs. Eftersom det är känt att distributionsnätet kommer att fortsätta ökasin lastkapacitet och mikrogenerering, är det lämpligt att skyddet förväntas varaanpassningsbart vilket innebär att det har en fast IED inställning när nätet expanderas.Analysen genomförs med mjukvarorna electrical transient analysis program (ETAP) ochMatlab Simulink. Kortslutningsanalysen, arbetssekvensen och obalanserad lastflödesimuleras av ETAP, medan skyddsstabiliteten simuleras av Matlab Simulink.
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22

Chen, Chien-Liang. "Design, Implementation, and Analysis for an Improved Multiple Inverter Microgrid System." Diss., Virginia Tech, 2011. http://hdl.handle.net/10919/26240.

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Distributed generation (DG) is getting more and more popular due to the environmentally-friendly feature, the new generation unit developments, and the ability to operate in a remote area. By clustering the paralleled DGs, storage system and loads, a microgrid (MG) can offer a power system with increased reliability, flexibility, cost effectiveness, and energy efficient feature. Popular energy sources like photovoltaic modules (PV), wind turbines, and fuel cells require the power-electronic interface as the bridge to connect to the utility grid for usable transmission. The inverter-based microgrid system, however, suffers more challenges than traditional rotational power system. Those challenges, including much less over current capability, the nature of the intermittent renewable energy sources, a wide-band dynamic of generation units, and a large grid impedance variation, call for more careful system hardware and control designs to ensure a reliable system operation. Major design interests are found in (i) precision power flow control, (ii) proper current sharing, (iii) smooth transition between grid-tie and islanding modes, and (iv) stability analysis. This dissertation will cover a complete design and implementation of an experimental microgrid with paralleled power conditioning systems operating in the gridtie mode, islanding mode, and mode transfers. A universal inverter is proposed with the LCL filter to operate in both grid-tie and standalone mode without any hardware modification. Next, controllers of individual inverters running in basic microgrid modes will be discussed to ensure high quality output characteristics. The admittance compensation will also be proposed to avoid reverse power flow during the grid-tie connection transient. Combining previous designed single inverters, a CAN-bus multiinverter microgrid system will be established. The current sharing with the proposed frequency-decoupled transmission will be implemented to extend the transmission distance. Next, smooth mode transfer procedures between grid-tie mode and islanding mode will be suggested based on the circuit principles to minimize the excessive electrical stresses. Finally, the state-space analysis of the proposed multi-inverter microgrid system will be conducted to investigate the stability under system variations and optimize the system performance. Experimental and simulation results show that the designed universal inverter can provide stable outputs in different basic microgrid operation modes. With the proposed current sharing scheme, the output current is equally shared among paralleled inverters without a noticeable circulating current. Both the simulation and experimental results of mode transfer show that the multi-inverter based microgrid system is able to switch between grid-tie and islanding modes smoothly to guarantee an uninterrupted power supply to the critical loads. Based on eigenvalue analysis, the study of stability analysis also shows the agreement of the design, simulation and test results which further verifies the reliability of the designed multi-inverter microgrid system.<br>Ph. D.
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23

Diagne, Ibrahima. "Dynamic Analysis and Control of Multi-machine Power System with Microgrids: A Koopman Mode Analysis Approach." Diss., Virginia Tech, 2017. http://hdl.handle.net/10919/84546.

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Electric power systems are undergoing significant changes with the deployment of large-scale wind and solar plants connected to the transmission system and small-scale Distributed Energy Resources (DERs) and microgrids connected to the distribution system, making the latter an active system. A microgrid is a small-scale power system that interconnects renewable and non-renewable generating units such as solar photo-voltaic panels and micro-turbines, storage devices such as batteries and fly wheels, and loads. Typically, it is connected to the distribution feeders via power electronic converters with fast control responses within the micro-seconds. These new developments have prompted growing research activities in stability analysis and control of the transmission and the distribution systems. Unfortunately, these systems are treated as separated entities, limiting the scope of the applicability of the proposed methods to real systems. It is worth stressing that the transmission and distribution systems are interconnected via HV/MV transformers and therefore, are interacting dynamically in a complex way. In this research work, we overcome this problem by investigating the dynamics of the transmission and distribution systems with parallel microgrids as an integrated system . Specifically, we develop a generic model of a microgrid that consists of a DC voltage source connected to an inverter with real and reactive power control and voltage control. We analyze the small-signal stability of the two-area four-machine system with four parallel microgrids connected to the distribution feeders though different impedances. We show that the conventional PQ control of the inverters is insufficient to stabilize the voltage at the point-of-common coupling when the feeder impedances have highly unequal values. To ensure the existence of a stable equilibrium point associated with a sufficient stability margin of the system, we propose a new voltage control implemented as an additional feedback control loop of the conventional inner and outer current control schemes of the inverter. Furthermore, we carry out a modal analysis of the four-machine system with microgrids using Koopman mode analysis. We reveal the existence of local modes of oscillation of a microgrid against the rest of the system and between parallel microgrids at frequencies that range between 0.1 and 3 Hz. When the control of the microgrid becomes unstable, the frequencies of the oscillation are about 20 Hz. Recall that the Koopman mode analysis is a new technique developed in fluid dynamics and recently introduced in power systems by Suzuki and Mezic. It allows us to carry out small signal and transient stability analysis by processing only measurements, without resorting to any model and without assuming any linearization.<br>Ph. D.
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24

Qiu, Quanwei. "Networked Model Predictive Control for Microgrids with Distributed PV Generators." Thesis, Griffith University, 2020. http://hdl.handle.net/10072/400460.

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More and more renewable energy sources are being integrated into microgrids—and while this causes many control challenges for microgrids, it can also yield numerous economic and environmental benefits. Therefore, it is necessary to develop proper control schemes for microgrids to address the different control issues in their hierarchical structure while adapting to the different time scales of the three control levels. Conversely, because model predictive control (MPC) has significant advantages—the inclusion of forecasts, the simplicity of the algorithm, and the flexibility to handle hard constraints—it has attracted significant attention in industrial control systems. Motivated by these factors, this research focuses on implementing MPC techniques in microgrids, which are solely supplied by photovoltaic (PV) generators, to address different control problems. For primary control of the microgrid hierarchy, which is mainly responsible for the inner control of the local distributed generation units, MPC can be applied to control of the power converters that serve as interfaces between the sources and the loads. Therefore, in this control level, a novel output-feedback MPC technique based on ellipsoidal set-membership state estimation is designed for a direct current to direct current (DC-DC) converter, considering the unknown-but-bounded external disturbances. A long-horizon finite-states (FS) MPC strategy is designed for the direct current to alternating current (DC-AC) inverter to reduce the sampling and switching frequency through a multi-step implementation approach and a control sequence rearrangement method. For secondary control, which is in charge of the compensation for the frequency and voltage deviations and is usually communication-based, the distributed MPC strategy can be used to realize the desired cooperative control among the geographically dispersed units. Thus, a novel distributed model predictive controller is developed to enhance system performance. It takes into account the fact that the distributed controllers’ communication network might be subject to switching topology due to the disconnection and reconnection of controllers, random failures, and recoveries of the links between controllers. A Markov chain with a time-varying probability transition matrix is used to describe the stochastic topology evolution of the control network. Tertiary control is used to coordinate the power flow between the microgrid and the utility grid and offers economic operations for microgrids. Since the integration of renewable energy sources causes low inertia and power fluctuation in microgrids, battery energy storage is essential to addressing these issues. To coordinate the charging/discharging schedule of the battery storage units, a networked MPC strategy can be adopted to realize the communication between different microgrid components and make use of the forecasts for PV power generation and load demand. The multi-microgrid system is considered subject to partial fault because of non-functional generators, batteries, or even transmission lines in this research. Hence, both the connection status of the electrical grid and the communication network are incorporated into the system modeling. In addition, the set-membership estimation is adopted to deal with the possible state unavailability caused by non-functional batteries or communication failures. In the theoretical section of this thesis, different sufficient conditions are established to ensure the stability of the investigated systems, and the optimal control inputs are obtained by solving the corresponding optimization problems. For easy implementation with MATLAB solvers, all the constraints and conditions of the optimization problems are transformed into linear matrix inequalities. Different recursive MPC algorithms are designed to control the target systems, and some extended algorithms are also developed to assist with the computation to determine the optimal solutions. In the demonstration section of this thesis, the designed controllers are all implemented in the numerical simulations or Simulink tests to verify their effectiveness, and an experimental test based on Raspberry Pi is conducted to demonstrate the wireless communication employing the designed networked model predictive controller.<br>Thesis (PhD Doctorate)<br>Doctor of Philosophy (PhD)<br>School of Eng & Built Env<br>Science, Environment, Engineering and Technology<br>Full Text
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Baxter, Bradley. "Control of a microgrid in islanded mode and Grid-connected modes." Thesis, Baxter, Bradley (2014) Control of a microgrid in islanded mode and Grid-connected modes. Other thesis, Murdoch University, 2014. https://researchrepository.murdoch.edu.au/id/eprint/25566/.

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Microgrids are small electrical power distribution networks that can be connected to a main utility power grid, or can operate in disconnected or islanded mode. They offer a potential solution to the world’s reliance on fossil fuel sourced electrical energy generation. They can improve energy security and reliability for customers connected to the microgrid. Microgrids usually incorporate distributed energy sources, including renewable sources. Many of the renewable sources are interfaced with power electronics which must be able to operate in conjunction with traditional forms of generation such as synchronous generators. Control of power electronic interfaced energy sources can pose challenges for coordinated control of the microgrid as a whole. The control systems main function is to ensure supply to critical loads is maintained, particularly when in islanded mode. This study investigated several strategies for control and management of a microgrid, including taking over voltage and frequency control in islanded mode. The distributed nature of energy sources that usually makes up a microgrid favours a control system with minimal communication infrastructure and that for the most part operates autonomously in both a grid connected and islanded mode. The current study investigated the general concepts for control of both centralised and decentralised configurations of a microgrid and the problems associated with each. In-depth investigations and simulations were carried out on two decentralised control strategies, a pure droop control method and an angle-frequency droop control method. The pure droop controller had the ability to autonomously perform equal power sharing and maintain stability in islanded mode of operation, but resulted in permanent steady state frequency offset. The angle-frequency droop also operated autonomously but with improved power sharing and frequency regulation. The investigation used the MATLAB® environment to perform calculations and carry out simulations of the proposed systems over a range of grid connected and islanded mode scenarios. Performance measures such as power sharing accuracy, disturbance transient behaviour and islanded-grid connection transition were used to assess the suitability of each control scheme. The P-f droop control has been widely reported on and has been proven to work over a range of conditions. The angle-frequency droop is a new proposal to improve the performance of a microgrid in islanded mode. Results demonstrated that both methods of control performed well in islanded mode. The angle-frequency droop had a slight increase in power sharing accuracy and superior frequency regulation. However it would appear that several design flaws may need addressing before the angle-frequency droop can be implemented as a truly decentralised topology.
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Liu, Zhaoyi. "Voltage and frequency droop control of a microgrid in islanded modes." Thesis, Liu, Zhaoyi (2016) Voltage and frequency droop control of a microgrid in islanded modes. Honours thesis, Murdoch University, 2016. https://researchrepository.murdoch.edu.au/id/eprint/30814/.

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Nowadays, there are increased amount of distributed generation and renewable resources (including geothermal, ocean tides, solar and wind) used in the microgrid systems, which are connected via the power inverters. Microgrid is a concept that the systems include at least one distributed generation resources and local loads can switch to islanded power distributed systems, [1]. Duo to the small scale of microgrid, the voltage and frequency of system will carry more severe fluctuations then the larger grids, which will be able to stable these fluctuations via the wider systems, [9]. The inverters can provide the stability and redundancy to the power systems. For the normally working of the high current electronic devices, it is deviation that several inverters operate in parallel in the systems, [3]. The inverter control methods which should be able to bring the reliable and efficient electricity to microgrid system have attracted much attention in recent years. Various droop control methods are regarded as the effective solving technique in conventional generation system. The droop control strategy is associated with using local power to detect the load changes of complex powers in the system and adjusting the outputs, automatically, [2]. The advantage of droop control method is to allow the distributed generators in the system can operate without external mechanism communications, [3]. No mechanical communication means the system can adjust and share the loads among distributed generators (connected via inverters) automatically when the loads change happen. This is based on the calculation of droop control characteristics. The droop control uses the real power to adjust the frequency of loads, and vary the reactive power to vary the voltage of loads. However, droop control scheme are different when the impact of complex impedance is considered. The experimental simulation results will be presented to illustrate how the droop control scheme impacts the power distributions of parallel-connected inverters.
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SAJJAD, MALIK INTISAR ALI. "Characterisation and Flexibility Assessment of Aggregate Electrical Demand." Doctoral thesis, Politecnico di Torino, 2015. http://hdl.handle.net/11583/2594365.

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The renewable energy sources (RES) are intermittent in their nature and their integration in electric power grid has introduced the mismatch between supply and demand. This mismatch can be leveled by using the flexibilities from the supply and the demand side. The demand side in a power system has key importance in the evolving context of the energy systems. Electrical load patterns that represent the consumption level are affected by different types of uncertainties associated with customer’s behavior and with keeping acceptable comfort level. The resulting aggregated load pattern indicates the system response that may be more or less flexible in different periods of time. The distribution system operator in a microgrid is responsible for its secure and economic operation. Enhancing the knowledge on the aggregated behavior of these customers is particularly important for the distribution system operator, also with the aim of determining the potential flexibility of the demand and setting up the economic terms of the electricity provision to the customers. Extra charges due to high energy demand and contract violation penalties can be avoided using demand side flexibility. Demand side flexibility has many benefits in normal as well as emergency conditions like less cost and quick response. The study of aggregate residential demand for flexibility measures is important due to the diverse energy usage behavior of individual residents and conceptually, its availability all around the year for load management. Exploitation of possible flexibilities of the group of residential customer’s behavior is considered as an important option to promote demand response programs and to achieve greater energy savings. As far as the residential sector is concerned, a reasonable work can be found in the literature to assess the flexibility for the individual appliances, the aggregation of selected appliances. However, little work is found on the aggregation of residential units. Also, despite of many discussions about the concept of flexibility, the few mathematical definitions of flexibility available do not address the variation in time of the overall demand aggregation. There is a need to develop a methodology to extract flexibility information from aggregate electricity consumption behavior of the residents and develop useful flexibility indices for the aggregate residential loads. For this purpose, the first action required is to augment availability of information about the characteristics of aggregate electricity demand. The analysis of aggregate demand patterns is carried out by considering the demand pattern data representing the average power determined from the energy referring to a given time step duration. This thesis contains a comprehensive statistical analysis to investigate the effect of time step duration and aggregation level on load variation profile. Then the customer behavior about the change is demand is modeled using the binomial probability distribution. This model has led towards some novel definitions of flexibility indices. A new method based on the Beta probability distribution has been developed to generate the time coupled aggregate residential demand patterns, whose evolution depends on the uncertainties associated with the customer’s behavior. The outcome of this research work has also led towards defining the role of customers in microgrid application. For this purpose, a structure of the business model for a smart (mini) grid is proposed. The data sets used for all kind of analysis are generated for the different aggregations of the extra-urban residential customers using a bottom-up approach. The tools presented in this research work can be helpful for a system operator or an aggregator to assess demand side flexibilities, manage resources and efficiently use demand response programs. The findings of this work are also supportive to determine the metering structure for a microgrid application in which, by using current ICT technologies, it is possible to decide a compromise solution between the aggregation level and time step duration for smart metering. On the other hand, the research findings also led to the conclusion that the flexibility level for the individual residential customers is not so high to give economic benefits that make it attractive to participate in DR programs. From the studies, it seems that the problem is not with the technical aspects but with the current business model of the smart grids. For the future extension of this work, a framework of a new smart business model for smart (mini) grids, centric to customers, is presented. It is expected that the developments using the proposed background of the business model can lead towards a different era in the development of the power systems with the new wave of research; as new tools are required to embed economic and social considerations in planning the proposed architecture.
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Rahman, Md Mustafizur. "Microgrid frequency control using multiple battery energy storage system (BESSs)." Thesis, Queensland University of Technology, 2015. https://eprints.qut.edu.au/90856/1/MD%20Mustafizur_Rahman_Thesis.pdf.

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The work is a report of research on using multiple inverters of Battery Energy Storage Systems with angle droop controllers to share real power in an isolated micro grid system consisting of inertia based Distributed Generation units and variable load. The proposed angle droop control method helps to balance the supply and demand in the micro grid autonomous mode through charging and discharging of the Battery Energy Storage Systems while ensuring that the state of charge of the storage devices is within safe operating conditions. The proposed method is also studied for its effectiveness for frequency control. The proposed control system is verified and its performance validated with simulation software MATLAB/SIMULINK.
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Moradinegade, Dizqah Arash. "Non-linear model predictive energy management strategies for stand-alone DC microgrids." Thesis, Northumbria University, 2014. http://nrl.northumbria.ac.uk/17747/.

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Due to substantial generation and demand fluctuations in stand-alone green micro-grids, energy management strategies (EMSs) are becoming essential for the power sharing purpose and regulating the microgrids voltage. The classical EMSs track the maximum power points (MPPs) of wind and PV branches independently and rely on batteries, as slack terminals, to absorb any possible excess energy. However, in order to protect batteries from being overcharged by realizing the constant current-constant voltage (IU) charging regime as well as to consider the wind turbine operational constraints, more flexible multivariable and non-linear strategies, equipped with a power curtailment feature, are necessary to control microgrids. This dissertation work comprises developing an EMS that dynamically optimises the operation of stand-alone dc microgrids, consisting of wind, photovoltaic (PV), and battery branches, and coordinately manage all energy flows in order to achieve four control objectives: i) regulating dc bus voltage level of microgrids; ii) proportional power sharing between generators as a local droop control realization; iii) charging batteries as close to IU regime as possible; and iv) tracking MPPs of wind and PV branches during their normal operations. Non-linear model predictive control (NMPC) strategies are inherently multivariable and handle constraints and delays. In this thesis, the above mentioned EMS is developed as a NMPC strategy to extract the optimal control signals, which are duty cycles of three DC-DC converters and pitch angle of a wind turbine. Due to bimodal operation and discontinuous differential states of batteries, microgrids belong to the class of hybrid dynamical systems of non-Filippov type. This dissertation work involves a mathematical approximation of stand-alone dc microgrids as complementarity systems (CSs) of Filippov type. The proposed model is used to develop NMPC strategies and to simulate microgrids using Modelica. As part of the modelling efforts, this dissertation work also proposes a novel algorithm to identify an accurate equivalent electrical circuit of PV modules using both standard test condition (STC) and nominal operating cell temperature (NOCT) information provided by manufacturers. Moreover, two separate stochastic models are presented for hourly wind speed and solar irradiance levels.
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K/bidi, Fabrice. "Développements et tests de stratégies de gestion de l’énergie à l’échelle de micro réseaux avec stockage et production d’hydrogène." Thesis, La Réunion, 2019. http://www.theses.fr/2019LARE0031.

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Avec le développement des technologies de pile à combustible (PàC) et d’électrolyse de l’eau, l’hydrogène électrolytique devient un pilier de la transition énergétique, substitut aux ressources fossiles et outil d’intégration des sources d’énergies renouvelables (SER) intermittentes. À l'échelle de micro-réseaux isolés ou îlotables, cette transition repose sur le développement de systèmes hybrides, couplant des panneaux photovoltaïques (PV) et des électrolyseurs pour la production de l'hydrogène, des systèmes de stockage — réservoirs d'hydrogène (H2) et batteries (Bat) — et des PàC pour la production de l’électricité. Cette étude présente des stratégies de contrôle pour un système PV-H2-Bat-PàC afin d'optimiser la gestion de l'énergie PV intermittente tout en respectant les conditions de fonctionnement des électrolyseurs et des PàC. Premièrement, une commande de type MPPT (Maximum Power Point Tracking) est développée pour assurer le fonctionnement des PV à puissance maximale, et une stratégie de contrôle basée sur des commandes prédictives est mise en œuvre pour définir un courant de référence pour la PàC, l'électrolyseur et les batteries. Deuxièmement, des contrôleurs IP sont utilisés pour réguler ces courants. Troisièmement, un problème d’optimisation permet de définir un plan d’engagement afin d’utiliser la PàC et l’électrolyseur en tenant compte de l’offre, de la demande et des stocks d’énergie<br>With the development of fuel cell (FC) and water electrolysis technologies, electrolytic hydrogen is becoming a pillar of the energy transition, a substitute for fossil resources and a tool for integrating intermittent renewable energy sources (RES). On the scale of isolated or islandable microgrids, this transition is based on the development of hybrid systems, coupling photovoltaic (PV) panels and electrolyzers for hydrogen production, storage systems - hydrogen (H2) tanks and batteries (Bat) - and FC for electricity production. This study presents control strategies for a PV-H2-Bat-FC system to optimize intermittent PV energy management while respecting the operating conditions of electrolyzers and FC. First, a MPPT (Maximum Power Point Tracking) control system is developed to ensure the operation of PV at maximum power, and a control strategy based on Model Predictive Control is implemented to define a current reference for the FC, the electrolyzer and the batteries. Secondly, IP controllers are used to regulate these currents. Thirdly, an optimization problem makes it possible to define a commitment plan to use the FC and the electrolyser taking into account energy supply, demand and stocks
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31

Xu, Ling. "Modeling, Analysis and Control of Voltage-Source Converter in Microgrids and HVDC." Scholar Commons, 2013. http://scholarcommons.usf.edu/etd/4967.

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The objective of this dissertation is to carry out dynamic modeling, analysis and control for Voltage-Source Converters (VSC). Two major applications of VSC will be investigated in this dissertation: microgrid application and High Voltage Direct Current (HVDC) application. In microgrid applications, VSC is used to integrate distributed energy sources such as battery and provide system functions: such as real and reactive power regulation, voltage and frequency support during islanding condition, and abnormal system condition mitigation. In HVDC applications, VSC is used to interconnect dc systems with ac systems. The functions supplied by VSC are similar to that in microgrids. However, the transfer capability and stability in such kind of system are of major interests. Therefore, Part I of this dissertation focuses on VSC's applications in microgrids. A battery's inverter can be operated in both grid-connected PQ regulation mode and voltage and frequency support mode during islanding condition. Transition scheme between these two control modes is firstly investigated to guarantee a smooth dynamic performance. Secondly, a coordinated control strategy between battery's and PV station's VSCs is developed to improve microgrid's power flow. Thirdly, power quality improvement through the battery's inverter is investigated. VSC's control and capability for microgrid operation at normal, transient, and abnormal conditions will be modeled and analyzed. Part II of this dissertation focuses on VSC's applications in HVDC. The following topics are investigated in this dissertation: (i) how to design VSC-HVDC's controller using system identification method? (ii) How to coordinate VSCs in multi-terminal HVDC scenarios? And (iii) how to determine VSC-HVDC system's transfer capability based on stability limits? High-fidelity simulation technology is employed to tackle control validation while frequency domain impedance modeling technique is employed to develop analytical models for the systems. With linear system analysis tools such as Nyquist plots and Bode plots, stability limits and impacting factors of VSC-HVDC systems can be identified. This dissertation led to four journal papers (two accepted, one request of revision, one to submit) and five conference papers. The major contributions of this dissertation include: 1) Developed VSC and microgrid models in high-fidelity simulation environment. Developed and validated VSC control schemes for variety of microgrid operations: normal, abnormal, and transient. The developed technologies can facilitate a battery to make up solar power, improve system dynamic performance during transients, and improve power quality. 2) Developed VSC-HVDC simulation models, including two-terminal HVDC and multi-terminal HVDC. Developed VSC-HVDC control schemes for two-terminal and multi-terminal systems. Developed analytical impedance models for VSC-HVDC systems and successfully carried out stability limit identification.
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32

Alvarez, Genesis Barbie. "Control Design for a Microgrid in Normal and Resiliency Modes of a Distribution System." Thesis, Virginia Tech, 2019. http://hdl.handle.net/10919/94627.

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As inverter-based distributed energy resources (DERs) such as photovoltaic (PV) and battery energy storage system (BESS) penetrate within the distribution system. New challenges regarding how to utilize these devices to improve power quality arises. Before, PV systems were required to disconnect from the grid during a large disturbance, but now smart inverters are required to have dynamically controlled functions that allows them to remain connected to the grid. Monitoring power flow at the point of common coupling is one of the many functions the controller should perform. Smart inverters can inject active power to pick up critical load or inject reactive power to regulate voltage within the electric grid. In this context, this thesis focuses on a high level and local control design that incorporates DERs. Different controllers are implemented to stabilize the microgrid in an Islanding and resiliency mode. The microgrid can be used as a resiliency source when the distribution is unavailable. An average model in the D-Q frame is calculated to analyze the inherent dynamics of the current controller for the point of common coupling (PCC). The space vector approach is applied to design the voltage and frequency controller. Secondly, using inverters for Volt/VAR control (VVC) can provide a faster response for voltage regulation than traditional voltage regulation devices. Another objective of this research is to demonstrate how smart inverters and capacitor banks in the system can be used to eliminate the voltage deviation. A mixed-integer quadratic problem (MIQP) is formulated to determine the amount of reactive power that should be injected or absorbed at the appropriate nodes by inverter. The Big M method is used to address the nonconvex problem. This contribution can be used by distribution operators to minimize the voltage deviation in the system.<br>Master of Science<br>Reliable power supply from the electric grid is an essential part of modern life. This critical infrastructure can be vulnerable to cascading failures or natural disasters. A solution to improve power systems resilience can be through microgrids. A microgrid is a small network of interconnected loads and distributed energy resources (DERs) such as microturbines, wind power, solar power, or traditional internal combustion engines. A microgrid can operate being connected or disconnected from the grid. This research emphases on the potentially use of a Microgrid as a resiliency source during grid restoration to pick up critical load. In this research, controllers are designed to pick up critical loads (i.e hospitals, street lights and military bases) from the distribution system in case the electric grid is unavailable. This case study includes the design of a Microgrid and it is being tested for its feasibility in an actual integration with the electric grid. Once the grid is restored the synchronization between the microgrid and electric must be conducted. Synchronization is a crucial task. An abnormal synchronization can cause a disturbance in the system, damage equipment, and overall lead to additional system outages. This thesis develops various controllers to conduct proper synchronization. Interconnecting inverter-based distributed energy resources (DERs) such as photovoltaic and battery storage within the distribution system can use the electronic devices to improve power quality. This research focuses on using these devices to improve the voltage profile within the distribution system and the frequency within the Microgrid.
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Zheng, Rongpeng. "An FPGA Based MPPT and Monitoring System : suitable for a photovoltaic based microgrid." Thesis, Linnéuniversitetet, Institutionen för fysik och elektroteknik (IFE), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-85558.

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Microgrids containing photovoltaic (PV) cells and wind power gain more and more interest. These microgrids may work in stand-alone mode ("islanding") or be conncted to the main grid. In both modes of operation, power quality must be monitored and controlled. This report focuses on microgrids and aims to implement a monitoring system based on FPGA. In the monitoring system, two applications can be achieved, firstly a PAS-MPPT algorithm in a DC-DC boost converter to improve the maximun power point tracking of a PV unit, and secondly a detection and switching system of the grid mode - stand-alone or connected to the main grid. Simulation results prove the Verilog programs in FPGA are suitable to be used in microgrids.
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Yin, Changjie. "Impact of diesel generator operating modes on standalone DC microgrid and control strategies implying supercapacitor." Thesis, Compiègne, 2018. http://www.theses.fr/2018COMP2411/document.

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La nature intermittente et aléatoire des sources renouvelables, telles que le photovoltaïque et l’éolien, nécessite un complément de stockage, tel une batterie et un système de secours énergétique, tel un générateur diesel, en particulier dans un système autonome. En ce qui concerne le générateur diesel, il a besoin d'un certain temps pour démarrer et il ne peut pas donner immédiatement la puissance nécessaire, en raison de son comportement dynamique. Alors, la qualité de l'énergie est abaissée pendant cette période en raison du manque de puissance. Par conséquent, pendant la période de démarrage du générateur diesel, un supercondensateur est suggéré pour équilibrer la puissance en raison de sa réponse rapide et de sa densité de puissance élevée. Une stratégie de contrôle de puissance est proposée pour réaliser la coordination entre le générateur diesel et le supercondensateur. La simulation et les résultats expérimentaux montrent que la stratégie de contrôle proposée est capable de réguler la tension du bus continu dans des limites acceptables et d’alimenter la charge pendant la sous production d'énergie renouvelable ou lors d'augmentation de la demande de la charge. De plus, le supercondensateur peut également être utilisé pour surmonter les limites de stockage électrochimique telles que son état de charge et son courant maximal. Ainsi, cette thèse propose le contrôle de puissance en temps réel pour un micro réseau continu avec un système hybride photovoltaïque-batterie-supercondensateur-diesel, visant à répondre à la demande de puissance de charge avec fiabilité et à stabiliser de la tension du bus continu. La simulation et les résultats expérimentaux montrent également que la stratégie de contrôle améliore les performances dynamiques et statiques du micro réseau continu pour différentes conditions de fonctionnement. De plus, afin de minimiser le coût énergétique du groupe diesel, le coût du carburant et la consommation de carburant sont analysés à travers plusieurs tests expérimentaux. Par conséquent, la valeur optimale de sa production d'énergie est déduite et appliquée dans une nouvelle stratégie de gestion de la puissance est proposée. Cette stratégie peut atteindre l'objectif de maximiser l'utilisation de l'énergie photovoltaïque et de prendre en compte la caractéristique de démarrage lent et le coût énergétique du générateur diesel. Les simulations et expérimentations sont réalisées en utilisant des données photovoltaïques réelles pour illustrer les performances et le comportement du système hybride. Les résultats obtenus vérifient l'efficacité de cette stratégie. De plus la comparaison avec la stratégie de gestion de la puissance précédente, dans laquelle le coût d’énergie du générateur diesel n'est pas pris en compte, démontre que la nouvelle stratégie de gestion peut réduire le coût total du système de puissance à courant continu hybride<br>The intermittent and random nature of renewable sources, such as photovoltaic and wind turbine, asks for the complement of storage, such as battery and back-up energy, such as diesel generator, especially in a standalone power system. Concerning the diesel generator, it needs some time to start up and cannot immediately offer the needed power, due to its dynamic behavior. Hence, the power quality is lowered down during this period because of the shortage of power. Therefore, during the period of the diesel generator starting up, a supercapacitor is suggested to compensate the power balance because of its fast response and high power density. A power control strategy is proposed to achieve the coordination between diesel generator and supercapacitor. Both simulation and experimental results show that the proposed control strategy is able to regulate the DC bus voltage within the acceptable limits and supplying the load during the renewable power under generation or load step-increase situations. In addition, the supercapacitor can be also used to overcome the electrochemical storage limits like its state of charge and maximum current. So, this thesis proposes the real time power control for a hybrid photovoltaic-battery-supercapacitor-diesel generator DC microgrid system, aiming to meet the load power demand with reliability and stabilizing the DC bus voltage. Both simulation and experimental results show that the designed control strategy improves the DC microgrid dynamic and static performances under different operating conditions. Furthermore, in order to minimize the diesel generator energy cost, the fuel cost and fuel consumption are analysed through several experimental tests. Therefore, the optimal value of its power generation is deduced and applied in a newly proposed energy management strategy. This strategy can achieve the goal of maximizing the utilization of photovoltaic energy and taking into account the slow start-up characteristic and energy cost of diesel generator. Both simulation and experimental studies are carried out by using the real photovoltaic data to illustrate the performance and the behavior of the hybrid system. The obtained results verify the effectiveness of this strategy. Furthermore, the comparison with the previous energy management strategy, in which the diesel generator energy cost is not considered, demonstrates that the newly proposed energy management strategy can reduce the total cost of the hybrid DC power system
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Angelova, Dafina. "Inducing age related changes in microglia as a model for neurodegenerative disease." Thesis, University of Bath, 2019. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.767601.

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Neurodegenerative diseases like Alzheimer's Disease and Parkinson's Disease are one of the biggest issues in healthcare that society is facing worldwide. Aging is a major risk factor for many neurodegenerative diseases and is thought to play a large role in their pathology. It is thought that the brain's resident immune cells microglia can change with age to obtain a detrimental phenotype that disrupts tissue homeostasis and promotes conditions for neurodegenerative disease to develop. Therefore, understanding and implementing microglial aging into the study of neurodegeneration could be important to further advances in the area.
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Li, Vivian S. M. Massachusetts Institute of Technology. "The Local Reference Electrification Model : comprehensive decision-making tool for the design of rural microgrids." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/104828.

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Thesis: S.M. in Technology and Policy, Massachusetts Institute of Technology, School of Engineering, Institute for Data, Systems, and Society, Technology and Policy Program, 2016.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (pages 97-98).<br>Current estimates indicate that an alarming 1 billion existing people still lack access to electricity around the world. Technological advancements have pushed off-grid solutions into the limelight as possible alternatives to the traditional method of electrification via extension of the centralized grid. When grid reliability is poor, the community is remote, or when the arrival of the grid is undetermined, off-grid systems may be suitable substitutes for traditional grid extension efforts. Nonetheless, severe resource constraints, the scale of planning, and the choice between electrification modes create a complicated environment under which planners in the developing world must devise electrification plans and relevant policies. This thesis demonstrates how computational tools can provide value to rural electrification planning. The Reference Electrification Model (REM) assists planners by identifying optimal regions for grid extension projects and off-grid solutions, along with technical design and associated financial metrics. In particular, this thesis focuses on the discussion of the Local Reference Electrification Model (LREM), an adaption of REM to localized electrification design. LREM is a comprehensive, decision-making tool that produces detailed generation and network designs for a singular microgrid system. It contributes to the electrification effort by providing the quantitative basis with which to explore financial, technical, and performance implications of various factors in microgrid design. In doing so, LREM improves the microgrid designs relied upon by REM in its regional planning decisions. This research emphasizes the ability for computational tools such as REM and LREM to assist in developing viable policies and regulations, as well as feasible designs and plans to accelerate electricity access globally.<br>by Vivian Li.<br>S.M. in Technology and Policy
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Liu, Jiannan. "Multi-Functional Inverter Based Microgrid for Power Quality Improvement with Smooth Transient Performance." Thesis, Griffith University, 2020. http://hdl.handle.net/10072/392404.

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The increasing utilisation of renewable energy sources (RESs) plays an important role in the modern power system. The high penetration of the RESs in the electrical power network leads to challenges to the system’s stability. Therefore, the microgrid concept is proposed to solve such problems due to its flexibility and practicality. The hybrid AC/DC microgrid configuration is compatible with AC power supplies, DC power supplies, AC loads and DC loads which is viewed as the most practical choice in the power system application. The microgrid utilises an interlinking converter for the system’s control and grid connection. In this case, the microgrid implementation provides the possibility to achieve the other power electronic device functions such as a static compensator (STATCOM) or an active power filter (APF) in addition to dealing with the RES problems. In this PhD thesis, a grid-connected-mode-based control strategy for the microgrid is proposed to regulate the power generation as well as to reduce the grid current harmonics and neutral current. A virtual synchronous generator (VSG) based control strategy is introduced for microgrid’s smooth transient performance purpose. The first contribution of this research is the combination of the notch filter and traditional grid-connected microgrid control strategy. The notch filter is introduced into a three-phase system for current harmonics detection. The obtained harmonics signals are converted into reference signals for a revised constant power control strategy so that the microgrid is able to achieve the power regulation and harmonics reduction simultaneously. The interlinking converter is designed with three transistor-based bridges and a split-capacitor-based bridge so that the system is decoupled from hardware without any internal signals interference. The second contribution of this research is the design for grid neutral current compensation. The interlinking converter is designed with another independent neutral module bridge for the neutral current compensation purpose and a controller is developed based on this. In the context, the microgrid is implemented as a traditional microgrid with STATCOM-APF functions embedded. The third contribution of this research is the introduction of an improved VSG controller with its specific pre-synchronisation module. The designed method conducts smooth transient performances for a microgrid under different scenarios. An exclusive pre-synchronisation block is designed for the improved VSG controller for the microgrid to reconnect to the utility network smoothly when there is a requirement. The final contribution of this research is the establishment of the microgrid system benchtop. The hardware setup achieves the traditional power regulation function as well as the power-sharing between two microgrids. The proposed STATCOM-APF-based grid-connected microgrid controller is also tested under different scenarios. The effectiveness is validated through experiment. Various case studies are conducted in this research to investigate the microgrid possibilities. The proposed methods are validated through simulation first. The hardware prototype also verifies the correctness of the proposed grid-connected microgrid control method. The microgrid setup finally realises the power regulation, the harmonics reduction, the neutral current compensation and the cooperative operation functions.<br>Thesis (PhD Doctorate)<br>Doctor of Philosophy (PhD)<br>School of Eng & Built Env<br>Science, Environment, Engineering and Technology<br>Full Text
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Al-Saedi, Waleed Abood Baddai. "Optimal Control of Power Quality in Microgrids Using Particle Swarm Optimisation." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2013. https://ro.ecu.edu.au/theses/611.

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Driven by environmental protection, economic factors, conservation of energy resources, and technical challenges, the microgrid has emerged as an innovative small-scale power generation network. Microgrids consist of a cluster of Distributed Generation units that encompass a portion of an electric power distribution system and may rely on different energy sources. Functionally, the microgrid is required to provide adequate levels and quality of power to meet load demands. The issue of power quality is significant as it directly affects the characteristics of the microgrid’s operation. This problem can be defined as an occurrence of short to long periods of inadequate or unstable power outputs by the microgrid. In a stand-alone operation mode, the system voltage and frequency must be established by the microgrid, otherwise the system will collapse due to the variety in the microgrid component characteristics. The harmonic distortion of the output power waveforms is also a serious problem that often occurs because of the high speed operation of the converter switches. The long transient period is a critical issue that is usually caused by changing the operation mode or the load demand. Power sharing among the Distributed Generation units is also an important matter for sharing the load appropriately, particularly given that some renewable energy resources are not available continuously. In a utility connected microgrid, the reliable power quality mainly depends on the regulation of both active and reactive power, because the microgrid’s behaviour is mostly dominated by the bulk power system. Therefore, an optimal power control strategy is proposed in this thesis to improve the quality of the power supply in a microgrid scenario. This controller comprises an inner current control loop and an outer power control loop based on a synchronous reference frame and conventional PI regulators. The power control loop can operate in two modes: voltage-frequency power control mode and active-reactive power control mode. Particle Swarm Optimisation is an intelligent searching algorithm that is applied here for real-time self-tuning of the power control parameters. The voltage-frequency power controller is proposed for an inverter-based Distributed Generation unit in an autonomous operation mode. The results show satisfactory system voltage and frequency, high dynamic response, and an acceptable harmonic distortion level. The active-reactive power controller is adopted for an inverter-based Distributed Generation unit in a utility operation mode. This controller provides excellent regulation of the active and reactive power, in particular when load power has to be shared equally between the microgrid and utility. The voltage-frequency and active-reactive power control modes are used for a microgrid configured from two DG units in an autonomous operation mode. The proposed control strategy maintains the system voltage and frequency within acceptable limits, and injects sustained output power from one DG unit during a load change. The reliability of the system’s operation is investigated through developing a small-signal dynamic model for the microgrid. The results prove that the system was stable for the given operating point and under the proposed power controller. Consequently, this research reveals that the microgrid can successfully operate as a controllable power generation unit to support the utility, thus reducing the dependency on the bulk power system and increasing the market penetration of the micro-sources.
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39

Hartley, Rebecca K. "Differential Reactivity of Microglia in Two Mouse Models of Multiple Sclerosis." VCU Scholars Compass, 2016. http://scholarscompass.vcu.edu/etd/4180.

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Multiple sclerosis (MS) is a neurodegenerative disorder characterized by CNS inflammation and axonal demyelination. In addition, axonal pathology has also been reported in MS and may be responsible for the functional deficits associated with this disease. Based on preliminary data from our laboratory, we propose that a specific domain of the neuron, known as the axon initial segment (AIS), is targeted in MS. Consistent with our work from the human tissue, we have also observed disruption of AIS integrity in a murine CNS inflammatory model and observations strongly implicate reactive microglia as mediators of AIS disruption. In contrast, a murine model of demyelination did not exhibit AIS pathology but reactive microglia were prevalent. Since we propose that reactive microglia drive AIS disruption in our inflammatory CNS model but observe no AIS pathology following demyelination even in the presence of reactive microglia, we propose that reactive microglia in these models exhibit different interactions and molecular profiles. To test this hypothesis, we employed immunofluorescence labeling combined with confocal microscopy to quantify microglia reactivity and microglia-AIS interaction. Additionally, we conducted a microarray using RNA isolated from microglia from both the inflammatory and demyelinating models. Our findings show that microglia are reactive prior to pathology in both models and that the extent of AIS-microglial contact is similar between the models but significantly increased as compared to naïve mice. Our microarray data reveal a substantial difference in gene expression indicating functional differences between the reactive microglia in the inflammatory and demyelinating models. Finally, following functional enrichment analysis of microarray data, the complement pathway emerged as a potential contributor to the AIS pathology observed in EAE.
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40

Hald, Andreas. "Pharmacological testing and investigations of spinal astrogliosis in a murine bone cancer pain model /." Cph. : Copenhagen University, Faculty of Pharmaceutical Sciences, Department of Pharmacology and Pharmacotherapy, 2007. http://www.farma.ku.dk/index.php/Andreas-Hald/4975/0/.

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41

Heiss, Kathrin. "Role of pentazocine in an in vitro model of hypoxia/reoxygenation." Doctoral thesis, Università di Catania, 2017. http://hdl.handle.net/10761/3623.

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Experimental research is making considerable efforts to understand the rules that regulate the balance between toxic and protective brain innate immunity. Sigma-1 receptor is expressed in both neurons and glia is a unique class of intracellular proteins and is involved in neurodegeneration. Our aim was to evaluate the biological effects of sigma-1 selective ligands, and bifunctional sigma-1 selective ligands conjugated with lipoil function in microglia following hypoxia/reoxygenation condition. BV2 cells were exposed to 3 hours of hypoxia and 24h of reoxygenation. Cells were treated with sigma-1 agonist (+)-Pentazocine, various bifunctional sigma-1 agonists conjugated with lipoil function and with lipoic acid alone. We assessed cell viability, apoptosis, reactive oxygen species (ROS) formation, mitochondria membrane potential, and total thiol groups content (GSH). Our results showed that 24h of reoxygenation resulted in a significant decrease of cell viability and increase in apoptosis when compared to control. No significant effect of (+)Pentazocine and tested compounds was observed on cell viability following 24h of reoxygenation. Furthermore, all treatments resulted in a significant decrease of ROS formation when compared to untreated cells. Finally, pharmacological treatments restored mitochondrial membrane potential when compared to the untreated group. Consistently with these results we also showed that GSH content was restored following pharmacological treatments. Our results showed that newly synthetized bifunctional sigma-1 compounds exhibited significant antioxidant activity and induce apoptosis in activated microglia thus providing a new tool for effective manipulation of brain inflammation, with the specific aim of favoring its protective arm and boosting innate neuroprotective mechanisms 6 GENERAL INTRODUCTION MICROGLIA The concept of microglia was introduced by Pio del Rio-Hortega as a defined cellular element
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42

Heiss, Kathrin. "role of pentazocine in an in vitro model of hypoxia/reoxygenation." Doctoral thesis, Università di Catania, 2017. http://hdl.handle.net/10761/3912.

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Experimental research is making considerable efforts to understand the rules that regulate the balance between toxic and protective brain innate immunity. Sigma-1 receptor is expressed in both neurons and glia is a unique class of intracellular proteins and is involved in neurodegeneration. Our aim was to evaluate the biological effects of sigma-1 selective ligands, and bifunctional sigma-1 selective ligands conjugated with lipoil function in microglia following hypoxia/reoxygenation condition. BV2 cells were exposed to 3 hours of hypoxia and 24h of reoxygenation. Cells were treated with sigma-1 agonist (+)-Pentazocine, various bifunctional sigma-1 agonists conjugated with lipoil function and with lipoic acid alone. We assessed cell viability, apoptosis, reactive oxygen species (ROS) formation, mitochondria membrane potential, and total thiol groups content (GSH). Our results showed that 24h of reoxygenation resulted in a significant decrease of cell viability and increase in apoptosis when compared to control. No significant effect of (+)Pentazocine and tested compounds was observed on cell viability following 24h of reoxygenation. Furthermore, all treatments resulted in a significant decrease of ROS formation when compared to untreated cells. Finally, pharmacological treatments restored mitochondrial membrane potential when compared to the untreated group. Consistently with these results we also showed that GSH content was restored following pharmacological treatments. Our results showed that newly synthetized bifunctional sigma-1 compounds exhibited significant antioxidant activity and induce apoptosis in activated microglia thus providing a new tool for effective manipulation of brain inflammation, with the specific aim of favoring its protective arm and boosting innate neuroprotective mechanisms 6 GENERAL INTRODUCTION MICROGLIA The concept of microglia was introduced by Pio del Rio-Hortega as a defined cellular element
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43

Mandrekar-Colucci, Shweta Dilip. "PPARɣ Activation Rapidly Ameliorates Amyloid Pathology and Restores Cognition in a Mouse Model of Alzheimer’s Disease". Case Western Reserve University School of Graduate Studies / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=case1307730357.

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44

Lam, Haces Gil Karla G. "Investigation into the epigenetic mechanisms involved in microglial activation in the animal model of multiple sclerosis." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:b4de0ef7-7588-4381-b099-9c8567805546.

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In patients with multiple sclerosis (MS), microglia become activated due to the autoimmune inflammatory response which is directed against the central nervous system (CNS). Following the first disease relapse, microglia remain activated and do not return to a resting state during remissions. Chronically-activated microglia release inflammatory mediators that cause CNS tissue damage, and as such, MS progression has been associated with widespread, chronic microglial activation that correlates with neurodegeneration. To date, only one histone demethylase, Jmjd3, has been described to have a role in inflammation. In agreement with this, up-regulation of Jmjd3 expression was observed following microglial treatment with several pro-inflammatory stimuli, including a range of toll-like receptors ligands and cytokines, suggesting a universal role of Jmjd3 during microglial activation. Subsequent ChIP-qPCR assays revealed that Jmjd3 was recruited to the promoters of Il6, Ccl3, Ccl5 and Nos2 following activation, which, in turn, presented a decrease in their H3K27me3 levels. Using an experimental autoimmune encephalomyelitis (EAE) mouse model of MS, Jmjd3 expression was shown to be increased in activated microglia from mice in the acute and late phases of disease. Immunization with complete Freud’s adjuvant (CFA) alone, also caused microglial activation with Jmjd3 induction, indicating a CFA-mediated TLR2 and TLR4 stimulation of microglia. Further investigation, in which primary microglia were isolated from mice deficient in Jmjd3 (Jmjd3-/-), however demonstrated that the absence of Jmjd3 alone had no resultant effect on the expression of a subset of immune response and inflammation related genes, including the Jmjd3 target genes Il6, Ccl3, Ccl5 and Nos2, before or after activation. This suggested that Jmjd3 acts in concert with a repertoire of other demethylases to facilitate microglia activation, and as such was rendered redundant in this setting. Deciphering the epigenetic profile of microglia in MS and determining whether it is involved in the maintenance of chronic microglial activation in the progressive phase of the disease remains an important line of investigation, and through a clearer understanding of its role in MS pathophysiology, could lead to the development of novel therapeutic interventions in the future.
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45

Emmer, Kathryn. "Mammary Tumor and Mastectomy Synergistically Promote Neuroinflammation in a Breast Cancer Survivor Model." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu155541980882918.

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46

Finneran, Dylan John. "Proteolysis of CX3CL1 Impacts CX3CR1 Signaling and Therapeutic Benefits in a Tauopathy Model." Scholar Commons, 2018. https://scholarcommons.usf.edu/etd/7504.

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Alzheimer’s disease (AD) is a progressive, neurodegenerative disorder and the most common form of dementia. The hallmark pathologies of AD are extracellular aggregates of amyloid-beta, intracellular aggregates of microtubule associated protein tau and increased neuroinflammation. Current therapeutics offer only symptomatic relief and clinical trials investigating therapeutic benefits of non-steroidal anti-inflammatory drugs have yielded no positive results. Therefore, recent work has focused on immunomodulators, such as CD200 and fractalkine, as potential therapeutic targets for AD. Fractalkine (CX3CL1; FKN) is expressed as a transmembrane protein with an N-terminal chemokine domain followed by a long, mucin-like stalk. FKN can signal as a membrane-bound protein or, upon cleavage, as a soluble ligand (sFKN). Upon binding its receptor, FKN reduces expression of pro-inflammatory genes in activated microglia. Disrupting FKN signaling has been shown to exacerbate neurodegeneration in a number or neurodegenerative diseases. Relevant to this study, there have been conflicting reports on how FKN signaling affects AD pathology and whether a soluble FKN is beneficial or not. Here, we examine the ability of soluble FKN over expression to impact tauopathy and the resulting cognitive deficits in the rTg4510 mouse model of tauopathy, focusing on cognitive improvement after the onset of tau deposition. Furthermore, we explore the functional activity of proteolytic fragments of FKN on activated microglia in vitro to rectify the contradictory findings in the literature. We observed that sFKN over expression can significantly reduce both soluble and insoluble phospho-tau in both a preventative and an early interventional study design. However, in animals with significant pathology and neurodegeneration we did not observe an impact of sFKN over expression on tau pathology. Interestingly, in these late stage animals we did observe an improvement in spatial learning and memory as well as a reduction in hyperactivity. This suggests that earlier intervention would likely be most beneficial in reducing tau pathology but in late stage AD FKN signaling can still have benefits on cognition, likely due to reductions in the inflammatory milieu. Current publications suggest that different proteolytic fragments of FKN may have different functional signaling. Here we demonstrate that the this may be due to differences in receptor binding. sFKN (which includes the mucin-like stalk) exhibited a lower EC50 than the ckFKN (soluble chemokine domain), which leads to reduced functional efficacy of ckFKN at low concentrations. More interestingly, we also observed that high concentrations of FKN, regardless of cleavage variant, is ineffective at reducing pro-inflammatory activation of microglial and may in fact elicit a proinflammatory response. We hypothesize that FKN may signal through an alternative receptor at high concentrations, suggesting an as yet unidentified signaling pathway for FKN. Furthermore, we show that the ckFKN does not rescue pathology in the rTg4510 mouse, as sFKN does. These data may clarify conflicts in the literature and demonstrate that care must be taken with respect to in vitro and in vivo studies using FKN.
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47

Agha, Kassab Fadi. "Co-optimisation of the sizing and control of an urban microgrid." Electronic Thesis or Diss., Compiègne, 2024. http://www.theses.fr/2024COMP2822.

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La modernisation du réseau électrique (RE) par la mise en œuvre de micro-réseaux offre un potentiel significatif pour améliorer la résilience énergétique, la durabilité et l'efficacité. Cependant, cette transition implique de naviguer dans un ensemble complexe de défis techniques, économiques et environnementaux. Les micro-réseaux nécessitent une planification et une optimisation méticuleuses pour équilibrer la génération, le stockage et la consommation d'énergie tout en minimisant les coûts et les émissions de carbone. Atteindre cet équilibre nécessite des stratégies d'optimisation avancées capables de traiter les subtilités des composants du système et des dynamiques opérationnelles. L'objectif de cette recherche est d'améliorer les capacités de prise de décision des concepteurs de micro-réseaux en fournissant une approche globale pour la planification des micro-réseaux. L'étude offre une analyse approfondie du projet sur toute sa durée de vie, du point de vue technique, économique et environnemental. Implémenté en Python et résolu à l'aide de CPLEX, le processus d'optimisation vise à minimiser à la fois le « Levelized Cost of Energy » (LCOE) et le « Life Cycle Emission » (LCE). L'étude utilise des données économiques et environnementales réelles, en tenant compte de la croissance de la charge ainsi que des données réelles d'irradiation solaire, de température ambiante et de vitesse du vent. La charge pour le bâtiment universitaire est basée sur des données de l'Université de Technologie de Compiègne, France, avec la charge des véhicules électriques (VE) modélisée à l'aide d'une modélisation probabiliste. L'étude introduit une stratégie d'optimisation multi-objectifs conjointe utilisant le « Mixed Integer Linear Programming » (MILP) pour garantir des solutions globalement optimales, facilitant ainsi des choix de conception plus informés et efficaces. Ces choix impliquent l'évaluation de diverses solutions proposées pour équilibrer les coûts et les émissions de carbone tout en abordant les complexités et les contraintes techniques du problème de gestion de l'énergie. Un aspect novateur de ce travail est l'intégration de la gestion d'énergie (GE) et du dimensionnement des composants dans un problème d'optimisation unifié, visant un écart d'optimalité de 0 % avec un temps de calcul réduit par rapport à la littérature existante. La méthode proposée évalue les compromis inhérents entre diverses solutions, identifiant le front de Pareto et permettant un équilibre optimal entre les objectifs économiques et environnementaux. Les résultats indiquent une réduction significative du LCOE et du LCE dans le GCMG par rapport à l'IMG. L'étude révèle que la capacité du système de stockage d'énergie par batterie (BESS) augmente à mesure que le LCE diminue, et que le nombre de systèmes photovoltaïques est plus élevé lorsque le LCOE est plus bas pour les deux modes de fonctionnement. Cela se produit parce que le BESS a un LCE légèrement inférieur à celui du PV, et que le LCOE du PV est également inférieur à celui du BESS. De plus, à mesure que la limite du RE augmente, les fronts de Pareto deviennent plus bas et plus raides. En outre, le même algorithme MILP est appliqué pour optimiser les micro-réseaux d'un campus universitaire tertiaire dans diverses villes. L'étude intègre également des éoliennes (WT) et des charges de VE dans le micro-réseau. L'étude fournit une analyse comparative de trois scénarios (PV/BESS, WT/BESS et PV/WT/BESS) dans différentes villes, évalue les impacts des fluctuations saisonnières sur le LCOE et le LCE, et évalue comment les technologies des composants des micro-réseaux influencent les résultats du LCOE et du LCE. Les résultats indiquent que les scénarios incluant PV/WT/BESS produisent les valeurs de LCOE et de LCE les plus basses, tandis que le scénario WT/BESS aboutit aux valeurs de LCOE et de LCE les plus élevées<br>The modernization of the electricity grid (EG) through the implementation of microgrids offers significant potential for enhancing energy resilience, sustainability, and efficiency. However, this transition involves navigating a complex web of technical, economic, and environmental challenges. Microgrids require meticulous planning and optimization to balance energygeneration, storage, and consumption while minimizing costs and carbon emissions. Achievingthis balance calls for advanced optimization strategies, which are capable of addressing theintricacies of system components and operational dynamics. The objective of this research is to enhance the decision-making capabilities of microgrid designers by providing a comprehensive approach for microgrid planning. The study offers an in-depth analysis of the project’s lifetime from technical, economic, and environmental perspectives. Implemented in Python and solved using CPLEX, the optimization process aims to minimize both the levelized cost of energy (LCOE) and the levelized cost of emissions (LCE). The study utilizes real economic and environmental data considering load growth as well as actual solar irradiation, ambient temperature, and wind speed data. The load for the university building is based on data from the Université de Technologie de Compiègne, France with the electric vehicle (EV) load modeled using probabilistic modeling. The study introduces a joint multi-objective optimization strategy usingMixed-Integer Linear Programming (MILP) to ensure globally optimal solutions, thereby that facilitates obtaining more informed and effective design choices. These choices involve evaluating various proposed solutions to balance cost and carbon emissions while addressing the complexities and technical constraints of the energy management (EM) problem. A novel aspect of this work is the integration of EM and component sizing into a unified optimization problem, aiming for an optimality gap of 0% with reduced computation time compared to existing literature. The proposed method evaluates the inherent trade-offs among various solutions by identifying the Pareto front and allowing for an optimal balance between economic and environmental objectives. The results indicate a significant reduction in LCOE and LCE in the GCMG compared to the IMG. The study reveals that Battery Energy Storage System (BESS) capacity increases as the LCE decreases, and the number of Photovoltaic (PV) systems is higher when the LCOE is lower for both operation modes. This occurs because the BESS has a slightly lower LCE compared to PV, and the LCOE of PV is also lower than that of BESS. Furthermore, as the limit of the EG increases, the Pareto fronts become lower and steeper. Additionally, the same MILP algorithm is applied to optimize microgrids from a tertiary university campus across various cities. The study further integrates wind turbines (WT) and EV loads into the microgrid. The study provides a comparative analysis of three scenarios (PV/BESS, WT/BESS, and PV/WT/BESS) across different cities for evaluating the impacts of seasonal fluctuations on LCOE and LCE, and for assessing how microgrid component technologies influence LCOE and LCE outcomes. The results indicate that scenarios including PV/WT/BESS yield the lowest LCOE and LCE values, while the WT/BESS scenario results in the highest LCOE and LCE. It is also observed that the order of cities based on average solar irradiation or wind speed does not necessarily correspond to the order of LCOE and LCE. Monthly and daily fluctuations in solar irradiation and wind speed significantly impact these results. Regarding the technologies, locally produced PV panels contribute positively to the overall LCE of the microgrid, with PV panels incorporating phase changing material showing higher LCE. The research also compares two distinct algorithms
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48

Hutchinson, Jessika Marie. "Elimination of microglia from the spinal cord: A model to examine plasticity following peripheral axon injury." Miami University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=miami1533205031089256.

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49

Bai, Wenshuai. "DC Microgrid optimized energy management and real-time control of power systems for grid-connected and off-grid operating modes." Thesis, Compiègne, 2021. http://www.theses.fr/2021COMP2586.

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Le travail de recherche de cette thèse se concentre sur l’élaboration de deux modes de fonctionnement du microréseau à savoir : mode connecté au réseau, mode hors réseau comprenant les modes îloté et isolé. Le problème de la défaillance du réseau en mode connecté au réseau et la faible fiabilité de l'alimentation électrique en mode hors réseau doivent être résolues. Ainsi, le but de cette thèse est de proposer un microréseau DC combinant à la fois les avantages du mode connecté au réseau et ceux du mode isolé. On obtient ainsi un microréseau DC qu’on peut qualifier de complet. Le microréseau DC complet contient les sources d'énergie renouvelables, le stockage et le réseau public, et les sources de secours sont utilisées pour réduire le délestage. Dans ce microréseau DC, un système de supervision est proposé dans le but de gérer le flux des puissances. La gestion de la puissance en temps réel dans la couche opérationnelle du système de supervision permet de maintenir l'équilibre de puissance. Dans la couche d'optimisation du système de supervision, l'optimisation journalière est proposée afin de minimiser le coût d'exploitation global. Les résultats de la simulation montrent que le microréseau DC complet peut minimiser les coûts d'exploitation. Ensuite, le système de supervision prend en compte l'efficacité dynamique du convertisseur pour résoudre le problème lié à la qualité de la puissance du microréseau qui peut être dégradée à cause de la tension instable du bus DC. Les résultats de la simulation montrent que la prise en compte de l'efficacité dynamique du convertisseur dans la couche opérationnelle du système de supervision permet de réduire les fluctuations de la tension du bus DC. En ce qui concerne l'importance de la prédiction PV pour l'optimisation de la veille, deux modèles de prédiction sont étudiés et comparés pour donner une puissance de prédiction PV précise. Les résultats montrent que les deux modèles ont presque les mêmes résultats<br>This thesis focus on the research of the DC microgrid following two operation models: grid-connected mode, and off-grid mode including the islanded and isolated modes. The aim of this thesis is to propose a DC microgrid combining the advantages of the grid-connected or the off-grid mode, which named full DC microgrid. ln the full DC microgrid, the renewable energy sources, storage, and public grid are included, and the back-up sources also applied to reduce the load shedding. ln the full DC microgrid, a supervisory system is proposed to manage the power. The real-time power management in the operational layer of the supervisory system can keep the power balance. ln the optimization layer of the supervisory system, the day-ahead optimization is proposed to achieve the global minimal operation cost. The simulation results show that the full DC microgrid combines both advantages of the grid-connected and the off-grid mode to minimize the operating cost. Then, the supervisory system considers the dynamic efficiency of the converter to solve the problem that the power quality of the microgrid is degraded due to the unstable DC bus voltage caused by the inaccurate power control. The simulation results show that considering the dynamic efficiency of the converter in the operational layer of the supervisory system, the fluctuation of the DC bus voltage can be reduced. Regarding the importance of the PV prediction for the day-ahead optimization, two prediction modes are studied and compared to give a robust PV prediction power. The results are that the two models almost have the same results
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50

Sherman, Genevieve Rose. "Sharing local energy infrastructure : organizational models for implementing microgrids and district energy systems in urban commercial districts." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/73823.

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Thesis (M.C.P.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 2012.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (p. 58-61).<br>There is a growing trend in cities toward establishing localized, shared energy infrastructure. As existing energy infrastructure ages and demand increases, cities face rising energy costs and security risks combined with mandates to decrease carbon emissions. Local energy infrastructure provides cities and neighborhoods with greater control over their energy production and consumption, including the ability to lower the cost of energy, move to low-carbon energy technologies, and improve energy reliability and security. This thesis seeks to understand how stakeholders in urban commercial districts are creating organizations to implement two types of shared local energy infrastructure: district energy and microgrids. Building district energy and microgrids is a complex undertaking, which is one reason that they proliferate in urban environments where that complexity is reduced, such as universities, hospitals, and military bases. These areas may have single property owners, single land-owners or preexisting energy infrastructure that simplifies regulatory, legal, and development complexities of building new energy systems. Commercial businesses districts are significantly more complicated; they have multiple properties that abut public right of ways and that are owned by multiple, unaffiliated customers of legacy energy utilities. Establishing such a system in a commercial district requires addressing local utility rights, public right-of-way and franchise issues, as well as creating a new organizational structure that allows for the involvement of multiple parties in developing the system. This thesis assesses the feasibility of two organizational models for implementing local energy infrastructure in commercial districts: a joint cooperative model and an independent provider model. In a joint cooperative, all properties in a district become customers of a jointly owned, operated, and managed energy system. With an independent provider, all district properties become customers of an independently owned and operated system. These models are evaluated through two cases in which they are currently being tested: a proposed district energy system in Portland, Oregon and a proposed microgrid in Stamford, Connecticut. Therein, barriers to implementation such as perception of risk and lack of familiarity with shared energy systems are also examined.<br>by Genevieve Rose Sherman.<br>M.C.P.
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