Formulating Connectedness in Security-Constrained Optimal Transmission Switching Problems

TL;DR

This paper introduces a novel approach to ensure network connectedness in security-constrained optimal transmission switching problems, enhancing reliability while maintaining computational tractability.

Contribution

It proposes new NC criteria based on electrical flow constraints and transforms them into a linear program compatible with existing models.

Findings

The approach effectively preserves network connectedness in case studies.

The formulation integrates seamlessly with current SCOTS models.

Results demonstrate improved reliability without increased computational complexity.

Abstract

This paper focuses on the issue of network connectedness (NC) in security-constrained optimal transmission switching problems, which is complicated by branch contingencies and corrective line switching. Two criteria are firstly proposed with the principle of preserving NC as much as possible within reasonable limits. By extending the electrical flow based NC constraints, a proposition is derived to associate different cases of NC with the optimum of a linear program, yielding the mathematical formulation of the NC criteria. By Karush-Kuhn-Tucker conditions, this formulation is further transformed into a tractable version which can be incorporated with existing SCOTS models without affecting the applicability of original solution approaches. Finally, case studies on various networks and SCOTS models demonstrate the efficacy of the proposed approach.