Multiobjective MILP model for optimal allocation of automated switching devices in electric power distribution systems

This paper presents an analytical mixed-integer linear programming model to improve reliability of distribution networks through the optimal allocation of automated switching devices. Optimal reliability is formulated as a multi-objective problem of minimizing customers´ interruptions and the investment costs related to devices´ acquisition, relocation and operation. In order to establish the optimal trade-off between these conflicting objectives the Goal Programming approach is proposed. The presented model considers post-fault restoration constraints which limit load transfers and thereby the system reconfiguration capability. Restoration feasibility is ensured by a linear formulation of power flow equations as functions of geographical locations of automated switching devices in the feeder. Therefore, the model´s solutions provide a more effective and economic application of automated switching devices, so that voltage and system capacity constraints are taken into account in selecting optimal locations of devices. The proposed methodology was validated using the IEEE 123-bus test feeder.