With environmental and policy pressure to move towards cleaner fuel sources, wind energy is a proven technology that can be successfully implemented at the utility-scale and provide clean energy to the grid. Wind energy consists of many distributed wind turbines that are paralleled and connected to inject power to one location on the transmission grid. There are real power losses and reactive power drops that must be taken into consideration for these projects for plant performance and compliance. The better the performance of each new and operating wind farm installed, the more efficiently the grid operates as well as the less greenhouse gases generated. This thesis will first review the creation of an Excel tool to perform a load flow study given inputs for a wind farm using Newton-Raphson algorithms. Next, the results of the load flow analysis will be compared to an actual operating wind farm located in Texas to review the accuracy of the scenarios. Finally, alternative design and operating states for the wind farm are proposed and cases are simulated to review the impact on wind farm energy generation and reactive power provided to the grid. Finally, preferred improvements for future design and operational considerations are provided along with future areas of research and development. / Master of Science / This thesis is focused on improvements for wind farm design and operation to help wind farms generate more clean power to the grid. The thesis involves the creation of an Excel tool which can be used to complete required grid studies for real and reactive power flows within the wind farm to the point of connection with the transmission system. This analysis helps inform the wind farm design and operation to be more effective and operate more efficiently. An operating wind farm in Texas is explained and depicted for an understanding of how utility-scale wind farms are set up. Additionally, a year of data from an operating wind farm is used to compare the Excel load flow tool to actual data and confirm it's accuracy. Alternate methods this plant could have been designed and operated are evaluated using the new tool and actual operating conditions from the plant for the year under analysis are performed to better understand and quantify possible improvements for wind farms. This thesis is less focused on the wind turbine generator (WTG) construction and operation of a single unit, but rather focused on the output from the WTG and the impact on an entire system containing many of these distributed generators and their operation to provide energy to the grid.

Orientador: Prof. Dr. Edmarcio Antonio Belati / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Engenharia Elétrica, 2017. / Esta pesquisa propõe uma metodologia baseada no Fluxo de Potência Ótimo Reativo (FPOR), para a operação dos sistemas de transmissão sob emergência usando o mínimo corte de carga em associação com dispositivos Static VAr Compensator (SVC). O SVC é modelado pelo método da susceptância variável e inserido no problema do FPOR. A função multiobjetivo é formada em três partes, perdas de potência ativa, desvio da tensão e cortes de carga. Propõese um procedimento para calcular os valores dos pesos das funções de perdas e desvio da tensão sendo uma das contribuições deste trabalho. A função de mínimo corte de carga foi associada a uma variável que pode ser contínua ou binária, que corta uma porcentagem (contínua) ou a totalidade (binária) da potência da barra candidata, tratando-se assim como problemas de programação não linear (PNL) ou programação não linear inteira mista (PNLIM) respectivamente. O conjunto de barras candidatas ao corte de carga foi formado pelas barras críticas do sistema para cada situação de contingência e foi definido por meio de uma estratégia proposta neste trabalho para identificar as barras mais susceptíveis ao corte de carga. Para o tratamento das variáveis binárias do problema, foi usado o algoritmo Branch &Bound associado com o FPOR. A metodologia foi testada nos sistemas IEEE de 14 e 118 barras modificados para as diferentes situações de contingência simuladas neste trabalho. / This research proposes a methodology based on the Optimal Reactive Power Flow (ORPF) for the operation of the emergency transmission systems using the minimum load shedding in association with Static VAr Compensator (SVC) devices. The SVC was modeled as a variable susceptance and inserted in the ORPF problem. A multi-objective function was formed by three parts, namely, active power losses, voltage deviation and load shedding was device. Propose a procedure to calculate the values of the weights of the loss functions and the voltage deviation, one of the contributions of this research. The minimum load shedding function uses a variable that can be continuous or binary, which turns off a percentage (continuous) or all (binary) loads of candidate power buses, resulting in a Nonlinear Programming Problems (NLP) or Mixed Integer Nonlinear Programming (MINLP) respectively. The critical buses of the system for each contingency formed the candidate set of buses for the load shedding and was defined by a strategy proposed in this research to identify the bus most susceptible to the load shedding. For the treatment of the binary variables of the problem, a Branch & Bound algorithms associated with the ORPF was used. This methodology was tested in the modified IEEE 14 and 118-bus systems for the different contingency situations simulated in this research.