Modelagem e análise de desempenho dinâmico de complexos elétricos contendo centrais eólicas dotadas de geradores síncronos

Abstract

New generation resources, with low implantation and operation costs and that provoke the minimum possible impact to the environment, are undoubtedly focuses of attention to all the segments of the society. From this common sense, the alternative or renewable sources of energy, and particularly the wind, have certainly had a significant penetration in the composition of the energetic matrix of several countries in the world. Similarly, in Brazil, the wind energy is playing a more and more significant role as a consequence of directing established by the government policy called Program for Incentive of Alternative Electrical Energy Sources PROINFA. It can be pointed out that the expressive growth verified in the whole word for the use of Wind Energy Conversion System (WECS) to produce electricity was fundamentally due to the technological progress in power electronics together with the shortage of fossil fuels. However, the development of more efficient control techniques, as for instance the vector theory, has also contributed to a greater competitiveness of systems driven by the wind, when compared to traditional hydro and thermal systems. Such development allowed the design of new wind energy conversion systems, appropriate to control the active and reactive power flows, Therefore, making flexible their connection to the electric power grid. Within this context, this thesis was proposed which is turned to accomplish studies with one of the WECS topologies presently available and with strong growth trend worldwide. It aims to present the complete modeling of a wind energy conversion system, with variable speed, horizontal axis, with pitch control of blades to restrict the aerodynamic power. The adopted topology employs a multipole synchronous generator which is the predominant in Brazil until now. The mathematical and computer modeling are initiated at the primary source, the wind, going through the other electromechanical and electronic components, until, finally, reaching the connection with the electric grid. Special attention is given to the control system, based on the referred vector theory which propitiates the adjustment of the active power flow by the aerodynamic power, and the reactive power as function of the voltage at point of common coupling. Several simulations are accomplished to evaluate the potentialities of the developed software package. In this sense, investigations of the dynamic behavior of an electric power system including a wind park are presented for the normal operation condition as well as after short-circuit type contingencies.