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Singh, Ravindra. "State estimation in power distribution network operation". Thesis, Imperial College London, 2009. http://hdl.handle.net/10044/1/5468.
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The majority of power distribution networks were planned, designed and built as a passive but reliable link between the bulk power transmission point and the in- dividual customer. Enough latent capacity in cables and lines to accommodate anticipated demand growth was allowed and so the system was left unmonitored. Following the signicant development in business regulation, technology evolutions and various government policies towards low carbon renewable generation, it has become necessary to operate the distribution systems efficiently and in a controlled manner. This obviously needs state estimation for network control functions. State estimation is the core function of any energy management system in transmission networks. However little emphasis have been given to the distribution system state estimation, mainly due to the absence of adequate network measurements and also lack of rigorous methodology and tools that could be applied on restricted measure- ments. The scarcity of measured information offers formidable challenge to the state estimator to provide reasonably meaningful estimates of the system states. This introduces bottlenecks in carrying out a range of substation and feeder automa- tion tasks that rely on the quality of the state estimator and opens up many issues like modelling of demand, identification of suitable estimator and placement of new measurements etc. This thesis attempts to address these issues. Thus, the objec- tives of this research are to model the demand as pseudo measurement, identify the state estimation methodology to suite the distribution scenarios and find the effec- tive locations for placing measurements for improving the quality of the estimated quantities. The thesis discusses in detail the criterion for identifying suitable solvers for the distribution system state estimation and stochastic optimisation methods to model the demand. It also discusses a probabilistic technique for identifying effective locations for measurement placement. The robustness of the state estimation algorithm against changes in network topology has been addressed in a statistical framework. All the concepts have been demonstrated on 12-bus radial and 95-bus UKGDS network models.
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Singh, Manish K. "Optimal Operation of Water and Power Distribution Networks". Thesis, Virginia Tech, 2018. http://hdl.handle.net/10919/86860.
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Under the envisioned smart city paradigm, there is an increasing demand for the coordinated operation of our infrastructure networks. In this context, this thesis puts forth a comprehensive toolbox for the optimization of electric power and water distribution networks. On the analytical front, the toolbox consists of novel mixed-integer (non)-linear program (MINLP) formulations; convex relaxations with optimality guarantees; and the powerful technique of McCormick linearization. On the application side, the developed tools support the operation of each of the infrastructure networks independently, but also towards their joint operation. Starting with water distribution networks, the main difficulty in solving any (optimal-) water flow problem stems from a piecewise quadratic pressure drop law. To efficiently handle these constraints, we have first formulated a novel MINLP, and then proposed a relaxation of the pressure drop constraints to yield a mixed-integer second-order cone program. Further, a novel penalty term is appended to the cost that guarantees optimality and exactness under pre-defined network conditions. This contribution can be used to solve the WF problem; the OWF task of minimizing the pumping cost satisfying operational constraints; and the task of scheduling the operation of tanks to maximize the water service time in an area experiencing electric power outage. Regarding electric power systems, a novel MILP formulation for distribution restoration using binary indicator vectors on graph properties alongside exact McCormick linearization is proposed. This can be used to minimize the restoration time of an electric system under critical operational constraints, and to enable a coordinated response with the water utilities during outages.Master of Science
The advent of smart cities has promoted research towards interdependent operation of utilities such as water and power systems. While power system analysis is significantly developed due to decades of focused research, water networks have been relying on relatively less sophisticated tools. In this context, this thesis develops Advanced efficient computational tools for the analysis and optimization for water distribution networks. Given the consumer demands, an optimal water flow (OWF) problem for minimizing the pump operation cost is formulated. Developing a rigorous analytical framework, the proposed formulation provides significant computational improvements without compromising on the accuracy. Explicit network conditions are provided that guarantee the optimality and feasibility of the obtained OWF solution. The developed formulation is next used to solve two practical problems: the water flow problem, that solves the complex physical equations yielding nodal pressures and pipeline flows given the demands/injections; and an OWF problem that finds the best operational strategy for water utilities during power outages. The latter helps the water utility to maximize their service time during power outages, and helps power utilities better plan their restoration strategy. While the increased instrumentation and automation has enabled power utilities to better manage restoration during outages, finding an optimal strategy remains a difficult problem. The operational and coordination requirements for the upcoming distributed resources and microgrids further complicate the problem. This thesis develops a computationally fast and reasonably accurate power distribution restoration scheme enabling optimal coordination of different generators with optimal islanding. Numerical tests are conducted on benchmark water and power networks to corroborate the claims of the developed formulations.
3
Waseem, Irfan. "Impacts of Distributed Generation on the Residential Distribution Network Operation". Thesis, Virginia Tech, 2008. http://hdl.handle.net/10919/36394.
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In this research, the impacts of installing DG on a residential distribution circuit are explored. The work is focused on analyzing the impact of DG installation on distribution network operation including voltage analysis, electric losses and reliability of the system. First, various DG penetration levels and the impact of distributing the DG across several locations are explored. Secondly, the impacts of installing DG on any one phase on the voltage profiles of the unbalanced three-phase distribution network are investigated. Thirdly, the losses of the system are analyzed. Next, the reliability analysis (SAIDI, CAIDI, ENS, and AENS) of the system is performed by installing DGs as backup generators. Different DG penetration levels, locations and the impacts of installing one large-scale DG on the main distribution line vs. several small-scale randomly distributed DGs are explored. A residential distribution circuit in Blacksburg, VA was built using its one-line diagram in DEW (Distributed Engineering Workstation) to perform detailed analysis. The research involves several case studies that explore the impacts of installing distributed generation (DG) on residential distribution network operation including the voltage profile, losses, and reliability indices of the system.Master of Science
4
Olivella, Rosell Pol. "Local electricity markets design and operation in distribution power systems". Doctoral thesis, Universitat Politècnica de Catalunya, 2020. http://hdl.handle.net/10803/669803.
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In the context of distributed generation growth, local grids could face operational issues. In that sense, smart grid deployment will give information to local grid operators about grid status at medium and low voltage levels for taking operational decisions on daily basis. This thesis presents local markets as a potential solution to avoid local grid congestions and over-costs. They mainly increase the negotiation power of end-users with distributed energy resources and allow activation of flexibility at local level.
First of all, this thesis analyses electric vehicles as a potential challenge for distribution grids and electricity markets in case of uncontrolled charging as it could cause consumption peaks. At the same time, electric vehicles could be part of the solution thanks to their capability of shifting forward their consumption. The first solution presented in this thesis is a building level electric vehicle management algorithm in order to reduce energy cost and consumption peaks.
However, local grid operators need a solution to deal with aggregated level problems like high demand or high generation periods. Such kind of problems vary over time and place, and they could be difficult to integrate in regular grid tariffs. Therefore, the present thesis provides two local market designs for these problems. The first local market presented is designed for taking advantage of renewable energy producers before and after the whole-sale day-ahead market without threatening distribution grids and increasing the local social welfare. However, this market implies significant regulatory changes because the local market operator should take sorne of the current local grid operator regulated activities.
Therefore, this thesis presents a second market design for managing portfolios of consumers, producers and prosumers, and it could be operated by retailers, balance responsible parties or aggregators for flexibility provision without regulatory issues. The work includes a description of roles, contracts and interactions of such local flexibility market, and three optimization algorithms depending on the application, complexity and portfolio scale. The first algorithm assumes limited information about each site, the second one includes such information but presents potential scalability limitations, and the last algorithm is based on a decomposition method to optimise the aggregator portfolio in a distributed way reducing the computational burden and time.En el context d'expansió de generadors d'electricitat renovable i distribuïda, les xarxes de distribució podrien presentar problemes d'operació. A més a més, en un context de desplegament de la xarxa elèctrica intel·ligent, les companyies distribuïdores tindran un millor coneixement de l'estat de la xarxa per prendre decisions d'operació en el dia a dia tant a nivell de mitja com en baixa tensió. Els mercats locals constitueixen una possible solució per a la resolució de congestions a les xarxes de distribució d'electricitat i reduir els sobre costos del sistema elèctric. Aquests mercats també permetrien incrementar el poder de negociació dels consumidors d'electricitat a petita escala amb capacitat de flexibilitat. Primerament s'analitza el potencial perill que poden suposar els vehicles elèctrics per a les xarxes de distribució en cas de no haver-hi gestió intel·ligent dels processos de carrega ja que podrien aparèixer nous pics de consum. Alhora, els vehicles elèctrics podrien ser part de la solució desplaçant el seu consum a la nit. El present treball inclou un algorisme de gestió de vehicles elèctrics a nivell d'edifici per a reduir el cost d'electricitat i els pics de consum. No obstant, les companyies distribuïdores necessiten una solució per als problemes de la xarxa que podrien ser diferents segons la zona o l'època de l'any. Es per això que aquest treball inclou dues propostes de mercat local per a aquests problemes. El primer mercat local esta dissenyat per a aprofitar l'avantatge dels productors d'energia renovable abans i després del mercat diari majorista sense comprometre l'operació de la xarxa de distribució. Tot i aixó, aquesta proposta de mercat local requeriria diversos canvis en matèria de regulació ja que l'operador del mercat local hauria de prendre algunes de les actuals responsabilitats de les companyies distribuïdores. Seguidament, la tesi presenta un segon mercat local per gestionar una cartera de consumidors, productors i prosumidors, com una activitat més dins de les activitats de les companyies comercialitzadores o agregadors de flexibilitat. El present document inclou una descripció dels rols, contractes i interaccions, i tres algorismes d'optimització des del més simple fins al més complex. El primer assumeix una limitació en la informació disponible de cada membre de la cartera, el segon inclou més informació però presenta limitacions d'escalabilitat, i finalment el tercer presenta un algorisme de descomposició per optimitzar la flexibilitat de manera distribuïda i així reduir el temps de computació i la complexitat de càlcul.
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Pregelj, Aleksandar. "Impact of Distributed Generation on Power Network Operation". Diss., Georgia Institute of Technology, 2003. http://hdl.handle.net/1853/5127.
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Tools and algorithms are proposed that are useful for planning, designing, and operating a distribution network with a significant penetration of distributed generation (DG). In Task 1, a PV system simulation program is developed, which incorporates the most rigorous models for the calculation of insolation, module temperature, and DC and AC power output of a PV system. The effect of random inverter failures is incorporated in the model of a PV system, and a novel performance-derating coefficient is introduced. Furthermore, a novel inverter control algorithm is presented for systems with multiple inverters. The algorithm is designed to increase overall DC/AC conversion efficiency by selectively shutting down some of the inverters during periods of low insolation, thus forcing the remaining inverters to operate at higher efficiency. In Task 2, a procedure is developed to incorporate the uncertainties imposed by stochastic, renewable DG into the conventional tools for analysis of distribution systems. A clustering algorithm is proposed to reduce large input data sets that result from the interaction of stochastic processes that drive DG output with field measurements of feeder load profiles. In addition, a procedure is proposed to determine the boundary points of the original data set, which yield feeder extreme operating conditions. Finally, a Monte Carlo analysis using a reduced data set is presented, to determine the effects of deploying a large number of renewable DG systems on a distribution feeder. In Task 3, the reliability model of an asymmetric, three--phase, non-radial distribution feeder equipped with capacity-constrained DGs is developed and used to quantify the potential reliability improvements due to the intentional islanded operation of parts of the feeder. A procedure for finding optimal positions for DG and protection devices is presented using a custom-tailored adaptive genetic algorithm.
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Zubo, Rana H. A. "Distribution Network Operation with High Penetration of Renewable Energy Sources. Joint Active/Reactive Power Procurement: A Market-Based Approach for Operation of Distribution Network". Thesis, University of Bradford, 2019. http://hdl.handle.net/10454/18267.
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Distributed generators (DGs) are proposed as a possible solution to supply
economic and reliable electricity to customers. It is adapted to overcome the
challenges that are characterized by centralized generation such as
transmission and distribution losses, high cost of fossil fuels and environmental
damage. This work presents the basic principles of integrating renewable DGs
in low voltage distribution networks and particularly focuses on the operation
of DG installations and their impacts on active and reactive power.
In this thesis, a novel technique that applies the stochastic approach for the
operation of distribution networks with considering active network
management (ANM) schemes and demand response (DR) within a joint active
and reactive distribution market environment is proposed. The projected model
is maximized based on social welfare (SW) using market-based joint active
and reactive optimal power flow (OPF). The intermittent behaviour of
renewable sources (such as solar irradiance and wind speed) and the load
demands are modelled through Scenario-Tree technique. The distributed
network frame is recast using mixed-integer linear programming (MILP) that is
solved by using the GAMS software and then the obtained results are being
analysed and discussed. In addition, the impact of wind and solar power
penetration on the active and reactive distribution locational prices (D-LMPs)
within the distribution market environment is explored in terms of the
maximization of SW considering the uncertainty related to solar irradiance,
wind speed and load demands. Finally, a realistic case study (16-bus UK
generic medium voltage distribution system) is used to demonstrate the
effectiveness of the proposed method. Results show that ANM schemes and
DR integration lead to an increase in the social welfare and total dispatched
active and reactive power and consequently decrease in active and reactive
D-LMPs.Ministry of Higher Education and Scientific Research - Iraq
The selected author's publications, the published versions of which were attached at the end of the thesis, have been removed due to copyright.
7
Tong, Shiqiong Miu Karen Nan. "Slack bus modeling for distributed generation and its impacts on distribution system analysis, operation and planning /". Philadelphia, Pa. : Drexel University, 2006. http://hdl.handle.net/1860/1229.
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Agalgaonkar, Yashodhan Prakash. "Control and operation of power distribution system for optimal accommodation of PV generation". Thesis, Imperial College London, 2014. http://hdl.handle.net/10044/1/24954.
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The renewable policies in various countries are driving significant growth of grid connected renewable generation sources such as the Photovoltaics (PVs). Typically a PV generation is integrated into power systems at the low and the medium voltage distribution level. The uptake of an intermittent power from the PVs is challenging the power system operation and control. The network voltage control is one of the major challenges during the operation of the distribution connected PVs. The active power injection from a PV plant causes variable voltage rise. This forces the existing voltage control devices such as on-load tap-changer (OLTC) and voltage regulator (VR) to operate continuously. The consequence is the reduction of the operating life of the voltage control mechanism. Also, the conventional non-coordinated reactive power control results in the operation of the VR at its control limit (VR runaway condition). This research focuses on the distribution voltage control in the presence of PV generation and helps to establish detailed insights into the various associated challenges. Firstly, the typical grid integrated PV topologies are discussed. The existing power system operational practices are presented and their limitations are identified. A voltage control methodology to tackle challenges such as over-voltage, excessive tap counts and VR runaway is presented. These challenges are alleviated through the coordinated reactive power control. The reactive power coordination is achieved through the deterministic distribution optimal power flow solved through the interior point technique. The irradiance and the load forecasting errors are another set of challenges from the distribution network operators' perspective. The stochastic optimal voltage control strategy is proposed to tackle the element of randomness associated with the forecast errors. The stochastic operational risks such as an over- voltage and a VR runaway are defined through a chance constrained optimization problem. The simulation study is performed using a realistic 95-bus UK generic distribution network model and a practically measured irradiance to demonstrate the effectiveness of the proposed control strategies. The thesis makes an effort to offer an insight into the operational challenges and propose strategies to achieve a seamless integration of the PVs into the power systems.
9
Jones, Gavin Wesley. "Distribution system operation and planning in the presence of distributed generation technology". Diss., Rolla, Mo. : University of Missouri-Rolla, 2007. http://scholarsmine.umr.edu/thesis/pdf/Jones_09007dcc803b193d.pdf.
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Thesis (M.S.)--University of Missouri--Rolla, 2007.Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed November 16, 2007) Includes bibliographical references (p. 71-74).
10
Feng, Yixue. "DC fault ride through operation of a full-bridge MMC converter". Thesis, University of Nottingham, 2016. http://eprints.nottingham.ac.uk/32426/.
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In recent years the growth of renewable energy has encouraged the development of HVDC grids. One challenge of building HVDC grids is the power converter response to DC side faults. The full-bridge Modular Multilevel Converter (MMC) is a desired power converter topology which is used in HVDC grids due to its scalability, modularity and capability of blocking DC side faults. Post fault operation of the full-bridge MMC requires the control of power flow, the energy of each sub-module capacitor and the elimination of circulating harmonic current to reduce power loss while DC line-to-ground or DC line-to-line faults exist. This thesis presents a post fault operation method for a full-bridge MMC in order to transmit partial power after a DC line-to-ground fault and provides reactive power after DC line-to-line fault. Simulated results are provide from a point-to-point HVDC system which consists of two eleven-level full-bridge MMC.
11
Pulazza, Giorgia <1993>. "Planning and flexible operation of storage systems in power grids: from transmission to distribution networks". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2022. http://amsdottorato.unibo.it/10487/1/PHD_Thesis_GiorgiaPulazza.pdf.
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The first part of the thesis has been devoted to the transmission planning with high penetration of renewable energy sources. Both stationary and transportable battery energy storage (BES, BEST) systems have been considered in the planning model, so to obtain the optimal set of BES, BEST and transmission lines that minimizes the total cost in a power network. First, a coordinated expansion planning model with fixed transportation cost for BEST devices has been presented; then, the model has been extended to a planning formulation with a distance-dependent transportation cost for the BEST units, and its tractability has been proved through a case study based on a 190-bus test system.
The second part of this thesis is then devoted to the analysis of planning and management of renewable energy communities (RECs).
Initially, the planning of photovoltaic and BES systems in a REC with an incentive-based remuneration scheme according to the Italian regulatory framework has been analysed, and two planning models, according to a single-stage, or a multi-stage approach, have been proposed in order to provide the optimal set of BES and PV systems allowing to achieve the minimum energy procurement cost in a given REC.
Further, the second part of this thesis is devoted to the study of the day-ahead scheduling of resources in renewable energy communities, by considering two types of REC. The first one, which we will refer to as “cooperative community”, allows direct energy transactions between members of the REC; the second type of REC considered, which we shall refer to as “incentive-based”, does not allow direct transactions between members but includes economic revenues for the community shared energy, according to the Italian regulation framework. Moreover, dispatchable renewable energy generation has been considered by including producers equipped with biogas power plants in the community.
12
Choi, Sungyun. "Autonomous state estimation and its application to the autonomous operation of the distribution system with distributed generations". Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/50250.
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The objective of this thesis is to propose guidelines for advanced operation, control, and protection of the restructured distribution system by designing the architecture and functionality for autonomous operation of the distribution system with DGs. The proposed architecture consists of (1) autonomous state estimation and (2) applications that enable autonomous operation; in particular, three applications are discussed: setting-less component protection, instant-by-instant management, and short-term operational planning. Key elements of the proposed approach have been verified: (1) the proposed autonomous state estimation has been experimentally tested using laboratory test systems and (2) the feasibility of the setting-less component protection has been tested with numerical simulations.
13
Behnood, Aref. "Optimal Operation of Battery Energy Storage Systems in Radial Distribution Networks". Thesis, Uppsala universitet, Elektricitetslära, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-397113.
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In recent years, power systems are facing with various challenges arising from the increased share of renewable energy systems. Among all sections of power systems, distribution grids are affected the most since the majority of renewable energy sources are connected to distribution grids. As the penetration of Variable Energy Sources increases in electric grids, energy storage systems have become more influential. In this context, this thesis presents a new algorithm for the optimal operation of Battery Energy Storage Systems in distribution grids. The proposed algorithm aims to define the optimal operation of Battery Energy Storage Systems considering the network topology, the output power of Variable Energy Sources and the electricity prices from the one-day ahead electric market as well as real time control of the batteries through smart appliances. In order to do this, firstly a comprehensive study on the existing Optimal Power Flow methods is carried out. Then, AR-OPF which is a novel Optimal Power Flow method for radial distribution systems is presented and the required mathematical constraints, equations and parameters of Battery Energy Storage Systems for modelling in distribution systems are described. Then, the problem formulation and the proposed algorithm are discussed in detail. Further to energy storage as the main function of Battery Energy Storage Systems, the impact of the proposed method on other functions of Battery Energy Storage Systems such as voltage control, grid support and loss reduction will be investigated. In order to do so, the proposed algorithm is applied to the IEEE 34 node test system as a case study. This will be carried out through defining several different scenarios. Finally, a sensitivity analysis is performed on the size of the existing batteries and the electricity price. The thesis will be concluded by the findings and possible future works.
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Castro, Erasmo Saraiva de. "Impact of electric vehicles in the steady state operation of distribution systems". Universidade Federal do CearÃ, 2015. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=14544.
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FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgicoThis work aims to quantify the impact in the steady state operation of a distribution system when electric vehicles are connected. It is worth noting that the connection of them may cause significant changes in the voltage profile, in the degree of voltage unbalance and in the electrical losses of the system. In order to make this analysis, a three-phase power flow program was developed in MATLAB language. This program is based on the Ladder Iterative Technique and it contains models of overhead distribution lines, underground distribution lines, spot loads, distributed loads connected in wye and delta, step voltage regulators, capacitor banks, three-phase transformers and the model of an electric vehicle. This model allows simulation of a real electric vehicle of model Tesla Roadster, produced by Tesla Motors. The test system used in all simulations was the IEEE 13 bus. Moreover, the methodology consisted in simulate the system with the voltage regulator and without the voltage regulator under heavy load and light load conditions. The electric vehicle was connected to a specific systemâs bus and it were considered that it could work as a load or as a distributed generator with or without positive sequence voltage control. Constants configurations of the electric vehicles were considered for the heavy load and light load cases. The results of the simulations reveal there was voltage violation due to the connection of electric vehicles acting as loads in the test system under heavy load conditions without voltage regulator. When they operate as generators, they can maintain the voltage unbalance under the allowed 2%, turning the systemâs voltages more balanced. There were significant reductions when the electric vehicles acted as a load (71.1%) and as generator (77.5%) on the total real power losses when the system operated with voltage regulator on the substation and the electric vehicles operated with positive sequence voltage control (specified at 1,0 pu).
Este trabalho tem o objetivo de quantificar o impacto da conexÃo de veÃculos elÃtricos na operaÃÃo em regime permanente de um sistema de distribuiÃÃo. à visto que a conexÃo dos mesmos pode causar mudanÃas significativas no perfil de tensÃes, no grau de desequilÃbrio de tensÃo e nas perdas elÃtricas do sistema. Para realizar essa anÃlise, desenvolveu-se um programa de fluxo de potÃncia trifÃsico na linguagem MATLAB. O programa à baseado na tÃcnica iterativa de escada. Foram implementados nesse programa modelos de linhas de distribuiÃÃo aÃreas e subterrÃneas, modelos de cargas concentradas e distribuÃdas conectadas em delta e em estrela, modelos de reguladores de tensÃo, modelos de banco de capacitores, modelo de transformadores trifÃsicos e o modelo do veÃculo elÃtrico. Esse modelo permite simular o veÃculo elÃtrico Tesla Roadster da Tesla Motors. O sistema teste utilizado em todas as simulaÃÃes foi o sistema IEEE 13 barras. A metodologia utilizada consistiu em simular o sistema sem regulador de tensÃo e com o regulador de tensÃo, em carga pesada e em carga leve. O veÃculo elÃtrico foi conectado a uma barra do sistema e considerou-se que o mesmo podia funcionar como carga ou gerador distribuÃdo sem e com controle de tensÃo de sequÃncia positiva no ponto de conexÃo. Adotou-se disposiÃÃes constantes de veÃculos elÃtricos para os casos de carga pesada e carga leve. Os resultados das simulaÃÃes revelam que houve violaÃÃo de tensÃo devido à inserÃÃo de veÃculos elÃtricos atuando como carga no sistema teste em carga pesada sem regulador de tensÃo. Jà quando operam como gerador, os veÃculos elÃtricos diminuem o grau de desequilÃbrio em mÃdia, podendo mantÃ-lo abaixo do limite permitido de 2 %, tornando assim as tensÃes das barras trifÃsicas do sistema mais equilibradas. Houve reduÃÃes significativas quando os veÃculos elÃtricos atuaram como carga (71,1 %) e como gerador (77,5 %) na perda de potÃncia ativa total do sistema quando o sistema operou com regulador de tensÃo na subestaÃÃo e os veÃculos elÃtricos operaram com controle de tensÃo de sequÃncia positiva (especificada em 1,0 pu).
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Harnoto, Monica. "Value of distribution-level reactive power for combined heat and power systems". Thesis, Massachusetts Institute of Technology, 2020. https://hdl.handle.net/1721.1/126901.
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Thesis: M.B.A., Massachusetts Institute of Technology, Sloan School of Management, in conjunction with the Leaders for Global Operations Program at MIT, May, 2020Thesis: S.M., Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, in conjunction with the Leaders for Global Operations Program at MIT, May, 2020
Cataloged from the official PDF of thesis.
Includes bibliographical references (pages 56-59).
As the U.S. electric grid continues to experience an increase in the penetration of distributed energy resources (DER), electric utilities are evaluating new approaches for utilizing DER to help cost-effectively maintain grid resilience and reliability. One such approach is to create a transactive market for DER to provide grid services, which are services required to support reliable grid operation. Though work has been done to understand some of the technical mechanisms of this type of market, gaps still exist in understanding the value and market opportunity of ancillary services at the distribution level. One type of ancillary service - reactive power - is of particular interest because of the theoretic ability to source from existing assets on the distribution network. This paper aims to build understanding of the value of procuring reactive power from one of these assets: Combined Heat and Power (CHP) systems. The value of procuring reactive power from a CHP system will be quantified by 1) characterizing CHP systems' capacity to produce and absorb reactive power, 2) assessing the annual cost of procuring reactive power from CHP systems, and 3) comparing the CHP system technical capability and cost to the utility's conventional solution: capacitor banks. This study finds that, while there are promising scenarios in which CHP systems can technically and economically provide reactive power in a comparable or slightly advantaged manner to capacitor banks, the overall statistics for the 29 CHP systems analyzed in the New York fleet do not conclusively demonstrate an advantage that supports outright replacement of capacitor banks. Further assessment of CHP systems as a complementary source of reactive power and site-specific case studies are recommended to inform the next step in the decision making process for determining whether this path should be pursued as a source of reactive power.
by Monica Harnoto.
M.B.A.
S.M.
M.B.A. Massachusetts Institute of Technology, Sloan School of Management
S.M. Massachusetts Institute of Technology, Department of Civil and Environmental Engineering
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Elsayed, Ahmed T. "Optimum Distribution System Architectures for Efficient Operation of Hybrid AC/DC Power Systems Involving Energy Storage and Pulsed Loads". FIU Digital Commons, 2016. http://digitalcommons.fiu.edu/etd/3005.
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After more than a century of the ultimate dominance of AC in distribution systems, DC distribution is being re-considered. However, the advantages of AC systems cannot be omitted. This is mainly due to the cheap and efficient means of generation provided by the synchronous AC machines and voltage stepping up/down allowed by the AC transformers. As an intermediate solution, hybrid AC/DC distribution systems or microgrids are proposed. This hybridization of distribution systems, incorporation of heterogeneous mix of energy sources, and introducing Pulsed Power Loads (PPL) together add more complications and challenges to the design problem of distribution systems. In this dissertation, a comprehensive multi-objective optimization approach is presented to determine the optimal design of the AC/DC distribution system architecture. The mathematical formulation of a multi-objective optimal power flow problem based on the sequential power flow method and the Pareto concept is developed and discussed. The outcome of this approach is to answer the following questions: 1) the optimal size and location of energy storage (ES) in the AC/DC distribution system, 2) optimal location of the PPLs, 3) optimal point of common coupling (PCC) between the AC and DC sides of the network, and 4) optimal network connectivity. These parameters are to be optimized to design a distribution architecture that supplies the PPLs, while fulfilling the safe operation constraints and the related standard limitations. The optimization problem is NP-hard, mixed integer and combinatorial with nonlinear constraints. Four objectives are involved in the problem: minimizing the voltage deviation (ΔV), minimizing frequency deviation (Δf), minimizing the active power losses in the distribution system and minimizing the energy storage weight. The last objective is considered in the context of ship power systems, where the equipment’s weight and size are restricted.
The utilization of Hybrid Energy Storage Systems (HESS) in PPL applications is investigated. The design, hardware implementation and performance evaluation of an advanced – low cost Modular Energy Storage regulator (MESR) to efficiently integrate ES to the DC bus are depicted. MESR provides a set of unique features: 1) It is capable of controlling each individual unit within a series/parallel array (i.e. each single unit can be treated, controlled and monitored separately from the others), 2) It is able to charge some units within an ES array while other units continue to serve the load, 3) Balance the SoC without the need for power electronic converters, and 4) It is able to electrically disconnect a unit and allow the operator to perform the required maintenance or replacement without affecting the performance of the whole array.
A low speed flywheel Energy Storage System (FESS) is designed and implemented to be used as an energy reservoir in PPL applications. The system was based on a separately excited DC machine and a bi-directional Buck-Boost converter as the driver to control the charging/discharging of the flywheel. Stable control loops were designed to charge the FESS off the pulse and discharge on the pulse. All the developments in this dissertation were experimentally verified at the Smart Grid Testbed.
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Slavickas, Rimas Anthony. "Trade-off decisions in distribution utility mangement /". *McMaster only, 1998.
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Oberley, Mark J. "The operation and interaction of the Auxiliary Resonant Commutated Pole Converter in a shipboard DC power distribution network". Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1996. http://handle.dtic.mil/100.2/ADA326394.
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Thesis (M.S. in Electrical Engineering) Naval Postgraduate School, December 1996.Thesis advisor(s): John G. Ciezki. "December 1996." Includes bibliographical references (p. 185-186). Also available online.
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Ami, Sumit Mazumder. "Power quality improvements in low voltage distribution networks containing distributed energy resources". Thesis, Queensland University of Technology, 2015. https://eprints.qut.edu.au/81410/1/Sumit%20Mazumder_Ami_Thesis.pdf.
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In this thesis various schemes using custom power devices for power quality improvement in low voltage distribution network are studied. Customer operated distributed generators makes a typical network non-radial and affect the power quality. A scheme considering different algorithm of DSTATCOM is proposed for power circulation and islanded operation of the system. To compensate reactive power overflow and facilitate unity power factor, a UPQC is introduced. Stochastic analysis is carried out for different scenarios to get a comprehensive idea about a real life distribution network. Combined operation of static compensator and voltage regulator is tested for the optimum quality and stability of the system.
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Tsai, Men-Shen. "Intelligent systems for distribution operational planning and alarm processing in power systems /". Thesis, Connect to this title online; UW restricted, 1993. http://hdl.handle.net/1773/6106.
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Fu, Hao. "Market-oriented micro virtual power prosumers operations in distribution system operator framework". Thesis, University of Birmingham, 2017. http://etheses.bham.ac.uk//id/eprint/7516/.
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As the European Union is on track to meet its 2020 energy targets on raising the share of renewable energy and increasing the efficiency in the energy consumption, considerable attention has been given to the integration of distributed energy resources (DERs) into the restructured distribution system. This thesis proposes market-oriented operations of micro virtual power prosumers (J.lVPPs) in the distribution system operator framework, in which the J.lVPPs evolve from home-oriented energy management systems to price-taking prosumers and to price-making prosumers. Considering the diversity of the DERs installed in the residential sector, a configurable J.l VPP is proposed first to deliver multiple energy services using a fuzzy logic-based generic algorithm. By responding to the retail price dynamics and applying load control, the J.lVPP achieves considerable electricity bill savings, active utilisation of energy storage system and fast return on investment. As the J.lVPPs enter the distribution system market, they are modelled as price-takers in a two-settlement market first and a chance-constrained formulation is proposed to derive the bidding strategies. The obtained strategy demonstrates its ability to bring the J.l VPP maximum profit based on different composition of DERs and to maintain adequate supply capacity to meet the demand considering the volatile renewable generation and load forecast. Given the non-cooperative nature of the actual market, the J.l VPPs are transformed into price-makers and their market behaviours are studied in the context of electricity market equilibrium models. The resulted equilibrium problems with equilibrium constraints (EPEC) are presented and solved using a novel application of coevolutionary approach. Compared with the roles of home-oriented energy management systems and price-taking prosumers, the J.lVPPs as price making prosumers have an improved utilisation rate of the installed DER capacity and a guaranteed profit from participating in the distribution system market.
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Jones, Charlie Alan. "Operational extensions to a power distribution design workstation for enhanced emergency restoration". Thesis, This resource online, 1990. http://scholar.lib.vt.edu/theses/available/etd-03042009-040652/.
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Jamalzadeh, Reza. "Microgrid Optimal Power Flow Based On Generalized Benders Decomposition". Case Western Reserve University School of Graduate Studies / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=case1512743611060712.
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López, Claudio David. "Shortening time-series power flow simulations for cost-benefit analysis of LV network operation with PV feed-in". Thesis, Uppsala universitet, Elektricitetslära, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-242099.
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Time-series power flow simulations are consecutive power flow calculations on each time step of a set of load and generation profiles that represent the time horizon under which a network needs to be analyzed. These simulations are one of the fundamental tools to carry out cost-benefit analyses of grid planing and operation strategies in the presence of distributed energy resources, unfortunately, their execution time is quite substantial. In the specific case of cost-benefit analyses the execution time of time-series power flow simulations can easily become excessive, as typical time horizons are in the order of a year and different scenarios need to be compared, which results in time-series simulations that require a rather large number of individual power flow calculations. It is often the case that only a set of aggregated simulation outputs is required for assessing grid operation costs, examples of which are total network losses, power exchange through MV/LV substation transformers, and total power provision from PV generators. Exploring alternatives to running time-series power flow simulations with complete input data that can produce approximations of the required results with a level of accuracy that is suitable for cost-benefit analyses but that require less time to compute can thus be beneficial. This thesis explores and compares different methods for shortening time-series power flow simulations based on reducing the amount of input data and thus the required number of individual power flow calculations, and focuses its attention on two of them: one consists in reducing the time resolution of the input profiles through downsampling while the other consists in finding similar time steps in the input profiles through vector quantization and simulating them only once. The results show that considerable execution time reductions and sufficiently accurate results can be obtained with both methods, but vector quantization requires much less data to produce the same level of accuracy as downsampling. Vector quantization delivers a far superior trade-off between data reduction, time savings, and accuracy when the simulations consider voltage control or when more than one simulation with the same input data is required, as in such cases the data reduction process can be carried out only once. One disadvantage of this method is that it does not reproduce peak values in the result profiles with accuracy, which is due to the way downsampling disregards certain time steps in the input profiles and to the averaging effect vector quantization has on the them. This disadvantage makes the simulations shortened through these methods less precise, for example, for detecting voltage violations.
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Bin-Ibrahim, Ahmad Asrul. "Operational planning and optimisation in active distribution systems for flexible and resilient power". Thesis, Durham University, 2018. http://etheses.dur.ac.uk/12872/.
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The electricity network is undergoing significant changes to cater to environmental-deterioration and fuel-depletion issues. Consequently, an increasing number of renewable resources in the form of distributed generation (DG) are being integrated into medium-voltage distribution networks. The DG integration has created several technical and economic challenges for distribution network operators. The main challenge is basically the problem of managing network voltage profile and congestion which is caused by increasing demand and intermittent DG operations. The result of all of these changes is a paradigm shift in the way distribution networks operate (from passive to active) and are managed that is not limited only to the distribution network operator but actively engages with network users such as demand aggregators, DG owners, and transmission-system operators. This thesis expands knowledge on the active distribution system in three specific areas and attempts to fill the gaps in existing approaches. A comprehensive active network management framework in active distribution systems is developed to allow studies on (i) the flexibility of network topology using modern power flow controllers, (ii) the benefits of centralised thermal electricity storage in achieving the required levels of flexibility and resiliency in an active distribution system, and (iii) system resiliency toward fault occurrence in hybrid AC/DC distribution systems. These works are implemented within the Advanced Interactive Multidimensional Modelling Systems (AIMMS) software to carry out optimisation procedure. Results demonstrate the benefit provided by a range of active distribution system solutions and can guide future distribution-system operators in making practical decisions to operate active distribution systems in cost-effective ways.
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Gutierrez, Lagos Luis Daniel. "Advanced voltage control for energy conservation in distribution networks". Thesis, University of Manchester, 2018. https://www.research.manchester.ac.uk/portal/en/theses/advanced-voltage-control-for-energy-conservation-in-distribution-networks(2718dcf1-f5db-45df-84e2-4890956ba8b1).html.
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The increasing awareness on the effect of carbon emissions in our planet has led to several countries to adopt targets for their reduction. One way of contributing to this aim is to use and distribute electricity more efficiently. In this context, Conservation Voltage Reduction (CVR), a well-known technique that takes advantage of the positive correlation between voltage and demand to reduce energy consumption, is gaining renewed interest. This technique saves energy by only reducing customer voltages, without relying on customer actions and, therefore, can be controlled by the Distribution Network Operator (DNO). CVR not only brings benefits to the electricity system by reducing generation requirements (fewer fossil fuel burning and carbon emissions), but also to customers, as energy bill reductions. The extent to which CVR can bring benefits mainly depends on the customers load composition and their voltages. While the former dictates the voltage-demand correlation, the latter constraints the voltage reduction that can be applied without violating statutory limits. Although CVR has been studied for many years, most of the studies neglect the time-varying voltage-demand characteristic of loads and/or do not assess end customer voltages. While these simplifications could be used to estimate CVR benefits for fixed and limited voltage reductions, realistic load and network models are needed to assess the performance of active CVR schemes, where voltages are actively managed to be close to the minimum limit. Moreover, distribution networks have been traditionally designed with limited monitoring and controllability. Therefore, CVR has been typically implemented by adopting conservative voltage reductions from primary substations, for both American and European-style networks. However, as new infrastructure is deployed in European-style LV networks (focus of this work), such as monitoring and on-load tap changers (OLTCs), the opportunity arises to actively manage voltages closer to end customer (unlocking further energy savings). Although these technologies have shown to effectively control voltages in LV networks, their potential for CVR has not been assessed before. Additionally, most CVR studies were performed in a context where distributed generation (DG) was not common. However, this has changed in many countries, with residential photovoltaic (PV) systems becoming popular. As this is likely to continue, the interactions of residential PV and CVR need to be studied. This thesis contributes to address the aforementioned literature gaps by: (i) proposing a simulation framework to characterise the time-varying voltage-demand correlation of individual end customers; (ii) developing a process to model real distribution networks (MV and LV) from DNO data; (iii) adopting a Monte Carlo-based quantification process to cater for the uncertainties related to individual customer demand; (iv) assessing the CVR benefits that can be unlocked with new LV infrastructure and different PV conditions. To accomplish (iv), first, a simple yet effective rule-based scheme is proposed to actively control voltages in OLTC-enabled LV networks without PV and using limited monitoring. It is demonstrated that by controlling voltages closer to customers, annual energy savings can increase significantly, compared to primary substation voltage reductions. Also, to understand the effect of PV on CVR, a centralized, three-phase AC OPF-based CVR scheme is proposed. This control, using monitoring, OLTCs and capacitors across MV and LV networks, actively manages voltages to minimize energy consumption in high PV penetration scenarios whilst considering MV-LV constraints. Results demonstrate that without CVR, PV systems lead to higher energy imports for customers without PV, due to higher voltages. Conversely, the OPF-based CVR scheme can effectively manage voltages throughout the day, minimising energy imports for all customers. Moreover, if OLTCs at secondary substations are available (and managed in coordination with the primary substation OLTC), these tend to regulate customer voltages close to the minimum statutory limit (lower tap positions), while the primary OLTC delivers higher voltages to the MV network to also reduce MV energy losses.
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Pantshwa, Athini. "Analysis of the reliability for the 132/66/22 KV distribution network within ESKOM’s Eastern Cape operating unit". Thesis, Nelson Mandela Metropolitan University, 2017. http://hdl.handle.net/10948/19750.
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A stable and reliable electrical power supply system is an inevitable pre-requisite for the technological and economic growth of any nation. Due to this, utilities must strive and ensure that the customer’s reliability requirements are met and that the regulators requirements are satisfied at the lowest possible cost. It is known fact around the world that 90% of the customer service interruptions are caused due to failure in distribution system. Therefore, it is worth considering reliability assessments as it provides an opportunity to incorporate the cost or losses incurred by the utilities customer as a result of power failure. This must be considered in the planning and operating practices. The system modelling and simulation study is carried out on one of the district’s distribution system which consists of 132 kV, 66 kV and 22 kV network in Aliwal North Sector ECOU. The reliability assessment is done on the 22, 66 and 132 kV system to assess the performance of the present system and also predictive reliability analysis for the future system considering load growth and system expansion. The alternative which gives low SAIDI, SAIFI and minimum breakeven costs is being assessed and considered. The reliability of 132 kV system could be further improved by constructing a new 132 kV line from a different source of supply and connecting with line coming from another district (reserve) at reasonable break even cost. The decision base could be further improved by having Aliwal North Sector context interruption cost. However, the historical data which may be used in Aliwal North Sector to acquire interruption costs from the customers are being proposed. The focus should be on improving the power quality on constrained networks first, then the reliability. Therefore for the Aliwal North power system network it is imperative that Eskom invest on the reliability of this network. This dissertation also analysed load reflected economic benefit versus performance expectations that should be optimized through achieving a balance between network performance (SAIDI) improvement, and total life cycle cost (to Eskom as well as the economy). Reliability analysis conducted in this dissertation used Aliwal North power system network as a case study; the results proved that the system is vulnerable to faults, planned and unplanned outages. Reliability evaluation studies were conducted on the system using DigSilent software in conjunction with FME. These two models gave accurate results with acceptable variance in most indices except for the ENS where the variance was quite significant. It can be concluded that DigSilent results are the most accurate results in all three reliability evaluation scenarios for the Aliwal North Power System, best interpretation being that of DigSilent.
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Araujo, Ricardo Augusto de 1982. "Algoritmos para o planejamento da operação de sistemas modernos de distribuição de energia elétrica = Algorithms for operation planning of modern electric distribution power systems". [s.n.], 2012. http://repositorio.unicamp.br/jspui/handle/REPOSIP/259529.
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Orientador: Madson Cortes de AlmeidaDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação
Made available in DSpace on 2018-08-21T03:46:06Z (GMT). No. of bitstreams: 1 Araujo_RicardoAugustode_M.pdf: 1212312 bytes, checksum: 401c38dac32e9784866225fb23096b21 (MD5) Previous issue date: 2012
Resumo: O problema do planejamento da operação de redes de distribuição de energia elétrica consiste em determinar os ajustes para os taps dos transformadores e reguladores de tensão, para os bancos de capacitores e para as injeções de potências ativas e reativas dos geradores distribuídos e da subestação, obedecendo aos limites físicos e operacionais da rede, a fim de melhorar o seu desempenho. Este pode ser formulado como um problema de Fluxo de Potência Ótimo (FPO) bastante complexo, pois envolve fatores técnicos, como a regulação de tensão em regime permanente, e econômicos, como a redução de perdas e a valoração da energia fornecida por produtores independentes. Este trabalho propõe dois algoritmos para resolver o problema de planejamento da operação. No primeiro, é usado um algoritmo genético similar ao desenvolvido por Chu e Beasley, somado a um esquema especial de criação da população inicial. Este algoritmo pode prover soluções de boa qualidade e até mesmo a solução ótima global do problema. O segundo algoritmo é baseado na análise de sensibilidades e é capaz de encontrar soluções de boa qualidade a um custo computacional bastante inferior ao custo do algoritmo genético proposto. Além de poder ser aplicado no planejamento de curto-prazo da operação de modernas redes de distribuição de energia elétrica, os métodos propostos podem, por exemplo, auxiliar as concessionárias de energia elétrica na definição de condições para o estabelecimento de contratos com produtores independentes de energia. Os resultados apresentados, baseados nos sistemas de distribuição radiais de 34, 70 e 135 barras, mostram que os algoritmos propostos são promissores
Abstract: The distribution system operation planning stage is concerned with the determination of capacitor bank, transformer and voltage regulator settings. This must be accomplished considering active and reactive power injections of distributed generators and at the main substation, as well as physical and regulatory issues in order to improve the network performance. This is a quite complex Optimal Power Flow (OPF) problem because it involves technical factors such as steady state voltage regulation, economic factors such as losses reduction and energy bids from independent power producers. This work proposes two approaches to solve this operation planning problem. The first one uses a genetic algorithm similar to that developed by Chu and Beasley, however with a different strategy to create the initial population. This algorithm can provide good quality solutions and in some cases even optimal solutions. The second one is based on the use of sensitivities, where good quality solutions are obtained at low computing times, much lower than those obtained using the proposed genetic algorithm. Besides being applicable in short-term operation planning of distribution networks, the proposed methods could also assist the utility operator in setting up conditions for establishing contracts with independent power producers. The results presented here using radial distribution systems of 34, 70 and 135 buses demonstrated the potential of the proposed algorithms
Mestrado
Energia Eletrica
Mestre em Engenharia Elétrica
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Lautenschleger, Ary Henrique. "Análise da operação de sistemas de distribuição considerando as incertezas da carga e da geração distribuída". reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2018. http://hdl.handle.net/10183/185256.
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Neste trabalho é apresentado um método probabilístico para avaliação do desempenho de redes de distribuição considerando incertezas na demanda das cargas e na potência gerada por sistemas distribuídos intermitentes. Os consumidores são divididos em agrupamentos por classe e faixa de consumo e a modelagem da demanda horária dos consumidores de cada agrupamento é realizada por uma lei de distribuição acumulada de probabilidade (CDF) adequada. A geração distribuída é contemplada pela consideração de fonte solar fotovoltaica. O procedimento de simulação do Método de Monte Carlo é empregado e a técnica da Joint Normal Transform é utilizada na geração de números aleatórios correlacionados, empregados na amostragem da demanda dos consumidores e da energia produzida pelos sistemas de geração distribuídos. O método proposto foi aplicado ao conhecido sistema de 13 barras do IEEE e os resultados dos indicadores de perdas na operação bem como indicadores de violação de tensão crítica e precária obtidos com o modelo probabilístico são comparados aos obtidos com o modelo determinístico convencional. É demonstrado que nem sempre a média é uma descrição suficiente para o comportamento dos componentes de redes de distribuição e que é mais adequado utilizar uma representação com intervalos de confiança para as grandezas de interesse.This work presents a probabilistic method for performance evaluation of distribution networks considering uncertainties in load demand and power generated by intermittent distributed systems. Consumers are divided into clusters by class and consumption range, so the modeling for the hourly demand of the consumers on each cluster is performed by a suitable cumulative probability distribution (CDF). Distributed generation is considered by means of solar photovoltaic sources. The Monte Carlo Simulation (MCS) Method is employed and the Joint Normal Transform technique is applied for correlated random numbers generation, used to sample consumer demand and the energy generated by distributed generation systems. The proposed method was applied in the well-known IEEE 13 node test feeder and the results of the operation losses as well as voltage violation indices obtained by the probabilistic model are compared to those obtained with the conventional deterministic model. It is shown that the mean is not always a sufficient description for the behavior of distribution network components and that it is more appropriate to use confidence intervals for the quantities of interest.
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Dam, Quang Binh. "Operating strategies to preserve the adequacy of power systems circuit breakers". Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/28232.
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Thesis (M. S.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2009.Committee Chair: Meliopoulos, A. P. Sakis; Committee Member: Divan, Deepakraj M.; Committee Member: Harley, Ronald G.; Committee Member: Johnson, Ellis L.; Committee Member: Taylor, David G.
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Malekpour, Ahmadreza. "Smart grid operational strategies for power distribution systems with large penetration of distributed energy resources". Diss., Kansas State University, 2016. http://hdl.handle.net/2097/34681.
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Doctor of PhilosophyDepartment of Electrical and Computer Engineering
Anil Pahwa
Power distribution systems are transitioning from traditional centralized-control distribution grids to the modern distribution grids that are more customer-interactive and include microgrids (MGs) as well as various unpredictable and multi-scale distributed energy resources (DERs). However, power fueled by renewable DERs such as wind and solar is highly variable and high penetration of renewable DERs in distribution system may potentially degrade the grid reliability and power quality. Moreover, the growth of such generation sources will increase the number of variables and cause scalability concerns for distribution system operators (DSOs) in handling system optimization problems. Further, with development of MGs, DSO and MG may have different owners and schedule renewable and non-renewable DERs based on their own economic rules and policies while secure and economic operation of the entire system is necessary. The widespread integration of wind and solar and deployment of MGs in distribution system make the task of distribution system operation management quite challenging especially from the viewpoint of variability, scalability, and multi-authority operation management. This research develops unique models and methodologies to overcome such issues and make distribution grid operation, optimization and control more robust against renewable intermittency, intractability, and operation complexity. The objectives of this research are as follows: 1) to develop a three-phase unbalanced large-scale distribution system to serve as a benchmark for studying challenges related to integration of DERs, such as scalability concerns in optimization problems, incremental power losses, voltage rise, voltage fluctuations, volt/var control, and operation management; 2) to develop a novel hierarchical and multilevel distributed optimization for power loss minimization via optimal reactive power provisioning from rooftop PVs which addresses the scalability issues with widespread DER integration in large-scale networks; 3) to develop a dynamic operational scheme for residential PV smart inverters to mitigate the fluctuations from rooftop PV integration under all-weather-condition (fully sunny, overcast and transient cloudy days) while increasing network efficiency in terms of power losses, and number of transformer load tap changer (LTC) operation; 4) to develop a stochastic energy management model for multi-authority distribution system operating under uncertainty from load and wind generation, which is able to precisely account interactions between DSO and MGs.
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Yuan, Wei. "Reliable Power System Planning and Operations through Robust Optimization". Scholar Commons, 2015. http://scholarcommons.usf.edu/etd/5807.
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In this dissertation, we introduce and study robust optimization models and decomposition algorithms in order to deal with the uncertainties such as terrorist attacks, natural disasters, and uncertain demand that are becoming more and more signicant in power systems operation and planning. An optimal power grid hardening problem is presented as a defender-attacker-defender (DAD) sequential game and solved by an exact decomposition algorithm. Network topology control, which is an eective corrective measure in power systems, is then incorporated into the defender-attacker-defender model as a recourse operation for the power system operator after a terrorist attack. Computational results validate the cost-eectiveness of the novel model. In addition, a resilient distribution network planning problem (RDNP) is proposed in order to coordinate the hardening and distributed generation resource placement with the objective of minimizing the distribution system damage under uncertain natural disaster events. A multi-stage and multi-zone based uncertainty set is designed to capture the spatial and temporal dynamics of a natural disaster as an extension to the N-K worst-case network interdiction approach. Finally, a power market day-ahead generation scheduling problem, i.e., robust unit commitment (RUC) problem, that takes account of uncertain demand is analyzed. Improvements have been made in achieving a fast
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Bernáth, František. "Rozptýlená výroba a jej vplyv na kvalitu dodávok elektrickej energie". Doctoral thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2014. http://www.nusl.cz/ntk/nusl-233625.
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This work deals with the deployment of distributed power sources into the electric power grid. The nature of these sources causes that the massive integration may experience problems with power quality in the local context, and also overall reliability of supply in the range of interconnected power systems may be endangered. Work is focused on local voltage quality problems with special emphasis on analysis and design of tools (e.g. reactive power compensation units of power plants or dynamic voltage control by transformers 110/22kV) for voltage control in power distribution systems. These tools should be used as a part of uniform concept of voltage control. The proposed concept is involved.
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Tomsovic, Kevin L. "Development of expert systems as on-line operational aids /". Thesis, Connect to this title online; UW restricted, 1987. http://hdl.handle.net/1773/5995.
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Zipf, Michael Markus [Verfasser], Dominik [Akademischer Betreuer] Möst, Dominik [Gutachter] Möst i Udo [Gutachter] Buscher. "Economics of Ancillary Services for Electricity : Managing Uncertain Power Generation and Grid Operation in the Distribution Network / Michael Markus Zipf ; Gutachter: Dominik Möst, Udo Buscher ; Betreuer: Dominik Möst". Dresden : Technische Universität Dresden, 2021. http://d-nb.info/1236990536/34.
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Nguyen, Van Liem. "Modeling and control coordination of power systems with FACTS devices in steady-state operating mode". University of Western Australia. School of Electrical, Electronic and Computer Engineering, 2008. http://theses.library.uwa.edu.au/adt-WU2009.0036.
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This thesis is devoted to the development of new models for a recently-implemented FACTS (flexible alternating current transmission system) device, the unified power flow controller (UPFC), and the control coordination of power systems with FACTS devices in steady-state operating mode. The key objectives of the research reported in the thesis are, through online control coordination based on the models of power systems having FACTS devices, those of maximising the network operational benefit and restoring system static security following a disturbance or contingency. Based on the novel concept of interpreting the updated voltage solutions at each iteration in the Newton-Raphson (NR) power-flow analysis as dynamic variables, the thesis first develops a procedure for representing the unified power flow controllers (UPFCs) in the steady-state evaluation. Both the shunt converter and series converter control systems of a UPFC are modeled in their dynamical form with the discrete time variable replaced by the NR iterative step in the power-flow analysis. The key advantage of the model developed is that of facilitating the process of UPFC constraint resolution during the NR solution sequence. Any relative priority in control functions pre-set in the UPFC controllers is automatically represented in the power-flow formulation. Although the developed UPFC model based on the dynamic simulation of series and shunt converter controllers is flexible and general, the number of NR iterations required for convergence can be large. Therefore, the model is suitable mainly for power system planning and design studies. For online control coordination, the thesis develops the second UPFC model based on nodal voltages. The model retains all of the flexibility and generality of the dynamic simulation-based approach while the number of iterations required for solution convergence is independent of the UPFC controller dynamic responses. Drawing on the constrained optimisation based on Newtons method together with the new UPFC model expressed in terms of nodal voltages, a systematic and general method for determining optimal reference inputs to UPFCs in steady-state operation is developed. The method is directly applicable to UPFCs operation with a high-level line optimisation control (LOC) for maximising the network operational benefit. By using a new continuation technique with adaptive parameter, the algorithm for solving the constrained optimisation problem extends substantially the region of convergence achieved with the conventional Newtons method. Having established the foundation provided by the comprehensive models developed for representing power systems with FACTS devices including the UPFC, the research, in the second part, focuses on real-time control coordination of power system controllers, with the main purpose of restoring power system static security following a disturbance or contingency. At present, as the cost of phasor measurement units (PMUs) and wide-area communication network is on the decrease, the research proposes and develops a new secondary voltage control where voltages at all of the load nodes are directly controlled, using measured voltages.
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Silva, Daniel Gomes da. "Integração entre as atividades de planejamento e operação em uma empresa de distribuição de energia elétrica". Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/3/3143/tde-10122013-143832/.
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O grau de integração entre as áreas de planejamento da expansão e de planejamento da operação de concessionárias de distribuição de energia elétrica ainda é insuficiente, pelo menos no caso brasileiro. Isso significa que a área de planejamento da operação não pode explorar plenamente e implementar os resultados e as recomendações trazidas pela área de planejamento da expansão em seus estudos de planejamento da operação. Como consequência, uma quantidade considerável de trabalho torna-se redundante, a eficiência é reduzida e há perda de qualidade. Além disso, uma concessionária de distribuição de energia elétrica geralmente possui vários sistemas independentes para a análise de redes elétricas de acordo com seu tipo (equilibrado ou desequilibrado), nível de tensão (subtransmissão, distribuição primária ou distribuição secundária) e sua topologia (radial ou malha). Obviamente, essa falta de integração também implica grandes dificuldades na realização de estudos de planejamento e de operação, ainda mais com a disponibilidade dos dados hoje difundida. Este trabalho tem como objetivo melhorar essa integração por meio de uma nova metodologia e de um sistema computacional de apoio. Uma das características mais interessantes da ferramenta é precisamente a sua capacidade de analisar qualquer tipo de rede elétrica, independentemente dos parâmetros. Por meio de alguns estudos de casos, demonstra-se como uma melhor integração entre as duas áreas dentro de um banco de dados significa redução de tempo na execução de atividades de ambas as áreas, eliminação de retrabalho e melhor qualidade dos resultados, que são posteriormente enviados para o operador nacional do sistema (ONS).The degree of integration between the expansion planning and the operational planning areas in electricity distribution utilities is still insufficient, at least in the Brazilian case. This means that the latter cannot fully exploit and implement results and recommendations brought about by the former in its planning studies. As a consequence, a considerable amount of work becomes redundant, with reduced efficiency and loss of quality. In addition, an electricity distribution utility usually possesses various independent systems for analyzing electrical networks according to their type (balanced or unbalanced), their rated voltage (subtransmission, primary feeder or low-voltage circuit) and their topology (radial or meshed). Obviously, this lack of integration also implies considerable difficulties when carrying out planning and operational studies, even more with today´s widespread data availability. This work focuses on improving such integration through a new methodology and a supporting computational system. One of the most interesting features of the software is precisely its ability to analyze any type of electrical network, regardless of the above parameters. Through some study cases, it is shown how a better integration between the two areas within a utility means reduced overall time, elimination of redundant work and better quality of results, which are later sent to the independent system operator (ISO).
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Hajdú, Lukáš. "Vliv decentrálních zdrojů na provozování distribuční soustavy 110 kV E.ON". Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2011. http://www.nusl.cz/ntk/nusl-219014.
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This Master´s thesis deals with problematics related to the connection of new decentralized power sources into electrical power grid. Due to advantageous legislative support of these new, especially photovoltaic power sources, a massive amount of these sources have been connected into the power grid between years 2009 and 2010. For theoretical understanding of processes during a steady-state, the initial parts of this paper are focused on a procedure which solves steady-state on every power line mentioned. When we speak of decentralized power sources connection, it is necessary to mention the connected legislative. National distribution grid operators in collaboration with national regulatory commission have decided on a legislative document Rules of distribution grid operation, which puts a set of demands and requirements on applicants wishing to connect a new power source to the grid. The text of this thesis is focused mainly on demands required after the latest change in 1/2010. Practical part of this work deals with verification of new power source influence on a related power grid and meeting the legislatively required demands. The most important demands are voltage change due to new power source operation and its transfer to other voltage levels, higher harmonics injection, power output fluctuation and last, not least, changes in load flow directions. For reasons previously mentioned an analysis is made and possibilities of reducing or removing of these influences are introduced. To achieve these goals, two computer programs, Siemens Sinaut Spectrum and NetCalc are used.
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Іваніцький, Сергій Борисович. "Моделювання режиму роботи розподільної електричної мережі з джерелами розосередженої генерації". Bachelor's thesis, КПІ ім. Ігоря Сікорського, 2019. https://ela.kpi.ua/handle/123456789/28482.
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Дипломна робота складається з пояснювальної записки та графічної частини. Пояснювальна записка виконана на 74 сторінках формату А4, яка включає в себе 33 рисунки, 13 таблиць, 16 джерел використаної літератури. Графічна частина містить 3 аркуші технічних креслень форматом А1. Ця робота присвячена вивченню впливу розосередженої генерації на режимні параметри мережі. В роботі також розглянуто проблеми функціонування розподільних електричних мереж з джерелами розосередженої генерації. Проведено розробку методу для визначення оптимального місця підключення джерел розосередженого генерування до електричної мережі та визначення оптимальної потужності генерації.
Режими роботи електричної мережі розраховано в програмному середовищі «PowerFactory», що використовує модифікований метод Ньютона-Рафсона для виконання розрахунку усталених режимівThesis consists of an explanatory note and graphical part. Explanatory note made 74 pages of A4, which includes 33 figures, 13 tables and 16 sources of literature. The graphical part contains 3 sheets of A1 technical drawings.The paper is dedicated to the exploring of the effects of distributed generation on the network parameters. The problems of functioning of distributed electric networks with distributed generation sources are also considered. A method has been developed to determine the optimal location for connecting sources of distributed generation to the electrical network and to determine the optimal generation power. Modes electrical network designed software environment in «PowerFactory», using a modified Newton-Raphson method for calculating the steady performance
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Fontana, Heron. "Logística operacional: alocação de bases operacionais em distribuição de energia elétrica". Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/3/3143/tde-11072016-151841/.
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Ser eficiente é um requisito para a sustentabilidade das empresas concessionárias de distribuição de energia elétrica no Brasil. A busca pela eficiência deve estar em harmonia com a melhoria contínua da qualidade, da segurança e da satisfação dos consumidores e das partes envolvidas. O desafio de atender múltiplos objetivos requer que as empresas do setor desenvolvam soluções inovadoras, com a mudança de processos, tecnologia, estrutura e a capacitação das pessoas. Desenvolver um modelo operacional eficiente e uma gestão rigorosa dos custos são fatores-chave para o sucesso das empresas, considerando o contexto regulatório de revisão tarifária que incentiva a melhoria do desempenho. O modelo operacional é definido a partir da organização logística dos recursos para atendimento da demanda de serviços, que define também os custos fixos e variáveis de pessoal (salário, horas extras, refeições), infraestrutura (manutenção de prédios, ferramentas e equipamentos) e deslocamentos (manutenção de veículos, combustível), por exemplo. A melhor alocação e o melhor dimensionamento de bases operacionais possibilitam a redução dos custos com deslocamento e infraestrutura, favorecendo o aproveitamento da força de trabalho em campo, a melhoria do atendimento dos clientes e da segurança dos colaboradores. Este trabalho apresenta uma metodologia de otimização de custos através da alocação de bases e equipes operacionais, com o modelamento matemático dos objetivos e restrições do negócio e a aplicação de algoritmo evolutivo para busca das melhores soluções, sendo uma aplicação de Pesquisa Operacional, no campo da Localização de Instalações, em distribuição de energia elétrica. O modelo de otimização desenvolvido possibilita a busca pelo ponto de equilíbrio ótimo que minimiza o custo total formado pelos custos de infraestrutura, frota (veículos e deslocamentos) e pessoal. O algoritmo evolutivo aplicado no modelo oferece soluções otimizadas pelo melhoramento de conjuntos de variáveis binárias com base em conceitos da evolução genética. O modelo de otimização fornece o detalhamento de toda a estrutura operacional e de custos para uma determinada solução do problema, utilizando premissas de produtividade e deslocamentos (velocidades e distâncias) para definir as abrangências de atuação das bases operacionais, recursos (equipes, pessoas, veículos) necessários para atendimento da demanda de serviços, e projetar todos os custos fixos e variáveis associados. A metodologia desenvolvida neste trabalho considera também a projeção de demanda futura para a aplicação no estudo de caso, que evidenciou a efetividade da metodologia como ferramenta para a melhoria da eficiência operacional em empresas de distribuição de energia elétrica.Being efficient is a requirement for the sustainability of electricity distribution companies in Brazil. The quest for efficiency must be in harmony with the continuous improvement of quality, safety and satisfaction of customers and all stakeholders involved. The challenge of attending multi-objectives requires companies in the sector to develop innovative solutions with the change of processes, technology, structure and enabling their professionals to drive this. Developing an efficient operational model and a strict cost management are keys for companies to achieve success, considering the regulatory context of tariff reviewing that encourages performance improvement. The operational model is defined from the logistics organization of resources to meet the demand of services, which also defines fixed and variable costs with people/teams (payments, overtime, meals), infrastructure (maintenance of building, tools and equipments) and fleet (maintenance of vehicles and fuel costs), for example. The best allocation and the best design of operational facilities (or operational bases) will reduce infrastructure costs and truck rolls, releasing workforce to attend customers and reducing displacements risks. This work presents a cost optimization methodology through the allocation of operational bases and teams, with the mathematical modelling of business objectives, constraints and using Evolutionary Algorithm to find the best solution, as an application of Operations Research in the field of Facility Location in electricity distribution. The optimization model enables the search for the optimal balance point that minimizes the total cost formed by infrastructure, fleet and people. The Evolutionary Algorithm applied in the model offers optimized solutions through the improvement of sets of binary variables based on genetic evolution concepts. The optimization model also gives detailed information about the operational structure and costs for a given allocation solution, using productivity and displacements (speed, distances) information to define the service regions for each operational base and resources (people, vehicles) needed to attend the demand of services, defining all fixed and variable costs for this. The methodology presented in this paper also considers the future demand of services (forecast), used in a case study that showed the effectives of this methodology as a tool for the improvement of operational efficiency in electricity distribution companies.
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Zhou, Xigen. "Electrical, Magnetic, Thermal Modeling and Analysis of a 5000A Solid-State Switch Module and Its Application as a DC Circuit Breaker". Diss., Virginia Tech, 2005. http://hdl.handle.net/10919/28900.
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This dissertation presents a systematic design and demonstration of a novel solid-state DC circuit breaker.
The mechanical circuit breaker is widely used in power systems to protect industrial equipment during fault or abnormal conditions. Compared with the slow and high-maintenance mechanical circuit breaker, the solid-state circuit breaker is capable of high-speed interruption of high currents without generating an arc, hence it is maintenance-free. Both the switch and the tripping unit are solid-state, which meet the requirements of precise protection and high reliability. The major challenge in developing and adopting a solid-state circuit breaker has been the lack of power semiconductor switches that have adequate current-carrying capability and interruption capability.
The high-speed, high-current solid-state DC circuit breaker proposed and demonstrated here uses a newly-emerging power semiconductor switch, the emitter turn-off (ETO) thyristor as the main interruption switch. In order to meet the requirement of being a high-current circuit breaker, ETO parallel operation is needed. Therefore the major effort of this dissertation is dedicated to the development of a high-current (5000A) DC switch module that utilizes multiple ETOs in parallel. This work can also be used to develop an AC switch module by changing the asymmetrical ETOs used to symmetrical ETOs.
An accurate device model of the ETO is needed for the development of the high-current DC switch module. In this dissertation a novel physics-base lumped charge model is developed for the ETO thyristor for the first time. This model is verified experimentally and used for the research and development of the emitter turn-off (ETO) thyristor as well as the DC switch module discussed in this dissertation.
With the aid of the developed device model, the device current sharing between paralleled multiple ETO thyristors is investigated. Current sharing is difficult to achieve for a thyristor-type device due to the large device parameter variations and strong positive feedback mechanism in a latched thyristor. The author proposes the "DirectETO" concept that directly benefits from the high-speed capability of the ETO and strong thermal couplings among ETOs. A high-current DC switch module based on the DirectETO can be realized by directly connecting ETOs in parallel without the bulky current sharing inductors used in other current-sharing solutions.
In order to achieve voltage stress suppression under high current conditions, the parasitic parameters, especially parasitic inductance in a high-current ETO switch module are studied. The Partial Element Equivalent Circuit (PEEC) method is used to extract the parasitics. Combined with the developed device model, the electrical interactions among multiple ETOs are investigated which results in structural modification for the solid-state DC switch module.
The electro-thermal model of the DC switch module and the heatsink subsystem is used to identify the "thermal runaway" phenomenon in the module that is caused by the negative temperature coefficient of the ETO's conduction drop. The comparative study of the electro-thermal coupling identifies a strongly-coupled thermal network that increases the stability of the thermal subsystem. The electro-thermal model is also used to calculate the DC and transient thermal limit of the DC switch module.
The high-current (5000A) DC switch module coupled with a solid state tripping unit is successfully applied as a high-speed, high-current solid-state DC circuit breaker. The experimental demonstration of a 5000A current interruption shows an interruption time of about 5 microseconds. This high-speed, high-current DC switch module can therefore be used in DC circuit breaker applications as well as other types of application, such as AC circuit breakers, transfer switches and fault current limiters.
Since the novel solid-state DC circuit breaker is able to extinguish the fault current even before it reaches an uncontrollable level, this feature provides a fast-acting, current-limiting protection scheme for power systems that is not possible with traditional circuit breakers. The potential impact on the power system is also discussed in this dissertation.Ph. D.
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Čáslava, Jiří. "Posouzení možnosti provozu zdrojů v dané oblasti při nestandardních provozních stavech sítě VN". Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2012. http://www.nusl.cz/ntk/nusl-219385.
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This Master's thesis deals with solution of nonstandard operation connection of E.ON's 22kV distribution network in given area, considering the possibilities of operating dispersed electric power sources currently available, as well as possible power sources connected to the distribution network in the future and its potential operation limitation. A part of this paper is a description of calculation methods used for network evaluation in steady state, with emphasis on linear calculations used by E-Vlivy program, in which the operational possibilities are simulated. Therefore, a description of this program is also included. Suggested operation possibilities correspond with E.ON's valid distribution network operation rules. The outcome of this paper will serve to E.ON's 22kV network's controllers as materials for network operating in nonstandard operation states.
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Restrepo, Juan Diego Echeverry. "Otimização em tempo real para o controle Volt/VAr em sistemas de distribuição de energia elétrica". Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/3/3143/tde-22092016-104547/.
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Atualmente, as concessionárias de energia enfrentam vários desafios na tentativa de fornecer energia com qualidade e confiabilidade, por exemplo, redes de distribuição com pouco monitoramento e controle, envelhecimento dos ativos, atender a crescente demanda dos consumidores e satisfazer padrões de qualidade, entre outros. No Brasil, para atingir os índices de qualidade no fornecimento de energia estabelecidos pela Agência Nacional de Energia Elétrica (ANEEL), tem-se como alternativa aumentar a inteligência da rede com sistemas de tecnologia de informação (TI), além de utilizar Dispositivos Eletrônicos Inteligentes (IEDs), medidores inteligentes e sensores. Adicionalmente é necessário o emprego de uma infraestrutura de comunicação que forneça uma visibilidade abrangente das condições de carga e do estado do sistema de distribuição, permitindo fazer uso de técnicas de otimização e tomada de decisão para aumento da inteligência. O controle da tensão e o gerenciamento da potência reativa (Volt/VAr) são práticas de automação que podem ser empregadas nos sistemas de distribuição. Estas práticas ajudam a aumentar o benefício, a confiabilidade e a eficiência no fornecimento da qualidade do produto, minimizando os custos de operação e manutenção nas concessionárias. Na presente dissertação foi desenvolvida uma metodologia de controle Volt/VAr descentralizado (subestação), por meio da coordenação e controle dos transformadores com mudança de tap sob carga - LTC, dos bancos de capacitores localizados na subestação e ao longo dos alimentadores, bem como dos reguladores de tensão instalados ao longo dos alimentadores. Destaca-se a utilização da técnica de Estimação de Estados, a qual possibilita o uso da metodologia de controle Volt/VAr em tempo real. O algoritmo de otimização desenvolvido neste trabalho foi implementado através de simulações numa rede teste e numa rede real que permitem mostrar o potencial da formulação matemática desenvolvida. Os resultados da metodologia proposta comprovam a melhoria do perfil de tensão dos alimentadores da rede testada ao longo do dia, assim como uma diminuição das perdas técnicas, as quais chegaram a diminuir 7% em energia. Estes resultados foram alcançados sem ultrapassar a quantidade de operações definidas por dia nos diferentes dispositivos de controle.Currently, power utilities face challenges in order to provide energy considering minimum requirements of power quality and reliability due to the absence of control and monitoring infrastructure, aging assets, growing demand, amongst others. In Brazil, the Agência Nacional de Energia Elétrica (ANEEL) establishes specific power quality and reliability indices. Power utilities should attend the limits for those indices by improving intelligence of network using IT systems, installing Intelligent Electric Devices (IEDs), smart meters and sensors, amongst others. Additionally, communication infrastructure is needed to provide the monitoring of load conditions and distribution system state. Optimization and decision-making tools are important for developing smart grids. Voltage control and reactive power management (Volt/VAr) are automation techniques that can be used in distribution systems. These practices lead to benefits for the utilities such as improvement of reliability and efficiency of the system, minimization of operation and maintenance costs, amongst others. In the present dissertation a methodology for decentralized control (Volt/VAr) was developed, through the coordination and control of load tap changers (LTCs) in power transformers and capacitors banks located at the substation, as well as capacitor banks and voltage regulators scattered throughout the feeders. State Estimation was utilized, which allows the application of the Volt/VAr Control methodology in real time environment. The optimization algorithm developed in this work was implemented through simulations in a test network and in a real network which validated the proposed methodology showing the potentiality of the mathematical model. The results of the proposed method showed voltage profile improvement over the day for the network tested as well as a 7% decrease in power energy losses. These results were achieved without exceeding the number of operations per day defined for all control devices.
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Alves, Alexandre Eberle. "Habilidades de resiliência em distribuidora de energia elétrica : recrutamento, seleção e treinamento de eletricistas e operadores do centro de operações da distribuição". reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2016. http://hdl.handle.net/10183/149797.
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A convergência das habilidades técnicas com as de resiliência contribui para promover um ambiente que opere de maneira segura e eficiente. Nesta busca, pretende-se obter um sistema que mantenha o processo operante durante os infortúnios, em especial, os inesperados. Além disso, utiliza-se o conhecimento de engenharia de resiliência, tema deste estudo, que é a capacidade de um sistema ajustar o seu desempenho e, desta forma, lidar com situações críticas. O objetivo geral desta dissertação é a identificação de habilidades de resiliência utilizadas na execução de atividades de manutenção emergencial de problemas na rede elétrica de uma distribuidora de energia. Neste trabalho, são abordadas as atividades de eletricistas e operadores do Centro de Operações da Distribuição (COD) da empresa estudada. Os objetivos específicos são: (1) investigar a forma de aplicação dos filtros utilizados no processo de recrutamento e seleção da empresa para verificar se as habilidades de resiliência são contempladas e (2) propor melhorias no processo de treinamento, com base nas informações e nos resultados obtidos, bem como nos processos da empresa para facilitar e minimizar a necessidade do uso das habilidades de resiliência identificadas. Assim, sob o prisma da Engenharia de Resiliência, este estudo visa à melhor compreensão do processo de seleção e recrutamento, bem como ao treinamento destes profissionais para a sua melhoria.The convergence of technical skills with resilience contributes to foster an environment that works safely and efficiently. The objective of this search is to obtain a system in which the functioning of the process is maintained during misfortunes, or unexpected events. Furthermore, the study approaches resilience engineering knowledge as its core subject, which is the capacity of a system to adjust its performance in order to be able to deal with critical situations. The main goal of this thesis is to identify resilience skills while performing emergency maintenance activities and diagnosing problems in the electrical network during events involving equipment failures at an energy distributor. This paper approaches the activities of the operators of the Distribution Operations Center (COD) of the company in the study. The specific objectives are: (1) to investigate the way the filters are used in the recruitment and selection process of the company to verify whether resilience skills are included, and (2) to propose improvements in the training process based on the data and results obtained, as well as on other processes of the company to facilitate and minimize the identified need for resilience skills. This way, under the Resilience Engineering perspective, this study aims at obtaining a better understanding of the recruitment and selection process, as well as improving professional training.
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Lopes, Guilherme Stivanin. "Reconfiguração de redes de distribuição em situações de contingências considerando operação ilhada de PCH". Universidade Federal de Santa Maria, 2014. http://repositorio.ufsm.br/handle/1/8557.
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One of the main concerns of the power utilities is secure, continuously supplying electric power to customers, thus meeting so satisfy these as to regulatory requirements. Thus, the proposed paper presents a method of restoring the electric power supply applying the concepts of automatic reconfiguration of the aggregate distribution networks the possibility of islanded operation of small hydro (SHP), since the use of PCH so islanded in certain circumstances, or becomes only, or the best solution to be adopted in a contingency situation in order to reduce the impact of unwanted interruptions. Since the intrinsic decision making process of reconfiguration of distribution networks involves multiple objectives and constraints, the proposed methodology uses the Analytic Hierarchy Process (AHP) method, which is a very useful tool for issues involving multicriteria decision taken. Additionally, case studies for analysis and validation of the proposed methodology are presented.Uma das principais preocupações das empresas distribuidoras de energia elétrica é garantir, de forma contínua, o fornecimento de energia elétrica aos seus clientes, atendendo assim tanto a satisfação desses quanto às exigências regulatórias. Sendo assim, o trabalho proposto visa apresentar uma metodologia de restabelecimento do fornecimento de energia elétrica aplicando os conceitos de reconfiguração automática das redes de distribuição agregados a possibilidade de operação ilhada de pequenas centrais hidroelétricas (PCHs), uma vez que a utilização de PCH de forma ilhada, em determinadas circunstâncias, torna-se ou a única, ou a melhor solução a ser adotada em uma situação de contingência com o objetivo de reduzir o impacto causado por interrupções indesejadas. Visto que a tomada de decisão intrínseca ao processo de reconfiguração das redes de distribuição envolve vários objetivos e restrições, a metodologia proposta utiliza o método Analytic Hierarchy Process (AHP) que representa uma ferramenta muito útil para questões envolvendo tomadas de decisão multicriteriais. Adicionalmente, são apresentados estudos de caso para análises e validações da metodologia proposta.
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Sendil, Halil. "Operation Of Water Distribution Networks". Master's thesis, METU, 2013. http://etd.lib.metu.edu.tr/upload/12615484/index.pdf.
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With continuously increasing urbanization, consumer demands and expansion of water supply systems, determination of efficient pump schedules became a more difficult task. Pumping energy costs constitute a significant part of the operational cost of the water distribution networks. This study aims to provide an effective daily pump schedule by minimizing the energy costs for constant and also for multi tariff of electricity (3 Kademeli Elektrik Tarifesi) in water distribution network. A case study has been performed in an area covering N8.3 and N7 pressure zones which are parts of Ankara water distribution network. Both pressure zones consists of 3 multiple pumps in pump station and one tank having 5000 m3 storage volume each. By using genetic algorithm based software (WaterCAD Darwin Scheduler) least-cost pump scheduling and operation policy for each pump station has been determined while satisfying target hydraulic performance requirements such as minimum and maximum service pressures, final water level of storage tank and maximum velocity in pipeline. 32 different alternative scenarios have been created which include multi tariff energy prices, constant tariff energy price, insulated system condition, uninsulated system condition and different pump combinations. The existing base scenario and alternative scenarios which were prepared by using optimal pump schedules have been compared and the achievements of optimizing pump operation have been analyzed. At the end of the study, a satisfying result has been observed that by using determined optimal pump schedule, minimum % 14 of total energy cost can be saved in existing water supply system.
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Bai, Wenshuai. "DC Microgrid optimized energy management and real-time control of power systems for grid-connected and off-grid operating modes". Thesis, Compiègne, 2021. http://www.theses.fr/2021COMP2586.
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Le travail de recherche de cette thèse se concentre sur l’élaboration de deux modes de fonctionnement du microréseau à savoir : mode connecté au réseau, mode hors réseau comprenant les modes îloté et isolé. Le problème de la défaillance du réseau en mode connecté au réseau et la faible fiabilité de l'alimentation électrique en mode hors réseau doivent être résolues. Ainsi, le but de cette thèse est de proposer un microréseau DC combinant à la fois les avantages du mode connecté au réseau et ceux du mode isolé. On obtient ainsi un microréseau DC qu’on peut qualifier de complet. Le microréseau DC complet contient les sources d'énergie renouvelables, le stockage et le réseau public, et les sources de secours sont utilisées pour réduire le délestage. Dans ce microréseau DC, un système de supervision est proposé dans le but de gérer le flux des puissances. La gestion de la puissance en temps réel dans la couche opérationnelle du système de supervision permet de maintenir l'équilibre de puissance. Dans la couche d'optimisation du système de supervision, l'optimisation journalière est proposée afin de minimiser le coût d'exploitation global. Les résultats de la simulation montrent que le microréseau DC complet peut minimiser les coûts d'exploitation. Ensuite, le système de supervision prend en compte l'efficacité dynamique du convertisseur pour résoudre le problème lié à la qualité de la puissance du microréseau qui peut être dégradée à cause de la tension instable du bus DC. Les résultats de la simulation montrent que la prise en compte de l'efficacité dynamique du convertisseur dans la couche opérationnelle du système de supervision permet de réduire les fluctuations de la tension du bus DC. En ce qui concerne l'importance de la prédiction PV pour l'optimisation de la veille, deux modèles de prédiction sont étudiés et comparés pour donner une puissance de prédiction PV précise. Les résultats montrent que les deux modèles ont presque les mêmes résultatsThis thesis focus on the research of the DC microgrid following two operation models: grid-connected mode, and off-grid mode including the islanded and isolated modes. The aim of this thesis is to propose a DC microgrid combining the advantages of the grid-connected or the off-grid mode, which named full DC microgrid. ln the full DC microgrid, the renewable energy sources, storage, and public grid are included, and the back-up sources also applied to reduce the load shedding. ln the full DC microgrid, a supervisory system is proposed to manage the power. The real-time power management in the operational layer of the supervisory system can keep the power balance. ln the optimization layer of the supervisory system, the day-ahead optimization is proposed to achieve the global minimal operation cost. The simulation results show that the full DC microgrid combines both advantages of the grid-connected and the off-grid mode to minimize the operating cost. Then, the supervisory system considers the dynamic efficiency of the converter to solve the problem that the power quality of the microgrid is degraded due to the unstable DC bus voltage caused by the inaccurate power control. The simulation results show that considering the dynamic efficiency of the converter in the operational layer of the supervisory system, the fluctuation of the DC bus voltage can be reduced. Regarding the importance of the PV prediction for the day-ahead optimization, two prediction modes are studied and compared to give a robust PV prediction power. The results are that the two models almost have the same results
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Munné, Collado Íngrid. "Flexibility services for distribution network operation". Doctoral thesis, Universitat Politècnica de Catalunya, 2021. http://hdl.handle.net/10803/672895.
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On the way towards a low carbon electricity system, flexibility has become one of the main sources for achieving it. Flexibility can be understood as the ability of a power system to cope with the variability and uncertainty of demand and supply. Both the generation-side and the demand-side can provide it. This research is focused on the role of the demand-side flexibility for providing a service to the distribution system operator, who manages the medium and low-voltage network. By activating this flexibility from the demand-side to the distribution network operator, the latter can avoid or mitigate congestions in the network and prevent grid reinforcement. This thesis starts with analyzing the current state of the art in the field of local electricity markets, setting the baseline for flexibility products in power systems. As a result of the previous analysis, the definition of flexibility is developed more specifically, considering the flexible assets to be controlled, the final client using this flexibility and the time horizon for this flexibility provision. Following the previous step, an aggregated flexibility forecast model is developed, considering a flexibility portfolio based on different flexible assets such as electric vehicles, water boilers, and electric space heaters. The signal is then modeled under a system-oriented approach for providing a service to the distribution network operator under the operation timeline on a day-ahead basis. The flexibility required by the distribution network operator is then calculated through an optimization problem, considering the flexibility activation costs and the network power flow constraints. Finally, since this scenario aims to lower the environmental impacts of the power system, its sustainability is assessed with the life-cycle assessment, considering the entire life cycle and evaluating it in terms of greenhouse gas emissions. This approach enhances the analysis of the potential role of flexibility in the power system, quantifying whether, in all cases, there is a reduction of emissions when shifting the consumption from peak hours to non-peak hours.En el camí cap a un sistema elèctric amb baixes emissions de carboni, la flexibilitat s'ha convertit en una de les principals fonts per aconseguir-ho. La flexibilitat es pot entendre com la capacitat d'un sistema de reaccionar davant la variabilitat i la incertesa provocades per la demanda i la generació. Tant la part de la generació com el costat de la demanda tenen actius per a poder proporcionar-ho. La recerca presentada en aquest manuscrit està enfocada en el paper de la flexibilitat oferta per la demanda, per a proporcionar un servei a l'operador del sistema de distribució, que gestiona les xarxes de mitja i baixa tensió. Gràcies a l'activació de la flexibilitat de la demanda, l'operador de les xarxes de distribució pot evitar o mitigar la congestió de la xarxa i evitar-ne les inversions per a reforçar-la, així com el seu impacte ambiental. Aquesta tesi comença amb l'anàlisi de l'estat de l'art en el camp dels mercats d'electricitat locals, establint-ne la línia base per a la definició dels productes de flexibilitat en els sistemes elèctrics. Com a resultat de l'estudi anterior, la definició de flexibilitat es desenvolupa més específicament, considerant els actius flexibles que han de controlar-se, el client final que utilitza aquesta flexibilitat i l'horitzó temporal per a aquesta disposició de flexibilitat. A continuació es desenvolupa un model de predicció de flexibilitat agregada, considerant una cartera de flexibilitat basada en diferents actius flexibles, com ara vehicles elèctrics, calderes d'aigua i escalfadors elèctrics, gestionats per la figura de l’agregador. El senyal es modela sota un enfocament orientat al sistema per proporcionar un servei a l'operador de la xarxa de distribució, per un horitzó temporal corresponent a l'operació de la xarxa de mitja i baixa tensió. El resultat és un model de la flexibilitat que pot oferir l’agregador. Una vegada desenvolupat el model de flexibilitat pel costat de l’agregador, la tesi s’enfoca al càlcul de la flexibilitat requerida per l’operador de la xarxa de distribució. Això es desenvolupa mitjançant un problema d'optimització, tenint en compte els costos d'activació de la flexibilitat, la localització dels punts on s’injectarà la flexibilitat i les restriccions de flux de potència de la xarxa de distribució. Finalment, atès que aquest escenari pretén reduir l'impacte mediambiental del sistema elèctric, la seva sostenibilitat s'avalua considerant tot el cicle de vida de les tecnologies que hi participen, i avaluant-la en termes d'emissions de gasos d'efecte d'hivernacle. L'ús d'aquest enfocament millora l'anàlisi del potencial paper de la flexibilitat en el sistema elèctric, quantificant si, en tots els casos, hi ha una reducció de les emissions traslladant el consum de les hores punta a hores vall.
Enginyeria elèctrica
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Garner, William Howard. "Iteration of the power operation". Virtual Press, 1995. http://liblink.bsu.edu/uhtbin/catkey/941367.
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This thesis is an investigation of the sequence of functions defined by fl (x) -xand fn+1 (x) -x , where the power is the principal value.In the case where the sequence is restricted to positive real this sequence of functions over thecomplex plane, we attack real numbers, the problem yields to the methods of analysis and we prove the behavior of the sequence.The more general problem of describing the behavior of both analytically and numerically. Though no full rigorous solution is given, the results presented suggest the behavior of the sequence over the complex plane is very interesting.Department of Mathematical Sciences
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Foo, Ming Qing. "Secure electric power grid operation". Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/106964.
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Thesis: S.M., Massachusetts Institute of Technology, School of Engineering, Center for Computational Engineering, Computation for Design and Optimization Program, 2015.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 87-91).
This thesis examines two problems concerning the secure and reliable operation of the electric power grid. The first part studies the distributed operation of the electric power grid using the power flow problem, which is vital to the operation of the grid. The power flow problem is a feasibility problem for finding an assignment of complex bus voltages that satisfies the power flow equations and is within operational and safety limits. For reliability and privacy reasons, it is desirable to solve the power flow problem in a distributed manner. Two novel distributed algorithms are presented for solving convex feasibility problems for networks based on the Method of Alternating Projections (MAP) and the Projected Consensus algorithm. These algorithms distribute computation among the nodes of the network and do not require any form of central coordination. The original problem is equivalently split into small local sub-problems, which are coordinated locally via a thin communication protocol. Although the power flow problem is non-convex, the new algorithms are demonstrated to be powerful heuristics using IEEE test beds. Quadratically Constrained Quadratic Programs (QCQP), which occur in the projection sub-problems, are studied and methods for solving them efficiently are developed. The second part addresses the robustness and resiliency of state estimation algorithms for cyber-physical systems. The operation of the electric power grid is modeled as a dynamical system that is supported by numerous feedback control mechanisms, which depend heavily on state estimation algorithms. The electric power grid is constantly under attack and, if left unchecked, these attacks may corrupt state estimates and lead to severe consequences. This thesis proposes a novel dynamic state estimator that is resilient against data injection attacks and robust to modeling errors and additive noise signals. By leveraging principles of robust optimization, the estimator can be formulated as a convex optimization problem and its effectiveness is demonstrated in simulations of an IEEE 14-bus system.
by Ming Qing Foo.
S.M.