Navegando por Assunto "Distribution system"

Agora exibindo 1 - 4 de 4

Acesso aberto (Open Access)
Avaliação do desempenho das funções de controle volt-watt e volt-var em inversores fotovoltaicos integrados nas redes de distribuição
(Universidade Federal do Pará, 2018-03-27) WANZELER, Tiago Machado; VIEIRA, João Paulo Abreu; http://lattes.cnpq.br/8188999223769913
This dissertation addresses some of the major operational problems faced by distribution system operators due to the high integration of photovoltaic (PV) generators, such as overvoltages and excessive tap counts in step voltage regulators (SVR). These situations are continually being studied, since they can cause voltage quality problems and damage in SVRs. The overvoltage problem can be caused by a significant injection of active power from the PV generation to the network. Moreover, the rapid and significant variations in PV generator active power associated with cloud transients result in an increase of voltage regulator tap counts, which can affect the useful life of device. In this context, the smart inverters Volt-Watt and Volt-Var control functions have been added in recent studies to mitigate the overvoltages. This work shows how Volt-Watt and Volt-Var control functions mitigate the overvoltage and voltage regulation problems in distribution networks with PV generation. Time series power flow simulations on LV and MV single feeders with PV solar plant have been performed in high and low solar variability scenarios.
Acesso aberto (Open Access)
Impacto técnico e econômico da integração de uma geração distribuída de alta capacidade em um sistema de distribuição com reguladores de tensão em cascata
(Universidade Federal do Pará, 2019-11-14) COSTA, Marcelo Sousa; VIEIRA, João Paulo Abreu; http://lattes.cnpq.br/8188999223769913
This dissertation analyzes the technical and economical impact of the integration of a high capacity distributed generation (DG) in a distribution system composed of two feeders, both with two cascaded step voltage regulators (SVRs). Distribution networks with the presence of high capacity DG may subject SVR to reverse active power flow scenarios, which, depending on the control modes “Active Bidirectional Flow up to Opposite Limit” and “Reverse Flow by Cogeneration”, result in abnormal situations that lead the SVR to lose its regulating capacity. As a consequence, consumers may be subjected to severe undervoltage or overvoltage. This phenomenon, in which the SVR loses its ability to control the desired bus voltage, is known in technical literature as the reverse power tap changer runaway condition. In addition, high capacity GDs, depending on their location in the distribution system, can cause critical overvoltages. Some actions can be taken to reduce or mitigate this effect, such as distribution system reconfiguration, adjusting the SVR setpoint, and modifying DG control mode. The economic assessment was accomplished for all studied operating scenarios, highlighting technical and financial impacts on the utility and customers.
Acesso aberto (Open Access)
Procedimentos para gestão de perdas não técnicas em sistemas de distribuição de energia elétrica
(Universidade Federal do Pará, 2012-11-01) SAMPAIO, Mayara Ferreira; TOSTES, Maria Emília de Lima; http://lattes.cnpq.br/4197618044519148
This dissertation aims to analyzing the management of non-technical losses of eletrical energy and understand the methodologies adopted in the design of losses combat developed by distribution concessionaires. Bringing thus to evidence the importance of efficient management of commercial losses to obtain good maintenance of their indices. It is in the power distribution system, where it occurs it the greatest percentage of loss of electric power systems. This way its is in the distribution on system where one has the greatest potential for reducing losses. Thus, the focus of this dissertation is to have an analysis of non-technical losses, the ways of acting on them and the methodologies currently used by utilities, which will be presented through a case study.
Acesso aberto (Open Access)
Usina de geração distribuída de energia elétrica através da incineração de resíduos sólidos com operação ilhada
(Universidade Federal do Pará, 2011-02-28) BARBOSA, Rosândela Oliveira; AFFONSO, Carolina de Mattos; http://lattes.cnpq.br/2228901515752720; TOSTES, Maria Emília de Lima; http://lattes.cnpq.br/4197618044519148
This work presents a proposal to supply eletricity to a distribution feeder for the operation of an isolated electric generating power plant that uses as primary source of energy heat from the incineration of solid waste. This suggested supply system is justified after the substation supplying capacity to this feeder is ex hausted. The capacity ex haustion is verified from simulations in the real Rede Celpa distribution system, located in the northeastern region of the state of Para, which supply the municipalities Santa Izabel do Para, Santo Antonio do Tauá, Colares, Vigia and São Caetano de Odivelas. In the simulations studies is used a load flow program specifically developed for distribution and subtransmission radial systems. The proposed supply system using electrical energy generation through incineration of the municipal solid wastes occurs from the comparison between the expansion alternatives namely the technical alternative used normally by the utility and technical-economical-enviromental alternative suggested in this paper that show the economic, social and environmental advantages of the proposal.