An adaptive current limiting strategy to prevent fuse-recloser miscoordination in PV-dominated distribution feeders

The ever-increasing penetration of photovoltaic (PV) systems in distribution networks has resulted in proposing a new control strategy to mitigate the negative impacts of PVs on the protection coordination. However, disconnecting DGs, limiting penetration level, using Fault Current Limiter (FCL) and executing communication-based adaptive approaches are not such affordable solutions. In this paper, an applicable communication-free adaptive technique is proposed to prevent miscoordination problems in distribution networks. It is not only cost effective, but also immune to PV penetration-changes. Firstly, according to the amount of fault current variation in the beginning of the feeder, the fault location is estimated. Next, using a new-added auxiliary control mode, the fault current contributions of PV systems are decreased. Given the parameters are locally measured in each amount of penetration, the proposed methodology needs no communication link to be adapted against penetration variations. The effectiveness of the proposed method for different types of fault scenarios, variations in the photovoltaic penetration rates and different fault resistances is evaluated via detailed simulation case studies. The results clearly show that the proposed adaptive approach can successfully prevent miscoordination problems.