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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.
111

Contributions d'un modèle microscopique à la résolution du problème de construction d'une grille horaire et à la planification des activités de maintenance de l'infrastructure ferroviaire / Contributions on microscopic approaches to solve the train timetabling problem and its integration to the performance of infrastructure maintenance activities

Arenas Pimentel, Luis Diego 14 December 2016 (has links)
La plupart des systèmes ferroviaires subissent une demande croissante de capacité. Pour y faire face, il faut construire de nouvelles infrastructures ou exploiter plus efficacement celles existantes, notamment en définissant des grilles horaires optimisées. Dans la littérature, la plupart des approches de construction des grilles sont basées sur des représentations macroscopiques de l'infrastructure, ce qui peut conduireà des solutions infaisables ou inefficaces. En revanche, les approches microscopiques reposent sur une modélisation réaliste du système ferroviaire, ce qui garantit la faisabilité et l'efficacité des résultats. Néanmoins, en raison de leur complexité, l'utilisation de ces approches est généralement limitée à une seule gare. Malgré l'optimisation de la grille horaire, les travaux de maintenance peuvent avoir un fort impact sur les circulations des trains. En présence de maintenances, il peut donc être nécessaire de redéfinir la grille horaire pour assurer une exploitation efficace de la capacité. Nous présentons deux contributions principales sous forme de deux approches microscopiques : une pour la conception de grilles horaires et l'autre pour leur redéfinition en cas de maintenance. La deuxième est la première approche microscopique qui apparaît dans la littérature pour aborder ce problème tout en considérant des aspects comme les limitations temporaires de vitesse. Nous démontrons la validité de nos approches et leur applicabilité dans des scénarios réels. De plus, nous montrons que les approches microscopiques peuvent être utilisées pour traiter des zones de l'infrastructure contenant plusieurs gares. / Most railway systems experience a growing demand of railway capacity. To face this demand, either new infrastructure must be built or a more efficient exploitation of the existing one must be attained. Timetables play a determinant role in the efficient capacity exploitation. Most timetabling approaches in the literature are based on macroscopic representations of the infrastructure. This may lead to inefficient and in some cases, impractical solutions. Instead, microscopic approaches are based on more realistic modelling of the elements of the railway system. This guarantees the feasibility of the timetables while promoting an efficient capacity exploitation. However, due to their complexity, the scope of microscopic approaches is typically restricted to main stations. Despite the optimization of timetables, the performance of infrastructure maintenance may severely impact the trains' circulations in the network. Therefore, the timetable may have to be rearranged to ensure an efficient capacity exploitation. We present two main contributions in this thesis: first, a microscopic approach for timetable design. Second, a microscopic approach for timetable rearrangement to cope with maintenance. This is the first microscopic approach in the literature to tackle this problem while also considering specific aspects as temporary speed limitations. After a thorough experimental analysis, we demonstrate the validity of our approaches and their practical applicability in real life scenarios. In particular, we show that microscopic approaches can be used to tackle large areas of the infrastructure, including several stations.
112

Short term load forecasting using quantile regression with an application to the unit commitment problem

Lebotsa, Moshoko Emily 21 September 2018
MSc (Statistics) / Department of Statistics / Generally, short term load forecasting is essential for any power generating utility. In this dissertation the main objective was to develop short term load forecasting models for the peak demand periods (i.e. from 18:00 to 20:00 hours) in South Africa using. Quantile semi-parametric additive models were proposed and used to forecast electricity demand during peak hours. In addition to this, forecasts obtained were then used to nd an optimal number of generating units to commit (switch on or o ) daily in order to produce the required electricity demand at minimal costs. A mixed integer linear programming technique was used to nd an optimal number of units to commit. Driving factors such as calendar e ects, temperature, etc. were used as predictors in building these models. Variable selection was done using the least absolute shrinkage and selection operator (Lasso). A feasible solution to the unit commitment problem will help utilities meet the demand at minimal costs. This information will be helpful to South Africa's national power utility, Eskom. / NRF
113

Power Plant Operation Optimization : Unit Commitment of Combined Cycle Power Plants Using Machine Learning and MILP

Hassan, Mohamed Elhafiz January 2019 (has links)
In modern days electric power systems, the penetration of renewable resources and the introduction of free market principles have led to new challenges facing the power producers and regulators. Renewable production is intermittent which leads to fluctuations in the grid and requires more control for regulators, and the free market principle raises the challenge for power plant producers to operate their plants in the most profitable way given the fluctuating prices. Those problems are addressed in the literature as the Economic Dispatch, and they have been discussed from both regulator and producer view points. Combined Cycle Power plants have the privileges of being dispatchable very fast and with low cost which put them as a primary solution to power disturbance in grid, this fast dispatch-ability also allows them to exploit price changes very efficiently to maximize their profit, and this sheds the light on the importance of prices forecasting as an input for the profit optimization of power plants. In this project, an integrated solution is introduced to optimize the dispatch of combined cycle power plants that are bidding for electricity markets, the solution is composed of two models, the forecasting model and the optimization model. The forecasting model is flexible enough to forecast electricity and fuel prices for different markets and with different forecasting horizons. Machine learning algorithms were used to build and validate the model, and data from different countries were used to test the model. The optimization model incorporates the forecasting model outputs as inputs parameters, and uses other parameters and constraints from the operating conditions of the power plant as well as the market in which the plant is selling. The power plant in this mode is assumed to satisfy different demands, each of these demands have corresponding electricity price and cost of energy not served. The model decides which units to be dispatched at each time stamp to give out the maximum profit given all these constraints, it also decides whether to satisfy all the demands or not producing part of each of them.
114

An Optimization Model for Electric Vehicle Routing with Tractor Swapping / En optimeringsmodell för ruttplanering av elektriska lastbilar med traktorbyten

Strid, Alexander, Liu, Daniel January 2022 (has links)
The purpose of this thesis is to investigate how tractor swapping can be implemented in Vehicle Routing Problems (VRP) with electric heavy goods vehicles, and to evaluate how a model that allows for tractor swapping performs, in terms of schedule cost, against a model that does not. Hence, this thesis introduces a new rich VRP variant which includes tractor swapping, as well as time windows, pickup and delivery, and electric vehicles. The model is named Electric Tractor Swap Vehicle Routing Problem (E-TSVRP) and is formulated as a mixed integer linear program. As for the solver, Gurobi is used. The results show that utilizing tractor swapping can reduce the total cost of serving customers significantly by reducing en-route charging and utilizing drivers more efficiently. Specifically, it is shown that the cost reduction comes mainly from reducing driver work time. By demonstrating how tractor swapping works and how the results can be visualized on smaller cases, this thesis aims to serve as a foundation for future research within the field. To be able to fully implement the model for large logistics problem instances however, alternative solution methods such as heuristics or metaheuristics should be developed so that the problems can be solved in a reasonable amount of time. / Syftet med denna uppsats är att undersöka hur traktorbyten kan implementeras i "Vehicle Routing Problem" (VRP) med tunga, elektriska lastfordon, och att utvärdera hur en modell som tillåter traktorbyten presterar mot en modell som inte tillåter det, med avseende på den totala schemakostnaden. I uppsatsen introduceras därför en ny och generell VRP som har stöd för traktorbyten, men som också modellerar energikonsumtion och laddning av elektriska lastbilar, samt tillåter tidsfönster för när leveranser kan levereras och hämtas upp på godtyckliga platser. Modellen kallas för "Electric Tractor Swap Vehicle Routing Problem" (E-TSVRP) och formuleras som ett linjärt, blandat heltalsprogram. Programmet löses sedan med lösaren Gurobi. Resultaten visar att utnyttjandet av traktorbyten kan märkbart minska den totala kostnaden av att leverera varor till kunder genom att minska tiden som föraren väntar på att traktorn laddar. Mer specifikt tillåts möjligheten att byta till en ny traktor när den tidigare får slut på energi, vilket möjliggör en högre utnyttjandegrad av förarna, och den fakturerade tiden associerad till förarna kan minskas. Detta sker genom en avvägning mellan å ena sidan högre hårdvarukostnader för fler traktorer och å andra sidan lägre förarkostnader. Genom att demonstrera hur traktorbyten fungerar och hur resultaten kan visualiseras på mindre transportproblem, strävar denna uppsats efter att verka som en grund för framtida forskning. För att modellen ska kunna användas för stora logistikproblem bör dock alternativa lösningsmetoder som till exempel lösningsheuristiker eller metaheuristiker utvecklas så att problemen kan lösas inom en rimlig tid.
115

[en] IMPACT OF SOCIOENVIRONMENTAL LICENSING ON TRANSMISSION EXPANSION PLANNING / [pt] IMPACTOS DOS LICENCIAMENTOS SOCIOAMBIENTAIS NO PLANEJAMENTO DA EXPANSÃO DA TRANSMISSÃO

CARLOS PHELIPE ROZA ANDRADE 26 April 2022 (has links)
[pt] O planejamento da expansão da transmissão tem por objetivo identificar o conjunto de novas linhas de transmissão que serão instaladas na rede elétrica, a fim de garantir a segurança e a qualidade do sistema, atendendo ao crescimento da demanda. No Brasil, o primeiro estágio do planejamento consiste em definir e avaliar o corredor para locação das linhas candidatas. Nesta etapa são definidas informações como cabo escolhido, preços médios, tempo de comissionamento, impactos socioambientais e informações sobre a região. No estágio seguinte ocorre o leilão de transmissão em que vários investidores competem pelos lotes de transmissão. No último estágio, o ganhador do leilão é o responsável pela instalação e comissionamento da linha de transmissão. Apesar do levantamento feito no estágio inicial, os projetos de linha de transmissão podem sofrer atrasos e aumentos no custo final, principalmente, por questões de licenciamentos ambientais, desvios do traçado devido a travessias e interferências com áreas protegidas. A presente dissertação propõe metodologia para dimensionamento e precificação da linha de transmissão, ambos de acordo com os critérios e banco de dados da ANEEL, de forma a acelerar e facilitar o processo de planejamento. Com o intuito de evitar atrasos e prever interferências socioambientais, a segunda parte do trabalho apresenta uma metodologia que consiste em localizar e identificar cruzamentos e interferências com áreas protegidas de caráter ambiental e/ou infraestrutural no território brasileiro, a partir das coordenadas do traçado da linha de transmissão em análise. A terceira parte do trabalho verifica, a partir dos resultados anteriores, o impacto no planejamento da expansão da transmissão através de um modelo de programação linear inteira mista considerando fluxo de potência CC, despacho econômico e critério N-1. / [en] The transmission expansion planning aims at identifying a set of new power lines to be installed on the grid, in order to guarantee the reliability and quality of the system, meeting the demand growth. In Brazil, the first stage of planning consists of defining e survey the corridor for the transmission line siting. At this stage it is defined data such as conductor chosen, average prices, commissioning time, socioenvironmental impacts and information about the region. In the following stage, occurs the auction which several investors compete for the transmission lots. In the last stage, the winner of the auction becomes responsible for the installation and commissioning. Despite the survey of the initial stage, the transmission lines undergo delays and additional costs, mainly, due to environmental licensing, changes of the defined route due to crossing and interferences with protected areas. The present dissertation proposes a methodology to design and price the transmission line, both accordingly to the ANEEL database and criteria, in order to accelerate and facilitate the planning process. Aiming to avoid delays and foreseeing socioenvironmental impacts, the second part of the dissertation presents a methodology that consists of locating and identifying crossings and interferences with protected areas of environmental and/or infrastructural aspect on the Brazilian territory, from the coordinates of the transmission line route in analysis. The third part verifies, from the previous results, the impact on the transmission expansion planning through a model based on a mixed-integer linear programming, considering a DC power flow, unit commitment and N-1 criteria
116

Mixed Integer Linear Programming for Allocation of Collateral within Securities Lending / Blandad heltalsprogrammering för optimal allokering av pant inom värdepapperslån

Wass, Martin January 2020 (has links)
A mixed integer linear programming formulation is used to solve the problem of allocating assets from a bank to its counterparties as collateral within securities lending. The aim of the optimisation is to reduce the cost of allocated collateral, which is broken down into the components opportunity cost, counterparty risk cost and triparty cost. A solution consists of transactions to carry out to improve the allocation cost, each transaction consisting of sending a quantity of some asset from a portfolio to the bank or from the bank to some portfolio. The optimisation process is split into subproblems to separate obvious transactions from more complex optimisations. The reduction of each cost component is examined for all the subproblems. Two subproblems transform an initial collateral allocation into a feasible one which is then improved by the optimisation. Decreasing opportunity cost is shown to be an easier task than decreasing counterparty risk and triparty costs since the latter costs require a comparatively large number of transactions. The optimisation is run several times in a row, performing the suggested transactions after each solved iteration. The cost reduction of k optimisation iterations with 10 transactions per iteration is shown to be similar to the cost reduction of 1 optimisation iteration with 10k transactions. The solution time increases heavily with the number of iterations. The suggested transactions may need to be performed in a certain order. A precedence constrained problem takes this into account. The problem is large and the execution time is slow if a limit is imposed on the number of allowed transactions. A strategic selection of portfolios can limit the number of suggested transactions and still reach a solution which comes close to the optimal one. This can also be done by requiring that all suggested transactions must reduce the cost by a minimum amount. The final model is ready to be used in a semi-automatic fashion, where transactions are verified by a human who checks if they are sound. A fully automated process requires further testing on historical and recent data. / Ett blandat-heltal linjärt optimeringsproblem används för att lösa uppgiften att tilldela värdepapper från en bank till dess kunder som pant för värdepapperslån. Målet med optimeringen är att minska kostnaden av den tilldelade panten. Kostnaden bryts ned i komponenterna alternativkostnad, motpartsrisk och tripartykostnad. En lösning består av föreslagna transaktioner som ska genomföras för att förbättra den nuvarande säkerhetstilldelningens kostnad. En transaktion består av att ta hem eller skicka ut en kvantitet av ett visst värdepapper från eller till en av bankens kunders portföljer. Optimeringsproblemet bryts ned i flera delproblem med syfte att särskilja uppenbara föreslagna säkerheter till en godkänd tildelning som sedan blir en startpunkt för optimeringen. Att minska alternativkostnad visar sig vara enklare än att minska motpartsrisk och tripartykostnader på så sätt att de sistnämnda kostnaderna kräver fler transaktioner för att minskas. Optimeringen körs flera gånger i rad, där alla föreslagna transaktioner från en iteration genomförs innan nästa iteration körs. Kostnadsminskningen av k körningar med 10 transaktioner visar sig vara väldigt nära, om än något mindre, än en körning med 10k transaktioner. Exekveringstiden ökar drastiskt med antalet iterationer. De föreslagna transaktionerna kan behöva genomföras i en viss ordning. En problemformulering konstrueras som tar höjd för detta, men exekveringstiden är extremt lång när antalet transaktioner begränsas. Ett strategiskt urval av portföljer kan begränsa antalet föreslagna transaktioner utan att försämra lösningen särskilt mycket. På ett liknande sätt kan antalet föreslagna transaktioner minskas genom att lägga till ett villkor som säger att lönsamheten av en transaktion måste överskrida en given minsta tröskel. Den slutgiltiga modellen är redo att användas om de föreslagna transaktionerna granskas manuellt innan de genomförs. En helt automatisk process ligger längre fram i tiden efter ytterligare tester på historisk och nuvarande data.
117

[pt] ABORDAGENS EXATAS E HEURÍSTICAS PARA VARIANTES DO PROBLEMA DE ROTEIRIZAÇÃO COM ESTOQUE / [en] EXACT AND HEURISTIC APPROACHES FOR INVENTORY ROUTING PROBLEM VARIANTS

DIEGO MOAH LOBATO TAVARES 06 December 2018 (has links)
[pt] Esta pesquisa trata de duas variantes do conhecido Problema de Roteirização de Veículos com Estoque (do inglês Inventory Routing Problem – IRP). O problema nasce num contexto de um sistema de Vendor Managed Inventory (VMI) no qual o fornecedor é responsável pela gestão de estoques do cliente. Tal problema é a junção dos problemas de transporte e gestão de estoques, que correspondem aos maiores custos em uma operação logística. Destarte este trabalho apresenta um modelo matemático para uma variante do IRP que considera que o fornecedor tem clientes dentro e fora do sistema de VMI. Este caso surge quando para alguns clientes não é interessante a realização do controle de seus estoques dentro do sistema de VMI, somente o atendimento de suas demandas. Além disto, o modelo contempla três diferentes tipos de políticas de gestão de estoques e é capaz de lidar com casos contendo vários períodos e vários veículos. Após sua elaboração, o modelo foi validado em instâncias do IRP, do Problema de Roteamento de Veículos (do inglês Capacitated Vehicle Routing Problem - CVRP) e instâncias próprias para a variante. Foram realizados também estudos sobre os impactos das diferentes políticas de gestão de estoques. Além do modelo matemático, foi desenvolvida uma meta-heurística híbrida que resolve uma variante do IRP considerando vários períodos e vários veículos. Cada movimento considerado durante a meta-heurística é divido em duas etapas, a primeira sendo a modificação da posição de um ou mais clientes nos veículos e períodos e uma segunda etapa que resolve de forma exata um Problema de Fluxo Máximo a Custo Mínimo para a atribuição ótima do volume de carga transportada para cada cliente por cada veículo em cada período. Esta abordagem é então testada em instâncias clássicas para esta variante do IRP, obtendo resultados que comprovam a eficiência do algoritmo. / [en] This research deals with two variants of the Inventory Routing Problem (IRP). This problem comes from the context of a Vendor Managed Inventory (VMI) system in which the vendor is responsible for managing the customer s inventory. It is the combination of transportation and inventory management problems, which correspond to the higher costs in a logistics operation. Hence, this paper presents a mathematical model for an IRP variant, in which the vendor has customers inside and outside the VMI system. This situation is presented when it is not interesting to manage the inventories of some clients within the VMI system, resulting only in meeting their demands. In addition, the model considers three different types of stock management policies and it can comprehend multiple periods and multiple vehicles. After its modelling, the model was validated using IRP instaces, the Vehicle Routing Problem (CVRP) and specific instances for this variant. The impacts of different inventory management policies were also analyzed. In addition to the mathematical model, a hybrid meta-heuristic was developed, which solves an IRP variant considering several periods and several vehicles. Each iteration of the metaheuristic is divided into two stages: the first is modifying the position of one or more customers attended by the vehicles and periods, and a second step that solves a Maximum Flow at Minimum Cost problem, to optimally assign the load volumes transported to each customer in each vehicle in each period. Then, this approach is tested in classical instances for this IRP variant, obtaining results that prove the efficiency of the algorithm.
118

[en] BUCKET-INDEXED FORMULATION: A NEW APPROACH TO SOLVE PARALLEL MACHINE SCHEDULING PROBLEM / [pt] FORMULAÇÃO BUCKET-INDEXED: UMA NOVA ABORDAGEM PARA RESOLVER O PROBLEMA DE PROGRAMAÇÃO DE MÁQUINAS PARALELAS

LUANA MESQUITA CARRILHO 20 December 2019 (has links)
[pt] A programação de máquinas é um processo de tomada de decisão que desempenha um importante papel na maioria das indústrias de manufatura e serviços. Esta dissertação aborda o problema de programação de máquinas paralelas idênticas sem preempção, considerando características da programação de data de liberação e data limite para execução do início das tarefas, restrição de precedência entre pares de tarefas, elegibilidade e disponibilidade de máquinas. Para resolver este problema, uma formulação de programação linear inteira mista é proposta. O novo modelo, chamado de bucket-indexed (BI), particiona o horizonte de planejamento em períodos de tempos de mesmo tamanho (buckets). O tamanho dos buckets é um par âmetro que varia de acordo com a instância e influencia o porte do modelo, podendo assumir valores entre 1 e o menor tempo de processamento das tarefas. Quanto maior o tamanho do bucket, menor é o número de buckets criados e, consequentemente, menor o porte do modelo. A formulação proposta é testada em instâncias reais referentes ao problema de programação de sondas para construção de poços de petróleo de uma indústria brasileira de óleo e gás. A fim de avaliar os resultados obtidos pela formulação BI, a formulação clássica time-indexed (TI) foi também implementada para comparação dos tempos computacionais e qualidade da solução. Os resultados da formulação proposta apontam um melhor desempenho nas instâncias testadas, reduzindo o tempo computacional em todos os casos e resolvendo instâncias de grande porte não resolvidas pela formulação TI. / [en] Machine scheduling is a decision-making process that plays an important role in most manufacturing and service industries. This dissertation tackles a nonpreemptive identical parallel machine scheduling problem, considering release dates, deadlines, precedences, eligibility, and machine availability constraints. To solve this problem, a mixed-integer linear programming formulation is proposed. The new model, called bucketindexed, partitions the planning horizon in periods of equal length (buckets). The bucket size is a parameter which varies according to instances and influences the model size, assuming values between 1 and the shortest processing time of jobs. The larger the bucket size, the smaller is the number of buckets created and, consequently, the smaller the model size. The proposed formulation is tested in real instances of the rig scheduling problem for a Brazilian oil and gas industry. To evaluate the results obtained by the BI formulation, the classical time-indexed (TI) formulation was also implemented for comparison of computational times and solution quality. The results of the proposed formulation highlight a better performance in all the tested instances, reducing computational time in all cases and solving large instances unsolvable by the TI formulation.
119

Demand Response In The Engineering Industry

Norberg, Johan January 2017 (has links)
The power utilities in Sweden are planning to replace the major part of thenuclear power plants with renewable energy resource by the year 2030. Some ofthe renewable energy resources are intermittent, which may endanger the powersystem stability. A solution to this problem could be increased exibility in theend-users consumption, which is known as demand response. This is a usefultool that can be used to facilitate the large integration of renewable energyresource into the power grid. Therefore, several of the Swedish governmentauthorities have stated that the possibilities for demand response should befurther investigated.During this thesis, a case study is carried out at Volvo Group Truck OperationsPowertrain Productions in Koping, with the purpose of deriving theirtechnical possibilities for DR in the factory. Volvo in Koping mainly producesgearboxes to all trucks within the Volvo Group concern and belongs to the engineeringindustry sector. The engineering industry has previously not beeninvestigated for DR purposes in Sweden. The main goal of the thesis is to derivethe DR capacity of the factory and the associated time parameters. Onlydemand response by shifting the production in time is considered.One production group (Midiblock 2) in the factory is modelled using MixedInteger Linear Programming and the optimization problem is used to minimizethe electricity cost while fullling the production requirements. The optimizationproblem is done on daily basis and the result is binary operating pointsfor CNC-machines. The output from the Mixed Integer Linear Programmingproblem is sent to a discrete event model, which is used to validate the resultsand display the optimal energy consumption.The simulation results indicates that the modelled production group can performa load shift of 270 kWh/h during 4 hours by scheduling production. Duringthe reduction it should be possible to perform actions such as maintenance andchanging settings of machines. If the results are true for the entire factory, theresulting load reduction is 1.35 MWh/h during 4 hours. However, the nancialincentives to perform load reductions are low. Also, Volvo in Koping does nothave any routines to shut-o the CNC-machines and an extensive work is requiredto make a load reduction possible. Resulting in that DR at the factory isat the moment unrealistic. In addition to the possibilities for DR, the possibleeconomic savings by shutting o the CNC-machines when they are not producingunits are also approximated. Volvo in Koping can save a large amount ofenergy and yearly cut the cost by at least 5 000 000 SEK on these actions, whichis also the rst step towards enabling DR in the factory. / Elkraftsbolagen i Sverige planerar att ersätta kärnkraftverken med förnybaraenergikällor fram till och med år 2030. Några av de förnybara energikällornaär intermittenta i sin produktion och kan på grund av detta medföra en faraför stabilitet i kraftsystemet. En del av lösningen till detta problem kan varaefterfrågeflexibiltet, vilket innebär att el-användarna är mer flexibla i förbrukningenoch anpassar sig till viss del efter kraftsystemets tillstånd. Efterfrågeflexibiltetär ett användbart verktyg som kan underlätta integreringen av de förnybaraenergikällorna. På grund av detta har era svenska statliga företag sagtatt er undersökning bör genomföras inom området efterfrågeflexibiltet.Under detta arbeta har en fallstudie utförts hos Volvo Group Truck OperationPowertrain Production i Köping. Syftet av fallstudien har varit attundersöka möjligheterna för efterfrågeflexibilitet i fabriken. Volvo i Köping producerartill största dels växellådor till samtliga lastbilar inom Volvo Group koncernenoch de tillhör därför industrisektorn verkstadsindustrier.En produktionsgrupp i fabriken modelleras med hjälp av linjärprogrammeringoch modellen används för att för att minimera elkostnaderna genom att föryttalast i tid och samtidigt uppfylla produktionskraven. Optimeringsproblemetberäknas med elpriser för ett dygn och resultatet av problemet är binära tillståndför CNC-maskinerna i produktionsgruppen. De binära tillstånden skickas tillen diskret modell i Matlab som används för att verifiera produktionskraven ochvisa den resulterande energiförbrukningen för produktionsgruppen.Resultatet visar att det är teoretiskt möjligt att förytta 270 kWh/h underen period på 4 timmar genom att förskjuta produktion i tid. Under produktionsstoppenär det möjligt att genomföra underhåll och att förändring iinställningarna på CNC-maskinerna. Om resultaten skalas upp till hela fabrikenskulle den resulterande lastförflyttningen vara 1.35 MWh/h under 4 timmar.Dock så är de ekonomiska incitamenten låga och lastföryttningen är inteekonomiskt hållbar. Ett ytterligare problem är att Volvo i Köping förtillfälletinte har några rutiner för att stänga av maskinerna. Därför krävs det ett omfattandearbete innan det skulle vara möjligt att genomföra en lastförflyttning.Efterfrågeflexibiltet hos Volvo i Köping är därför orealistiskt. Utöver att undersöka möjligheterna för efterfrågeflexibiltet i fabriken, har en del av arbetetsom mål att undersöka de möjliga energi- och kostnadsbesparingar som skapasav att stänga av CNC-maskinerna när de inte producerar enheter. Arbetet harvisat att Volvo i Köping kan varje är spara 5 000 000 SEK på att stänga avmaskinerna, vilket också är ett första steg mot efterfrågeflexibilitet i fabriken.
120

Short Term Regulation in Hydropower Plants using Batteries : A case study of hydropower pants in lower Oreälven river

Baskar, Ashish Guhan, Sridhar, Araavind January 2020 (has links)
Hydropower is one of the oldest renewable energy (RE) sources and constitutes a major share in the Swedish electricity mix. Though hydropower is renewable, there exist some issues pertaining to the local aquatic conditions. With more environmental laws being implemented, regulating the use and management of water is jeopardizing the flexibility of hydropower plants. The decided national plan for new environmental conditions in Sweden is expected to start being implemented in 2025 and more restrictions are expected. Analysing a battery energy storage system's capabilities plants may improve flexibility in hydropower plant operation. This thesis is focused on the short-term regulation in lower Oreälven river where the hydropower plants Skattungbyn, Unnån and Hansjö are located. The combined hydropower plant and battery system is simulated being employed in the day-ahead market and a techno-economic optimization of the combined system is performed. The combined system's operation is modelled using Mixed Integer Linear Programming. The future electricity market analysis is modelled using Machine Learning techniques. Three different electricity market scenarios were developed based on different Swedish nuclear energy targets for 2040 to capture the future. The first scenario developed complies with the Swedish energy target of 100 % renewable production in 2040. The second scenario has still two nuclear power plants in operation by 2040 and the third scenario has the same nuclear capacity as of 2020. It is observed from the results that with the current battery costs (~3,6 Million SEK/MWh), the implementation of a battery system for the short term regulation of the combined battery/hydropower system is not profitable and the cost of battery needs to be less than 0,5 Million SEK/MWh to make it profitable. The thesis also discusses the possibility of utilizing batteries’ second life and the techno-economic analysis of their performance. / Vattenkraft är en av de allra äldsta förnybara energikällorna och utgör idag en väsentlig del av Sveriges energimix. Trots att vattenkraft är förnybar, har den lett till vissa utmaningar i den lokala vattenmiljön. Som en följd av att fler miljölagar har implementerats för att reglera nyttjandet av vattendrag och sjöar, minskar flexibiliteten i vattenkraftproduktionen. Den av den svenska regeringen i juni 2020 beslutade nationella planen för miljöanpassning av vattenkraften i Sverige, förväntas börja genomföras med start 2025 och tros då resultera i fler flexibilitetsbegränsningar. Genom att analysera driften av batteriers energilagringssystem kombinerade med vattenkraftverk, bedöms flexibiliteten i sådana kombinerade system kunna ökas. Denna studie fokuserar på den kortsiktiga regleringen av nedre Oreälven med vattenkraftverken Skattungbyn, Unnån och Hansjö. En kombination av vattenkraftverken med batterisystem simuleras mot spot-marknaden och en teknisk-ekonomisk optimering av det kombinerade systemet utförs. Driften av det kombinerade systemet modelleras med linjärprogrammering och den framtida analysen av elmarknaden modelleras med maskininlärningstekniker. Tre olika scenarier för elmarknaden utvecklades baserade på målen för den svenska kärnkraften år 2040. Det första scenariot som utvecklades är i linje med det svenska energimålet om 100 % förnybar produktion till 2040. Det andra scenariot utvecklades med två kärnkraftverk fortfarande i drift 2040 och det tredje scenariot med samma kärnkraftskapacitet som 2020. Från resultaten kan särskilt noteras att med nuvarande batterikostnader (~3,6 miljoner SEK/MWh) kommer införandet av batterier för att kortsiktigt reglera vattenkraftverken inte att vara lönsamt om inte batterikostnaden reduceras till som högst 0,5 miljoner SEK/MWh. Denna studie diskuterar även möjligheterna att använda andrahandsbatterier samt en teknisk-ekonomisk analys för dess prestanda.

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