Adaptive Overcurrent Protection for Power Systems with Distributed Generators

The current electrical power distribution networks are normally connected in a radial structure. It is expected to have a high penetration of distributed generators (DG) in the future electrical power distribution systems. The impact of DG on the protection system is one of the major challenges for the operation of modern power systems. Typically, the fault current level of a power system depends on the sources of the grid. However, when the distribution system is connected to DG, the fault current increases. The fault current level changes due to the penetration level of DG. As a result, it changes the setting of protection coordination and causes malfunctioning. Thus, one of the proposed solutions for protection is the use of adaptive overcurrent protection. This paper presents the impact of the distributed generators on power system protection and the use of adaptive overcurrent protection to overcome these challenges. The advantage of this protection is that it adapts real-time changes automatically. The proposed protection solution was applied to the IEEE-9 bus electrical power system where several DGs are connected. Also, an extracting part of a complex microgrid is used as another case study to verify the proposed solution. These studies were carried out on ETAP software and shows the capability of adopting the protection system when there is a high presence of DGs.