published_or_final_version / Computer Science and Information Systems / Doctoral / Doctor of Philosophy

Under deregulated environments, transmission system is playing an increasingly vital role in the modern power markets. Despite the widespread experience of electricity restructuring during the past decade, important issues remain open about the best way to organize transmission to support reliability management and market trading. In the absence of an appropriate mechanism for the transmission services unbundling, it is unlikely to take into consideration the effects of power flows that diverge from the contract path. When individuals do not confront the respective responsibility for the transmission services, the market outcome will be inefficient. Allocations of transmission loss and costs to the market participants are essential for the transmission services unbundling. In this respect, two methods are proposed in this dissertation to provide technical and economical signals for the allocations. Based on circuit theory, the first method proposes a new procedure to trace the power flows on the transmission lines. Starting with the computation of an individual generator¡¦s or load¡¦s contributions to the line currents, the network is then decomposed into different networks. In each decomposed network, bus injections and line power flows are replaced by components related to only one generator or load. Based on the components of real power flow on the transmission lines, the allocations of transmission loss and supplementary cost can be easily performed. In the second method, AC power flow based injection shift distribution factors (ISDFs) are exploited for calculating generalized generation distribution factors (GGDFs) and generalized load distribution factors (GLDFs). GGDFs and GLDFs can be used to derive the components of the real powers on each transmission line contributed by the generators and loads. Three bus-oriented schemes are proposed to allocate the transmission loss. They are aimed to reduce the number of distribution factor computation and to reflect the activity in a competitive market. The reactive powers incurred on transmission lines due to the generators and loads are also derived using the reactive power distribution factors (RPDFs). Based on the components of complex power flow on the transmission lines, transmission cost allocation methods are proposed to charge the impacts of power transactions on the network. In order to take the service reliability into account the service charges consist of the components representing normal and the contingency states respectively.

[pt] A alta inserção de geração fontes de energia renovável variável (ERV) tem criado uma demanda por reforços e ampliações do sistema de transmissão existente, demanda essa que traz consigo altos custos de implantação e operação de novos equipamentos de rede. Neste contexto, o processo de cálculo de tarifas de uso do sistema de transmissão ganha destaque, já que este tem o potencial de integrar o planejamento da transmissão ao da geração, e fornecer sinalização econômica locacional aos geradores, revelando os verdadeiros custos de implantação dos geradores do ponto de vista do sistema. No entanto, os processos tarifários atualmente empregados na maioria dos países não promovem esta sinalização adequadamente, principalmente por não levarem em conta características intrínsecas da rede e de e seu planejamento. Este é o caso do Brasil que aplica um processo tarifário que promove sinalização econômica locacional diminuta e distorcida. Muitos estudos sobre o tema, tem focado nos algoritmos de alocação de custos aplicados nos processos tarifários em busca da solução para este problema. No entanto, poucos comentam que este processo conta com uma etapa anterior à alocação de custos, ligada a formulação do cenário de operação do sistema que será utilizado como referência para o cálculo tarifário, e tem grande impacto sobre este. Dessa forma, esta dissertação tem como objetivo o desenvolvimento de um processo de tarifação com foco na construção e seleção de múltiplos cenários de operação, aderentes aos níveis de confiabilidade utilizados no planejamento, e à sazonalidade das fontes, como referência para alocação de custos baseado no uso do sistema. Por meio desta abordagem, pretende-se embutir maior eficiência, e justiça ao cálculo tarifário, promovendo intensificação da sinalização locacional. Este procedimento proposto, foi aplicado ao sistema Brasileiro a fim de testar suas propriedades e viabilidade em sistemas de grande porte. Seus resultados estão comparados com aplicação da metodologia proposta pela ANEEL na Consulta Pública 39/2021 e se mostram promissores quanto aos objetivos desta dissertação. / [en] The high insertion of generation variable renewable energy sources (ERV) has created a demand for reinforcements and expansions of the existing transmission system, which brings high costs of deployment and operation of new network equipment. In this context, the process of calculating transmission system usage rates gains prominence since it can integrate transmission planning with generation and provide locational economic signaling to generators, revealing the actual costs of implementing generators from the system s point of view. However, the tariff processes currently employed in most countries do not promote this signaling properly, essentially because they do not consider the network s intrinsic characteristics and its planning. This is the case in Brazil that applies a tariff process that promotes small and distorted localist economic signaling. Most studies on the subject have focused on the algorithms of cost allocation applied in tariff processes in search of the solution to this problem. However, few mention that a system operation scenario must be formulated to serve as a reference for the tariff calculation prior to cost allocation. Thus, this dissertation aims to develop a tariff process focused on the construction and selection of multiple operating scenarios, adhering to the reliability levels used in planning and the sources seasonality as a reference for cost allocation based on the use of the system. This approach intends to embed greater efficiency and justice to the tariff calculation, promoting the enhancement of locational signaling. This proposed procedure will be evaluated in terms of desired properties and feasibility in large systems in a case study developed with the Brazilian system. The case study results will be compared with applying the methodology proposed by ANEEL in public consultation 39/2021.