Dissertations/Thesis

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2019
Dissertations
1
  • MATEUS DIAS BRAGA
  • Capacidade de Hospedagem de Sistemas de Distribuição com Inserção de Geração Distribuída Utilizando o OpenDSS

  • Advisor : PAULO FERNANDO RIBEIRO
  • MEMBROS DA BANCA :
  • BENEDITO ISAIAS LIMA FULY
  • ELIANE VALENCA NASCIMENTO DE LORENCI
  • JOSE LUIZ REZENDE PEREIRA
  • PAULO FERNANDO RIBEIRO
  • Data: Apr 25, 2019


  • Show Abstract
  • The use of distributed generation - mainly of photovoltaic solar panels - have been
    increasing in the last years. Promoting the development of renewable energy has become a
    common goal of the World and Brazil as well. The seek for alternative energy sources allied
    with the generation of clean energy has increased considerably the use of photovoltaic solar
    energy. In addition, agreements such as the Kyoto Protocol and Paris have also influenced it.
    Another factor that is interesting to mention is the price reduction in this type of energy, since
    in previous decades it was unfeasible, presenting very high prices. Moreover, the growth of
    this type of energy is quite beneficial to the society because it diversifies the energy matrix,
    decreasing the dependence on large hydroelectric and/or thermal plants. On the other hand, it
    also generates technical, economic and social uncertainties and concerns. Within this context,
    this work seeks to present the impacts of the distributed generation on the electric power
    systems. From the technical point of view, the main problems reported in the literature due to
    high insertion of distributed photovoltaic systems are: overvoltage, harmonic distortions,
    voltage imbalances, thermal capacity of lines and transformers, among others. In this way,
    this paper work aims to analyze the hosting capacity of a distribution system against
    overvoltage and harmonics. OpenDSS software is used with MATLab in order to evaluate the
    system against high insertion of distributed generation. Some factors that directly influence
    the hosting capacity values of this test system (13 buses) against overvoltages and harmonic
    distortions are presented, compared and discussed.

Thesis
1
  • PEDRO EUGÊNIO MARCONDES JUSTINO RIBEIRO
  • Compensação de Harmônicas Utilizando Máquina Síncrona

  • Advisor : LUIZ EDUARDO BORGES DA SILVA
  • MEMBROS DA BANCA :
  • JOAO ONOFRE PEREIRA PINTO
  • LUIGI GALOTTO
  • LUIZ EDUARDO BORGES DA SILVA
  • RAYMUNDO CORDERO GARCIA
  • ROBSON BAUWELZ GONZATTI
  • RONDINELI RODRIGUES PEREIRA
  • Data: Mar 29, 2019


  • Show Abstract
  • The development of electronics and semiconductors brought the circulating of harmonic currents in the electric power grids. These currents can cause losses in conductors and unwanted resonances and have become one of the biggest problems in electric power systems. Therefore, many solutions are presented in the literature, such as, i) specials design transformers windings; ii) reactors; iii) passive resonant filters; iv) parallel active filter; v) hybrid filters. However, none of these solutions has good applicability in high-voltage high-power systems. This dissertation proposes an alternative method off using synchronous machine to compensate the harmonic content of a non-linear load, by controlling its field current. For this equipment, it is being proposed the name of Supersynchronous Active Filter (FAZ). This equipment can be implemented by retrofitting of installed synchronous machines, or in new projects.
    The viability of the synchronous operation for the reactive power compensation is described; it was presents the field and flux machine modeling. The simulation off the operation is shown, for a compensation of a non-linear load, and a comparison with a reference model (parallel active filter) was done. Finally, discussions are made considering the results and the implementation difficulties.

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