Development of a Reliability-Oriented Investment Planning for Switching Devices in Power Distribution Networks with Distributed Generation Using an MILP Approach

This study presents a reliability-based investment planning method for distribution networks considering both load and distributed generation (DG). A new reliability index is proposed to quantify the impacts of power interruptions on load consumption and DG output. The normalized sub-indices are integrated into a comprehensive reliability measure. In addition, a mixed-integer linear programming based service restoration model is formulated to estimate outage durations under realistic operating conditions, explicitly considering network constraints as well as the different operating times of remote-controlled and manual-controlled switches during fault restoration. Sensitivity analysis of the proposed index assesses the reliability improvement achieved by sectionalizing switch investments, leading to a priority-based investment procedure. The proposed index and planning framework are tested on a model of distribution system of KEPCO. The simulation results demonstrate the difference in reliability before and after DG integration and validate the effectiveness of the proposed method.