Coordinated Optimization of Recloser Placement and Distributed Generation Considering Protection Sensitivity

The rapid expansion of distributed generation (DG) in radial distribution networks introduces bidirectional power flows that fundamentally disrupt traditional unidirectional protection coordination. This paper proposes a multi-criteria optimization method for the optimal placement of reclosers in distribution networks with DG. The approach incorporates analytical short-circuit current calculations to determine the critical DG capacity required to maintain protection sensitivity and avoid protection maloperation. The method is applied to a rural medium-voltage feeder. The results demonstrate the existence of a permissible DG capacity threshold beyond which relay sensitivity is compromised; the optimal placement of a recloser reduces the annual energy not supplied by 14.3%, while the integration of DG further improves supply reliability and can eliminate the annual energy deficit. The study confirms that reliability improvement measures must be coordinated with protection constraints to ensure the safe and reliable transition toward decentralized power systems.