Orientador: Sérgio Kurokawa / Resumo: Nos sistemas de potência, o conhecimento dos parâmetros das linhas de transmissão possibilita o ajuste preciso dos sistemas de proteção, facilita a aplicação de ferramentas e técnicas de análise do sistema elétrico, permite a correta localização de faltas, assim como o monitoramento de indicadores comuns de faltas, como a temperatura e a catenária do condutor. As metodologias de estimação de parâmetros de linha de transmissão baseadas na teoria da decomposição modal são restritas a configurações de torre específicas, nas quais a matriz de transformação da linha de transmissão é conhecida. Neste trabalho apresenta-se um método para a estimação de parâmetros de linhas de transmissão genéricas em regime permanente, utilizando os fatores de correntes e tensões nos terminais da linha. Estabelece-se um sistema de equações não linear indeterminado, a partir das relações fase-modo das correntes e tensões nos terminais da linha e as matrizes de impedância e admitância da linha. Para uma linha trifásica genérica as relações fase-modo são escritas em função dos elementos da matriz transformação, os quais são desconhecidos e uma parte das incógnitas do sistema de equações. O sistema de equações é complementado com equações adicionais para ser resolvido mediante o algoritmo de Newton-Raphson e estimar os parâmetros de linha de transmissão. Foram estimados os parâmetros para uma linha de transmissão trifásica com diferente configuração de torre operando com diferentes cargas para vários co... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Accuracy in transmission lines parameters is essential in power systems since it allows precise adjustment of the protection systems, the application of tools and techniques for analysis of the electrical system, the correct identification of fault location, as well as the monitoring of fault indicators such as the temperature and the catenary of the conductor. Transmission line parameter estimation methodologies based on modal decomposition theory are restricted to specific tower configurations in which the transformation matrix of the transmission line is known. This work presents a method to estimate parameters of generic transmission lines in the steady state, using the voltage and currents phasor at the terminals of the line. A system of consistent non-linear equations is established from the phase-mode relations of these voltage and current phasors and the impedance and admittance matrices of the line. The phase-mode relations are written as a function of the elements within the transformation matrix, which are unknown and part of the variables to be estimated. The system of equations is solved using the Newton-Raphson algorithm to estimate both the transmission line parameters and the transformation matrix. The parameters were estimated for three-phase transmission lines for a particular tower configuration operating under different loads and lengths. The relative error of the estimated parameters evaluates the method’s accuracy and the influence of the line’s lumped r... (Complete abstract click electronic access below) / Doutor

Decision problems in operation and planning of power systems often rely on large-scale models and data sets. Lack of historical power flow data due to regulatory restrictions often limits researchers to study the system with aggregated network models. Aggregated data from the electricity market operators (Nordpool in the Nordics) and the Transmission System Operator (TSO) (from ENTSO-E) are openly available, and can be used to study the power flow and exchanges between different regions but do not directly provide information about intra-region flows. This project builds upon the Nordic 490 system, a previously built model of the Nordic power system. The main objective of this work is to improve the existing open source power flow model of the Nordic power system, in order to become in turn available for the multi-energy modelling and simulation software Spine. The N490 model generates a model of the Nordic power system consisting of various nodes/buses which represent substations at different voltage levels. Then, it distributes the aggregated production, consumption and power exchange data from Nordpool to the various buses. In this project, different possible improvements are evaluated for the model, aiming at estimating a set of network parameters that minimize the errors between the calculated inter-region flows and the ones from the open data repositories. The different improvements which are evaluated are the following. Firstly, the load distribution is modified and reassigned to match the regional electricity consumption. The generators and wind farms are then reallocated to different bus based on their bidding region and proximity to the bus. The databases are improved and the power balance relation modified. Transmission line parameters are then investigated, first to standard recommended values and then by solving an optimisation problem formulated to extract the parameters from the market data. Finally, the model is also tested with wind and solar generation modelled as a generator rather than as a negative load. / Beslutsproblem gällande drift och planering av kraftsystemet baseras ofta på storskaliga modeller och datamängder. Bristen på historiska data gällande effektflöden beror på säkerhetsrestriktioner vilket begränsar forskare till att enbart studera aggregerade nätverksmodeller. Det finns tillgängliga aggregerade data från den nordiska elmarknadsplatsen Nordpool och organisationen ENTSO-E som kan användas för att studera effektflöden mellan olika regioner, dock finns det inte direkta data för flöden inom regionerna. Det här projektet bygger på det nordiska 490-systemet, en tidigare byggd modell av det nordiska kraftsystemet. Huvudsyftet med detta arbete är att förbättra den existerande effektflödesmodellen av det nordiska kraftsystemet, för att i sin tur bli tillgänglig för multienergimodelleringar och simuleringsprogramvaran Spine. N490-modellen genererar en modell för det nordiska kraftsystemet som innehåller olika noder som presenterar ställverk med olika spänningsnivåer och modellen ger också aggregerade data för produktion, konsumtion och effektutbyte mellan de olika noderna från Nordpool. I detta projekt utvärderades olika möjliga förbättringar för modellen som syftar till att uppskatta nätverkets parametrar som kan minimera felen mellan beräkningar av flöde inom regionen och data från öppna datalagringskällor. Följande förbättringar gjordes: Först har lastens fördelning modifierats och ändrats för att matcha den regionala elkonsumtionen. Generatorer och vindkraftsparker allokerades till olika noder baserad på elhandelsområden och närhet till noderna. Databasen förbättrades för att erhålla en bättre effektbalans per område. Kraftledningarnas parametrar ändrades först till rekommenderade standardvärden, vilka sedan förbättrades genom att formulera ett optimeringsproblem för att extrahera parametrarna från markandsdata. Slutligen testades modellen genom att presentera vind- och sol-produktion som generatorer istället för som negativ förbrukning.