Navegando por Assunto "Estabilidade de sistemas de potência"

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Acesso aberto (Open Access)
Análise do impacto de geradores fotovoltaicos na estabilidade transitória de geradores síncronos distribuídos
(Universidade Federal do Pará, 2018-02-19) PINHEIRO, Wanessa Tâmiris de Souza; NUNES, Marcus Vinícius Alves; http://lattes.cnpq.br/9533143193581447
This dissertation aims to present a comparative analysis between two models of inverter control for the study of the transient stability analysis and voltage stability, with the insertion of the photovoltaic generation in the distribution electric grid. It is also proposed an analysis of the influence, both negative and positive, caused by the control modes of these inverters in the stability of synchronous machine connected to the grid. Another proposed solution to be investigated in this work will be the use of the reactive power control mode of photovoltaic generators via the inverter, which can contribute to the relief of the reactive demand of distributed synchronous generators interconnected in the same electric system, in order to reduce the possibility of generating a voltage instability condition, after a big disturbance, or in the occurrence of contingencies in the electric power system that may affect weak or overloaded electrical grids and with large insertion of photovoltaic generators. The analysis of the control models will be carried out through simulations in the time domain, through the ANATEM and ANAREDE computational tools.
Acesso aberto (Open Access)
Investigação de estratégias de controle de ordem fracionárias aplicadas a sistemas elétricos e industriais
(Universidade Federal do Pará, 2018-11-14) AYRES JÚNIOR, Florindo Antonio de Carvalho; LENZI, Marcelo Kaminski; http://lattes.cnpq.br/8471869055654497; COSTA JÚNIOR, Carlos Tavares da; http://lattes.cnpq.br/6328549183075122
The use of control techniques is of great importance to maintain competitive performance for electrical and industrial systems suitable to trace behavior adjustment points as close as possible to a desired set point of operation for deviation and oscillation reduced. In this work, fractional automatic control techniques are investigated to improve the performance of industrial systems. Two fractional-order control techniques are studied: one of the Lead-Lag based fractional order (FOLL) type based on the frequency response method and applied to the improvement of power system stabilizers (ESP). Control laws are implemented in the form of digital control in an embedded system, based on microcontroller. The performance of the compensators is evaluated by performing several experimental tests on a 10 kVA reduced scale power system located at the UFPA Electrical Engineering Laboratory. Variation tests are carried out at one pulse in the generator voltage reference at various power operation points of the micro generator system, in addition to the robustness analysis of the system using a robust plot tool from the Bode diagram known as RBode. Second, there is an investigation of a fractional pole allocation technique (FOPP) which takes into account temporal response criteria of fractional systems to three terms, which, in this work, are overtime, settlement time, applied in a coupled tanks system, and in a Buck DC / DC converter, where the FOPP technique is compared with two other techniques: these are the classical technique of integer pole allocation (IOPP), and a tuning technique of FOPID controllers based on Gain Margins and Phase Margins (GMPM). The results are corroborated by simulations in Matlab / Simulink Environment. The results show a reduction of approximately 15% at least in the ITAE and ISE indexes related to the dynamic performances of the systems addressed in this study associated with the controlled variable, with the insertion of the fractional controllers based on both the topology using the FOLL and using the FOPP and GMPM techniques, compared to the values obtained from these indexes of the controllers tuned by conventional whole order techniques.