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ESTGV - DEE - Documentos de congressos (comunicações, posters, actas)

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Browsing ESTGV - DEE - Documentos de congressos (comunicações, posters, actas) by Author "Gouveia, Eduardo"

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  • Flexible Power Control of Photovoltaic Plants Connected to Distribution Networks
    Publication . Ribeiro, Susana; Costa, Paulo Moisés; Gouveia, Eduardo; Sousa, Pedro; Albuquerque, Daniel
    This paper presents a system to control the power injected by a photovoltaic (PV) plant on the receiving network. This control is intended to mitigate some of the negative impacts that these units may produce on such networks, while increasing the installed power of the plant. The controlled parameters are the maximum allowed value of injected active power and the corresponding power factor, whose setpoints values may be fixed or dynamic. The developed system allows a local and a remote control. The injected power and the corresponding power factor may be set by following a predetermined profile or by real time adjustments to fulfill specific operation constraints on the receiving network. The system acts by adjusting the control parameters on the PV inverters. The main goal of the system is, in the end, to control the PV plant, ensuring the accomplishment of technical constraints and, at the same time, maximizing the installed power of the PV plant, which may be an important issue concerning the economic performance of such plants
    2016Journal article Restricted access Show more
  • Probabilistic Security Constrained Fuzzy Power Flow Models
    Publication . Gouveia, Eduardo; Costa, Paulo Moisés; Sagredo, Jesus; Soroudi, Alireza
    In restructured power systems, generation and commercialization activities became market activities, while transmission and distribution activities continue as regulated monopolies. As a result, the adequacy of transmission network should be evaluated independent of generation system. After introducing the constrained fuzzy power flow (CFPF) as a suitable tool to quantify the adequacy of transmission network to satisfy 'reasonable demands for the transmission of electricity' (as stated, for instance, at European Directive 2009/72/EC), the aim is now showing how this approach can be used in conjunction with probabilistic criteria in security analysis. In classical security analysis models of power systems are considered the composite system (generation plus transmission). The state of system components is usually modeled with probabilities and loads (and generation) are modeled by crisp numbers, probability distributions or fuzzy numbers. In the case of CFPF the component’s failure of the transmission network have been investigated. In this framework, probabilistic methods are used for failures modeling of the transmission system components and possibility models are used to deal with 'reasonable demands'. The enhanced version of the CFPF model is applied to an illustrative case.
    2016Journal article Restricted access Show more