Electrical energy is one of the most common forms of energy these days. Consequently, electric power system is an indispensable part of any society. However, due to the deregulation of electricity markets and the growth in the share of power generation by uncontrollable renewable energies such as wind and solar, power system simulations are more challenging than earlier. Thus, new techniques for simplifying these simulations are needed. One important example of such simplification techniques is the power system reduction. Power system reduction can be used at least for four different purposes: a) Simplifying the power system simulations, b) Reducing the computational complexity, c) Compensating the data unavailability, and d) Reducing the existing uncertainty. Due to such reasons, power system reduction is an important and necessary subject, but a challenging task to do. Power system reduction is even more essential when system operators are facing very large-scale power systems and when the renewable energy resources like hydro, wind, and solar have a high share in power generation. This thesis focuses on the topic of large-scale power system reduction with high penetration of renewable energy resources and tries to pursue the following goals: • The thesis first reviews the different methods which can be used for simplifying the power system studies, including the power system reduction. A comparison among three important simplification techniques is also performed to reveal which simplification results in less error and more simulation time decrement. • Secondly, different steps and methods for power system reduction, including network aggregation and generation aggregation, are introduced, described and discussed. • Some improvements regarding the subject of power system reduction, i.e. on both network aggregation and generation aggregation, are developed. • Finally, power system reduction is applied to some power system problems and the results of these applications are evaluated. A general conclusion is that using power system simplification techniques and specially the system reduction can provides many important advantages in studying large-scale power systems with high share of renewable energy generations. In most of applications, not only the power system reduction highly reduces the complexity of the power system study under consideration, but it also results in small errors. Therefore, it can be used as an efficient method for dealing with current bulk power systems with huge amounts of renewable and distributed generations. / <p>The Doctoral Degrees issued upon completion of the programme are issued by Comillas Pontifical University, Delft University of Technology and KTH Royal Institute of Technology. The invested degrees are official in Spain, the Netherlands and Sweden, respectively. QC 20150116</p>

Made available in DSpace on 2014-06-11T19:22:32Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-02-25Bitstream added on 2014-06-13T18:49:30Z : No. of bitstreams: 1 lopezquizhpi_jc_me_ilha.pdf: 769238 bytes, checksum: 591b6116b31bf1d4b2d4b7817c38a698 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Neste trabalho apresenta-se uma metodologia para resolver o problema de planejamento ótimo de reativos em sistemas de potência interconectados multi-áreas, utilizando a técnica de decomposição de Dantzig-Wolfe. O problema original multi-área é separado em subproblemas (um para cada área) e um problema mestre (coordenador). A solução do problema decomposto é baseada na aplicação de programação linear sucessiva para a resolução dos subproblemas de planejamento de reativos de cada área, e o esquema de coordenação é baseado nos custos marginais de potência reativa nas barras de fronteiras. Desta forma, o problema de planejamento do sistema é resolvido usando a estratégia descentralizada por regiões ou por áreas, onde os operadores dos sistemas podem planejar a opera- ção e a expansão de seus sistemas, independentemente das outras áreas, obtendo uma solução ótima coordenada, porém descentralizada de cada área. O objetivo do modelo é proporcionar mecanismos para realizar o planejamento preservando a autonomia e confidencialidade para cada área, garantindo a economia global do sistema multi-área completo. Utilizando-se o modelo matemático e a imple- mentação computacional da metodologia proposta, apresentam-se resultados, análises e discussões de testes efetuados em 3 sistemas de 3 áreas, onde cada uma das áreas é composta por 3 sistemas iguais formados pelos sistemas IEEE30, IEEE118 e IEEE300 / In this thesis presents a methodology for solving the optimal reactive power planning problem in inter- conected multi-area electric power systems, using the Dantzig-Wolfe technique. The original multi- area problem is separated into subproblems (one for each area) and a master problem (coordinator). The solution of the decomposed problem is based on the application of sucessive linear programming for solving the reactive planning subproblems in each area, and the coordination scheme is based on the reactive power marginal costs in the border bus. Thus the planning problem system is solved using a descentralized approach by regions or areas, where de transmission system operator in each area can planning the operation and expansion of its system regardless of the other areas, obtaining a optimal solution coordinated by descentralized in each area. The purpose of the mathematical model is to provide mechanism for develope the planning preserving the autonomy and confidentiality for each area, ensuring the economy of the overal multi-area full system. Using the mathematical model and computational implementation of the methodology proposed results are presented analisys and discussion of testes performed on three systems in three areas where each area is composed of three equal systems formed by IEEE30, IEEE118, and IEEE300 bus system