On selection of transmission line candidates for optimal transmission switching in large power networks

Transmission lines are traditionally treated as non-dispatchable assets by electric utilities and regional transmission organizations. Co-optimizing transmission topology and generation dispatch could be a viable way to improve economic efficiency of market and system operations. Optimal transmission switching (OTS) can leverage grid controllability for enhancing system performance. This paper discusses the enhancement of mathematical model for optimal transmission switching within the context of a security-constrained economic dispatch algorithm, and present several criteria for selecting candidates for transmission-line switching to achieve better market surplus within a reasonable time frame. Using a combined set of selection criteria, our approach focuses on reducing production cost, congestion and violation penalties of transmission based on the model of Locational Marginal Pricing (LMP). The proposed method is tested using a large-scale power system. Simulation results will be presented to demonstrate the effectiveness of the proposed methods to select transmission line candidates for OTS.