Investigação do amortecimento de modos de oscilação eletromecânicos em sistemas elétricos de potência utilizando rede de modelos locais fuzzy considerando os princípios de LMI

Abstract

This study aim develops a power system stabilizer for an electrical system that corresponds to a machine-bus-infinite (SMIB). Three methodologies to design the power system stabilizer are investigated, such as classic methodology based on frequency analysis, pole placement technique, and finally, the methodology based on linear matrix inequalities (LMI). These methodologies were applied with the local Takagi Sugeno fuzzy input-output models, which maintain a network of local controllers designed for three different operating points, to consider the condition such as light, medium, and heavy load. The methodology based on Takagi-Sugeno system that is responsible for the development of a network of local controllers, joint with the PSS controller with the PSS project making use of the dynamic feedback principle and LMI is proposed in this study, aiming to improve the dynamic system performance as well as improving system stability. Several tests were carried out via simulation, to assess whether the proposed methodology presents a better performance and robustness of the EPS in comparison with the other approaches. Three different tests were performed, such as setpoint voltage variation, heavy load insertion in the system, e.g. a transmission line, and finally, increasing the mechanical power that supplies the generator. These tests aim to evaluate the system stability against small and large oscillations of the electro-mechanical modes of the electrical power system. The results show that the proposed methodology outperforms the other approaches, showing the effectiveness and robustness of the methodology to design the PSS system when occurs small and large oscillations decurrent of the electromechanical modes of the electrical power system.