Study of Distributed Generation Systems with the Connection with Asynchronous Generators

Abstract

This research project proposes the use of modal estimation technique to analyze possible stability problems (such as oscillations poorly damped, for example) resulting from asynchronous generation connection (wind turbines) in distribution networks operating with unbalanced loads, composing the so-called systems with distributed generation. For the mentioned modal estimation was used the technique known as Prony method. The Prony method is based on the estimation of a model to sampled data of a signal through a linear combination of complex exponentials, which can directly determine the frequency and damping of electromechanical modes. In order to make an assessment of stability and performance indicators in systems with asynchronous distributed generation operating under unbalanced three-phase conditions, the proposal also aims to analyze the problems Low Voltage Ride-Through (LVRT) and Fault Induced Delayed Voltage Recovery (FIDVR) to asynchronous generators, studying the impact of these problems on the stability of these generators. The LVRT curve is a requirement to be met by wind farms. FIDVR events are initiated by electrical faults in the system. Once the fault is eliminated, the voltage can remain at significantly reduced levels for several seconds. This time delay is generally caused by high concentration of induction motors. From this it will be proposed possible solutions for the treatment of such problems.