Simultaneous placement of tie-lines and distributed generations to optimize distribution system post-outage operations and minimize energy losses

This study proposes a new method which aims to optimally install tie-lines and distributed generations simultaneously. This is done to optimize the post-outage reconfiguration and minimize energy losses and energy not supplied of distribution systems. The number and location of tie-lines, as well as the number, size, and location of DGs, are pinpointed through teaching the learning-based optimization (TLBO) method. The objective function in the current research is to minimize the costs pertaining to the investment, operation, energy losses, and energies not supplied. In addition to the normal operational condition, fault operational condition is also evaluated. Therefore, the optimal post-fault reconfigurations for fault occurrences in all lines are established. Moreover, the operational constraints such as the voltage and line current limits are taken into account in both normal and post-fault operational modes. Finally, the modified IEEE 33-bus and 69-bus distribution test systems are selected and tested to demonstrate the effectiveness of the simultaneous placement of DGs and tie-line technique proposed in this paper.