L'amélioration de l'efficacité énergétique est devenue aujourd'hui une nécessité dans tous les domaines techniques. La réduction de la consommation, et donc du bilan carbone, est placée parmi les priorités mondiales tel que le paquet énergie-climat 2020 de l'Union Européenne.Les systèmes ferroviaires font partie des plus grands consommateurs d'énergie. Des solutions électriques sont développées pour réduire les pertes dans ces systèmes, optimiser la consommation et donc réduire la facture énergétique globale. Étant donné la diversité de ces systèmes, deux catégories principales sont considérées. La première regroupe les lignes urbaines caractérisées par une électrification en mode DC et un trafic relativement dense. Dans ce cas, l'énergie de freinage brûlée dans les rhéostats des trains constitue une perte considérable. La solution proposée consiste à récupérer cette énergie à l'aide d'un DC micro-grid installé dans une station passager. Elle permettra une interaction avec son environnement non-ferroviaire comme par exemple réutiliser cette énergie pour charger des bus électriques hybrides stationnant à proximité. Ce micro-grid contient un premier convertisseur DC/DC qui récupère l’excès d'énergie de freinage d'un train et l'injecte dans un DC busbar. Un deuxième convertisseur DC/DC va ensuite la stocker dans un système de stockage hybride pour que le bus électrique puisse se charger une fois branché au DC busbar. Le micro-grid est relié au réseau par un onduleur réversible AC/DC de faible puissance. L'ensemble est géré localement par un système gestion de puissance. Une évaluation énergétique montre que cette solution est intéressante lorsqu’un investissement, station de charge, est nécessaire pour charger les bus. En plus, dans le cas du DC micro-grid, aucun contrat avec le fournisseur d’électricité n’est nécessaire. La stabilité du système est aussi étudiée et une commande de stabilisation, le backstepping, est appliquée. Ce nouveau concept d’une future station intelligente permettra au système ferroviaire de communiquer avec son environnement qui est en pleine évolution.La deuxième catégorie est constituée par les lignes régionales et les lignes à grandes vitesses fonctionnant en mode AC. Contrairement au cas précédent, l’excès d’énergie de freinage est renvoyé à travers les sous-stations d’alimentation. Par conséquence, une deuxième solution propose la réduction de la consommation totale par l’optimisation du profile de vitesse de chaque train et la synchronisation de la grille horaire. Ceci est réalisé à l’aide d’un algorithme d’évolution différentielle. Chaque profile de vitesse est découpé en zones auxquelles sont attribuées des paramètres de conduite. L'optimisation de ces derniers permet de générer un nouveau profile de conduite optimal. Les résultats montrent la possibilité de faire des économies d’énergie tout en respectant la ponctualité des trains. / Increasing energy efficiency is nowadays a requirement in all technical fields. The reduction of global consumption, thus carbon footprint, has become the world's priority, as for example, the climate and energy package of the European Union.Railways' share of energy consumption is one of the highest. Electrical solutions are developed in order to reduce these systems' losses, optimize their consumption and reduce global energy bill. Given their diversity, two main categories are considered in this study. The first one consists of urban lines that are characterized by a DC electrification and a relatively dense traffic. In this case, braking energy burned in trains' rheostats represents the main share of losses. The proposed solution is to recuperate this energy using a DC micro-grid implemented in a passengers' station. It allows an interaction with the non-railway electrical environment, for example, re-using this energy in charging electric hybrid buses parked nearby. The excess of braking energy is recuperated using a DC/DC converter and injected into a DC busbar. A second DC/DC converter will store it in a hybrid storage system. It will then serve to charge the buses connected to the DC busbar. The micro-grid is also connected to the grid using a low power AC/DC converter. A power management system ensures optimizing power flow between different components. An energy evaluation showed that this solution is a good Investment especially because no contract is needed with the energy provider. The system's stability is studied and a stabilizing command, the backstepping, is applied. This new smart station allows railways to communicate, energetically, with its evolving environment.The second category is suburban and high speed lines that are AC electrified. Contrarily to the previous case, braking energy is reinjected to the upper grid through substations. Therefore, a second solution is to reduce global energy consumption by optimizing trains' speed profiles and timetable's synchronization. It is done using a differential evolution algorithm. Each speed profile is divided into zones to which are associated driving parameters. The optimization of the latter allowed generating new optimal speed profiles and a less-consuming timetable. Simulation results showed that it is possible to make important energy savings while respecting train's punctuality.

Today, there is a growing number of buildings in a neighborhood and business parks that are utilizing renewable energy generation, to reduce their electric bill and carbon footprint. The most current way of implementing a renewable energy generation is to use solar panels or a windmill to generate power; then use a charge controller connected to a battery bank to store power. Once stored, the user can then access a clean source of power from these batteries instead of the main power grid. This type of power structure is utilizing a single module system in respect of one building. As the industry of renewable power generation continues to increase, we start to see a new way of implementing the infrastructure of the power system. Instead of having just individual buildings generating power, storing power, using power, and selling power there is a fifth step that can be added, sharing power. The idea of multiple buildings connected to each other to share power has been named a microgrid by the power community. With this ability to share power in a microgrid system, a catastrophic event which cause shutdowns of power production can be better managed. This paper then discusses the data from simulations and a built physical model of a resilient microgrid utilizing these principles.

Rapid advances in the smart grid technology are making it possible to tackle a lot of problems in the aged power systems. High-speed data acquisition system, high-voltage power electronic equipment, advanced utility and customer interaction technologies, as well as distributed renewable generation are enabling the revolution in the electric power generation, delivery and distribution. Through the implementation of ubiquitous metering and communication networks, the customers would no longer be a passive receiver of the electrical energy, but instead, an active participant in the power system and electricity market. They can not only sell their own energy to the utility, but also take part in the emergency restoration in the power grid. Nonetheless, some technical barriers are encountered during this revolution, such as difficulties in integrating home automation, smart metering, customer interaction and power system operation into the whole system. This thesis proposes a customer involved load shedding algorithm for both the power system frequency control and the micro-grid islanding. This new algorithm possesses the features of centralized load control and distributed load control, which fully utilizes the advantages of hierarchical communication networks along with the home automation. The proposed algorithm considers the reliability of the power grid as well as the comfort of the electricity users. In the power distribution system, the high-level control centre is responsible for coordinating the local load controllers, whilst the local controller takes charge of frequency monitoring and decision making. In the micro-grid, a centralized control strategy is adopted to better serve the system with the wide set of information available at the micro-grid control centre. The simulation results have demonstrated the correctness and feasibility of the proposed algorithm. Finally, the hardware implementation further tests the validity of the wireless sensor networks serving as the system’s monitoring and communication technology. / Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2013-09-24 20:01:37.098

This dissertation is to design the operation strategy and protective scheme of micro-grid systems with dispersed generation (DG). The industrial power system with cogeneration units and the distribution feeder with wind power generators were selected as the study micro-grids for computer simulation. The mathematical models of cogeneration units and wind generators were included in the computer simulation by considering the operation control modes of DGs. The micro-grid systems and the nearby utility networks were constructed to solve the power flows of the micro-grids with various operation scenarios of power generation and load demand. For the severe external fault contingencies, the micro-grids have to be isolated from the utility power system in time to prevent the tripping of critical loads and DGs. By considering the fault ride through capability of cogenerators and voltage tolerance curves of critical loads, the critical tripping time (CTT) of tie circuit breaker of the micro-grids was determined according to the transient stability analysis. To maintain the stable operation of the micro-grids after tie line tripping, the load shedding scheme was designed by applying the under frequency and under voltage relays to disconnect the proper amount of non-critical loads according to the governor responses of cogeneration units. For the micro-grid of distribution feeder with wind power generator, the STATCOM was used to provide adaptive reactive power compensation for the mitigation of voltage fluctuation due to the variation of wind speed and feeder loading. The STATCOM can also be applied for the support of terminal voltage of wind generator (WG) to enhance the transient response of the micro-grid. The CTT of tie circuit breaker was determined by considering the low voltage ride through (LVRT) capability and the critical fault cleaning time of WG. To achieve more effective islanding operation of the micro-grids, the artificial neural network (ANN) was applied to determine the proper timing for tie line tripping and the proper amount of load shedding by using the wind speed, feeder loading and the voltage of micro-grid system as the input of ANN. To verify the effectiveness of the proposed tie line tripping and load shedding scheme, different fault contingencies of the external utility network have been simulated by using the computer program for the transient stability analysis. It is found that the critical and voltage sensitive loads of the micro-grid can be maintained when the tie circuit breaker is activated to isolate the external fault in time and followed by the execution of load shedding scheme.

This research focuses on empirical observations of horizontal series arc faults. These faults differ from ground faults, for series faults encompass the electromagnetic transient effects of arc formations in series with sustained current flow when there is a break in the circuit. This may happen intentionally (as in a breaker) or unintentionally (as in a loose, damaged, or severed cable). This paper studies some of those transient effects during arc ignition, propagation, and cessation. Emphasis is on dc systems, for series faults present some of the more challenging safety concerns relating to widespread dc micro-grid acceptance and proliferation. However, arc behavior is also compared to that of ac systems under “quasi-equivalent”, passive circuit parameters. Variables of study primarily include arc voltage, current, and their relationship to electrode spacing under dynamic conditions. Results indicate that interruptions in dc current, while appearing more chaotic from a localized standpoint, do not produce the fast-acting transients associated with ac disturbances. Additionally, if dc arcs propagate over a slowly increasing distance of separation, they can be modeled as quasi-static in nature. An equation model is developed and curve-fitting parameters match well with historically tabulated constants. / text

This dissertation studies hybrid dc-dc power conversion systems based on multiple-input converters (MICs), or more generally, multiport converters. MICs allow for the integration of multiple distributed generation sources and loads. Thanks to the modular design, an MIC yields a scalable system with independent control in all sources. Additional characteristics of MICs include the improved reliability and reduced cost. This dissertation mainly studies three issues of MICs: efficiency improvement, modeling, and control. First, this work develops a cost-effective design of a highly-efficient non-isolated MIC without additional components. Time-multiplexing (TM) MICs, which are driven by a time-multiplexing switching control scheme, contain forward-conducting-bidirectional-blocking (FCBB) switches. TM-MICs are considered to be subject to low efficiency because of high power loss introduced by FCBB switches. In order to reduce the power loss in FCBB switches, this work adopts a modified realization of the FCBB switch and proposes a novel switching control strategy. The design and experimental verifications are motivated through a multiple-input (MI) SEPIC converter. Through the design modifications, the switching transients are improved (comparing to the switching transients in a conventional MI-SEPIC) and the power loss is significantly reduced. Moreover, this design maintains a low parts-count because of the absence of additional components. Experimental results show that for output power ranging from 1 W to 220 W, the modified MIC presents high efficiency (96 % optimally). The design can be readily extended to a general n-input SEPIC. The same modifications can be applied to an MI-Ćuk converter. Second, this dissertation examines the modeling of TM-MICs. In the dynamic equations of a TM-MIC, a state variable from one input leg is possible to be affected by state variables and switching functions associated with other input legs. In this way, inputs are coupled both topologically and in terms of control actions through switching functions. Coupling among the state variable and the time-multiplexing switching functions complicate TM-MICs’ behavior. Consequently, substantial modeling errors may occur when a classical averaging approach is used to model an MIC even with moderately high switching frequencies or small ripples. The errors may increase with incremental number of input legs. In addition to demonstrating the special features on MIC modeling, this dissertation uses the generalized averaging approach to generate a more accurate model, which is also used to derive a small-signal model. The proposed model is an important tool that yields better results when analyzing power budgeting, performing large-signal simulations, and designing controllers for TM-MICs via a more precise representation than classical averaging methods. Analyses are supported by simulations and experimental results. Third, this dissertation studies application of a decentralized controller on an MI-SEPIC. For an MIC, a multiple-input-multiple-output (MIMO) state-space representation can be derived by an averaging method. Based on the averaged MIMO model, an MIMO small-signal model can be generated. Both conventional method and modern multivariable frequency analysis are applied to the small-signal model of an MI-SEPIC to evaluate open-loop and closed-loop characteristics. In addition to verifying the nominal stability and nominal performance, this work evaluates robust stability and robust performance with the structured singular value. The robust performance test shows that a compromised performance may be expected under the decentralized control. Simulations and experimental results verify the theoretical analysis on stability and demonstrate that the decentralized PI controller could be effective to regulate the output of an MIC under uncertainties. Finally, this work studies the control of the MIMO dc-dc converter serving as an active distribution node in an intelligent dc distribution grid. The unified model of a MIMO converter is derived, enabling a systematical analysis and control design that allows this converter to control power flow in all its ports and to act as a power buffer that compensates for mismatches between power generation and consumption. Based on the derived high-order multivariable model, a robust controller is designed with disturbance-attenuation and pole-placement constraints via the linear matrix inequality (LMI) synthesis. The closed-loop robust stability and robust performance are tested through the structured singular value synthesis. Again, the desirable stability and performance are verified by simulations and experimental results. / text

Depuis plusieurs années, le secteur de l’énergie subit des changements importants. La prise de conscience du réchauffement climatique, la volonté d’introduire un mix énergétique permettant de réduire les émissions de gaz à effet de serre, mais aussi la raréfaction des sources d’énergies fossiles, tendent à favoriser la production d’électricité à partir d’énergies renouvelables. Les « microgrids » ou micro­réseaux électriques sont une de ces opportunités de nouveaux marchés, sur lequel souhaite se positionner fortement Schneider Electric.Les microgrids sont des versions à échelles réduites d’un réseau national, comportant des objectifs particuliers comme la sécurisation de l’énergie, la baisse d’émissions de gaz à effet de serre, etc. Ils sont composés de diverses sources de puissance : renouvelable (PV ; éolien, etc.), générateurs diesel, mais aussi de stockage et de consommateurs. Ils peuvent être connectés à un réseau principale, ou îlotés. Les microgrids îlotés étant intrinsèquement composés de producteurs à base d’énergie renouvelable et donc de convertisseurs statiques, l’inertie naturelle du réseau est très faible, comparée à celle d’un réseau classique composé de machine tournante. Dans ce type de configuration, un appel de charge, une baisse soudaine de production due à l’intermittence de certaines énergies, peut déstabiliser le réseau et créer des réactions en chaîne aboutissant à une perte totale du réseau.Parmi les marchés visés des microgrid, celui des îles, dont le réseau électrique est majoritairement assuré par des groupes électrogènes, présente l’objectif attirant d’améliorer une base existante en ajoutant des sources renouvelables à la production. Ces réseaux font face à de fortes contraintes de communication qui peut être difficile à établir, voir non existante. Ainsi, les commandes conventionnelles d’un microgrid ne permettent pas de répondre à la problématique présentée.Les travaux se résument en quatre étapes principales, dans un premier temps, différents modèles de simulations des sous-systèmes seront définis pour répondre à la problématique.Ces modèles serviront ensuite à la définition des lois de contrôle-commande d’un microgrid décentralisé à communication limité, et permettront, entre autres, de comparer les performances d’un tel contrôle avec un contrôle centralisé classique.La troisième étape de la thèse présentera la certification probabiliste des algorithmes décentralisés, afin d’assurer les performances souhaitées.Enfin, les travaux se termineront par des résultats de simulation et une phase d’expérimentation réelle, avec la mise en place d’un microgrid d’une puissance totale de 100kW, pour valider le fonctionnement des algorithmes. / Since many years, the energy sector is undergoing significant changes. Awareness of global warming, the objective to use reduce greenhouse gas but also the scarcity of fossil energy, encourage the world to promote the use of more and more renewable energies. Electric microgrid are one of the opportunities new market on which Schneider Electric wants to launch.Microgrid are a scaled-down version of a national grid with specific objectives such as energy security, lower greenhouse gas emissions and so on. They are composed of several renewable sources (photovoltaic, wind for example), generators set, but also storage and consumers. They can be connected to a main grid or islanded. Since islanded microgrid are intrinsically composed of renewable producers with static converters, the natural grid inertia is particularly low compared to that of a classic grid with rotating machine. With this consideration, a load impact or a sudden drop of production due to renewable intermittency can destabilize the network and create chain reactions leading to a total grid blackout.Among the microgrids target markets, island whose electricity production is mostly provided by generators set presents the objective of improving an existing grid by adding renewable sources to production. These grid face strong communication constraints which can be difficult to establish, unreliable or non-existent. Thus, conventional microgrid commands do not allow to answer the presented problem.Objective of this thesis is to design the control algorithms of islanded microgrid without communication to ensure both frequency stability and to maximize renewable energy use.The presented work can be summarized in four main stages. First, several simulation models of microgrid subsystem will be defined for islanded microgrid analysis.These models will then be used to define control laws of a decentralized microgrid without communication. They will be used, inter alia, to compare performances of this decentralized control with a conventional centralized control.The third stage of the thesis will present the probabilistic certification of the decentralized algorithms in order to guarantee the desired performance.Finally, the work will end with simulation results and a real experimentation phase with the test on a 100 kVA microgrid to validate operation of algorithms.

Magíster en Ciencias de la Ingeniería, Mención Eléctrica / Las micro redes (MR o μG) se constituyen como una solución para la electrificación mediante el aprovechamiento de los recursos energéticos renovables locales, tanto en zonas remotas como en sistemas interconectados. Sin embargo, en zonas aisladas el uso de combustibles fósil para el transporte local prevalece como un desafío a su suministro energético. Ante esta problemática, los vehículos eléctricos (VE) se perfilan como una solución en la medida que tengan la capacidad de operar coordinadamente con una MR existente en la localidad. En esta tesis se diseña, construye y valida en laboratorio un conversor de potencia que permite el intercambio de energía entre una fuente DC y una máquina de inducción trifásica o una MR aislada, con el objetivo de materializar el concepto de V2μG (del inglés Vehicle to Micro-Grid). Se propone la utilización de un inversor trifásico, tetrapolar y multifuncional, cuyo sistema eléctrico permite dos modos de operación: el modo VE, diseñado para manipular el torque del motor de inducción trifásico del vehículo, basado en la estrategia IFOC (del inglés Indirect Field Oriented Control); y el modo V2μG, que mediante estrategias de control basadas en Acondicionadores de Potencia tipo Filtro Activo permite su integración con la MR a través de los sub-modos IDLE, COMPENSACIÓN DE COMPONENTES DE SECUENCIA CERO (CCS0), COMPENSACIÓN DE COMPONENTES DE SECUENCIA NEGATIVA (CCS-), SUAVIZADOR P-Q (SPQ) y CONTROL DE TENSIÓN BUS DC (CTBDC). Los resultados experimentales de la operación en modo VE muestran que la estrategia IFOC implementada en el conversor funciona correctamente siempre que la medición de velocidad del rotor de la máquina sea suficientemente precisa. En este caso, se observa que la respuesta del sistema ante cambios en la referencia de tipo escalón es menor a 27[ms]. Por otro lado, en el modo V2μG, se comprueba que en el sub-modo IDLE el conversor no inyecta ni absorbe potencia de la red. Se verifica que los otros sub-modos operan correctamente y de forma independiente. Sin embargo, se obtienen mejores resultados al combinar los sub-modos CCS0, CCS- Y CTBDC, logrando reducir el THD y desbalance de corriente aguas arriba al punto de conexión desde 12,5[%] a 4[%] y de 100[%] a menos del 2[%] respectivamente. Al combinar los sub-modos CCS0, CCS-, CTBDC y SPQ se logra suavizar los escalones de potencia activa y reactiva producto de la dinámica del sistema aguas arriba del punto de conexión. Para futuros trabajos se propone implementar una estrategia de carga de baterías, mejorar los controladores de corriente para el modo V2μG, integrar la operación en isla para cargas monofásicas y trifásicas e integrar funciones de control remoto para su operación en redes inteligentes. Finalmente, se plantea agregar la funcionalidad de dar soporte ante fallas en la red.

Government of Sri Lanka has policy target to achieve 100% electrification by end of year 2012. Grid-based electrification is possible up to maximum 95% of the population in Sri Lanka. Balance 5% of the electrification has to be mainly depending on off-grid technologies such as solar PV, wind, biomass and micro hydro.   Use of renewable based off-grid technologies is limited by the seasonal variation of the resource. This barrier could be overcome by coupling renewable based power generation technologies with a diesel generation thereby forming a hybrid power system. Given the comparatively higher investment cost, a hybrid power plant needs to be carefully designed and optimized to generate electricity at competitive prices.   There are some Isolated Islands located in the Jaffna Peninsula (Northern part of Sri Lanka) called Eluvaithivu, Analaithivu, Nainathivu and Delft Islands. These islands are far away from mainland. At present diesel generators are supplying electricity to these islands for limited hours. Electrification rate of these islands are very low due to the Grid limitations. Also cost of electricity generation is very high due to the high diesel price.   The main objective of the present study is “Selection of optimized mix of renewable based power generation technologies to form a mini-grid and to supply reliable, cost effective electricity supply to the people living in Eluvaithivu Island’ and thereby support the 100% electrification target by Govt. of Sri Lanka in 2012.   Data collection, survey has been conducted in the Eluvaithivu Island to find out the status of present system, priority needs, resource data and load data to propose suitable power system for this Island. An extensive analyse was conducted using HOMER software model and the result is presented in the report. Optimum design emerges as a wind-diesel hybrid power system having wind turbines generator, diesel generators, battery bank, converter and a hybrid controller.   The result revealed that the economic viability of the project, in the form of a community owned wind-diesel hybrid power system operated on cost-recovery basis is not feasible. But it is an attractive option for CEB to reduce its long term losses on diesel fuel. In other words, if CEB implement this project, it would be an ideal win-win situation where both the CEB and the island community are benefited.

Samhällets beroende av fossila bränslen leder till en varmare atmosfär och högre havsnivåer. För att bromsa utvecklingen måste utsläppen minska. En lösning är att implementera förnybara elproduktionsanläggningar och energilagring i större utsträckning. Då Sveriges vattenkraftsutbyggnad har stannat av de senaste 30 åren behövs en implementering av andra förnybara metoder, i kombination med den redan utbyggda vattenkraften, för att förse framtidens elbehov. För arbetet ligger fyra olika orter med redan installerade vattenkraftverk i fokus, nämligen Fredriksberg, Hällefors, Grythyttan och Sävenfors. Syftet med arbetet är att se hur man kan integrera solcellsanläggningar med och utan batterienergilagring i redan installerade vattenkraftsystem för energiproduktion i mindre lokala elnät. Målet med arbetet är indelat i två olika delmål. Det första målet är att få fram hur stora solcellsanläggningar som är implementerbara i mindre orter utifrån ett ekonomiskt perspektiv, det vill säga hur stor kapacitet som är möjligt att installera samtidigt som anläggningen är ekonomiskt lönsam. Det andra delmålet är att få fram hur stor del av orternas egna elbehov som kan täckas med vattenkraft, solceller och med eller utan batterilagring. En modell för systemet byggdes i Simulink, där vattenkraften antogs producera kontinuerligt över året vid vissa tider på dygnet. En känslighetsanalys gjordes på solcellsanläggningarnas ekonomiska lönsamhet vid olika framtidsscenarier gällande elprisutveckling i Sverige fram till år 2050. Resultat från simuleringar visar på att orterna får olika hög grad ekonomisk lönsamhet vid olika mängd installerad kapacitet solceller. Generellt ger ett högre elbehov och ett lägre förhållande mellan producerad el från vattenkraft och elbehov ekonomisk möjlighet att installera större solcellsanläggningar. Gällande de olika framtidsscenarierna finns det vissa scenarier som kan förlänga solcellsanläggningarnas återbetalningstid. Ett scenario, med stor implementering av småskalig förnybar energi i Sverige, medför att mindre kapacitet solceller bör installeras för att garantera ekonomisk säkerhet för investeringen. Batterilagring bidrar till ett ökat försett behov då det finns ett överskott på producerad el från solcellerna. Andelen egenförsett behov ökar dock mer på orter där vattenkraften är mindre dominerande. Det kan bero på att det finns fler tillfällen då det kan förse ett elbehov på orten, vilket vattenkraften annars tagit över i andra orter. En viktig grundpelare till att batterilagringen inte resulterar i en ekonomisk förlust är multifunktionen att förse eget behov och vara kopplad till en stödtjänst. Stödtjänsten är en uppreglering av nätets frekvensvariation vilket behöver prioriteras över stora delar av dygnet. Över de tre olika orterna resulterade förhållandet installerad MWp solceller genom MWh batterier på cirka 3. / Society's dependency on fossil fuels leads to a warmer atmosphere and rising sea levels.  Emission levels need to be reduced to slow down this development. One solution is to implement renewable energy and renewable energy storage systems on a wider scale. Sweden’s expansion of hydro power has come to a stop 30 years ago, which leads the focus to other methods of renewable energy generation in combination with the already built hydro power plants for future energy supply. This work focuses on already built-in hydro power plants in smaller communities as Fredriksberg, Hällefors, Grythyttan and Sävenfors. The scope of this work is to investigate the possibilities of integrating photovoltaic systems, with and without battery energy storage, in operating hydro power plants in smaller local grids. The goal of this work is divided into two sub-goals. The first sub-goal is to find out what size of photovoltaic systems can be implemented in smaller communities from an economic perspective, that is, how much capacity is possible to install at the same time as the plant is economically profitable. The other sub-goal is to find out how much of the communities’ own electrical demands are covered with hydro power, photovoltaics and with or without battery energy storage. A model was built in Simulink, where the hydro power was assumed to produce electricity continuously throughout the year at certain times of the day. A sensitivity analysis was performed on the profitability of the photovoltaic systems using different scenarios for the future electrical price in Sweden until the year of 2050. Results from the simulations show that different communities have different degrees of profitability for varying capacities of photovoltaics. A higher electricity demand and a lower ratio between produced electricity from hydro power and electricity demand provides financial opportunities to install larger capacities of photovoltaic systems. Regarding the future price scenarios, there are some scenarios that will prolong the photovoltaics payback-time. One scenario, with a great implementation of small-scale renewable systems, results in a recommendation to install lower capacities of photovoltaics to ensure financial security on the investment. Battery energy storage contributes to increased provided demands because of the surplus electricity produced from the photovoltaics. The proportion of provided demands is increasing more in communities where hydro power is less available. It can be a result of opportunities where the hydro usually is providing needs in those timeframes in other communities. An important pillar in the positive result of the economy of battery energy storage is its multifunction to supply demands and provide a support service, where the service of regulating frequency on the main grid needs to be prioritized over large parts of the day. The ratio between installed MWp photovoltaics and MWh battery energy storage resulted in approximately three across three different communities.