Impacto de diferentes estratégias de controle dos parques eólicos na estabilidade de frequência de sistemas de energia elétrica

Abstract

The purpose of this dissertation is to analyze the impact of a high wind power penetration on the frequency stability of electric power systems. The gradual replacement of conventional generators by wind farms implies reducing the overall inertia of the system, impacting, among other aspects, frequency performance, especially in events that result in large unbalances between load and generation. Facing this fact, control strategies in wind farms have been evaluated aimed to recompose the performance standards in the frequency of the electric system. Initially, the simulations are performed in a small-scale system which the conventional generators are gradually replaced by wind farms up to the limit of operation with only one synchronous generator. This approach has been useful to understand the effects of inertia reduction and as well as the result of control strategies on frequency behavior. After that, simulations have been carried out in the Brazilian Interconnected Power System, which has presented an exponential increase in wind energy sources in recent years. A light load scenario is analysed with high power exports from the Northeast region, composed exclusively by wind power generation. This scenario has been chosen because the growth of this source has occurred mainly in this region of the country. Based on this scenario, the impact of control resources in the electric frequency performance are evaluated. Additionally, a second scenario has been developed based on the first one where the substitution of all wind generation in the Northeast region is carried out by hydroelectric and thermoelectric power plants, whose performance is compared with the case with exclusively wind power generation.