Impact of High Penetration of Photovoltaic Distributed Generation on the Protection Coordination in Distribution Networks

Nowadays, it is increasingly common to see an increase in the interconnection of Distributed Generation Systems, mainly using photovoltaic modules, in the Distribution Networks. This is because of the reduction in the cost of buying these generation systems. The continuous increase of Distributed Generation Systems brings some technical challenges that must be addressed. One of these technical challenges occurs in the Distribution Networks' protection schemes since a high concentration of photovoltaic generation systems can cause changes in the operating times of the protection devices and therefore cause a loss of coordination between them. Thus, to comply with the operating criteria of the Distribution Networks' protections, the change caused by a large concentration of Photovoltaic Distributed Generation Systems must be considered. This paper evaluates the impact on the Distribution Networks protection schemes caused by different Photovoltaic Distributed Generation Systems penetration under different scenarios. It is considered in the analysis of the technical restrictions required to protect Distribution Networks, as well as the limits to interconnect Photovoltaic Distributed Generation Systems. To evaluate this impact, the DIgSILENT PowerFactory software and the IEEE 13 Node Test Feeder are used. The obtained results show how the increasing penetration of Photovoltaic Distributed Generation Systems in the Distribution Networks affects its protection schemes up to 20% of the operating time of the protection device closest to the point of failure.