Este trabalho foi baseado na metodologia desenvolvida para modelagem computacional de equivalentes dinâmicos de sistemas elétricos de potência apresentada em BRITO, 2009 [5]. Sendo que nesse trabalho desenvolveu um método de modelagem de equivalentes dinâmicos de sistemas elétricos de potência com geradores, máquinas e seus controladores. O equivalente dinâmico consiste em uma substituição de uma parcela de um Sistema Elétrico de Potência, composta por linhas de transmissão, barras de carga e barras geradoras, de forma que estas serão sintetizadas e minimizadas de forma que o número de elementos seja diminuído, mas conservem o comportamento dinâmico elétrico da área original, sendo o mais próximo possível do encontrado no sistema elétrico de potência original. Foram realizados cálculos teóricos para obtenção dos equivalentes estáticos e dinâmicos do referido sistema de potência. Para isso utilizamos o programa ANAREDE para obtenção dos resultados dos fluxos de carga do sistema completo e do sistema reduzido. Estes resultados foram utilizados em um programa de análise de pequenas perturbações, denominado PACDYN, o qual verifica o comportamento dinâmico dos sistemas. Para possibilitar essa análise foi inclusa uma pequena perturbação de tensão no sistema, próxima à sua barra de referência angular. Os resultados encontrados pelo programa PACDYN foram exportados para um programa de análise matemática e simulações, denominado MATLAB, onde foram gerados os gráficos dos resultados obtidos e aplicada a técnica de mínimos quadrados, para ajuste dos resultados. Por meio da comparação dos fluxos de potência dos sistemas completo e equivalente, obteve-se a validação do trabalho, sendo utilizado o sistema New England, como sistema-teste. Neste trabalho aplicamos a metodologia desenvolvida em BRITO, (2009) [5] no sistema de potência-teste New England, complementando o trabalho original, em que a parte interna e externa do sistema, escolhida para construção do equivalente dinâmico eram interligadas por uma única barra de fronteira. Em nosso trabalho utilizamos uma área que nos demandou a utilização de quatro barras de fronteira, quatro linhas de transmissão e uma barra fictícia de acoplamento, onde foi conectado o gerador equivalente e cargas equivalentes. Comparando os resultados do sistema completo e reduzido obtivemos valores próximos o bastante para comprovar a robustez do sistema fictício e validar mais uma vez a metodologia. / This work was based on the methodology developed for computer modeling of dynamic of electric power systems equivalents presented in BRITO, 2009 [5]. And in this work we developed a method of modeling of dynamic equivalents of electric power systems with generators, machines and their controllers. The dynamic equivalent consists of a substitution of a portion of an Electric Power System, consisting of transmission lines, the load buses and generating bars, so that these will be synthesized and minimized so that the number of elements is decreased, but retain the electric dynamic behavior of the original area, with the closest to the found in the electrical system of original power. Theoretical calculations for obtaining the static and dynamic equivalents of said power system were performed. For that use the ANAREDE program to obtain the results of the full system load flows and reduced system. These results were used in a parsing program small disturbances, called PACDYN, which checks the dynamic behavior of the system. To enable this analysis has included a small voltage perturbation in the system, next to its angular reference bar. The results found by PACDYN program were exported to a mathematical analysis and simulation program called MATLAB, which graphs the results obtained and applied the technique of least squares were generated to adjust the results. By comparing the equivalent of complete systems and power flows obtained if the validation work, by using the New England system as test system. In this paper we apply the methodology developed in BRITO, (2009) [5] in the New England power test system, complementing the original work, in which the inside and outside of the system, chosen to build the dynamic equivalent were joined by a single border bar. In our work we use an area which required us to use four border bars, four transmission lines and a dummy coupling bar, which was connected to the equivalent generator and equivalent charges. Comparing the results of the full and reduced system obtained values close enough to demonstrate the robustness of the dummy system and to validate again the methodology.

Orthogonal frequency division multiplexing (OFDM) in next generation wireless systems provides high downlink data rates by employing frequency-domain scheduling and rate adaptation at the base station (BS). However, in order to control the significant feedback overhead required by these techniques, feedback reduction schemes are essential. Best-m feedback is one such scheme that is implemented in OFDM standards such as Long Term Evolution. In it, the sub channel (SC) power gains of only the m strongest SCs and their corresponding indices are fed back to the BS. However, two assumptions pervade most of the literature that analyze best-m feedback in OFDM systems. The first one is that the SC gains are uncorrelated. In practice, however, the SC gains are highly correlated, even for dispersive multipath channels. The second assumption deals with the treatment of unreported SCs, which are not fed back by the best-m scheme. If no user reports an SC, then no data transmission is assumed to occur. In this thesis, we eschew these assumptions and investigate best-m feedback in OFDM systems with correlated SC gains. We, first, characterize the average throughput as a function of correlation and m. A uniform correlation model is assumed, i.e., the SC gains are correlated with each other by the same correlation coefficient. The system model incorporates greedy, modified proportional- fair, and round robin schedulers, discrete rate adaptation, and non-identically distributed SC gains of different users. We, then, generalize the model to account for feedback delay. We show in all these cases that correlation degrades the average throughput. We also show that this effect does not arise when users report all the SC power gains to the BS. In order to mitigate the reduction in the average throughput caused by unreported SCs, we derive a novel, constrained minimum mean square error channel estimator for the best-m scheme to estimate the gains of these unreported SCs. The estimator makes use of the additional information, which is unique to the best-m scheme, that the estimated SC power gains must be less than those that were reported. We, then, study its implications on the downlink average cell throughput, again for different schedulers. We show that our approach reduces the root mean square error and increases the average throughput compared to several approaches pursued in the literature. The more correlated the SC gains, greater is the improvement.