The deregulation of the electricity industry has introduced many opportunities as well as challenges to the once monopolised industry. This recent reform towards a competitive electricity industry advocates a need for charging energy losses to market participants through a more satisfactory and transparent mechanism. Market participants, whether they are generators or consumers, would want a loss allocation scheme that is able to reflect each market participants' contribution of generation or usage in the network. However, as electricity is an indistinguishable entity, there is no accurate method to trace the flow of electricity thus far. Hence, the issue of power loss allocation within the deregulated market still remains an unresolved setback to progress to a fully competitive electricity market. Many loss allocation methods have been introduced, however, none have been universally accepted. This thesis investigates existing power flow tracing and loss allocation methods in order to critically analyse the advantages and disadvantages of each method. They include loss allocation methods currently employed in Australia’s National Electricity Market (NEM) and Great Britain Market, as well as a selection of better known loss allocation methods that are introduced in the academic research field. Understanding of these methods makes it easier to choose a method that is more suitable for each electricity market. Many researchers believe that a resolution is through a fair and equitable allocation of losses. However, the definition of “fair and equitable” varies from one literature to another. In general, a fair and equitable loss allocation method should meet electrical laws as well as economical laws. This is because market driven transactions have become the new independent decision variables that define the behaviour of electric power systems. This definition is then used as the basis to assess the results obtained from the implementation of each existing method analysed. It was found that a key limitation of existing methods is the lack of a method that is able to trace the usage allocation of each generator to each load in an electrically justifiable manner. Any improvement to existing loss allocation methods should address this limitation. Thus, the main objective of this thesis is to present two transaction based methods that have been developed and tested by the author of this thesis. Fundamentally, both methods hold the capability to analyse losses involved in the transfer of power from one point of the network to another point. The first investigated method is based on the network reduction method, where a system is reduced to the nodes of interest. The second method is based on the loop frame of reference. Instead of representing the network flows through the commonly accepted nodal frame of reference, power flows within the network are instead expressed as the sum of power flows around loops that links loads to active sources. This provides the loop-based method with an advantage in which it allows the power requirements of a load to be viewed as emanating from an active source and also the advantage of assessing the viability of contract agreements within a hybrid market model. The final objective of this thesis is to analytically compare selected existing loss allocation schemes with the proposed loop-based method. As there are no standard means of judging the accuracy of any loss allocation methods, the author of this thesis proposed a different way to distinguish different loss allocation methods. That is, through the type of competition that each method promotes. A wide range of results is obtained in which the loss allocations of some methods are dependent only on the real power injection at each bus. On the other hand, the loss allocations of other methods such as the loop-based method are dependent on network operation efficiency. The comprehension of the different type of competitions each method promotes aims to assist market regulators in recognising the feasibility of employing each loss allocation method.

This thesis reports findings from a number of modern machine learning techniques applied to electricity market price forecasting. The techniques evaluated were Support Vector Machines, Boosting, Bayesian networks, neural networks and a weekly average method. All techniques were evaluated on seven day into the future forecasting of the Regional Reference (pool) Prices (RRP) for the New South Wales (NSW) region of the Australian National Electricity Market (NEM). Due to highly volatile and non-repetitive nature of the NSW RRP, all complex machine learning methods provided inferior accuracy forecasts compared to a weekly average method. The weekly average method was computationally less expensive and more transparent to the user than any of the machine learning techniques. The Support Vector Machine (SVM) was chosen for its novel application to electricity price forecasting because it is considered to be the next generation to neural networks. The structured SVM training algorithm proved more consistent and reliable than the neural network algorithm. Bayesian networks offer the adaptability of a neural network with the advantage of providing a price forecast with confidence intervals for each half-hour determined from the actual data. The SVM and Bayesian techniques were found to provide acceptable forecasts for NSW demand. An investigation of international electricity markets found that each market was unique with different market structures, regulations, network topologies and ownership regimes. Price forecasting techniques and results cannot be universally applied without careful consideration of local conditions. For instance, price data for the Spanish and Californian electricity markets were investigated and found to have significantly lower price volatility than the NSW region of the NEM. An extensive examination of the NSW RRP showed that the price exhibited no consistent long-term trend. A stationary data set could not be extracted from the price data. Thus, making forecasting unsuited to techniques using large historical data sets. The strongest pattern found for NSW prices was the weekly cycle, so a weekly average method was developed to utilise this weekly cycle. Over 25 weeks of NSW RRP from February to July 2002, the seven day into the future price forecast mean absolute error (MAE) for the SVM technique was 27.8%. The weekly average method was more accurate with an MAE of 20.6% and with a simple linear price adjustment for demand, the error was reduced to 18.1%. The price spikes and uneven distribution of prices were unsuitable for the Boosting or Bayesian network techniques.

The deregulation of the electricity industry has introduced many opportunities as well as challenges to the once monopolised industry. This recent reform towards a competitive electricity industry advocates a need for charging energy losses to market participants through a more satisfactory and transparent mechanism. Market participants, whether they are generators or consumers, would want a loss allocation scheme that is able to reflect each market participants' contribution of generation or usage in the network. However, as electricity is an indistinguishable entity, there is no accurate method to trace the flow of electricity thus far. Hence, the issue of power loss allocation within the deregulated market still remains an unresolved setback to progress to a fully competitive electricity market. Many loss allocation methods have been introduced, however, none have been universally accepted. This thesis investigates existing power flow tracing and loss allocation methods in order to critically analyse the advantages and disadvantages of each method. They include loss allocation methods currently employed in Australia’s National Electricity Market (NEM) and Great Britain Market, as well as a selection of better known loss allocation methods that are introduced in the academic research field. Understanding of these methods makes it easier to choose a method that is more suitable for each electricity market. Many researchers believe that a resolution is through a fair and equitable allocation of losses. However, the definition of “fair and equitable” varies from one literature to another. In general, a fair and equitable loss allocation method should meet electrical laws as well as economical laws. This is because market driven transactions have become the new independent decision variables that define the behaviour of electric power systems. This definition is then used as the basis to assess the results obtained from the implementation of each existing method analysed. It was found that a key limitation of existing methods is the lack of a method that is able to trace the usage allocation of each generator to each load in an electrically justifiable manner. Any improvement to existing loss allocation methods should address this limitation. Thus, the main objective of this thesis is to present two transaction based methods that have been developed and tested by the author of this thesis. Fundamentally, both methods hold the capability to analyse losses involved in the transfer of power from one point of the network to another point. The first investigated method is based on the network reduction method, where a system is reduced to the nodes of interest. The second method is based on the loop frame of reference. Instead of representing the network flows through the commonly accepted nodal frame of reference, power flows within the network are instead expressed as the sum of power flows around loops that links loads to active sources. This provides the loop-based method with an advantage in which it allows the power requirements of a load to be viewed as emanating from an active source and also the advantage of assessing the viability of contract agreements within a hybrid market model. The final objective of this thesis is to analytically compare selected existing loss allocation schemes with the proposed loop-based method. As there are no standard means of judging the accuracy of any loss allocation methods, the author of this thesis proposed a different way to distinguish different loss allocation methods. That is, through the type of competition that each method promotes. A wide range of results is obtained in which the loss allocations of some methods are dependent only on the real power injection at each bus. On the other hand, the loss allocations of other methods such as the loop-based method are dependent on network operation efficiency. The comprehension of the different type of competitions each method promotes aims to assist market regulators in recognising the feasibility of employing each loss allocation method.

This thesis reports findings from a number of modern machine learning techniques applied to electricity market price forecasting. The techniques evaluated were Support Vector Machines, Boosting, Bayesian networks, neural networks and a weekly average method. All techniques were evaluated on seven day into the future forecasting of the Regional Reference (pool) Prices (RRP) for the New South Wales (NSW) region of the Australian National Electricity Market (NEM). Due to highly volatile and non-repetitive nature of the NSW RRP, all complex machine learning methods provided inferior accuracy forecasts compared to a weekly average method. The weekly average method was computationally less expensive and more transparent to the user than any of the machine learning techniques. The Support Vector Machine (SVM) was chosen for its novel application to electricity price forecasting because it is considered to be the next generation to neural networks. The structured SVM training algorithm proved more consistent and reliable than the neural network algorithm. Bayesian networks offer the adaptability of a neural network with the advantage of providing a price forecast with confidence intervals for each half-hour determined from the actual data. The SVM and Bayesian techniques were found to provide acceptable forecasts for NSW demand. An investigation of international electricity markets found that each market was unique with different market structures, regulations, network topologies and ownership regimes. Price forecasting techniques and results cannot be universally applied without careful consideration of local conditions. For instance, price data for the Spanish and Californian electricity markets were investigated and found to have significantly lower price volatility than the NSW region of the NEM. An extensive examination of the NSW RRP showed that the price exhibited no consistent long-term trend. A stationary data set could not be extracted from the price data. Thus, making forecasting unsuited to techniques using large historical data sets. The strongest pattern found for NSW prices was the weekly cycle, so a weekly average method was developed to utilise this weekly cycle. Over 25 weeks of NSW RRP from February to July 2002, the seven day into the future price forecast mean absolute error (MAE) for the SVM technique was 27.8%. The weekly average method was more accurate with an MAE of 20.6% and with a simple linear price adjustment for demand, the error was reduced to 18.1%. The price spikes and uneven distribution of prices were unsuitable for the Boosting or Bayesian network techniques.

Orientador: José Pissolato Filho / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-17T05:27:30Z (GMT). No. of bitstreams: 1 Castilho_RenatoMaioli_M.pdf: 2356762 bytes, checksum: ada04c502811c2989682af0e17b5a512 (MD5) Previous issue date: 2010 / Resumo: Este trabalho apresenta um método de análise do carregamento de linhas de transmissão aérea em tempo real o qual relaciona o respectivo carregamento da linha de transmissão com fatores externos que, direta ou indiretamente, exercem influência sobre os limites de operação da linha. Através da implementação de um sistema de monitoramento em uma linha de 230 kV da Eletronorte, informações atmosféricas e da própria linha foram coletadas e transmitidas via cabo OPGW para um centro de controle onde, a partir de um software, obteve-se a ampacidade da linha em tempo real. Fazendo uso do banco de dados gerado com as informações coletadas pelo sistema de monitoramento e utilizando técnicas de redes neurais artificiais, foi desenvolvido um módulo preditor da temperatura superficial do cabo, possibilitando estimar a ampacidade da linha no curto prazo. A pesquisa se deu em três fases, na primeira foi feito o desenvolvimento dos equipamentos que compõem o sistema de monitoramento, na segunda fase foi feita a implementação do sistema na linha de 230 kV e na terceira fase foi dado o tratamento matemático às informações coletadas. A abordagem realizada dos dados obtidos pelo sistema de monitoramento proposto gerou resultados interessantes no que tange a busca pelo melhor aproveitamento da linha e mostrou ser um sistema bastante útil para a operação no despacho de carga. O sistema de monitoramento analisado neste trabalho de pesquisa, foi desenvolvido pelo Centro de Pesquisa e Desenvolvimento em Telecomunicações - CPqD em parceria com a Universidade Federal do Pará - UFPA e faz parte do programa de pesquisa e desenvolvimento das Centrais Elétricas do Norte do Brasil S.A. - Eletronorte. / Abstract: This paper presents a method of transmission line load analysis in real time, which relates of the transmission line loading with external factors that directly or indirectly exert influence over the operating range of the line. By setting up a monitoring system in a line of 230 kV, weather and line parameters information were collected and transmitted via OPGW cable to a control center where, using dedicated software, we obtained the ampacity of the line in real time. Making use of the database generated with information collected by the monitoring system and using techniques of artificial neural networks, we developed a predictor module surface temperature of the cable, allowing use to estimate the ampacity of the line in the short term. The research was divided in three phases, at first was developed the equipment that make up the monitoring system in the second round was implemented the monitoring system at 230 kV line and in the third stage was given the mathematical treatment of collected information. The data obtained by the proposed monitoring system, has generated interesting results allowing an optimized use of the line the system proved to be very useful for the line loading operation. The monitoring system of loading examined in this research work was developed by the Center for Research and Development in Telecommunications - CPqD in partnership with the Federal University of Pará - UFPA and is part of Centrais Elétricas do Norte do Brasil S.A - Eletronorte research and development program. / Mestrado / Energia Eletrica / Mestre em Engenharia Elétrica

Orientador: Dílson Amâncio Alves / Banca: Luiz Fernando Bovolato / Banca: Luis Carlos Origa de Oliveira / Banca: Vivaldo Fernando da Costa / Banca: Eduardo Nobuhiro Asada / Resumo: Este trabalho apresenta uma metodologia alternativa para a melhoria da margem de carregamento e redução da perda total de potência ativa com base no método da continuação. Para atingir esta meta, uma equação de parametrização baseada na perda de potência ativa total e as equações da potência reativa nas barras de geração são acrescentadas às equações de fluxo de carga convencional. As tensões nas barras PV são consideradas como variáveis de controle e um novo parâmetro é escolhido para reduzir as perdas de potência ativa nas linhas de transmissão. Os resultados mostram que este procedimento, em geral, conduz a um aumento no ponto de máximo carregamento e por conseguinte, melhoria na margem estática da estabilidade de tensão. Este procedimento também leva a uma redução nos custos operacionais e, simultaneamente, uma melhoria no perfil da tensão. / Abstract: This work presents an alternative methodology for loading margin improvement and total real power losses reduction by using a continuation method. In order to attain this goal, a parameterizing equation based on the total real power losses and the equations of the reactive power at the slack and generation buses are added to the conventional Power Flow equations. The voltages at these buses are considered as control variables and a new parameter is chosen with to reduce the real power losses in the transmission lines. The results show that this procedure leads to maximum loading point increase and consequently, in static voltage stability margin improvement. Besides, this procedure also takes to a reduction in the operational costs and, simultaneously, to voltage profile improvement. / Doutor

Made available in DSpace on 2014-06-11T19:22:34Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-02-03Bitstream added on 2014-06-13T20:08:31Z : No. of bitstreams: 1 berardo_bl_me_bauru.pdf: 467989 bytes, checksum: 1b7cb5967b4080092b9a0c9ae7a58c49 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Este trabalho mostra o estudo de uma linha de transmissão onde ocorreram desligamentos causados por descargas atmosféricas. Esse estudo foi feito a partir de informações de desligamentos de linhas de transmissão da concessionária e dados extraídos de um sistema de análise e monitoramento de descargas atmosféricas. Para esse trecho da linha de transmissão foram identificadas incidências de descargas atmosféricas que causaram desligamentos, bem como descargas que não causaram desligamentos. Baseados nestas informações foram efetuadas medições em campo de resistência de aterramento dos contrapesos e da resistividade do solo, onde foi possível constatar através dos resultados que algumas torres apresentaram valores que ultrapassaram os valores normatizados. O levantamento dessas informações é o principal foco deste estudo, que visa fornecer subsídios para a identificação de torres problemáticas. Uma proposta clássica utilizada para melhorar o desempenho desta linha de transmissão frente à incidência de descargas atmosféricas foi testada mas seu resultado não foi muito satisfatário / This paper shows the study of a transmission line where outages occurred because of lightnings. The study was made from information that came from the power utility transmission line disconnection and data obtained from lightnings analyses and monitoring system. For this part of the transmission line it was identified incidence of lightning that caused outages, as well as incidences that did not cause outages. Based on this information, it was performed field measurements of ground resistance counterpoise and resistivity where is was possible to find, trough the results that some of the towers present numbers trepassed the normal values. Coming up with this information is this information is the main goal of this study that aims to offer to identify the towers that contains problems. A classical proposal used to improve the performance of this transmission line facing the incidence of lightnings was tested but the result wasn't very satisfactory

Orientador: André Christóvão Pio Martins / Coorientador: André Nunes de Souza / Banca: Oscar Armando Maldonado Astorga / Banca: Pedro da Costa Junior / Resumo: Este trabalho mostra o estudo de uma linha de transmissão onde ocorreram desligamentos causados por descargas atmosféricas. Esse estudo foi feito a partir de informações de desligamentos de linhas de transmissão da concessionária e dados extraídos de um sistema de análise e monitoramento de descargas atmosféricas. Para esse trecho da linha de transmissão foram identificadas incidências de descargas atmosféricas que causaram desligamentos, bem como descargas que não causaram desligamentos. Baseados nestas informações foram efetuadas medições em campo de resistência de aterramento dos contrapesos e da resistividade do solo, onde foi possível constatar através dos resultados que algumas torres apresentaram valores que ultrapassaram os valores normatizados. O levantamento dessas informações é o principal foco deste estudo, que visa fornecer subsídios para a identificação de torres problemáticas. Uma proposta clássica utilizada para melhorar o desempenho desta linha de transmissão frente à incidência de descargas atmosféricas foi testada mas seu resultado não foi muito satisfatário / Abstract: This paper shows the study of a transmission line where outages occurred because of lightnings. The study was made from information that came from the power utility transmission line disconnection and data obtained from lightnings analyses and monitoring system. For this part of the transmission line it was identified incidence of lightning that caused outages, as well as incidences that did not cause outages. Based on this information, it was performed field measurements of ground resistance counterpoise and resistivity where is was possible to find, trough the results that some of the towers present numbers trepassed the normal values. Coming up with this information is this information is the main goal of this study that aims to offer to identify the towers that contains problems. A classical proposal used to improve the performance of this transmission line facing the incidence of lightnings was tested but the result wasn't very satisfactory / Mestre

This thesis draws on techniques from Management Science and Artificial Intelligence to explore organisational aspects of asset management in electricity transmission enterprises. In this research, factors that influence policies and practices of asset management within electricity transmission enterprises have been identified, in order to examine their interaction and how they impact the policies, practices and performance of transmission businesses. It has been found that, while there is extensive literature on the economics of transmission regulation and pricing, there is little published research linking the engineering and financial aspects of transmission asset management at a management policy level. To remedy this situation, this investigation has drawn on a wide range of literature, together with expert interviews and personal knowledge of the electricity industry, to construct a conceptual model of asset management with broad applicability across transmission enterprises in different parts of the world. A concise representation of the model has been formulated using a Causal Loop Diagram (CLD). To investigate the interactions between factors of influence it is necessary to implement the model and validate it against known outcomes. However, because of the nature of the data (a mix of numeric and non-numeric data, imprecise, incomplete and often approximate) and complexity and imprecision in the definition of relationships between elements, this problem is intractable to modelling by traditional engineering methodologies. The solution has been to utilise techniques from other disciplines. Two implementations have been explored: a multi-level fuzzy rule-based model and a system dynamics model; they offer different but complementary insights into transmission asset management. Each model shows potential for use by transmission businesses for strategic-level decision support. The research demonstrates the key impact of routine maintenance effectiveness on the condition and performance of transmission system assets. However, performance of the transmission network, is not only related to equipment performance, but is a function of system design and operational aspects, such as loading and load factor. Type and supportiveness of regulation, together with the objectives and corporate culture of the transmission organisation also play roles in promoting various strategies for asset management. The cumulative effect of all these drivers is to produce differences in asset management policies and practices, discernable between individual companies and at a regional level, where similar conditions have applied historically and today.

Made available in DSpace on 2014-06-11T19:30:50Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-11-07Bitstream added on 2014-06-13T19:47:13Z : No. of bitstreams: 1 malange_fcv_dr_ilha.pdf: 1077798 bytes, checksum: 6e2455ed107dc7931eb5bc7473ecce8a (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Este trabalho apresenta uma metodologia alternativa para a melhoria da margem de carregamento e redução da perda total de potência ativa com base no método da continuação. Para atingir esta meta, uma equação de parametrização baseada na perda de potência ativa total e as equações da potência reativa nas barras de geração são acrescentadas às equações de fluxo de carga convencional. As tensões nas barras PV são consideradas como variáveis de controle e um novo parâmetro é escolhido para reduzir as perdas de potência ativa nas linhas de transmissão. Os resultados mostram que este procedimento, em geral, conduz a um aumento no ponto de máximo carregamento e por conseguinte, melhoria na margem estática da estabilidade de tensão. Este procedimento também leva a uma redução nos custos operacionais e, simultaneamente, uma melhoria no perfil da tensão. / This work presents an alternative methodology for loading margin improvement and total real power losses reduction by using a continuation method. In order to attain this goal, a parameterizing equation based on the total real power losses and the equations of the reactive power at the slack and generation buses are added to the conventional Power Flow equations. The voltages at these buses are considered as control variables and a new parameter is chosen with to reduce the real power losses in the transmission lines. The results show that this procedure leads to maximum loading point increase and consequently, in static voltage stability margin improvement. Besides, this procedure also takes to a reduction in the operational costs and, simultaneously, to voltage profile improvement.