To see the other types of publications on this topic, follow the link: Unit commitment.
Dissertations / Theses on the topic 'Unit commitment'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Unit commitment.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Sheblé, Gerald B. "Unit commitment for operations." Diss., Virginia Polytechnic Institute and State University, 1985. http://hdl.handle.net/10919/49977.
Full textAbstract:
The topic of unit commitment has been and continues to be of interest to many researchers and is a primary operation for most utilities. Past research has utilized integer programming, dynamic programming, linear programming, gradient, and heuristic techniques. This research combines both linear programming and dynamic programming for unit commitment decisions within a weekly time frame. The result provides most of the advantages of linear programming and dynamic programming with less stringent requirements on the pre solution information needed for unit transition sequences. Further, the research yields a new tool for the solution of the Transaction Evaluation problem.<br>Ph. D.<br>incomplete_metadata
2
Rottner, Cécile. "Aspects combinatoires du Unit Commitment Problem." Electronic Thesis or Diss., Sorbonne université, 2018. http://www.theses.fr/2018SORUS272.
Full textAbstract:
Le Min-up/min-down Unit Commitment Problem (MUCP) consiste à trouver un plan de production de coût minimum pour un ensemble d’unités de production électrique sur un intervalle de temps discrétisé. A chaque pas de temps, la production totale doit satisfaire la demande prévue. Chaque unité respecte des temps minimum de marche et d’arrêt. Nous montrons que le MUCP est fortement NP-difficile, mettant ainsi en valeur l’impact du couplage dynamique des contraintes de demande sur la difficulté du problème. Pour appréhender cette difficulté, nous introduisons les inégalités interval up-set, généralisant les contraintes de min-up et les extended cover du sac à dos. Les facettes sont caractérisées, et un Branch & Cut est implémenté. Afin de briser les symétries du problème, nous définissons les sous-symétries comme des symétries apparaissant dans des sous-ensembles de solution. Nous considérons des PLNE dont les groupes de sous-symétrie sont des groupes symétriques agissant sur certaines sous-colonnes des matrices solutions. Nous proposons un cadre générique pour gérer les sous-symétries apparaissant dans ce type de problèmes. Deux techniques pour briser les sous-symétries sont proposées : la première est un algorithme de fixing orbitopal pour le full sub-orbitope, la seconde est basée sur des inégalités. Les résultats expérimentaux montrent que les techniques proposées sont plus performantes que les techniques de la littérature. Enfin, nous comparons différentes structures de décomposition pour le MUCP. Des bornes de bonne qualité sont obtenues par dualisation des contraintes dynamiques. Notre Branch&Price&Cut montre que les interval up-set sont utiles dans ce contexte<br>The Min-up/min-down Unit Commitment Problem (MUCP), is to find a minimum-cost production plan on a discrete time horizon for a set of units producing electric power. At each time period, the total production has to meet a forecast demand. Each unit must satisfy minimum up and down time constraints. We show that the MUCP is strongly NP-hard, thus highlighting that the dynamic coupling of demands by minimum up and down time constraints represents one major source of difficulty. To cope with this difficulty, we introduce interval up-set inequalities, a new class of valid inequalities for the MUCP polytope, generalizing both min-up and extended cover inequalities from the 0-1 knapsack polytope. Facet defining cases are characterized and a Branch & Cut algorithm is devised. To deal with the symmetries impairing the solution process, we define sub-symmetries, as symmetries arising from a solution subset. We focus on integer linear programs whose (sub-)symmetry groups are symmetric groups acting on sub-columns of solution matrices. We propose a general framework to handle sub-symmetries in such problems. On this basis, two symmetry-breaking techniques are introduced. The first technique is an orbitopal fixing algorithm for the full (sub-)orbitope. The second technique is based on sub-symmetry breaking inequalities. Experimental results on MUCP instances show that the proposed techniques outperform state-of-the-art techniques. Finally we compare various Dantzig-Wolfe structures for the MUCP. We show that good quality lower bounds can be obtained by dualization of time-coupling constraints. Branch & Price results show that interval up-set inequalities are useful in this context
3
Okuslug, Ali. "Price Based Unit Commitment With Reserve Considerations." Master's thesis, METU, 2013. http://etd.lib.metu.edu.tr/upload/12615475/index.pdf.
Full textAbstract:
In electricity markets of modern electric power systems, many generation companies, as major market participants, aim to maximize their profits by supplying the electrical load in a competitive manner. This thesis is devoted to investigate the price based unit commitment problem which is used to optimize generation schedules of these companies in deregulated electricity markets. The solution algorithm developed is based on Dynamic Programming and Lagrange Relaxation methods and solves the optimization problem for a generation company having many generating units with different cost characteristics. Moreover, unit constraints including ramp-rate limits, minimum ON/OFF times, generation capacities of individual units and system constraints such as total energy limits, reserve requirements are taken into account in the problem formulation. The verification of the algorithm has been carried out by comparing the results of some sample cases with those in the literature. The effectiveness of the algorithm has been tested on several test systems. Finally, the possible utilization of the method by a generation company in Turkish Electricity Market to develop bidding strategies is also examined based on some case studies.
4
Schulze, Tim. "Stochastic programming for hydro-thermal unit commitment." Thesis, University of Edinburgh, 2015. http://hdl.handle.net/1842/15775.
Full textAbstract:
In recent years the deregulation of energy markets and expansion of volatile renewable energy supplies has triggered an increased interest in stochastic optimization models for thermal and hydro-thermal scheduling. Several studies have modelled this as stochastic linear or mixed-integer optimization problems. Although a variety of efficient solution techniques have been developed for these models, little is published about the added value of stochastic models over deterministic ones. In the context of day-ahead and intraday unit commitment under wind uncertainty, we compare two-stage and multi-stage stochastic models to deterministic ones and quantify their added value. We show that stochastic optimization models achieve minimal operational cost without having to tune reserve margins in advance, and that their superiority over deterministic models grows with the amount of uncertainty in the relevant wind forecasts. We present a modification of the WILMAR scenario generation technique designed to match the properties of the errors in our wind forcasts, and show that this is needed to make the stochastic approach worthwhile. Our evaluation is done in a rolling horizon fashion over the course of two years, using a 2020 central scheduling model of the British National Grid with transmission constraints and a detailed model of pump storage operation and system-wide reserve and response provision. Solving stochastic problems directly is computationally intractable for large instances, and alternative approaches are required. In this study we use a Dantzig-Wolfe reformulation to decompose the problem by scenarios. We derive and implement a column generation method with dual stabilisation and novel primal and dual initialisation techniques. A fast, novel schedule combination heuristic is used to construct an optimal primal solution, and numerical results show that knowing this solution from the start also improves the convergence of the lower bound in the column generation method significantly. We test this method on instances of our British model and illustrate that convergence to within 0.1% of optimality can be achieved quickly.
5
Bond, S. D. "Evaluation of unit commitment techniques for the economic scheduling of thermal units." Thesis, Queen's University Belfast, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.372951.
Full text
6
Beltran, Royo César. "Generalized unit commitment by the radar multiplier method." Doctoral thesis, Universitat Politècnica de Catalunya, 2001. http://hdl.handle.net/10803/6501.
Full textAbstract:
This operations research thesis should be situated in the field of the power generation industry. The general objective of this work is to efficiently solve the Generalized Unit Commitment (GUC) problem by means of specialized software. The GUC problem generalizes the Unit Commitment (UC) problem by simultane-ously solving the associated Optimal Power Flow (OPF) problem. There are many approaches to solve the UC and OPF problems separately, but approaches to solve them jointly, i.e. to solve the GUC problem, are quite scarce. One of these GUC solving approaches is due to professors Batut and Renaud, whose methodology has been taken as a starting point for the methodology presented herein.<br/>This thesis report is structured as follows. Chapter 1 describes the state of the art of the UC and GUC problems. The formulation of the classical short-term power planning problems related to the GUC problem, namely the economic dispatching problem, the OPF problem, and the UC problem, are reviewed. Special attention is paid to the UC literature and to the traditional methods for solving the UC problem. In chapter 2 we extend the OPF model developed by professors Heredia and Nabona to obtain our GUC model. The variables used and the modelling of the thermal, hydraulic and transmission systems are introduced, as is the objective function. Chapter 3 deals with the Variable Duplication (VD) method, which is used to decompose the GUC problem as an alternative to the Classical Lagrangian Relaxation (CLR) method. Furthermore, in chapter 3 dual bounds provided by the VDmethod or by the CLR methods are theoretically compared.<br/>Throughout chapters 4, 5, and 6 our solution methodology, the Radar Multiplier (RM) method, is designed and tested. Three independent matters are studied: first, the auxiliary problem principle method, used by Batut and Renaud to treat the inseparable augmented Lagrangian, is compared with the block coordinate descent method from both theoretical and practical points of view. Second, the Radar Sub- gradient (RS) method, a new Lagrange multiplier updating method, is proposed and computationally compared with the classical subgradient method. And third, we study the local character of the optimizers computed by the Augmented Lagrangian Relaxation (ALR) method when solving the GUC problem. A heuristic to improve the local ALR optimizers is designed and tested.<br/>Chapter 7 is devoted to our computational implementation of the RM method, the MACH code. First, the design of MACH is reviewed brie y and then its performance is tested by solving real-life large-scale UC and GUC instances. Solutions computed using our VD formulation of the GUC problem are partially primal feasible since they do not necessarily fulfill the spinning reserve constraints. In chapter 8 we study how to modify this GUC formulation with the aim of obtaining full primal feasible solutions. A successful test based on a simple UC problem is reported. The conclusions, contributions of the thesis, and proposed further research can be found in chapter 9.
7
Rahmqvist, Elin. "On stochastic unit commitment for thermal power plants." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-285519.
Full textAbstract:
Climate change is a fact, a crisis threatening every country, economy and human. Toprevent this crisis, the emission of greenhouse gases needs to decrease dramatically. 72%of global greenhouse gas emissions in 2016 came from energy production where electricityand heat account for 42% of the 72%. Nevertheless, coal power grew with 28% in2018 to meet the increased demand of electricity. It is therefore of utmost importancethat the resources used in power plants are distributed as efficiently as possible. Unitcommitment is a short-term planning formulation which is part of the planning chain forproduction of electrical energy. An accurate unit commitment can decrease emissionsand costs.The aim of this study is to implement a model for the stochastic behavior of the electricalload into unit commitment. With this, it shall be evaluated, whether this solutionis robust enough for usage in network control. The evaluation needs to assess the reliability,economic impact and the computational e↵ort for solving the stochastic unitcommitment problem.A test system has been created in MATLAB to evaluate the stochastic versus deterministicunit commitment formulation. Scenarios for the stochastic unit commitmenthave been generated by using a stationary, discrete-time Markov Chain to generate loadforecast errors. The Fast Forward Selection method has been used to reduce number ofscenarios to minimize computational e↵ort. The quality of the solution has then beenevaluated with value of the stochastic solution for economic analysis. Loss of load probabilityand energy not served have been used to evaluate the reliability.A stochastic approach gives a more robust solution but can be more expensive in termsof costs. Five scenarios were the optimal choice for the stochastic unit commitmentformulation. Increasing number of scenarios did not improve the reliability and resultedin a more expensive solution. The conclusion of this work can be contradictory but highlightsone of the challenges in electric power systems. A more robust system is usuallymore costly and therefore the players in the system must decide what is most desirablein this particular system. A more reliable but expensive system or a less reliable andless costly system.<br>Klimatförändringarna är ett faktum, en kris som hotar varje land, ekonomi och människa.För att förebygga denna kris måste utsläppen av växthusgaser minska dramatiskt. 72 % av de globala utsläppen av växthusgaser år 2016 kom från energiproduktion där värme och elektricitet stod för 42 % av dessa utsläpp. Trots detta växte kolkraften med 28% år 2018 för att kunna möta den ökande efterfrågan på elektricitet. Det är därför av yttersta vikt att dessa resurser används på ett så e↵ektivt sätt som möjligt. En bra och exakt korttidsplanering av kraftsystem kan minska utsläppen och kostnaderna.Målet med denna studie är att implementera stokastisk last i korttidsplaneringen för ett mindre elkraftsystem med 11 enheter. Detta kräver en robust metod som begränsar beräkningstiden för att säkerställa kontinuerlig och säker drift av elkraftsystemet. Analysen måste utvärdera tillförlitligheten, ekonomiska e↵ekterna och beräkningstiden för att lösa det stokastiska korttidsplaneringsproblemet.Ett testsystem har skapats i MATLAB för att utvärdera den stokastiska kontra deterministiska korttidsplaneringsproblemet. Scenarier för det stokastiska korttidsplaneringen har genererats genom att använda en stationär Markov-kedja för att generera felen i lastprognosen och sedan använda Fast Forward Selection metoden för att minska antalet scenarier för att minimera beräkningsinsatsen. Stokastisk korttidsplanering har sedan utvärderats med värdet av den stokastiska lösningen för ekonomisk analys. Sannolikheten för bortkoppling av last samt icke levererad energi har beräknats för att utvärdera tillförlitligheten.En stokastisk metod ger en mer robust lösning men kan vara dyrare vad gäller kostnader. Fem scenarier var det optimala valet för den stokastiska korttidsplaneringsformuleringen. Ö kande av antal scenarier förbättrade inte tillförlitligheten och resulterade i en dyrare lösning. Slutsatsen i detta arbete kan kännas motsägelsefullt då den deterministiska metoden visar på lägre kostnader medans den stokastiska är mer robust. Detta belyser en av utmaningarna i elkraftsystem. Ett mer robust system är vanligtvis dyrare och därför måste aktörerna i systemet bestämma vad som är mest önskvärt i det specifika systemet. Ett mer tillförlitligt men dyrare system eller ett mindre pålitligt och billigaresystem.
8
Al-awaji, Saleh Hussein. "Investigation and comparison of solution methods of the unit commitment problem for thermal units." Thesis, University of Strathclyde, 1990. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=21293.
Full textAbstract:
This thesis deals with a general investigation and comparison of methods of solution of the unit commitment problem for thermal generating units. An intensive mathematical model for this problem has been developed and presented. The most commonly implemented methods for solving the problem of unit commitment were reviewed and discussed. Every reviewed method had been coded in FORTRAN 77 on a VAX11/785 machine. On the basis of the results obtained, a comprehensive comparison of the different methods ha; been carried out. For the comparison to be realistic and practical, each method was tested on three power systems of different sizes. As a result of the comparison, the unit commitment problem for a case study system has been solved by using the most appropriate method(s) from those discussed in the thesis. A new approach for solving the problem has also been proposed and tested.
9
Zhuang, Fulin 1956. "Optimal generation unit commitment in thermal electric power systems." Thesis, McGill University, 1988. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=75896.
Full textAbstract:
This thesis is devoted to the optimal commitment of generation units in an all-thermal, single or multiple area, power system. The problem, known as unit commitment, is a nonlinear mixed program typically with thousands of 0-1 integer variables and diverse constraints. An exact optimal solution to the problem is only possible via (explicit or implicit) enumeration, which requires a prohibitively long computation time for large problem instances.<br>Two optimization approaches, Lagrangian relaxation and simulated annealing, are explored in this thesis for efficient and near-optimal unit commitment.<br>Lagrangian relaxation combines the solution of the dual of the unit commitment problem with feasibility search to obtain primal feasible solutions. The feasibility search is necessary because a solution to the dual seldom solves the primal, and because little theory is available to bridge the optimal dual and primal solutions. In this thesis, several new feasibility search procedures to find a near-optimal primal feasible solution from the dual solution are developed and tested. These procedures are independent of the data constituting different problem instances, and are more rigorous and systematic than the existing ones. With these procedures, Lagrangian relaxation is successfully and efficiently applied to both single and multiple area unit commitment.<br>Simulated annealing exploits the resemblance between a minimization process and the cooling of a molten metal. The method generates feasible solution points randomly and moves among these points following a strategy which leads to a global minimum in a statistical sense. Simulated annealing is very flexible for handling diverse and complicated constraints, such as those typical of the unit commitment problem. Simulated annealing is analyzed, evaluated and implemented for unit commitment in this thesis.<br>Five major algorithms, proposed in this thesis for unit commitment and reserve-constrained economic dispatch, are extensively tested and compared by numerical simulation on sample power systems of 10 to 100 units. The simulation results show the efficiency of the tested algorithms for large-scale unit commitment and demonstrate the general applicability of simulated annealing. A comparison with the priority list method and a study of the convergence rates of the subgradient type algorithms are also included in the simulation.
10
Allen, Eric H. (Eric Hickcox). "Stochastic unit commitment in a deregulated electric utility industry." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/9951.
Full textAbstract:
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1998.<br>Also issued in leaves.<br>Includes bibliographical references (p. 237-239).<br>by Eric H. Allen.<br>Ph.D.
11
Costley, Mitcham Hudson. "Prosumer-based decentralized unit commitment for future electricity grids." Diss., Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/54890.
Full textAbstract:
The contributions of this research are a scalable formulation and solution method for decentralized unit commitment, experimental results comparing decentralized unit commitment solution times to conventional unit commitment methods, a demonstration of the benefits of faster unit commitment computation time, and extensions of decentralized unit commitment to handle system network security constraints. We begin with a discussion motivating the shift from centralized power system control architectures to decentralized architectures and describe the characteristics of such an architecture. We then develop a formulation and solution method to solve decentralized unit commitment by adapting an existing approach for separable convex optimization problems to the nonconvex domain of unit commitment. The potential computational speed benefits of the novel decentralized unit commitment approach are then further investigated through a rolling-horizon framework that represents how system operators make decisions and adjustments online as new information is revealed. Finally, the decentralized unit commitment approach is extended to include network contingency constraints, a crucial function for the maintenance of system security. The results indicate decentralized unit commitment holds promise as a way of coordinating system operations in a future decentralized grid and also may provide a way to leverage parallel computing resources to solve large-scale unit commitment problems with greater speed and model fidelity than is possible with conventional methods.
12
Chen, Richard Li-Yang, Neng Fan, Ali Pinar, and Jean-Paul Watson. "Contingency-constrained unit commitment with post-contingency corrective recourse." SPRINGER, 2014. http://hdl.handle.net/10150/623036.
Full textAbstract:
We consider the problem of minimizing costs in the generation unit commitment problem, a cornerstone in electric power system operations, while enforcing an -- reliability criterion. This reliability criterion is a generalization of the well-known - criterion and dictates that at least fraction of the total system demand (for ) must be met following the failure of or fewer system components. We refer to this problem as the contingency-constrained unit commitment problem, or CCUC. We present a mixed-integer programming formulation of the CCUC that accounts for both transmission and generation element failures. We propose novel cutting plane algorithms that avoid the need to explicitly consider an exponential number of contingencies. Computational studies are performed on several IEEE test systems and a simplified model of the Western US interconnection network. These studies demonstrate the effectiveness of our proposed methods relative to current state-of-the-art.
13
Prada, Jose Fernando. "Ensuring the Reliable Operation of the Power Grid: State-Based and Distributed Approaches to Scheduling Energy and Contingency Reserves." Research Showcase @ CMU, 2017. http://repository.cmu.edu/dissertations/1101.
Full textAbstract:
Keeping a contingency reserve in power systems is necessary to preserve the security of real-time operations. This work studies two different approaches to the optimal allocation of energy and reserves in the day-ahead generation scheduling process. Part I presents a stochastic security-constrained unit commitment model to co-optimize energy and the locational reserves required to respond to a set of uncertain generation contingencies, using a novel state-based formulation. The model is applied in an offer-based electricity market to allocate contingency reserves throughout the power grid, in order to comply with the N-1 security criterion under transmission congestion. The objective is to minimize expected dispatch and reserve costs, together with post contingency corrective redispatch costs, modeling the probability of generation failure and associated post contingency states. The characteristics of the scheduling problem are exploited to formulate a computationally efficient method, consistent with established operational practices. We simulated the distribution of locational contingency reserves on the IEEE RTS96 system and compared the results with the conventional deterministic method. We found that assigning locational spinning reserves can guarantee an N-1 secure dispatch accounting for transmission congestion at a reasonable extra cost. The simulations also showed little value of allocating downward reserves but sizable operating savings from co-optimizing locational nonspinning reserves. Overall, the results indicate the computational tractability of the proposed method. Part II presents a distributed generation scheduling model to optimally allocate energy and spinning reserves among competing generators in a day-ahead market. The model is based on the coordination between individual generators and a market entity. The proposed method uses forecasting, augmented pricing and locational signals to induce efficient commitment of generators based on firm posted prices. It is price-based but does not rely on multiple iterations, minimizes information exchange and simplifies the market clearing process. Simulations of the distributed method performed on a six-bus test system showed that, using an appropriate set of prices, it is possible to emulate the results of a conventional centralized solution, without need of providing make-whole payments to generators. Likewise, they showed that the distributed method can accommodate transactions with different products and complex security constraints.
14
Gomez, Martinez Jonathan. "Investigating the flexibility of low-carbon power systems : wind variability and carbon capture." Thesis, University of Manchester, 2017. https://www.research.manchester.ac.uk/portal/en/theses/investigating-the-flexibility-of-lowcarbon-power-systems-wind-variability-and-carbon-capture(3df46bcf-aa09-4ed2-b528-1c473900ba37).html.
Full textAbstract:
Increasing concerns about global warming have led to the exploration of options to abate CO2 emissions. Recent studies have identified the energy sector as the largest emitting source worldwide. Therefore, the transition towards low-carbon power systems has incorporated larger volumes of renewable generation. This situation is prompting the necessity of improving current strategies to operate power systems, as more variability is introduced in the decision making process. This thesis contributes in two aspects to manage the generation mix of future power systems. Firstly, it addresses the question of how many scenarios are enough to represent the variability of wind power. Results obtained indicate that a balance should be pursued between quality of solution and computational burden, as more scenarios does not significantly change the operational cost. Secondly, an original method to narrow down the number of scenarios is proposed. The so-called severe scenarios outperform typical reductions in the sense that fewer adjustments are required to the generation scheduling programme. Despite the growing renewable generation capacity, the operation of the electric system is likely to continue its reliance on thermal plants. Hence, the need to curb CO2 emissions in the existing thermal plants has led to the development of technologies such as carbon capture. The technical maturity of this technology is still in its early stages, since its application to thermal plants is under development. This thesis bridges the gap of current knowledge on carbon capture in three aspects. Firstly, it presents an innovative methodology to quantify the value of flexibility provided by carbon capture in the context of the British system. Secondly, the role of retrofitted generators as reserve providers is addressed. Finally, the synergy between carbon capture and wind power is assessed. The evaluation considers CO2 pricing, two strategies to manage CO2 capture rate, variability and different levels of wind integration.
15
Radinskaia, Elene. "An investigation into the use of switching curves for unit commitment." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ37281.pdf.
Full text
16
Restrepo, Jose Fernando. "Unit commitment with primary frequency regulation constraints in electric power systems." Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=18210.
Full textAbstract:
The unit commitment problem with secondary and tertiary reserve requirements with time constants ranging from two to thirty minutes has been broadly studied in electric power systems. In contrast, the scheduling of units offering primary frequency regulation reserve deployable within seconds of a contingency has received relatively little attention. In this dissertation we formulate and solve a unit commitment problem explicitly accounting for the characteristic that primary frequency regulation has a single common degree of freedom, namely, the system frequency deviation. The simultaneous scheduling of energy, primary and tertiary reserves is then studied through a number of cases of up to 34 generating units.<br>Le problème de la planification de l’opération des unités de production d’électricité comprenant des spécifications des niveaux de régulation secondaire et tertiaire (celles-ci agissant sur un horizon de temps compris entre deux et trente minutes) a été amplement étudié. Le problème de planification de la production comprenant les aspects relatifs à la régulation primaire, agissant en fonction des variations de fréquence du réseau dans un horizon de temps de quelques secondes, n’a cependant reçu que peu d’attention jusqu’à maintenant. Dans ce mémoire, nous développons et solutionnons le problème de la planification de la production d’électricité en incluant la notion de la régulation primaire. On démontre que celle-ci est gouvernée explicitement et uniquement par la variation de la fréquence du réseau. Ensuite, la planification simultanée de la production d’énergie et de la fourniture des services de régulation primaire et tertiaire est étudiée via des études de cas sur des systèmes types possédant jusqu’à 34 unités de production.
17
Tengberg, Oskar. "Implementation of Hydro Power Plant Optimization for Operation and Production Planning." Thesis, Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-74274.
Full textAbstract:
Output power of hydro power plant was modelled and an optimization algorithm was implemented in a tool for optimizing hydro power plants. The tool maximizes power output of a hydro power plant by distributing water over a set of active units in the power plant which will be used in planning of electricity production. This tool was built in a MATLAB environment, using the optimization toolbox, and a GUI was developed for Vattenfall. The optimization tool was based on the same architecture as the current tool used for this kind of optimization which is to be replaced by the work presented in this thesis. Therefore, the goal was to achieve the same optimal results as the current optimization tool. Power output of three of Vattenfall’s hydro power plants were computed and two of these plants were optimized. These power output results were compared to results from the optimization tool currently used. This showed differences within the inaccuracy of measurements of ≤ 0.3%. These three power plants proved that the new tool is sufficient to replace the current tool but further testing is recommended to be conducted on more of Vattenfall’s hydro power plants to prove its consistency.
18
Dannhauser, Zani. "The relationship between servant leadership, follower trust, team commitment and unit effectiveness." Thesis, Link to the online version, 2007. http://hdl.handle.net/10019/375.
Full text
19
Radulesco, Romain. "Unit commitment model development for hydropower on the Day-Ahead spot market." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-273979.
Full textAbstract:
In the aftermath of the liberalization of European Energy Markets in the 2000s, Power Exchange platforms have constantly evolved towards more integrated and competitive designs, where quality forecasts and effective optimization strategies play decisive roles. This study presents the development of a hydropower scheduling optimization algorithm for the Day-Ahead spot market using Mixed Integer Linear Programming (MILP). This work was supported by the hydro asset management team of ENGIE Global Energy Markets (GEM) located in Brussels. The model developed is focusing on the optimization of Coindre Hydraulic Power Plant (HPP), located in the highlands of Massif Central in France. With the combined water discharge of its two interconnected reservoirs, Grande-Rhue and Petite-Rhue, the powerhouse can reach up to 36 MW of power output capacity. The two reservoirs are located kilometres apart from each other and have different storage capacities and catchment areas. The reservoirs naturally exchange water due to the level difference along an interconnection pipe. Maximum power output is limited by water level differences in both reservoirs, which makes modelling complicated. These operational constraints are a limiting factor in terms of operability, as a result the scheduling process is a non-trivial task and is time-consuming. A framing study of the power plant was conducted over a hydraulic year to identify the governing parameters of the model. The multi-reservoir nature of the optimization problem oriented the model development towards a Mixed Integer Linear Formulation. After experimenting with different solvers, Gurobi 28.1.0 was chosen for its performance in the Branch and Cut Algorithm for the power scheduling task. The performance of the new model has been validated by re-running the model on past production plans, results show that reservoir volume errors are less than 5% of their respective capacities on a 5 days’ time-horizon. After backtesting it was found that the new optimization strategy results in higher revenue for the plant due to the optimized operation at higher average energy prices. The results also bring out the importance of proper valve actuation in the optimization strategy, as well as the need for future studies.<br>Till följd av liberaliseringen av de europeiska energimarknaderna under 2000-talet har energiföretagen och elbörserna ständigt utvecklats mot mer integrerade och konkurrenskraftiga lösningar, där kvalitetsprognoser och effektiva optimeringsstrategier spelar avgörande roller. Detta examensarbete presenterar utvecklingen av en algoritm för optimering av vattenkraftplaneringen på Day-Ahead elmarknaden med hjälp av en matematisk modell av typen Mixed Integer Linear Programming (MILP). Arbetet initierades av och utfördes hos ENGIE Global Energy Markets (GEM) i Bryssel. Modellen som utvecklats är tänkt att optimera Coindre vattenkraftverk, som ligger på höglandet inom Massif Central i Frankrike. Med det kombinerade vattenutsläppet från dess två fördämningar, Grande-Rhue och Petite-Rhue, kan kraftverket leverera upp till 36 MW el netto till elnätet. Vattenreservoarerna ligger flertalet kilometer ifrån varandra och har mycket olika kapacitet och upptagningsområden. Båda reservoarerna är kopplade till varandra genom det gemensamma tilloppsröret till kraftverket, där en reglerventil finns endast vid Petite-Rhue. Vatten kan växlas naturligt mellan de två dammarna när ventilen är öppen på grund av skillnaden i varderas vattennivå. Den maximala effekten från kraftverket är begränsad av vattennivåerna i båda reservoarerna vilket gör optimeringsmodelleringen komplicerad. Dessa operationella begränsningar är mycket hindrande vad gäller valet av driftsregim, eftersom kalkylering av driftsplaneringen blir en svår och tidskrävande uppgift. En ramstudie av vattenkraftverket genomfördes under ett typiskt hydrauliskt år för att identifiera modellens styrparametrar. Den möjliga vattenöverföringen mellan de två dammarna orienterade modellutvecklingen mot en Mixed Integer Linear Programming (MILP) formulering. Efter att ha experimenterat med olika kalkylverktyg valdes Gurobi 28.1.0 för sin bra prestation i lösningen av Branch and Cut-algoritmen. Systemets hydraulik har validerats genom att injicera realiserade produktionsplaner som input till modellen. Resultaten visar att volymfelet är mindre än 5% av deras respektive kapacitet under en 5-dagars tidshorisont. Efter tvärstester mot historiska data konstaterades det att den nya optimeringsstrategin resulterar i bättre genomsnittliga elpriser på varje kWh inmatad till nätet och högre intäkter för kraftverket. Resultaten visar också på vikten av korrekt ventilmanövrering i optimeringsstrategin. Modellen körs i rimliga beräkningstider och redan används i den dagliga optimeringen av Coindre kraftverket, vilket sparar mycket tid. Specifika exempel på den optimerade prestandan och framtida förbättringar hittas i slutet av denna rapport.
20
Luciano, Edson José Rezende [UNESP]. "Um modelo de unit commitment hidrotérmico para o ambiente de mercados de energia." Universidade Estadual Paulista (UNESP), 2010. http://hdl.handle.net/11449/87200.
Full textAbstract:
Made available in DSpace on 2014-06-11T19:22:34Z (GMT). No. of bitstreams: 0
Previous issue date: 2010-08-27Bitstream added on 2014-06-13T19:26:23Z : No. of bitstreams: 1
luciano_ejr_me_bauru.pdf: 912610 bytes, checksum: 8374c6e06cc40c16b0d99dbb004d73c7 (MD5)<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)<br>Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)<br>Este projeto tem como objetivo descrever, implementar e avaliar um modelo de Unit Commitment (UC) hidrotérmico para o ambiente de mercados de energia. O modelo deve considerar aspectos que têm sido negligenciados na abordagem atualmente vigente no Brasil, ou seja, o modelo deve apresentar as seguintes contribuições: i) a discretização do problema deve ser feita em base horária e não semanal, de modo a permitir o estabelecimento de um mercado de curtíssimo prazo efetivo; ii) o modelo deve levar em conta os custos de partida/parada de máquinas, comparando a solução do modelo proposta com o modelo em que essses custos não são considerados; iii) as inter-relações entre os mercados pool e bilateral são descritas de forma explícita em um único problema de otimização de UC; iv) a inserção dos custos de oportunidade hidráulica propostos no âmbito desse trabalho na função de custos<br>This project aims to describe, implement and evaluate a model of Unit Commitment (UC) for the hydrothermal environment of energy markets. The model takes into account aspects that have been neglected in the approach currently used in Brazil, and present the following contributions: i) discretization of the problem is performed in an hourly basis, instead of the weekly-based approach currently used, to allow the establishment of an effective market for short term generation planning; ii) the model takes into account unit start-up and shut down costs; the outcomes of the proposed model are compared with those of a model in which these costs are not considered; iii) the interrelationships between pool and bilateral markets are described explicity within a single optimization problem in the proposed UC model; iv) the inclusion of opportunity costs associated with hydraulic utility, proposed in the context of this research
21
Wu, Zhi. "Transmission expansion planning and unit commitment with large-scale integration of wind power." Thesis, University of Birmingham, 2016. http://etheses.bham.ac.uk//id/eprint/6738/.
Full textAbstract:
The large-scale integration of wind generation into the power system brings great challenges to transmission expansion planning (TEP) and unit commitment (UC). The intermittence nature of wind generation needs to be fully considered in these two problems, which stimulates the research of this thesis. The selection of candidate lines is the prerequisite for the TEP problem. Considering the limitations of manual selection approach, a method to select candidate lines automatically is proposed, which consists of five stages to reinforce existing corridors and new corridors. Results of the two test systems illustrate that the locational marginal price difference is neither sufficient nor necessary condition for candidate lines. The uncertainty of load demand and wind power is studied both in the TEP and UC problems. In the term of TEP, a two-stage stochastic formulation of TEP is proposed. The stochastic dual dynamic programming (SDDP) approach is applied to consider the uncertainty, and the whole model is solved by Benders decomposition (BD) technique. In the term of UC, the chance-constrained two-stage programming formulation is proposed for the day-ahead UC problem. The chance-constrained stochastic programming formulation is converted into an equivalent deterministic formulation by a sequence of approximation and verification.
22
Cheung, Chak H. "A unified approach to unit commitment and economic dispatch in power system control." Thesis, Durham University, 1990. http://etheses.dur.ac.uk/1155/.
Full text
23
Luciano, Edson José Rezende. "Um modelo de unit commitment hidrotérmico para o ambiente de mercados de energia /." Bauru : [s.n.], 2010. http://hdl.handle.net/11449/87200.
Full textAbstract:
Resumo: Este projeto tem como objetivo descrever, implementar e avaliar um modelo de Unit Commitment (UC) hidrotérmico para o ambiente de mercados de energia. O modelo deve considerar aspectos que têm sido negligenciados na abordagem atualmente vigente no Brasil, ou seja, o modelo deve apresentar as seguintes contribuições: i) a discretização do problema deve ser feita em base horária e não semanal, de modo a permitir o estabelecimento de um mercado de curtíssimo prazo efetivo; ii) o modelo deve levar em conta os custos de partida/parada de máquinas, comparando a solução do modelo proposta com o modelo em que essses custos não são considerados; iii) as inter-relações entre os mercados pool e bilateral são descritas de forma explícita em um único problema de otimização de UC; iv) a inserção dos custos de oportunidade hidráulica propostos no âmbito desse trabalho na função de custos<br>Abstract: This project aims to describe, implement and evaluate a model of Unit Commitment (UC) for the hydrothermal environment of energy markets. The model takes into account aspects that have been neglected in the approach currently used in Brazil, and present the following contributions: i) discretization of the problem is performed in an hourly basis, instead of the weekly-based approach currently used, to allow the establishment of an effective market for short term generation planning; ii) the model takes into account unit start-up and shut down costs; the outcomes of the proposed model are compared with those of a model in which these costs are not considered; iii) the interrelationships between pool and bilateral markets are described explicity within a single optimization problem in the proposed UC model; iv) the inclusion of opportunity costs associated with hydraulic utility, proposed in the context of this research<br>Orientador: Leonardo Nepomuceno<br>Coorientador: Paulo Sérgio da Silva<br>Banca: Eduardo Nobuhiro Asada<br>Banca: Antonio Roberto Balbo<br>Mestre
24
TAVERNA, ANDREA. "ALGORITHMS FOR THE LARGE-SCALE UNIT COMMITMENT PROBLEM IN THE SIMULATION OF POWER SYSTEMS." Doctoral thesis, Università degli Studi di Milano, 2017. http://hdl.handle.net/2434/487071.
Full textAbstract:
Lo Unit Commitment Problem (UCP) è un problema di programmazione matematica dove un insieme di impianti termoelettrici deve essere programmato per soddisfare la domanda di energia e altri vincoli di sistema. Il modello è impiegato da decenni per supportare la pianificazione operazionale di breve termine dei sistemi elettrici.
In questo lavoro affrontiamo il problema di risolvere UCP lineari di larga-scala per realizzare simulazioni accurate di sistemi elettrici, con i requisiti aggiuntivi di impiegare capacità di calcolo convenzionali, ad esempio i personal computers, ed un tempo di soluzione di poche ore. Il problema, sotto le medesime condizioni, è affrontato abitualmente dal nostro partner industriale RSE S.p.A. (Ricerche Sistema Energetico), uno dei principali centri ricerche industriali su sistemi energetici in Italia.
L’ottimizzazione diretta di queste formulazioni con solutori generici è impraticabile. Nonostante sia possibile calcolare buone soluzioni euristiche, ovvero con un gap di ottimalità sotto il 10%, in tempi ragionevoli per UCP di larga scala, si richiedono soluzioni più accurate, per esempio con gap sotto l’1%, per migliorare l’affidabilità delle simulazioni ed aiutare gli esperti di dominio, che potrebbero non essere familiari con i dettagli dei metodi di programmazione matematica, a supportare meglio le loro analisi.
Tra le idee che abbiamo esplorato i seguenti metodi risultano i più promettenti: una mateuristica per calcolare efficientemente buone soluzioni e due metodi esatti di bounding: column generation e Benders decomposition. Questi metodi decompongono il problema disaccoppiando il commitment degli impianti termoelettrici, rappresentati da variabili discrete, e il loro livello di produzione, rappresentato da variabili continue.
I nostri esperimenti dimostrano che il modello possiede proprietà intrinseche come degenerazione e forma della funzione obbiettivo piatta che ostacolano o impediscono la convergenza in risolutori allo stato dell’arte. Tuttavia, i metodi che abbiamo sviluppato, sfruttando efficacemente le proprietà strutturali del modello, permettono di raggiungere soluzioni quasi ottime in poche iterazioni per la maggior parte delle istanze.<br>The Unit Commitment Problem (UCP) is a mathematical programming problem where a set of power plants needs to be scheduled to satisfy energy demand and other system-wide constraints. It has been employed for decades to support short-term operational planning of power plants.
In this work we tackle the problem of solving large-scale linear UCPs to perform accurate medium-term power systems simulations, with the additional requirements of employing conventional computing power, such as personal computers, and a solution time of a few hours. The problem, under such conditions, is routinely faced by our industry partner, the Energy Systems Development department at RSE S.p.A. (Ricerche Sistema Energetico), a major industrial research centre on power systems in Italy.
The direct optimization of these formulations via general-purpose solvers is impractical. While good heuristic solutions, that is with an optimality gap below 10%, can be found for large-scale UCPs in affordable time, more accurate solutions, for example with a gap below 1%, are sought to improve the reliability of the simulations and help domain experts, who may not be familiar with the details of mathematical programming methods, to better support their analysis.
Among the ideas we explored, the following methods are the most promising: a matheuristic to efficiently compute good solutions and two exact bounding methods: column generation and Benders decomposition. These methods decompose the problem by decoupling the commitment of thermal plants, represented by discrete variables, and their level of production, represented by continuous variables.
Our experiments proved that the model posses inherent properties as degeneracy and objective flatness which hinder or prevent convergence in state-of-the-art solvers. On the other hand, the methods we devised, by effectively exploiting structural properties of the model, allow to reach quasi-optimal solutions within a few iterations on most instances.
25
Sahin, Cem. "Optimization Of Electricity Markets In The Price Based And Security Constrained Unit Commitment Problems Frameworks." Phd thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612242/index.pdf.
Full textAbstract:
Operation of the electricity markets is subject to a number of strict and specific constraints such as continuous load-generation balance, security of supply, and generation technology related limitations. Contributions have been made to two important problems of the Electricity Markets, in the context of this study.
In this study, Price Based Unit Commitment problem in the literature, which is a tool for the GENCO for operations planning, is extended considering the interdependencies between the Natural Gas (NG) and Electricity infrastructures and the uncertainty of Wind Power generation. The effect of the NG infrastructure physical limitations is considered via linearized NG transmission system equations, and the Wind energy sources and conventional generation resource uncertainties are simulated by Monte-Carlo simulations. The contribution of the forward energy Bilateral Contracts (BC), as a financial risk hedging tool is also included by modeling these in the proposed PBUC framework. In the case studies , it is observed that a GENCO could prevent its financial losses due to NG interruptions, by depositing only a portion of the midterm interrupted NG in the storage facilities.
The Security Constrained Unit Commitment (SCUC) Problem is widely accepted tool in the industry which models the market clearing process. This study integrates two novelties to the SCUC problem<br>&bull<br>A discrete demand response model to consider active participation of the consumers,
&bull<br>A hybrid deterministic/stochastic contingency model to represent the N-1 contingencies together with the uncertainties related with the wind power generation and system load.
It is observed that the curtailment of available wind power capacity would enable the TSO to take corrective actions against occurrence of the contingencies and realization of the uncertainties in the most possible economical manner.
26
"Unit Commitment with Uncertainty." Doctoral diss., 2016. http://hdl.handle.net/2286/R.I.40808.
Full textAbstract:
abstract: This dissertation carries out an inter-disciplinary research of operations research, statistics, power system engineering, and economics. Specifically, this dissertation focuses on a special power system scheduling problem, a unit commitment problem with uncertainty. This scheduling problem is a two-stage decision problem. In the first stage, system operator determines the binary commitment status (on or off) of generators in advance. In the second stage, after the realization of uncertainty, the system operator determines generation levels of the generators. The goal of this dissertation is to develop computationally-tractable methodologies and algorithms to solve large-scale unit commitment problems with uncertainty.
In the first part of this dissertation, two-stage models are studied to solve the problem. Two solution methods are studied and improved: stochastic programming and robust optimization. A scenario-based progressive hedging decomposition algorithm is applied. Several new hedging mechanisms and parameter selections rules are proposed and tested. A data-driven uncertainty set is proposed to improve the performance of robust optimization.
In the second part of this dissertation, a framework to reduce the two-stage stochastic program to a single-stage deterministic formulation is proposed. Most computation of the proposed approach can be done by offline studies. With the assistance of offline analysis, simulation, and data mining, the unit commitment problems with uncertainty can be solved efficiently.
Finally, the impacts of uncertainty on energy market prices are studied. A new component of locational marginal price, a marginal security component, which is the weighted shadow prices of the proposed security constraints, is proposed to better represent energy prices.<br>Dissertation/Thesis<br>Doctoral Dissertation Industrial Engineering 2016
27
CHEN, JUN-LONG, and 陳俊隆. "Dynamic programming for unit commitment." Thesis, 1992. http://ndltd.ncl.edu.tw/handle/03193138060563478279.
Full text
28
JIAN, JING-YANG, and 簡靖陽. "Unit commitment and generation reliability." Thesis, 1989. http://ndltd.ncl.edu.tw/handle/63873659475414659803.
Full text
29
Yu-LinChen and 陳昱霖. "Application of Unit Clustering Concept to Mid-term Unit Commitment." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/64p42q.
Full text
30
CHEN, SHI-LIN, and 陳石麟. "Truncated dynamic programming for unit commitment." Thesis, 1989. http://ndltd.ncl.edu.tw/handle/62991084899636621631.
Full text
31
Shen, Ji-Shan, and 沈吉山. "Heuristic Rules For the Unit Commitment." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/08237333374473452484.
Full textAbstract:
碩士<br>國立臺灣海洋大學<br>電機工程學系<br>98<br>As the global economic recovery and the rising of the hi-tech industry, the power demand is more and more high. The uncertainty of global economic development has been increased significantly since the 2007 financial tsunami has been happen, the entry into force of the 2005 Kyoto Protocol, and sharp rise in energy prices, will make the future electricity production plans developed is more difficult. In the past, most of the Unit Commitment (UC) simulated takes always one week as the simulation period, and takes the first day simulation results as the basis for the day ahead system operation. If a middle term generation schedule to be developed, UC will be executed separately along the time-axis to find the results needed, lacks a complete model for analysis.
UC is an integer programming problem, the solution speed affected seriously by the size of integer variables. So a fast UC algorithm developed in this thesis, the integer variable combinations reduced significantly using the continuous variable model and fuzzy logic concept, is to speed up the solution process. A UC model developed in this thesis, in addition to the traditional constraints of UC, the power interchange, monthly fuel contracts, unit’s capacity factors and the start/stop number of IPP will be also considered. This algorithm can be applied to the monthly power production plan developed.
32
Gangavarapu, R. "Unit Commitment in Restructured Power systems." Thesis, 2014. http://raiith.iith.ac.in/126/1/EE12M1017.pdf.
Full textAbstract:
As the power industry across the world is experiencing a radical change by
separation of transmission from generation activities, creation of competition by
bidding or through provision of bilateral transactions in spot markets, there is need
for the unit commitment in power industry with generation biddings, load biddings
and bilateral transaction biddings.
In general Unit Commitment can be formulated as non-linear, large scale,
mixed integer combinatorial optimization problem. For Better optimized result
with quick response, piece-wise linearization of cost function and slack terms with
high penalty factor are incorporated in unit commitment along with all generator,
system, operator and line constraints.
In order to get convergence solution with UC, OPF is performed with fixed
unit status from unit commitment solution by taking account of generator ramp
rates.
Unit Commitment with 3-part generator bidding, load bidding and bilateral
transaction with both elastic and inelastic parts is performed which is suitable for
the recent power industry.
33
Chang, Ching-Hsien, and 張靜嫻. "OPTIMAL UNIT COMMITMENT SCHEDULING FOR COGENERATION SYSTEMS." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/97055445160788646563.
Full textAbstract:
碩士<br>大同大學<br>電機工程研究所<br>91<br>ABSTRACT
The main purpose of this thesis is to find the optimal unit commitment schedule in non-summer season for a real cogeneration system with back-pressure and extraction turbines by using “Genetic Algorithms”. This thesis is first to determine at which hour the unit should be shut down and at which hour the unit should be started up during specified period, and then to solve the economic dispatch of units at each hour while considering the time-of-use (TOU) rates and the relative constraints subject to satisfying the process steam demand to reduce production costs and save energy.
Genetic algorithms are based on probabilistic transition rules and can adapt to nonlinearities and discontinuities commonly found in power systems, so they are less likely to converge to local optima. In addition, the GAs can manage time-dependent constraints. This thesis also proposes some improved methods to increase the probability of finding the global optima and save the computation time. A real cogeneration system will be used to verify the feasibility of the proposed scheme.
34
Pinto, Rui Filipe Carneiro Barbosa. "Wind power forecasting uncertainty and unit commitment." Master's thesis, 2014. https://repositorio-aberto.up.pt/handle/10216/75904.
Full text
35
Gow, Hong-Jey, and 郭宏傑. "Profit-Based Unit Commitment and Risk Analysis." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/80671717368869654840.
Full textAbstract:
博士<br>國立中山大學<br>電機工程學系研究所<br>98<br>For the power market participators, there are competition and more trade opportunities in the power industry under the deregulation. In the electricity market, the bidding model is adopted instead of the cost model. GenCos try to maximize the profit under bidding model according to the power demand. Electricity becomes commodity and its price varies with power demand, bidding strategy and the grid. GenCos perform the unit commitment in a price volatile environment to reach the maximal profit. In a deregulation environment, Independent System Operator (ISO) is very often responsible for the electricity auction and secured power scheduling. The ISO operation may involve all kinds of risks. These risks include price volatility risk, bidding risk, congestion risk, and so on. For some markets, it is very important how GenCos determine the optimal unit commitment schedule considering risk management. A good risk analysis will help GenCo maximize profit and purse sustainable development. In this study, price forecasting is developed to provide information for power producers to develop bidding strategies to maximize profit. Profit-Based Unit Commitment (PBUC) model was also derived. An Enhanced Immune Algorithm (EIA) is developed to solve the PBUC problem. Finally, the Value-at-Risk (VAR) of GenCos is found with a present confident level. Simulation results provide a risk management rule to find an optimal risk control strategy to maximize profit and raise its compatibility against other players.
36
Pinto, Rui Filipe Carneiro Barbosa. "Wind power forecasting uncertainty and unit commitment." Dissertação, 2014. https://repositorio-aberto.up.pt/handle/10216/75904.
Full text
37
WANG, JUN-JIE, and 王俊傑. "Short-term Unit Commitment Considering Equivalent Operation Hour (EOH) of Combined-Cycle Units." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/6x68wa.
Full textAbstract:
碩士<br>國立中正大學<br>電機工程研究所<br>105<br>In recent years, power industries have been aggressive in reducing costs or improving operation efficiency because of higher international energy's prices. Fortunately, gas power generation benefit from the realization of the combined cycle technology, which greatly improve the power generation efficiency. However, it will become more difficult to do electrical dispatch when a large of combined cycle units are built.
In this thesis, Pyomo is adopted to establish unit commitment model with short-term scheduling of combined cycle plants and thermal units by considering Minimum cost and generator characteristics including combined cycle unit’s Equivalent Operation Hour. The mathematical model proposes Mixed Integer Linear Programing (MILP) for based approaches, and piecewise linear approximation is used to get units input/output curves.
38
"Generalized unit commitment by the radar multiplier method." Universitat Politècnica de Catalunya, 2001. http://www.tesisenxarxa.net/TDX-0720101-132715/.
Full text
39
Huang, Kai-Wen, and 黃楷雯. "Unit Commitment Of Steam-Turbine For Multi-Constraints." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/71132445909724353963.
Full textAbstract:
碩士<br>國立臺灣海洋大學<br>電機工程學系<br>102<br>The age of power industry competition is coming, the important business point is how to reduce cost and increase operating profit. The main variable cost of power industry is fuel cost. How to develop a day ahead operation plan, to maintain the security constrained economic dispatch, is very important. The actual system operation constraints have to satisfy the power balance, minimum up/down time and spinning reserve traditionally. In addition to above mention constraints that system has to consider unit’s output on the start-up/shut-down periods and unit ramping up/down rate.
In this paper we will build up an integer mixed linear programming model, which considers the unit operation characteristics. The simulation results of Taipower thermal unit system
The unit commitment problem is an integer variable problem, so when considering constraint and the system greater, the solution combinations are more, and need the temporary space used larger in the hardware and the solving time is longer. So, this paper proposed a simplified model, combined with two-stage algorithm. First, the problems is used by the simplified model, and then use the solution of the simplified model to make parameters setting of the complete model, and then solve the problem with the complete model to speed up the solution. Simulation result show that the single cycle unit commitment model can satisfy the actual system operation condition.
40
LIAO, GUO-QING, and 廖國清. "An expert system for short term unit commitment." Thesis, 1991. http://ndltd.ncl.edu.tw/handle/07734727812900643423.
Full text
41
Chen, Wei-De, and 陳維德. "Using Immune Algorithm to Optimal Thermal Unit Commitment." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/v4hb92.
Full textAbstract:
碩士<br>國立臺北科技大學<br>電機工程系所<br>96<br>Aim of the thesis is to optimal thermal unit commitment of transmission system. In general, the major purpose of thermal unit commitment is to schedule the on/off status, real power output of units at each hour and minimize the total production cost under constraints in the system. This thesis first consider point is transmission line loss, then take the economic dispatch that include losses to obtain the output of each unit, and apply Immune Algorithm to acquire the most favorable generation schedule.
Immune Algorithm has self-organizing ability and simulates the immune response in the human body, use surface of lymphocyte to discern the antigen and use the suppressor cell to restrain to high affinity antibodies, increase the diversity between the antibodies, that can avoid drop into the local optimal solution. Immune system can use antibody self-organizing ability and dispersal search to solve the large question. Immune system use memory function to save the better antibodies to next generation that can help to have the good answer quickly.
This thesis simulates the proposed method for 24-hour unit commitment on an IEEE 30-bus power system and a reduced Taipower system. The dispatch solutions are then compared to their counterparts obtained by Genetic Algorithm(GA), Ant Colony System (ACS), Ant System (AS) and Dynamic Programming (DP) to verify the proposed method as a better approach for achieving the optimal cost of power generation. The proposed method can therefore be expected to help dispatchers perform more economical dispatch.
42
Aldridge, C. J., S. McKee, J. R. McDonald, et al. "A knowledge-based genetic algorithm for unit commitment." 2001. http://hdl.handle.net/10454/3689.
Full textAbstract:
No<br>A genetic algorithm (GA) augmented with knowledge-based methods has been developed for solving the unit commitment economic dispatch problem. The GA evolves a population of binary strings which represent commitment schedules. The initial population of schedules is chosen using a method based on elicited scheduling knowledge. A fast rule-based dispatch method is then used to evaluate candidate solutions. The knowledge-based genetic algorithm is applied to a test system of ten thermal units over 24-hour time intervals, including minimum on/off times and ramp rates, and achieves lower cost solutions than Lagrangian relaxation in comparable computational time.
43
Huang, Shun-Hsien, and 黃舜賢. "OPTIMAL UNIT COMMITMENT SCHEDULING FOR COGENERATION BY GENETIC ALGORITHMS." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/58368871050506905003.
Full textAbstract:
碩士<br>大同工學院<br>電機工程研究所<br>87<br>The main purpose of this thesis is to find the optimal unit commitment schedule during off-peak period in non-summer season by using "Genetic Algorithms", and to find the optimal economic operation mode by using "Real-Code Modified Genetic Algorithms". This thesis includes solving the economic dispatch of units at each hour and the unit commitment schedule during specified period, and finding how many hours are needed in the off-peak period that is worth of considering the unit commitment in cogeneration system. At which hour the unit should be shut down and at which hour the unit should be started up in the unit commitment also included in this thesis. Besides, the variation of fuel price in the unit commitment problem is analyzed in this thesis.
The major advantages of using GA are that it can replace the shortcomings of mathematical programming approaches more efficiently. Through the proposed improvement method in this thesis, we can rapidly increase search speed. A real cogeneration system will be used as an example to verify the feasibility of the proposed scheme.
44
Chang, Yu-Ming, and 張育銘. "Planning unit commitment of hybrid power systems in Penghu." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/93394334730237616504.
Full textAbstract:
碩士<br>東南科技大學<br>電機工程研究所<br>102<br>Penghu is one of the mainly Taiwanese outlying island, also the biggest stand-alone power system except Taiwan, it’s mainly powered by twelve diesel engine generators in Chienshan power plant. For efficiently use the wind power in Penghu, it built eight 600kW and six 900kw wind turbines to the system one after another, but because the wind turbines peak load are no output in summer, and off-peak are the biggest output that can’t load in winter, so the plan isn’t considered to integrated into the wind farm in Penghu, and as far as Penghu, every diesel engine generators in Chienshan power plant is large. In particular in off-peak period, it cause the Generator power in total Power generation ratio over loaded, when system happened diesel engine generators trip disturbances, or all wind turbines tripped, it cause the seriously Impact to system frequency.
In this paper, we used the power system analyze software PSS/E (Power System Simulator for Engineering) to simulate that use many of the small generators replace the large generators in Chienshan power plant to reduce the Generator power in total Power generation ratio, when system happened trip disturbances, it reduce the effect to the frequency, the simulate result can provide to Taiwan Power Company for reference of upgrade.
45
Chuang, Ching-Lin, and 莊沁霖. "Study of Unit Commitment with Cascade Hydro Power Plants." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/20464006670195153663.
Full textAbstract:
碩士<br>國立臺灣海洋大學<br>電機工程學系<br>105<br>Ta-Chia River, as one of the most important river in Taiwan, has plentiful water resources and steep topography, and thus is suitable for hydro power generation. Ta-Chia River hydro power plant is accounting for about a quarter of hydro unit installed capacity and 40% of hydro unit generating capacity in Taiwan. Besides, Ta-Chia River hydro power plant can remove peak load and start to modulate frequency, and emergency backup to stabilize the power system, playing an irreplaceable role in the taipower hydroelectric power system. However, the spatial and tempora distribution of rainfall is uneven in Taiwan and the short distances of hydro power plants along the Ta-Chia River area, it is an important issue to use the limited water resources efficiently.
In this study, we build a model of unit commitment with cascade hydro power plants to simulate with thermal units, and solving it by mixed integer linear programming. The systems we simulate are thermal units, combined-cycle units, and hydro units in Ta-Chia river hydraulic power plant, recording the system load by every 15 minutes in 24 hours. Systems including hydro units are far more complicated than Systems including thermal units. Except the unit operation characteristics of thermal units, a coordination of cascaded hydro units dispatch should also consider the requied amount of water, the limit of reservoir water level…etc. Under the premise that system operation security is satisfied, proving water resources use as far as possible and reduce fuel costs of thermal units can achieve maximizing the benefits by thermal units.
To meet the requirements of secure operation of the system, this thesis analyzes cases of water requirement of downsterm, reservoir water level, and reserve capacity of Ching-Shan hydro units. The simulation results are justify the cases that can be applied in reality.
Keywords: Unit Commitment with Cascade Hydro Power Plants, Mixed Integer Linear Programming, Unit Operation Characteristics
46
WANG, SHUN-ZHONG, and 王順忠. "Branch-and-bound for short-term thermal unit commitment." Thesis, 1992. http://ndltd.ncl.edu.tw/handle/78037718427620699629.
Full text
47
Huang, Shih-Ting, and 黃詩婷. "Day Ahead Unit Commitment in Microgrid Using Genetic Algorithm." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/12011228454223745459.
Full textAbstract:
碩士<br>國立臺灣海洋大學<br>電機工程學系<br>99<br>Primary energy is facing the problem of running out fuel and it makes too much pollution so that developing green energy, which has low pollution and zero fuel cost, has become the main issue in the world. In order to increase the National competitiveness, it is important to integrate renewable energy into power system. In this study, we construct a microgrid model of solar power, wind power, battery energy storage system, traditional thermal power and utility grid and we solve a unit commitment problem in the microgrid by using a genetic algorithm to reach the minimum cost. To confirm the proposed program is availability under different operating conditions, the criteria of microgrid are discussed with different power system connection types, load curves and capacity of battery energy storage system in simulation cases. The result of this study can efficiently use the renewable energy in the microgrid and reduce generation costs.
48
Hsu, Hao-Hsuan, and 徐晧軒. "The Two-Stage Solution of Long Term Unit Commitment." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/04788361410364578763.
Full textAbstract:
碩士<br>國立臺灣海洋大學<br>電機工程學系<br>99<br>Abstract
Power industry is one of major energy industries, and Taiwan’s electricity consumption is affected by the global economy with uncertainty, making power production plan is difficult to develop, needing a analysis tools considering the actual scheduling constraints to help. The long term unit commitment model is proposed in this paper do for the power production plans aids, in addition to considering the traditional unit and system constraints, also considering annual fuel consumptions, monthly fuel consumptions, the total number of private power plants start-up and shut-down, emissions of CO2 and other long-term planning restrictions. The solving method used in this paper is mixed integer linear programming, the unit commitment problem is an integer variable problem, so when considering the system the greater and the simulation period the longer, the solution combinations are more, and need the temporary space used larger in the hardware and the solving time the longer. So, this paper proposed a simplified model of the energy viewpoint, combined with two-stage algorithm. First, the problem with the simplified model is solved, and then uses the solutions of the simplified model to make parameters setting of the complete model, and then solve the problem with the complete model to speed up the solution.
49
Li, Yuan-hui, and 李元輝. "A Study for Price-Based Unit Commitment with Carbon." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/645nd4.
Full textAbstract:
碩士<br>國立中山大學<br>電機工程學系研究所<br>97<br>In this thesis, the Hybrid Genetic Algorithm-Ant Colony Optimization (GACO) approach is presented to solve the unit commitment problem (UC), and comparison with the results obtained using literature methods. Then this thesis applied the ability of the Genetic Algorithm (GA) operated after Ant Colony Optimization (ACO) can promote the ACO efficiency. The objective of GA is to improve the searching quality of ants by optimizing themselves to generate a better result, because the ants produced randomly by pheromone process are not necessary better. This method can not only enhance the neighborhood search, but can also search the optimum solution quickly to advance convergence. The other objective of this thesis is to investigate an influence of emission constraints on generation scheduling. The motivation for this objective comes from the efforts to reduce negative trends in a climate change. In this market structure, the independent power producers have to deal with several complex issues arising from uncertainties in spot market prices, and technical constraints which need to be considered while scheduling generation and trading for the next day. In addition to finding dispatch and unit commitment decisions while maximizing its profit, their scheduling models should include trading decisions like spot-market buy and sell. The model proposed in this thesis build on the combined carbon finance and spot market formulation, and help generators in deciding on when these commitments could be beneficial.
50
Sen, Subir. "On some aswpects of optimal thermal generating unit commitment." Thesis, 1997. http://localhost:8080/xmlui/handle/12345678/6437.
Full text