Implementação de estratégias passivas para aumento da suportabilidade de aerogeradores DFIG

Abstract

The growth of the country, investments in the expansion of the electrical system are becoming increasingly necessary. The generation model most used in Brazil is based on hydroelectric power plants, despite being a source that does not release pollutants into the atmosphere, generate a large environmental impact at the time of its construction. Faced with the prospect many investments are being made in the area of generation by thermal power plants, solar and wind. The wind generation, to be renewed, fits perfectly in the sustainable model, so recently discussed in our society. Technological advances in this area are contributing to make deployment of this type of development more technique/financial attractive, as well as causing less environmental impact; modern wind turbines currently developed are able to perform optimal control of reactive power and contribution to network supportability at the point of connection. The development of these machines is due to advances in power electronics since it was possible to control variables such as active and reactive power in critical cases such as low-intensity winds. In this respect it is essential that these machines contribute to the stability of the system. For example, could be done with rate control system through the order of active power and voltage levels while maintaining adequate control of reactive power entered into the system. This work will be discussed the turbine's behavior during the voltage sag. The main objective is to validate the service to the network connection requirements. The most commonly used wind generator topology is DFIG, where the stator circuit is directly connected to the grid and the rotor connected to a back-to-back converter responsible for controlling the variables. The use of the chopper circuit for protection of the DC bus and Crowbar for protection of the rotor circuit will be exemplified. The study is performed through simulated results of a representative model of a 2MW system implemented in MATLAB / Simulink software.