Similar to numerous other nations, Thailand aims to achieve carbon neutrality by 2050 by reducing reliance on fossil fuels and increasing the amount of renewable energy sources in electricity generation. The objective of the Thai Provincial Electricity Authority (PEA) is to ensure electricity access for all Thai households and villages. The expansion of electricity production to small islands raises concerns about economic and environmental impact. Electricity accessibility on Thai islands is significantly limited due to difficulties of extending the electrical grid, as well as the comparatively higher costs associated with grid access in remote areas, in contrast to the mainland. One way to mitigate energy losses and emissions is by promoting decentralized electricity production and adopting renewable energy sources. Microgrids provide a solution that addresses these aspects, making them an attractive option to meet the growing demand of electricity sustainably in rural areas. This study examines the electricity situation in Thailand through a literature review of the current status of electricity and microgrid electrification. The case study then evaluates economic and environmental aspects of a microgrid project planned for Phaluai island, which has been chosen by the Ministry of Energy as a pilot project for the "Green Island" initiative, part of the "Reducing the Global Warming for King" campaign. The objective of the “Green Island” project is partly to promote clean energy on Phaluai. The study aims to optimize a microgrid design for Phaluai to compare with the proposed PEA project design, which includes a battery energy storage system, diesel generator, converter and solar power plant. However, the optimization also includes the potential use of wind turbine generators and biogas as additional fuel in the generator. To determine the optimal design, economical methods such as Net Present Cost (NPC) and Levelized Cost of Energy (LCOE), as well as environmental methods such as renewable fraction and CO2 emissions, are employed. These calculations are carried out using the HOMER Pro software. The results reveal that the optimal dimension for the microgrid includes 1,250 kW of solar PV, 300 kW generator, 500 kW converter and 1,925 kW of batteries, resulting in an NPC of 5.75 million USD and LCOE of 0.393 USD/kWh. Moreover, the microgrid demonstrates a renewable fraction of 89.6 % and CO2 emissions of 121,000 kg/year. Compared to the PEA proposed design, the obtained results have lower CO2 emissions and LCOE while higher NPC and renewable fraction. The optimized system also has more installed kW PV and battery than the PEA project plan. In the sensitivity analysis, the following variables are evaluated: electric load, diesel fuel price, discount rate, inflation rate, wind turbine price and biomass resources. All variables except wind turbine price affect the result in the form of changes in NPC, LCOE, CO2 emissions and renewable fraction. For some variable changes, e.g electric load, the optimal size of PV and batteries are also affected. In those cases, the optimal size for PV is instead 1,000 kW and for batteries, either 1,650 or 2,200 kW capacity. / Likt flera andra länder, strävar Thailand mot att nå koldioxidneutralitet till år 2050 genom att minska beroendet av fossila bränslen och öka mängden förnybara energikällor i elproduktionen. Samtidigt har Provincial Electricity Authority (PEA) målet att säkerställa tillgången till elektricitet för alla thailändska hushåll och byar. Utbyggnaden av elproduktion till små öar medför en osäkerhet kring ekonomisk och miljömässig påverkan. Tillgängligheten till elektricitet är på vissa thailändska öar avsevärt begränsad på grund av svårigheter kopplade till utbyggnaden av det nationella elnätet, såväl som de högre kostnaderna för utbyggnation av elnät i avlägsna områden, jämfört med fastlandet. Ett sätt att minska energiförluster och utsläpp är genom att främja decentraliserad elproduktion samt utnyttja förnybara energikällor. Microgrids är en lösning som tar hänsyn till dessa aspekter, vilket gör det till ett attraktivt alternativ för att, på ett hållbart sätt, möta en växande efterfrågan på el i mer avlägsna områden. Studien undersöker elsituationen i Thailand genom en litteraturstudie som redogör för den nuvarande statusen för elektricitet i landet samt microgrids. Fallstudien utvärderar ekonomiska och miljömässiga aspekter av implementering av en microgrid på ön Phaluai, som har valts ut av Ministry of Energy som pilotprojekt för initiativet "Green Island", en del av kampanjen "Reducing the Global Warming for King". Målet med "Green Island"- projektet är bland annat att främja grön energi på Phaluai. Studien syftar till att optimera en microgrid för Phaluai och jämföra med den av PEA föreslagna microgriddesignen, som inkluderar ett batterienergilagringssystem, dieselgenerator, växelriktare samt solcellspark. Optimeringen som genomförs inkluderar dock även möjlig användning av vindkraftsgeneratorer och biogas som ytterligare bränsle i generatorn. För att bestämma den optimala storleken används ekonomiska värden som Net Present Cost (NPC) och Levelized Cost of Energy (LCOE), samt miljömässiga värden som förnybar kvot och CO2-utsläpp. Beräkningar utförs med hjälp av programvaran HOMER Pro. Resultatet visar att den optimala dimensioneringen för microgriden inkluderar 1 250 kW solceller, 300 kW generator, 500 kW växelriktare och batterier på 1 925 kW, vilket resulterar i ett system med NPC på 5,75 miljoner USD och en LCOE på 0,393 USD/kWh. Dessutom har microgriden en förnybar kvot på 89,6 % och CO2-utsläpp på 121 000 kg/år. Jämfört med PEAs föreslagna design har det erhållna resultatet lägre CO2-utsläpp och LCOE samt högre NPC och förnybar kvot. Det optimerade systemet har även fler installerade kW solcell och batteri än PEAs projektplan. Det genomförs även en känslighetsanalys av den erhållna optimala dimensioneringen. I känslighetsanalysen utvärderas variablerna: elektrisk belastning, dieselpris, diskonteringsränta, inflationstakt, vinturbinspris och tillgång på biomassa. Alla variabler utom vindturbinspris påverkar resultatet i form av förändringar i NPC, LCOE, CO2-utsläpp och förnybar kvot. Vid vissa av dessa variabelförändringar, exempelvis elektrisk belastning, påverkas även den optimala storleken på PV och batterier. I de fallen är den optimala storleken för PV istället 1 000 kW och för batterierna antingen 1 650 eller 2 200 kW.

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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. / 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.

The Sustainable Development Goal n°7 is calling for a prompt response to guarantee affordable and clean energy for all. While the electrification rate is rapidly increasing around the world, much work still remains to achieve electricity access in remote areas or Non-Interconnected Zones, such as the numerous small islands that compose Indonesia. This thesis work sought to understand which standalone microgrid design would represent the most sustainable solution for a rural electrification challenge, where the final scope is to provide 24 h/d stable and reliable electricity connection to the local communities of Sulawesi, Indonesia. To achieve such a result, two diametrically opposed microgrid layouts are outlined in terms of renewables share: a Business As-Usual Scenario, in which the microgrid is powered by a standard diesel set, and an integrated renewable-based scenario, in which the microgrid envisions the implementation of biopower, PV system and Li-ion batteries as a storage option. A thorough comparison on a series of Key Parameter Indicators (KPIs), such as Carbon Footprint, Levelized Cost Of Electricity and job creation, led to the identification of the renewable-based scenario as the most sustainable option. This system layout resulted in a biomass powered electricity production covering 80% of the total electricity demand, with the remaining 20% supplied by solar power and storage means and a LCOE of 0.18 USD/kWh. At the price of a higher upfront cost than the one of BAU case, the renewable-based alternative entitles a higher profitability when compared to the business-asusual one, together with reduced carbon dioxide emissions and a higher number of jobs directly created. / Hållbarhetsmål nr 7 kräver ett snabbt svar för att garantera överkomlig och ren energi för alla. Medan elektrifieringsgraden snabbt ökar runt om i världen, återstår mycket arbete för att nå elåtkomst i avlägsna områden eller icke-sammankopplade zoner, såsom de många små öarna som utgör Indonesien. Detta avhandlingsarbete försökte förstå vilken fristående mikronätdesign som skulle representera den mest hållbara lösningen för en elektrifieringsutmaning på landsbygden, där det slutliga utrymmet är att tillhandahålla 24 timmars stabil och pålitlig elanslutning till lokalsamhället Sulawesi, Indonesien. För att uppnå ett sådant resultat beskrivs två diametralt motsatta mikronätlayouter när det gäller andelen förnybara energikällor: ett Business As-Usual-scenario, där mikronätet drivs av en standarddiesel och ett integrerat förnyelsebaserat scenario, där microgrid ser implementeringen av biokraft, solcellssystem och litiumjonbatterier som ett lagringsalternativ. En noggrann jämförelse av en serie nyckelparametrar (KPI), såsom koldioxidavtryck, nivåiserad elkostnad och skapande av jobb, ledde till att det förnyelsebaserade scenariot identifierades som det mest hållbara alternativet. Systemlayouten resulterade i en biomassadriven elproduktion som täckte 80% av det totala elbehovet, med de återstående 20%som levereras av solenergi och lagringsmedel och en LCOE på 0,18 USD / kWh. Till priset av en högre kostnad i förskott än i BAU-fallet ger det förnyelsebaserade alternativet högre lönsamhet jämfört med det som vanligt, tillsammans med minskade koldioxidutsläpp och ett högre antal direkt skapade jobb.

Cette thèse porte sur les problèmes de stabilité en fréquence et en tension des microréseaux isolés avec forte pénétration d'énergies renouvelables en utilisant des dispositifs de stockage d'énergie, et se divise en deux parties principales.Dans la première partie, nous proposons une conception systématique d'une structure de commande robuste multi-variable pour le réglage de fréquence dans un système de génération de puissance hybride diesel-photovoltaïque-supercondensateur fonctionnant en mode autonome. La structure de commande proposée repose sur une architecture à deux niveaux: les contrôleurs d'asservissement de courant basés sur commande PI classique sont placés sur le niveau de commande inférieur et reçoivent des références d'un niveau supérieur qui, lui, est basé sur commande H-infini. Une méthodologie compréhensive qui traduit les demandes d'ingénierie spécifiques de l'opération du microréseau dans le formalisme de commande H-infini est détaillée. Nous montrons également comment les spécifications de performance dynamiques en boucle fermée doivent à leur tour être prises en compte dans la configuration et le dimensionnement initiaux du microréseau, c'est-à-dire en choisissant de manière appropriée et en évaluant le système de stockage d'énergie. Ensuite, une analyse de performance robuste du contrôleur H-infini synthétisé en présence de diverses perturbations de charge, des variations de puissance active de la source photovoltaïque, et des incertitudes du modèle est effectuée afin de déterminer la plage de variation maximale des paramètres pour laquelle les performances de commande imposées sont respectées pour le point de fonctionnement considéré. Les simulations numériques réalisées avec MATLAB/Simulink montrent l'efficacité de la stratégie de commande robuste de fréquence proposée sur un microréseau d'ordre de quelques MVA. Un banc de test de prototypage rapide, qui est composé d'un système de stockage d'énergie réel à base de supercondensateurs et un réseau diesel-photovoltaïque-charge émulé, est développé afin de valider expérimentalement cette stratégie de commande.La deuxième partie de cette thèse se concentre sur le calcul d'un contrôleur de tension multi-variable basé sur commande H-infini afin de forcer robustement l'amplitude de tension du point de couplage commun à satisfaire des spécifications dynamiques. La même idée de la structure de commande à deux niveaux en cascade - où ce contrôleur est placé sur un niveau de commande supérieur et fournit les références de courant aux contrôleurs de courant placés sur un niveau inférieur - est également adoptée. Ensuite, la performance et la robustesse du contrôleur H-infini proposé en présence de diverses perturbations de puissance réactive de la charge et de la source photovoltaïque, ainsi que des incertitudes du modèle, sont étudiées en utilisant des simulations temporelles MATLAB/Simulink. / This thesis addresses the frequency and voltage stability issues of stand-alone microgrids with high penetration of renewable energy by making use of energy storage devices, and is divided into two main parts.In the first part, we propose a systematic design of a multi-variable robust control structure for frequency regulation in a diesel-photovoltaic-supercapacitor hybrid power generation system operating in stand-alone mode. The proposed control structure relies on a two-level architecture: classical PI-based current tracking controllers are placed on the low control level and receive references from an H-infinity-control-based upper level. A comprehensive methodology that casts the specific engineering demands of microgrid operation into H-infinity control formalism is detailed. It is also shown how closed-loop dynamic performance requirements must at their turn be taken into account in the initial microgrid setup and sizing, namely in appropriately choosing and rating the energy storage system. Then, a robust performance analysis of the synthesized H-infinity controller in the presence of various load disturbances, photovoltaic output active power variations, and model uncertainties is carried out in order to determine the maximum parameter variation range for which the imposed control performances are respected for the considered operating point. Numerical simulations performed with MATLAB/Simulink show the effectiveness of the proposed frequency robust control strategy on a MVA-rated microgrid. A rapid-prototyping test bench, which is composed of a real supercapacitor-based energy storage system and an emulated diesel-photovoltaic-load grid, is developed in order to experimentally validate this control strategy.The second part of this thesis focuses on computing an H-infinity-based multi-variable voltage controller in order to robustly force the voltage magnitude of the point of common coupling to satisfy dynamic specifications. The same idea of cascaded two-level control structure - where this controller is placed on an upper control level and provides the references to current controllers placed on a lower level - is aslo adopted. Then, the performance and robustness of the proposed H-infinity controller in the presence of various load and photovoltaic reactive power disturbances, as well as model uncertainties, are studied based on MATLAB/Simulink time-domain simulations.

This Master thesis investigates how Renewable Energy Microgrid Systems (REMS) can enhance resilience for a rural grid-connected community in El Salvador. The study examines the optimally resilient design of a grid-connected PV-Wind-Battery hybrid energy system. The optimally resilient system configuration was determined based on energy affordability, defined as minimum net present cost (NPC) and energy reliability, which was defined as a 1% maximum annual capacity shortage. The system modelling and optimisation was performed in the HOMER (Hybrid Optimisation of Multiple Energy Resources) software, where the system was optimised for different scenarios. The results of this study show that REMS can enhance resilience by lowering electricity costs for the community and thus increasing energy affordability. However, the REMS did not manage to make an equally substantial impact on energy reliability, due to the grid performance that proved to be high with few annual power outages. Besides the grid connection, the optimally resilient system was driven entirely by PV energy since it proved to be highly profitable. Wind power and battery storage were excluded from the optimally resilient system since they did not contribute to affordability and the capacity shortage limit was met already from the PV unit and the grid. Furthermore, the results show that self-sufficiency can be provided with REMS from the local energy resources, but that it is unrealistic with current costs due to the high battery prices. The study concludes that REMS should be considered as a legitimate resilience measure in rural El Salvador.

Expanding access to electricity is central to development in East Africa but massive increases in investment are required to achieve universal access. Private sector participation in electrification is essential to meeting electricity access targets. Policy makers have acknowledged that grid extension in many remote rural areas is not as cost effective as decentralized alternatives such as microgrids. Microgrid companies have been unable to scale beyond pilot projects due in part to challenges in raising capital for a business model that is perceived to be risky. This thesis aims to identify and quantify the primary sources of investment risk in microgrid utilities and study ways to mitigate these risks to make these businesses more viable. Two modeling tools have been developed to this end. The Stochastic Techno-Economic Microgrid Model (STEMM) models the technical and financial performance of microgrid utilities using uncertain and dynamic inputs to permit explicit modeling of financial risk. This model is applied in an investment risk assessment and case study in Rwanda. Key findings suggest that the most important drivers of risk are fuel prices, foreign exchange rates, demand for electricity, and price elasticity of demand for electricity. The relative importance of these factors is technology dependent with demand uncertainty figuring stronger for solar and high solar penetration hybrid systems and fuel prices driving risk in diesel power and low solar penetration hybrid systems. Considering uncertainty in system sizing presents a tradeoff whereby a decrease in expected equity return decreases downside risk. High solar penetration systems are also found to be more attractive to lenders. The second modeling tool leverages electricity consumption and demographic data from four microgrids in Tanzania to forecast demand for electricity in newly electrified communities. Using statistical learning techniques, improvements in prediction performance was achieved over the historical mean baseline. I have also identified important predictors in estimating electricity consumption of newly connected customers. These include tariff structures and prices, preconnection sources of electricity and lighting, levels of spending on electricity services and airtime, and pre-connection appliance ownership. Prior exposure to electricity, disposable income, and price are dominant factors in estimating demand.

Made available in DSpace on 2017-07-10T17:11:45Z (GMT). No. of bitstreams: 1 DAVID RODRIGO FRANCO LEON2.pdf: 2087252 bytes, checksum: a70bd4795d62e855f534a86b2beafa7b (MD5) Previous issue date: 2013-11-29 / The increasing use of renewable energy to produce electricity, including photovoltaic, is an alternative used to meet growing electricity demand. Particularly, has been discussed the possibility of inserting these sources associated to loads, which is related with the concept of micro grids. A simulation model that allows to determine the behavior of the PV system, connected to the micro grid in different weather conditions, is essential to validate and predict future problems that may exist. Thus, this paper proposes a simulation model of a photovoltaic system, which includes the representation of the inverter and a bidirectional converter with storage unit, allowing the insertion of photovoltaic in a micro grid in steady state under different conditions of solar irradiation. The results show the behavior of the micro grid to different environment conditions of irradiation, different values of loadsconnected to the node generation and behavior of bidirectional converter, as in the storage of electrical for the conditions simulated. The behavior of the PV system as a source of energy within a micro grid was analyzed by simulating different load values, irradiation and electrical characteristics of the micro grid. / As fontes renováveis de energia para produção de energia elétrica, entre elas a que utiliza a tecnologia fotovoltaica, são alternativas utilizadas para atender a crescente demanda de energia elétrica. Particularmente vem sendo discutida a possibilidade de inserção dessas fontes junto às cargas, ao qual está associado o conceito de microrredes. Um modelo de simulação que permita determinar o comportamento do sistema fotovoltaico ao ser ligado à microrrede, em distintas condições ambientas, é fundamental para validar e prever futuros problemas que possam existir. Desta forma, o presente trabalho propõe um modelo de simulação de um sistema fotovoltaico, que inclui a representação do inversor e de um conversor bidirecional com unidade de armazenamento, que permite inserir a energia fotovoltaica numa microrrede elétrica em regime estacionário em distintas condições de irradiação solar. Os resultados mostram o comportamento da microrrede para distintas condições ambientais de irradiação, diferentes valores de cargas ligadas ao nó de geração e o comportamento do conversor bidirecional, quanto ao armazenamento ou não de energia para as condições simuladas. O comportamento do sistema fotovoltaico, como fonte de energia dentro de uma microrrede, foi analisado simulando diferentes valores de carga, irradição e características elétricas da microrrede.

Avec le développement de la production décentralisée d'électricité à partir de sources renouvelables, il est fort probable que les micro-réseaux joueront un rôle central dans les réseaux du futur, non seulement pour réduire les émissions de gaz à effet de serre et maximiser l'utilisation d'énergie produite localement, mais également pour améliorer la résilience du système global. Du fait de l'intermittence et de l'incertitude sur la production renouvelable (par exemple, photovoltaïque ou éolien), des systèmes de stockage de l'énergie doivent être intégrés. Cependant, déterminer leur dimensionnement et comment les contrôler pose plusieurs défis, en particulier parce que le dimensionnement optimal dépend de la stratégie de gestion utilisée, ou encore lorsque différents types d'énergie sont utilisés. Cette thèse contribue à résoudre les problèmes de dimensionnement et de gestion de micro-réseaux électriques et multi-énergies (électricité, gaz, chaleur, froid et/ou hydrogène) intégrant du stockage. Tout d'abord, à l'aide des caractéristiques des différents composants, un modèle mathématique de micro-réseau est développé. Le problème de sa gestion est ensuite formulé comme un problème de programmation linéaire (MILP), utilisant une fonction objectif (minimiser le coût de fonctionnement) et différentes contraintes (puissance maximum, durée de démarrage/arrêt, limites d'état de charge, etc.). Ensuite, une structure permettant une co-optimisation est présentée pour résoudre le problème du dimensionnement à l'aide d'un algorithme génétique. Cette structure permet de explorer l'espace des valeurs de dimensionnement en fonction des résultats de la stratégie de gestion, ce qui permet de tendre vers le meilleur dimensionnement possible pour la stratégie sélectionnée. A l'aide de la méthode ci-dessus, quatre problèmes spécifiques sont étudiés. Le premier s'intéresse au dimensionnement d'un micro-réseau îloté entièrement électrique, combinant stockage par batteries et hydrogène-énergie pour du stockage à court et long terme, respectivement. Les résultats pour deux stratégies de gestion sont comparés : l'approche proposée (MILP) et une stratégie basée sur des règles. Une simulation à horizon glissant d'une heure sur un an est ensuite utilisée pour vérifier la validité du dimensionnement obtenu. Un second problème s'intéresse un à micro-réseau multi-énergies îloté avec différents types de charges. L'influence de trois facteurs sur les résultats du dimensionnement est en particulier étudiée : la stratégie de gestion, la précision des prévisions de consommation et de production renouvelable, ainsi que la dégradation des moyens de stockage. Une troisième partie de la thèse traite du dimensionnement d'un micro-réseau connecté aux réseaux de gaz, électricité et chaleur. La résilience du réseau est étudiée de façon à maximiser la résistance à une panne ou un défaut. La notion de centralité intermédiaire est utilisée pour déterminer le cas le plus défavorable pour une contingence et analyser son impact sur le dimensionnement. Deux systèmes de test de tailles différentes sont utilisés pour valider l'application de la méthode proposée et sa sensibilité à différents paramètres. / With the development of distributed, renewable energy sources, microgrids can be expected to play an important role in future power systems, not only to reduce emissions and maximize local energy use, but also to improve system resilience. Due to the intermittence and uncertainty of renewable sources (such as photovoltaics or wind turbines), energy storage systems should also be integrated. However, determining their size and how to operate them remains challenging, especially as the adopted control strategy impacts sizing results, and for systems considering multiple, interdependent forms of energy. This thesis therefore contributes to solving the sizing and operation problems of full-electric and multi-energy (electricity, gas, heat, cooling and/or hydrogen) microgrids integrating storage systems.First, based on the characteristics of different components, a mathematical model of a microgrid is built. Then, the operation problem is formulated as a mixed integer linear problem (MILP), based on an objective function (minimize the operation cost) and different constraints (maximum power, startup/shutdown times, state-of-charge limits, etc.). Next, a co-optimization structure is presented to solve the sizing problem using a genetic algorithm. This specific structure enables to search for sizing values based on the operation results, which enables determining the best sizing for the selected operation strategy.Using the above method, four specific problems are then studied. The first one focuses on sizing a full-electric islanded microgrid combining battery and hydrogen storage systems for short and long-term storage, respectively. Results for two types of operation strategies are compared: the MILP approach and a rule-based strategy. A one-hour one-year rolling horizon simulation is used to check the validity of the sizing results.Second, a multi-energy islanded microgrid with different types of loads is studied. Specifically, the influence of three factors on sizing results is analyzed: the operation strategy, the accuracy of load and renewable generation forecasts, and the degradation of energy storage systems.Third, the work focuses on a grid-connected microgrid attached to a gas, electricity and heat hybrid network. Specifically, the resilience of the network is considered in order to maximize resistance to contingency events. Betweenness centrality is used to find the worst case under contingency events and analyze their impact on sizing results. Two test systems of different sizes are used with the proposed method and a study of its sensitivity to various parameters is carried out.Fourth, a structure with multiple grid-connected multi-energy-supply microgrids is considered, and an algorithm for determining electricity prices is developed. This price is used for energy exchanges between microgrids and load service entities interacting with the utility. The proposed co-optimization method is deployed to search for the best price that maximizes benefits to all players. Simulations on a large system show that the obtained price returns better results than a basic time-of-use price and helps reduce the operation cost of the whole system. To reduce the computation time, a neural network is presented to estimate the operation of the whole system and enable obtaining results faster with a limited impact on performance. At last, a sizing algorithm for grid-connected multi-energy supply microgrids operating under different prices is presented.The obtained results on these different applications show the usefulness of the proposed method, which is a promising contribution toward the creation of advanced design tools for such microgrids.

Recently, the concept of Microgrids (MG) has been introduced in the distribution network. Microgrids are defined as small power systems that consist of various distributed micro generators that are capable of supplying a significant portion of the local demand. Microgrids can operate in grid-connected mode, in which they are connected to the upstream grid, or in isolated mode, where they are disconnected from the upstream grid and the local generators are the only source of power supply. In order to maximize the benefits of the resources available in a microgrid, an optimal scheduling of the power generation is required. Renewable resources have an intermittent nature that causes uncertainties in the system. These added uncertainties must be taken into consideration when solving the generation scheduling problem in order to obtain reliable solutions. This research studies the scheduling of power generation in a microgrid that has a group of dispatchable and non-dispatchable generators. The operation of a microgrid during grid-connected mode and isolated mode is analyzed under variable demand profiles. Two mixed integer linear programming (MILP) models for the day-ahead unit commitment problem in a microgrid are proposed. Each model corresponds to one mode of operation. Uncertainty handling techniques are integrated in both models. The models are solved using the General Algebraic Modeling System (GAMS). A number of study cases are examined to study the operation of the microgrid and to evaluate the effects of uncertainties and spinning reserve requirement on the microgrid’s expenses.