Analise do comportamento do dfig em uma rede elétrica diante de afundamentos de tensão e falhas internas utilizando técnicas de controle pi e lqi

Abstract

In this work an analysis of the main parameters of a double fed induction generator(DFIG) connected to a wind power grid is performed when there are balanced voltage sag, unbalanced voltage sag and internal faults. The analysis is based on the response of two control strategies, the proportional-integral controller (PI) and the quadratic linear regulator with integral action (LQI). It is part of the scope of this work to present the methodologies for tuning controller gains and the characteristics of the electric grid in which the wind generator is connected. Four scenarios with disturbances to analyze the results are considered. In the first scenario is analyzed the occurrence of voltage sags balanced in two points of the system under study, in the second scenario is evaluated the effect of unbalanced sinkings, in the third scenario is considered electrical asymmetry at the rotor terminals and in the fourth scenario simulates the disturbance of internal faults(short circuit) in the rotor and stator terminals of the machine. As a result, it is shown that, in general, the performance of the LQI controller is higher than the PI controller with smaller oscillations in the four scenarios.