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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Marginaler för morgondagen : En kvantitativ analys av flexibiliteten hos aggregerade laddande elbilar / Margins for tomorrow : A quantitative analysis of the flexibility from aggregated electric vehicles

Karlén, Albin, Genas, Sebastian January 2021 (has links)
Elektrifieringen av bilflottan sker i rasande takt. Även andra samhällssektorers efterfrågan på el väntas öka drastiskt under kommande decennier, vilket i kombination med en växande andel intermittenta energikällor trappar upp påfrestningarna på elnätet och ställer krav på anpassningar. En föreslagen dellösning till kraftsystemets kommande utmaningar är att utnyttja efterfrågeflexibiliteten i laddande elbilar genom att en aggregator styr ett stort antal elbilsladdare och säljer den sammanlagda kapaciteten på till exempel Svenska kraftnäts stödtjänstmarknader.  För att avgöra hur mycket flexibilitet som elbilsladdning kan bidra med behöver aggregatorn upprätta prognoser över hur mycket effekt som mest sannolikt finns tillgänglig vid en viss tidpunkt – en punktprognos – men också en uppskattning av vilken effektnivå man kan vara nästan säker på att utfallet överstiger – en kvantilprognos. I den här studien har en undersökning gjorts av hur prognosfelet förändras om gruppen av aggregerade elbilsladdare ökas, och hur mycket en aggregator på så sätt kan sänka sina marginaler vid försäljning av efterfrågeflexibiliteten för att med säkerhet kunna uppfylla sitt bud. Det gjordes genom att kvantifiera flexibiliteten för 1 000 destinationsladdare belägna vid huvudsakligen arbetsplatser, och genom att skala upp och ner datamängden genom slumpmässiga urval. För dessa grupper gjordes sedan probabilistiska prognoser av flexibiliteten med en rullande medelvärdes- och en ARIMA-modell. Utifrån prognoserna simulerades slutligen potentiella intäkter om aggregatorn skulle använda den flexibla kapaciteten för uppreglering till stödtjänsten FCR-D upp, vilket är en frekvensreserv som aktiveras vid störningar av nätfrekvensen.  Resultaten visar att en tiodubbling av antalet aggregerade elbilsladdare mer än halverar det relativa prognosfelet. De båda prognosmodellerna visade sig ha jämförbar precision, vilket talar för att använda sig av den rullande medelvärdesmetoden på grund av dess lägre komplexitet. Den ökade säkerheten i prognosen resulterade dessutom i högre intäkter per laddare.  De genomsnittliga intäkterna av att leverera flexibilitet från 1 000 aggregerade elbilsladdare till FCR-D uppgick till 6 900 kr per månad, eller 0,8 kr per session – siffror som troligen hade varit högre utan coronapandemins ökade hemarbete. En 99-procentig konfidensgrad för kvantilprognosen resulterade i en säkerhetsmarginal med varierande storlek, som i genomsnitt var runt 90 procent för 100 laddpunkter, 60 procent för 1 000 laddpunkter samt 30 procent för 10 000 laddpunkter. Mest flexibilitet fanns tillgänglig under vardagsförmiddagar då ungefär 600 kW fanns tillgängligt som mest för 1 000 laddpunkter.  Att döma av tio års nätfrekvensdata är den sammanlagda sannolikheten för att över 50 procent aktivering av FCR-D-budet skulle sammanfalla med att utfallet för den tillgängliga kapaciteten är en-på-hundra-låg i princip obefintlig – en gång på drygt 511 år. Att aggregatorn lägger sina bud utifrån en 99-procentig konfidensgrad kan alltså anses säkert. / The electrification of the car fleet is taking place at a frenetic pace. Additionally, demand for electricity from other sectors of the Swedish society is expected to grow considerably in the coming decades, which in combination with an increasing proportion of intermittent energy sources puts increasing pressure on the electrical grid and prompts a need to adapt to these changes. A proposed solution to part of the power system's upcoming challenges is to utilize the flexibility available from charging electric vehicles (EVs) by letting an aggregator control a large number of EV chargers and sell the extra capacity to, for example, Svenska kraftnät's balancing markets. To quantify how much flexibility charging EVs can contribute with, the aggregator needs to make forecasts of how much power that is most likely available at a given time – a point forecast – but also an estimate of what power level the aggregator almost certainly will exceed – a quantile forecast. In this study, an investigation has been made of how the forecast error changes if the amount of aggregated EV chargers is increased, and how much an aggregator can lower their margins when selling the flexibility to be able to deliver according to the bid with certainty. This was done by quantifying the flexibility of 1000 EV chargers located at mainly workplaces, and by scaling up and down the data through random sampling. For these groups, probabilistic forecasts of the flexibility were then made with a moving average forecast as well as an ARIMA model. Based on the forecasts, potential revenues were finally simulated for the case where the aggregator uses the available flexibility for up-regulation to the balancing market FCR-D up, which is a frequency containment reserve that is activated in the event of disturbances. The results show that a tenfold increase in the number of aggregated EV chargers more than halves the forecast error. The two forecast models proved to have comparable precision, which suggests that the moving average forecast is recommended due to its lower complexity compared to the ARIMA model. The increased precision in the forecasts also resulted in higher revenues per charger. The average income from delivering flexibility from 1000 aggregated electric car chargers to FCR-D amounted to SEK 6900 per month, or SEK 0.8 per session – figures that would probably have been higher without the corona pandemic's increased share of work done from home. A 99 percent confidence level for the quantile forecast resulted in a safety margin of varying size, which on average was around 90 percent for 100 chargers, 60 percent for 1000 chargers and 30 percent for 10,000 chargers. Most flexibility was shown to be available on weekday mornings when approximately 600 kW was available at most for 1000 chargers. By examining frequency data for the Nordic power grid from the past ten years, the joint probability that a more than 50 percent activation of the FCR-D bid would coincide with the outcome for the available capacity being one-in-a-hundred-low, was concluded to be nearly non-existent – likely only once in about 511 years. For the aggregator to place bids based on a 99 percent confidence level can thus be considered safe.
42

Potenciál nefrekvenčních podpůrných služeb pro provozovatele distribuční sítě / Potential of non-frequency ancillary services for a distribution system operator

Reiskup, Filip January 2020 (has links)
This thesis provides a basic overview of the ancillary services in a transmission system. It summarizes changes regarding the implementation of European directives SOGL and EBGL. It describes in detail a portfolio of non-frequency ancillary services used in the distribution systems. It evaluates the demand of E.ON distribution system potential for those services in particular locations. Practical part is focused on a potential of reactive power management in this distribution area. It evaluates reactive power flow into transmission system and indicates the most critical substations. This thesis also covers analysis of existing resources in this distribution area and assign their possible potential in reactive power management.
43

An Economical & Technical Study of the Participation of a Virtual Power Plant on the Swiss Balancing Market : WRITTEN IN COLLABORATION WITH SWISSELECTRICITY

Bourdette, Romain January 2016 (has links)
The current shift towards renewable energy resources creates volatility in the electricity production that must be compensated by nevi sources of balancing energy. To ensure a normal operation of the power system, the transmission system operators procure power reserves able to provide regulation energy through market processes. Virtual power plants are now likely to participate on the balancing markets. In this study, the technical and economic feasibility of having virtual power plants participate in the Swiss balancing market is assessed. The study begins with the evaluation and compa.rison of four European balancing market designs and continues with the clarification of the concept of virtual power plant. The focus is then set on the Swiss ancillary services market, recently open to virtual pmver plants. After a detailed market description, an economic model simulating the participation of a virtual power plant made of industrial resources on the secondary and tertiary control markets has been developed. This model \Vas evaluated on an actual market design: the Sv.riss ancillary servicel:l market. 5 cases were simulated, allowing to estimate the opportunity fom both the capacity and the energy market productl:l. The simulations indicated that an example company (based on an actual situation) could hope a decrease in its energy cost between :3 and 4% by participating in a control pool over a year. Other simulations demonstrated the greater profit expected from secondary reserves compared to tertiary rel:lerves, and the need to develop an automatized activation system. The encouraging economic study is followed by a technical overview of the envisioned system. A generic technical characterization of virtual power plant is presented, on v.rhich the Swiss use-case is later applied. The breakdown into functional requirements allowed to highlight specific issues. The design of the control strategy, particularly to deliver secondary control, as well as the hardware communication interface to use are tvw aspects that ,vill require further analysis. Additionally, on an economic level, the investment cost for remote communication modules are acceptable with respect to the economic potentials estimated in the first part, for medium­sized industrial energy resources. In conclusion, the study established the profitability of an aggregation project on the Swisl:l market but also demonstrated the need to pursue research for the project to be fully feasible on a technical level.
44

Investigation of a balanced Swedish energy system in 2045 : Analysis of technical specifications for flexibility needed in a future Swedish intermittent electricity system.

Larsson, Petter January 2023 (has links)
As part of Sweden's goal of zero carbon dioxide emissions, renewable energy will play an increasingly important role in the future. A major change in the electrification of industries and the transport sector will lead to an ever-increasing need for electricity production. Modern electricity production in the form of solar energy and wind power brings new challenges for the Swedish electricity system. Electricity production and consumption must always be the same momentarily. This is so that the frequency can be controlled and kept at 50 Hz. As the Swedish electricity system is designed according to a frequency of 50 Hz, there are major consequences, such as power outages, if the frequency deviates from this for a longer period of time. The Swedish Transmission System Operator (TSO) is responsible for balancing the production and consumption to be on the same level at all time. To do so with weather dependent intermittent power sources that lacks natural inertia needs additional and external balancing assets. This report investigates the technical specifications needed for a balanced future Swedish energy system. This rapid regulation is a problem in today's system, but in this report it is assumed that the rapid regulation is not a problem in a future system, instead it is examined how large the need for regulation is when consumption is significantly higher than today, and when this increased consumption is covered by weather-dependent renewable energy. In this report, six different scenarios are modeled on how a future electricity system could be designed. These scenarios are based on Svenska Kraftnät's long-term market analysis, where different scenarios are based on different degrees of electrification and scaling of the respective producer. The different scenarios are modeled so that increased consumption is met with different scaling by the respective electricity producer. The production profile and the consumption profile are then compared in order to find how much the two deviates and for how long. This in order to find the technical specifications needed for external balancing assets in the different system designs. The results of the modeling show that what will be decisive in the future is the extent to which there is flexibility in both production and consumption. It shows that it will not be sustainable to only expand production, but this must also be met by consumption. This consumption can be energy storage or export, but as both storage and export are limited, there must also be an opportunity to control surplus production. The result shows how much flexibility is required for each specific future scenario, i.e. what maximum capacity must exist, as well as how sustainable this resource must be for the system to be stable. In the report there is one scenario were the system is optimized according to available balancing reserve, adjusted consumption profile and a large increase in consumption and weather dependent power sources. This leads to the need for a flexibility with a peak hour demand of 0,3 GW; duration time of 5 hours and a total capacity of 1,5 GWh. / Som en del i Sveriges mål om noll koldioxidutsläpp kommer förnybar kraft att spela en allt större roll i framtiden. En stor omställning inom elektrifiering av industrier samt inom transportsektorn kommer att medföra ett allt större behov av elproduktion. Den moderna elproduktionen i form av solenergi samt vindkraft medför nya utmaningar för det svenska elsystemet. Elproduktionen och konsumtionen måste momentant alltid vara densamma. Detta för att frekvensen skall kunna kontrolleras och hållas vid 50 Hz. Då det svenska elsystemet är dimensionerat efter en frekvens på 50. Hz innebär det stora konsekvenser om frekvensen avviker från detta under en längre tid. Svenska Transmissionssystemoperatören (TSO) ansvarar för att balansera produktion och förbrukning för att hela tiden vara på samma nivå. För att göra det med väderberoende intermittenta kraftkällor som saknar naturlig tröghet krävs ytterligare och externa balanseringstillgångar. Denna rapport undersöker de tekniska specifikationer som behövs för ett balanserat framtida svenskt energisystem. Denna snabba reglering är ett problem i dagens system, men i denna rapport antas det att den snabba regleringen inte är ett problem i ett framtida system, istället undersöks hur stort behovet är av reglering då konsumtionen är avsevärt högre än idag, och när detta ökade behov täcks av väderberoende förnybar energi. I denna rapport modelleras sex olika scenarier för hur ett framtida elsystem skulle kunna utformas. Dessa scenarier bygger på Svenska Kraftnäts långsiktiga marknadsanalys, där olika scenarier utgår från olika grader av elektrifiering och skalning av respektive producent. De olika scenarierna är modellerade så att ökad förbrukning möts med olika skalning av respektive elproducent. Produktionsprofilen och konsumtionsprofilen jämförs sedan för att ta reda på hur mycket de två avviker och hur länge. Detta för att hitta de tekniska specifikationer som behövs för externa balanseringstillgångar i de olika systemdesignerna. Resultaten av modelleringen visar att det som kommer att vara avgörande i framtiden är i vilken utsträckning det finns flexibilitet i både produktion och konsumtion. Det visar att det inte kommer att vara hållbart att bara utöka produktionen utan detta måste också mötas av konsumtion. Denna förbrukning kan vara energilagring eller export, men då både lagring och export är begränsad måste det också finnas möjlighet att styra överskottsproduktionen. Resultatet visar hur mycket flexibilitet som krävs för varje specifikt framtidsscenario, det vill säga vilken maximal kapacitet som måste finnas, samt hur hållbar denna resurs måste vara för att systemet ska vara stabilt. I rapporten finns ett scenario där systemet är optimerat efter tillgänglig balansreserv, justerad förbrukningsprofil och en stor ökning av förbrukningen och väderberoende kraftkällor. Detta leder till behovet av en flexibilitet med en maximal kapacitet på 0,3 GW; uthållighet på 5 timmar och en total kapacitet på 1,5 GWh.
45

Framtidens vätgassystem : En fallstudie om vätgasproduktion mot en industriell marknad med el från havsbaserad vindkraft / Hydrogen systems in the future : A case study regarding hydrogen production for an industrial market utilizing offshore wind power

Nedar, Herman, Celsing, Alexander January 2023 (has links)
Vätgas producerad från förnybar el har en stor potential att minska utsläppen från flera olika branscher. Detta genom att införa nya innovativa ändamål och även genom storskalig ersättning av vätgas som idagproduceras med fossila bränslen. Men för en storskalig förändring behöver kostnaden för förnybar vätgasproduktionsjunka. Förutom den generella teknikutveckling och storskalighetsfördelar finns det effektivasätt att bättre nyttja existerade teknik för att sänka kostnaden för vätgas mot slutkund. Exempel på detär försäljning av spillvärme från systemet till lokala fjärrvärmesystem samt nyttjandet av vätgassystemetför att agera på balansmarknader. Denna studie undersökte hur ett vätgassystem innehållandes elektrolysörer, lager, kompressor och gasturbinerkan utformaras och driftas för att på ett effektivt sätt agera på marknader för el och vätgas. Det gjordes genom att studera hur en anläggning kopplat till vindkraftsproduktion genom ett Power purchaseagreement (PPA) kan utformas och driftas för att tillgodose ett industriellt vätgasbehov. Stort fokus ladespå hur ett sådant system kunde nyttjas för att agera på balansmarknader genom att sälja stödtjänsteroch hur erbjudandet av stödtjänster påverkade resten av vätgassystemet. Fallstudien som genomfördes utgick från ett potentiellt vätgassystem i Helsingborg med två stora industriellakunder som ville skifta från nyttjandet av vätgas producerad genom ångreforming till vätgasproducerad genom elektrolys med förnybar el. Då mycket fokus i studien var på balansmarknader ochflexibilitet ansågs PEM-elektrolsyören var den bäst lämpade. Vidare valdes komprimerad vätgaslagringoch ett antal alternativ för vätgasturbiner. Då produktionen var kopplad till en intermittent energikällagjordes bedömningen att systemet skulle vara assisterat med möjligheten att handla el på dagenföre- ochintradagsmarknaden. Om all eltillförsel skulle ske från vindkraften hade lagret behövt vara orimligt stortför att säkerställa förmågan att klara leveranskrav under perioder med låg elproduktion. För att analyseradet valda systemet modellerades ett vätgassystem i Energy Optima 3, en programvara som nyttjar linjärprogrammering för totaloptimering av energisystem. För att undersöka hur dem olika komponenternaskulle dimensioneras gjordes ett antal helårsoptimeringar med tidsupplösning om en timme för att se hursystemet presterade med olika kombinationer av storlek på elektrolysör, lager samt typ av gasturbin. Vid värdering av vilken konfiguration som var mest lämpad användes den utjämnade vätgaskostnaden.Den konfiguration som bedömdes vara mest lämpad för det studerade fallet var en PEM-elektrolysör på 55MW, ett komprimerat lager som motsvarade 12 timmars behov från kunderna och en gasturbin på 24 MW.Den konfigurationen kunde under den studerade tidsperioden producera vätgas till en utjämnad kostnadpå 4,7 EUR/kg. Allmänt kan sägas att studien visade att agerande på balansmarknaden gav stor intäkterför systemet och hade en betydande påverkan på systemets lönsamhet. Försäljning av spillvärme hade idet studerade fallet inte en lika kritiskt påverkan på systemet då intäkter var betydligt lägre. En viktigtinsikt från studien var att värdet av att agera på dem olika marknaderna ofta ställdes mot varandradå deltagande på balansmarknaden ibland innebar att elektrolysören inte kunde nyttja all kapacitet.Samtidigt innebar uppbunden kapacitet på balansmarknaden att flexibiliteten i systemet inte kundenyttjas för att agera på intradagsmarkanden och/eller hantering av prognosfel från vindkraftsproduktion. Studien visade allmänt att utformning och prissättning av PPA har en avgörande roll i ett vätgassystemsgångbarhet. I studien användes ett pay-as-produced-avtal, vilket resulterade i att elektrolysören vid vissatillfällen hade underskott på el (och el från intradagsmarknaden behövde köpas in för att kompensera)och vid vissa tillfällen var det överskott på el (och el behövde säljas vidare på dagenföre- eller intradagsmarknaden.)Vidare bedömdes försäljning av vätgas med långsiktiga kontrakt vara det mest lämpadealternativet då det säkrar intäkter för vätgas producenter och tillgången på vätgas till för industrierna. / Hydrogen produced from renewable electricity has significant potential to reduce emissions in variousindustries, both through new innovative applications and as a large-scale replacement for hydrogen currentlyproduced using fossil fuels as a feed stock. However, in order for large scale adaptation of renewablehydrogen the costs associated with it must decrease. In addition to technological advancements and economiesof scale, there are effective ways to better utilize existing technology to lower the cost of hydrogenfor end user. Examples include selling excess heat from the system to local district heating networks ifthe location of the electrolyzer allows for it, as well as utilizing the hydrogen system to participate inbalancing markets. This study investigated how hydrogen systems containing electrolyzers, storage, compressors, and gasturbines can be designed and operated to effectively participate in electricity and hydrogen markets. Itwas done by studying how a facility connected to wind power production through a Power PurchaseAgreement (PPA) can be designed and operated to meet an industrial hydrogen demand. A major focuswas placed on how such a system could be utilized to participate in balancing markets by providingancillary services and how offering these services affected the rest of the hydrogen system. The case study was focused on a potential hydrogen system in Helsingborg with two large industrialcustomers interested in transitioning from steam reforming hydrogen production to electrolysis using renewableelectricity. As the study heavily emphasized balancing markets and flexibility, a PEM electrolyzerwas chosen over other technologies. Additionally, compressed hydrogen storage and several options forhydrogen gas turbines were selected. Since the production was linked to an intermittent energy source,it was assessed that the system would need to be supported by trading electricity on the day-ahead andintraday markets. If all electricity supply were to come from wind power, the hydrogen storage wouldhave to be unreasonably large to ensure the ability to meet delivery requirements during periods of lowelectricity production. To analyze the selected system, a hydrogen system was modeled using EnergyOptima 3, a software that utilizes linear programming for total optimization of energy systems. Severalyear-long optimizations with 1-hour resolution were performed to examine how the system performedwith different combinations of electrolyzer and storage sizes, as well as types of gas turbines. When evaluating which configuration was most suitable, the levelized cost of hydrogen (LCOH) was used.The configuration deemed most suitable for the studied case consisted of a 55 MW PEM electrolyzer,compressed storage equivalent to 12 hours of customer demand, and a 24 MW gas turbine. This configurationcould produce hydrogen at a levelized cost of 4.7 EUR/kg during the studied period. Overall,the study demonstrated that participating in the balancing market generated significant revenue for thesystem and had a substantial impact on its profitability. The sale of waste heat had a less critical effecton the system in the studied case, as the revenues were considerably lower. An important insight fromthe study was that the value of participating in different markets was often weighed against each other,as participating in the balancing market some times meant that the electrolyzer could not utilize itsfull capacity, while having tied-up capacity in the balancing market limited the system’s flexibility toparticipate in the intraday market and/or manage forecast errors related to wind power production. The study generally showed that the design and pricing of Power Purchase Agreements (PPAs) plays acrucial role in the viability of a hydrogen system. In the study, a pay-as-produced design was used, whichresulted in both electricity deficits and surpluses at certain times. Furthermore, selling hydrogen throughlong-term contracts was deemed the most suitable option for large industrial producers, as it ensuresrevenue for hydrogen producers and a stable supply of hydrogen for the industries.
46

Short-term Forecasting of EV Charging Stations Power Consumption at Distribution Scale / Korttidsprognoser för elbils laddstationer Strömförbrukning i distributionsskala

Clerc, Milan January 2022 (has links)
Due to the intermittent nature of renewable energy production, maintaining the stability of the power supply system is becoming a significant challenge of the energy transition. Besides, the penetration of Electric Vehicles (EVs) and the development of a large network of charging stations will inevitably increase the pressure on the electrical grid. However, this network and the batteries that are connected to it also constitute a significant resource to provide ancillary services and therefore a new opportunity to stabilize the power grid. This requires to be able to produce accurate short term forecasts of the power consumption of charging stations at distribution scale. This work proposes a full forecasting framework, from the transformation of discrete charging sessions logs into a continuous aggregated load profile, to the pre-processing of the time series and the generation of predictions. This framework is used to identify the most appropriate model to provide two days ahead predictions of the hourly load profile of large charging stations networks. Using three years of data collected at Amsterdam’s public stations, the performance of several state-of-the-art forecasting models, including Gradient Boosted Trees (GBTs) and Recurrent Neural Networks (RNNs) is evaluated and compared to a classical time series model (Auto Regressive Integrated Moving Average (ARIMA)). The best performances are obtained with an Extreme Gradient Boosting (XGBoost) model using harmonic terms, past consumption values, calendar information and temperature forecasts as prediction features. This study also highlights periodical patterns in charging behaviors, as well as strong calendar effects and an influence of temperature on EV usage. / På grund av den intermittenta karaktären av förnybar energiproduktion, blir upprätthållandet av elnäts stabilitet en betydande utmaning. Dessutom kommer penetrationen av elbilar och utvecklingen av ett stort nät av laddstationer att öka trycket på elnätet. Men detta laddnät och batterierna som är anslutna till det utgör också en betydande resurs för att tillhandahålla kompletterande tjänster och därför en ny möjlighet att stabilisera elnätet. För att göra sådant bör man kunna producera korrekta kortsiktiga prognoser för laddstationens strömförbrukning i distributions skala. Detta arbete föreslår ett fullständigt prognos protokoll, från omvandlingen av diskreta laddnings sessioner till en kontinuerlig förbrukningsprofil, till förbehandling av tidsserier och generering av förutsägelser. Protokollet används för att identifiera den mest lämpliga metoden för att ge två dagars förutsägelser av timförbrukning profilen för ett stort laddstation nät. Med hjälp av tre års data som samlats in på Amsterdams publika stationer utvärderas prestanda för flera avancerade prognosmodeller som är gradient boosting och återkommande neurala nätverk, och jämförs med en klassisk tidsseriemodell (ARIMA). De bästa resultaten uppnås med en XGBoost modell med harmoniska termer, tidigare förbrukningsvärden, kalenderinformation och temperatur prognoser som förutsägelse funktioner. Denna studie belyser också periodiska mönster i laddningsbeteenden, liksom starka kalendereffekter och temperaturpåverkan på elbilar-användning.
47

Electric cars for grid services : A system perspective study of V2G in a future energy system of Sweden and a local perspective study of a commercial car fleet

Søgaard Vallinder, Isak, Carlsson, Matilda January 2022 (has links)
One of the biggest challenges of today is to mitigate climate change and adjust our way of living in accordance with sustainability. To reduce the climate impact of the transport sector the electrification of the road transport sector is commonly seen as having a key role to play. The rate of increase in number of electric cars has increased dramatically the recent years. Substantial electrification of the transport sector highlights the need of efficient integration of EVs with the electricity grid in order to handle the extra electricity demand. A potentia lway of efficiently integrating EVs to the grid could be to apply the concept of vehicle to grid (V2G). V2G simply means that the battery within an EV is seen as a storage component of the electricity grid that can be charged and discharged. Hence, in this thesis, the potential of V2G is explored. This thesis comprises of two parts. The first part investigates this potential impact of V2G in a future Swedish energy system. The second part investigates the optimized economic value, a car sharing company can achieve using different charging modes as well as the potential for participation in Swedish ancillary service markets. For the first part, the dispatch model EnergyPLAN was used to simulate a future energy system in Sweden in 2045. For the second part, an optimization model was designed using Python Optimization Modeling Objects (PYOMO) to optimize the charging and V2G usage of a car sharing fleet. Additionally, the battery degradation cost due to V2G was calculated as well as the potential income from participation in the FCR-D up and FCR-D down market. For both parts of the thesis different scenarios were developed. Scenarios with different electrification rate of the transport sector, V2G compatibility as well as different electricity production mix were considered for energy systems model of Sweden. For participation of shared cars in ancillary services market, scenarios related to different charging modes, rated charging power and the impact of including or excluding tax on sold electricity were created. While analysing the impact of V2G on Swedish energy system in future, it was observed that V2G has a marginal system impact on an annual basis, regardless of transport electrification rate, V2G compatibility and energy mix. The analysis of optimization algorithm for participation of shared pool of 255 cars resulted in economic savings when implementing smart charging and V2G. Due to battery degradation, the savings from integrating V2G in the system were marginal compared to the smart charging annual cost. For both the FCR-D up market and FCR-D down market, the revenue for participation was higher than electricity arbitrage through V2G. Both parts of the methodology, highlight the need for in centives inorder to make V2G an attractive business model and for electric cars to be able to provide flexibility services in a future Swedish energy system. / En av dagens största utmaningar är att begränsa klimatförändringarna och anpassa vårt sätt att leva i enlighet med hållbarhet. För att minska transportsektorns klimatpåverkan anses elektrifieringen av vägtransportsektorn allmänt ha en nyckelroll att spela. ökningstakten i antalet elbilar har ökat dramatiskt de senaste åren. En betydande elektrifiering av transportsektorn belyser behovet av en effektiv integrering av elfordon med elnätet för att hantera den extra efterfrågan på el. Ett potentiellt sätt att effektivt integrera elfordon i nätet skulle kunna vara att tillämpa begreppet fordon till nät (V2G). V2G innebär helt enkelt att batteriet i en elbil ses som en lagringskomponent i elnätet som kan laddas och laddas ur. Därför undersöks potentialen för V2G i detta examensarbete. Detta examensarbete består av två delar. Den första delen undersöker den potentiella påverkan av V2G i ett framtida svenskt energisystem. Den andra delen undersöker det optimerade ekonomiska värde som ett bildelningsföretag kan uppnå med olika laddningslägen samt potentialen för deltagande på svenska stödtjänstmarknader. För den första delen användes modeller-ingsverktyget EnergyPLAN för att simulera ett framtida energisystem i Sverige 2045. För den andra delen gjordes en optimeringsmodell med hjälp av Python Optimization Modeling Objects (PYOMO) för att optimera laddningen och V2G-användningen av en bildelningsflotta. Dessutom beräknades batterinedbrytningskostnaden på grund av V2G samt de potentiella intäkterna från deltagande på FCR-D upp och FCR-D ned-marknaden. För båda delarna av examensarbetet utvecklades olika scenarier. I den första delen jämförs scenarier med olika elektrifieringstakter inom transportsektorn, V2G-kompatibilitet samt olika elproduktionsmixar. För deltagande av bildelningsbilar på stödtjänstemarknader, skapades scenarion kopplat till olika laddningslägen, nominell laddningseffekt och effekterna av att inkludera eller exkludera skatt på såld el. Vid analys av V2G:s inverkan på det svenska energisystemet i framtiden observerades det att V2G har en marginell systempåverkan på årsbasis, oavsett transporteltrifikationshastighet, V2G-kompatibilitet och energimix. Analysen av optimeringsalgoritm för deltagande av delad bilpool med 255 bilar resulterade i ekonomiska besparingar vid implementering av smart laddning och V2G. På grund av batteriförsämring, blev besparingarna frĂĽn att integrera V2G i systemet marginella jämfört med den årliga kostnaden för smart laddning. För både FCR-D upp och FCR-D ned marknaderna var intäkterna för deltagande högre än el arbitrage genom V2G. Båda delarna av metodiken belyser behovet av incitament i för att göra V2G till en attraktiv affärsmodell och för att elbilar ska kunna tillhandahålla flexibilitetstjänster i ett framtida svenskt energisystem.
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Modelagem de inversores em fluxo de potência considerando suporte de potência reativa como serviço ancilar na distribuição / Modeling inverters in power flow considering reative power support as ancillary service on distribution

Sarmiento, Jonattan Emanuel 23 June 2016 (has links)
Made available in DSpace on 2017-07-10T16:41:34Z (GMT). No. of bitstreams: 1 Dissert Jonattan Emanuel Sarmiento2.pdf: 1326992 bytes, checksum: eeb1918a0e5e9c45ad54043cd1ea9c5e (MD5) Previous issue date: 2016-06-23 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / In recent years there has been a great increase in the use of distributed generators. This occurred not only by advances in production technologies of small generators and frequency inverters, but also by the benefits that brings to the distribution systems and the incentive policies. In the analysis of these systems is essential to calculate the power flow and properly solve it and the modeling of the inverter should be reviewed together with its implementation in the method employed, attempting to the fact that the inverters are beginning to use advanced functions that can to provide ancillary services. In this work the modelling of inverter with advanced functions such as Basic Intelligent Volt-Var Control (BIVV) and Intelligent Volt-Var With Hysteresis (IVVH) are reviewed, therefore it is propose methods the implements this models in the method sweep. In proposal implementation it is use of elements of the sensitivity matrix of nodes PV defined in the compensation method. In the analyzed cases, the implementations were effectiveness achieving solutions in convergent values and in accordance to the control strategies. In the results of simulations there were differences in the operating points of the inverter acting on a node of the distribution system comparing the different modeling analyzed in different system load conditions and different levels of active power supply. When comparing the voltage profiles of the various modeling, in general notice that there is a greater variation when it has large reactive power capacity. If in the future of distributed generation evolve to provide reactive support as the ancillary service, it shall be careful properly modelling the inverter avoiding mistaken results that will affect the plans of the concessionaires. / Nos últimos anos verificou-se um grande aumento no uso de geradores distribuídos. Isso ocorreu não apenas pelos avanços nas tecnologias de produção de pequenos geradores e inversores de frequência, mas também pelos benefícios que estes trazem aos sistemas de distribuição e pelas políticas de incentivos. Nas análises desses sistemas é fundamental calcular o fluxo de potência e, para resolvê-lo adequadamente, deve-se revisar a modelagem do inversor e sua implementação no método empregado, atentando-se ao fato de que os inversores estão começando a utilizar funções avançadas passíveis de fornecer serviços ancilares. Neste trabalho são revisadas as modelagens dos inversores com funções avançadas, tais como o controle Basic Intelligent Volt-Var (BIVV) e Intelligent Volt-Var With Hysteresis (IVVH), além de propor métodos de implementação para o método da varredura. Nas implementações propostas se faz uso de elementos da matriz de sensibilidade dos nós PV definida no método da compensação. Nos casos analisados, as implementações tiveram eficácia, conseguindo atingir soluções em valores convergentes e em concordância às estratégias de controle. Já nos resultados das simulações, ilustram-se as diferenças dos pontos operativos do inversor atuando em um nó do sistema de distribuição comparando-se as diferentes modelagens analisadas em distintas condições de carga do sistema e diversos níveis de fornecimento de potência ativa. Ao comparar-se os perfis de tensão das diversas modelagens, em geral, nota-se que há uma variação maior quando se tem maior capacidade de potência reativa. Se no futuro a geração distribuída evoluir para prestar suporte de potência reativa como um serviço ancilar, é necessário tomar precauções para modelar adequadamente o inversor, de modo a evitar obter resultados equivocados que afetarão os planejamentos das concessionárias.
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Coordination de GEDs pour la fourniture de services systèmes temps réel / Distributed Energy Resources coordination toward the supply of ancillary services in real-time

Lebel, Gaspard 26 April 2016 (has links)
Les politiques entreprises dans le domaine de la production d’électricité pour lutter contre le changement climatique reposent communément sur le remplacement des moyens de production fossiles et centralisés par de nouveaux moyens de type renouvelables. Ces énergies renouvelables sont en grande partie distribuées dans les réseaux moyenne et basse tension et sont le plus souvent intermittentes (énergies éolienne et photovoltaïque principalement). Les gestionnaires de réseaux s’attentent à ce que ce changement de paradigme induise des difficultés conséquences dans leurs opérations. Les mondes de la recherche et de l’industrie se sont ainsi structurés depuis le milieu des années 2000 afin d’apporter une réponse aux problèmes anticipés. Cette réponse passe notamment par le déploiement de technologies de l’information et de la communication (TIC) dans les réseaux électriques, des centres de contrôle jusqu’au sein même des moyens de production distribués. C’est ce que l’on appelle le Smart Grid. Parmi le champ des possibles du Smart Grid, ces travaux de thèses se sont en particulier attachés à apporter une réponse aux enjeux de stabilité en fréquence du système électrique, mise en danger par la réduction anticipée de l’inertie des systèmes électriques et la raréfaction des moyens de fourniture de réserve primaire (FCR), auxquels incombent le maintien de la fréquence en temps réel. En vue de suppléer les moyens de fourniture de réserve conventionnels et centralisés, il a ainsi été élaboré un concept de coordination de charges électriques délestables distribuées, qui se déconnectent et se reconnectent de manière autonome sur le réseau au gré des variations de fréquence mesurées sur site. Ces modulations de puissance répondent à un schéma préétabli qui dépend de la consommation électrique effective de chacune des charges. Ces travaux ont été complétés d’une étude technico-économique visant à réutiliser cette infrastructure de coordination de charges délestables pour la fourniture de services systèmes ou de produits de gros complémentaires. Ce travail de thèse réalisée au sein des équipes innovation de Schneider Electric et du laboratoire de Génie Electrique de Grenoble (G2Elab), est en lien avec les projets Européens EvolvDSO et Dream, financés dans le cadre du programme FP7 de la Commission Européenne. / Climate change mitigation policies in the power generation industry lead commonly on the replacement of bulk generation assets by Renewable Energy Resources (RES-E). Such RES-E are largely distributed among the medium and low voltage grids and most of them are intermittent like photovoltaic and wind power. System Operators expect that such new power system paradigm induces significant complications in their operations. The communities of research and industry started thus to structure themselves in the mid-2000s in order to respond to these coming issues, notably through the deployment of Information and Communication Technology (ICT) in power systems assets, from the Network Operations Centers (NOCs) down to Distributed Energy Resources (DERs) units. This is the Smart Grid. Among the range of possibilities of the Smart Grid, this Ph.D work aims in priority to provide a solution to handle the issue of frequency stability of the power system that are endangered by the combined loss of inertia of the power system and the phasing-out of conventional assets which used to be in charge of the maintain of the frequency in real time through the supply of Frequency Containment Reserve (FCR). The concept developed lead on a process of coordinated modulation of the level of loads of DERs, whose evolve depending on the system frequency measured in real time on-site. The strategy of modulation of each DER follows a pattern which is determined at the scale of the portfolio of aggregation of the DER, depending on the effective level of load of the DER at normal frequency (i.e. 50Hz in Europe). This work is completed by a cost benefit analysis that assesses the opportunity of sharing of the previous infrastructure of coordinated modulation of DERs for the supply of ancillary services and wholesale products. This thesis conducted within Schneider Electric’s Innovation teams and Grenoble Electrical Engineering Laboratory (G2Elab) is linked with the European projects Dream and EvolvDSO, and funded under European Commission’s FP7 program.
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Inclusão de energia eólica em sistemas elétricos e controle de frequência utilizando lógica Fuzzy.

MACÊDO, Ana Vitória de Almeida. 24 August 2018 (has links)
Submitted by Maria Medeiros (maria.dilva1@ufcg.edu.br) on 2018-08-24T14:29:39Z No. of bitstreams: 1 ANA VITÓRIA DE ALMEIDA MACÊDO - TESE (PPgEE) 2017.pdf: 3449345 bytes, checksum: ff78e54595b43261343d5050a8dc3e50 (MD5) / Made available in DSpace on 2018-08-24T14:29:39Z (GMT). No. of bitstreams: 1 ANA VITÓRIA DE ALMEIDA MACÊDO - TESE (PPgEE) 2017.pdf: 3449345 bytes, checksum: ff78e54595b43261343d5050a8dc3e50 (MD5) Previous issue date: 2017-03-29 / CNPq / Um controle para auxílio do controle de frequência é projetado utilizando um método baseado em lógica fuzzy e no controle do ângulo de passo de turbinas eólicas de velocidade variável. O controle visa que as turbinas eólicas operem abaixo do seu valor nominal, estando sempre prontas para aumentar sua geração no caso de evento na rede elétrica, contribuindo para o controle de frequência. Com os esforços para converter tanta energia quanto seja possível com o vento disponível, a potência desperdiçada pela maioria dos controles estudados para elaboração desta tese vale a pena em relação aos benefícios do controle de frequência em sistemas com grande penetração das usinas eólicas, proporcionando a participação da energia eólica nos serviços ancilares. Ressaltando que a introdução de qualquer nova tecnologia de geração no sistema deve ser feita de modo que seja compatível com os princípios operacionais do sistema existente. O controle fuzzy de potência foi desenvolvido no Matlab®/Simulink e permite o bom funcionamento da turbina eólica utilizando uma metodologia alternativa aos controles clássicos. Com isto foi desenvolvido o controle de frequência também baseado em lógica fuzzy. Como grande vantagem do controle fuzzy destaca-se sua fácil adaptação a outros modelos de turbina que utilizem o controle de pitch (turbinas eólicas de velocidade variável), uma vez que o algoritmo é o mesmo, havendo a necessidade apenas de fazer testes para adaptação das faixas de operação do controle. / A control to support the frequency control is designed using a method based on fuzzy logic and pitch angle control in variable speed wind turbines. The control aims that some wind turbines operate below their rated value (derated or deloaded), being always ready to increase their generation in case of some event in the power grid, contributing to the frequency control. With efforts to convert as much energy as possible with the available wind, the power wasted by most controls studied in this work worth of the benefits of frequency control in systems with high power plants penetration, providing wind power to participate on ancillary services. Recalling that the introduction of any new generation technology into the system must be made in a way that is compatible with the operating principles of the existing system. The fuzzy control developed in Matlab®/Simulink for power control enables a suitable operation of the wind turbine using an alternative methodology to the classic controls, it was developed the frequency control also based on fuzzy logic. The fuzzy control great advantage highlight is its easy adaptation to other turbine design which use pitch control (variable speed wind turbines), since the algorithm is the same, just by doing tests for adjustment of the control operation ranges.

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