Determination of Optimal Topology for Transmission Networks with Distributed Generation using Optimal Transmission Switching (OTS)

Abstract

Optimal Transmission Switching (OTS) is the strategic removal of transmission lines to be out of service to optimize power system operating parameters. This technique has been established by several research to produce significant cost savings while maintaining the voltage security, stability, flexibility, and reliability for a transmission network. Thus, the network topology optimization through OTS is a promising solution to address inefficiencies of a fixed and static transmission network by making the transmission network more dynamic, flexible, and efficient across varying generating and loading profiles. However, the increasing renewable energy penetration can significantly affect the successful application of OTS in a transmission network. This research aims to identify the OTS solutions of a transmission network with varying renewable energy penetration and assess power system reliability in each case. Overall, the findings show that OTS utilization can help improve the economic dispatch and transmission line power flows of the network with several systems of constraints. However, the removal of one line from the transmission system does not necessarily improve its Expected Demand Not Supplied (EDNS) which varies from case to case. A new reliability index was proposed, which is the Wind Optimality Probability (WOP), and the results show that the system can better withstand the uncertainties introduced by the wind-powered generation in the network. Moreover, an indirect relationship was observed between varying levels of renewable energy penetration and the power system reliability indices.