Effects Analysis of the Integration of Distributed Generation on the Timed Overcurrent Protection: Necessity of New Settings on the Relay to Guarantee the Coordination Time

The growth of distribution systems with the inclusion of distributed generators (DG) is a reality that is taking place in several countries. The use of DGs in these systems brings benefits and challenges. One of these challenges is the effect of DGs on overcurrent protection, which makes it important to investigate through computational tools that evidence such effects and serve as a support for evaluating the necessary adaptations by the protection engineer. So, this work is a complementing of an earlier conference paper [1] that contains simulation analyses to evaluate these questions. For this, overcurrent protection devices were incorporated into the original system, in the places where DGs were inserted, for an evaluation of the network's behavior. The impact of these DGs was evaluated in the application of symmetrical three-phase faults in specific locations of the system, for a given DG size. An analysis of current variation, selectivity and protection coordination was performed in numerical and graphical form, in different scenarios. From the results obtained, it was observed that new settings for the protection devices are necessary so that the system remains correctly coordinated and protected with the inclusion of DGs.