Modeling and evaluation of the protection of distributed synchronous generators connected to unbalanced systems

The study of the imbalance effect on the behavior of protection functions used in synchronous generators, which are directly connected in the distribution and sub transmission systems, is the subject of this work. Very few studies are available for this type of generation, commonly known as Distributed Synchronous Generation (DSG), in spite of its great potential in countries like Brazil, for instance. Within this context, this work presents a detailed modeling for DSG protection and its corresponding evaluation with a full representation of the three-phase system. The results from simulations show the effect of imbalance on the performance and behavior of the types of protection present in distribution systems with DSGs. It was verified that there are cases where the representation of the unbalanced system is necessary for the correct analysis of the protection system performance and its adjustments.