Estratégias de controle no suporte de potência reativa da geração eólica e seu impacto na estabilidade de tensão da Rede Básica utilizando regiões de segurança: uma aplicação na Região Nordeste do Brasil

Abstract

This dissertation presents a discussion about some technical characteristics of the wind turbines, their electrical and energetic implications and how these equipments can contribute in a static and dynamic regime from the point of view of voltage stability for the performance of electrical power systems focusing on the Northeast Region of Brazil. Throughout this dissertation, different energy scenarios and configurations of systems are presented based on the Brazilian Electric System in 2020. The massive insertion of intermittent renewable sources, mainly in the Northeast Region, has been changing the operating conditions of this system in view of the behavioral profiles intrinsic to these sources, with high quotas being added every year in view of the large "wind fields" available in this region. Despite contributing to the increase in generation capacity from an energy point of view, this source adds little or no inertia to the system, which reflects stability in the face of disturbances, resulting in risk conditions for the regulation and control of voltage stability and consequently operational security of the network. In view of this, voltage stability has become a point of concern, arousing the interest of engineers and researchers worldwide. The control resources in the reactive power support present in the network are not always sufficient to accommodate this entire generation. That is why it is studied here the performance of the control strategies of the reactive power support of the wind turbines in order to assist in mitigating the effects caused by voltage instability in an attempt to increase the safety margin of the system. In order to provide an assessment of the conditions of safe operation, in different electroenergetic scenarios where wind power is present, the use of the Safety Regions feature is used, enabling a representative and safe mapping of the analyzed system and subsidizing the decision making of the operation. In a static regime, the voltage and load levels are evaluated in situations of increase and reduction of wind generation in the Northeast through the Security Regions. In a dynamic regime, where the study begins with the presentation of wind turbines in three different control strategies that assist in regulating the voltage of the machine and in turn of the system in which it is inserted. This analysis has three distinct cases in the Northeast where wind behavior differs from each other to illustrate the impact they can cause on the dynamic performance of a system. The results obtained from the simulations show significant gains in improving the performance of the electrical system in the Northeast Region with the increase in the generation runoff margin, in which the wind turbines operate.