Exploiting Symmetry in Transmission Lines for Transmission Switching

Symmetry caused by the presence of identical transmission lines in the transmission switching problem can have a significant negative impact on mixed-integer linear programming methods due to the redundant computation of identical subproblems. Unfortunately, it is not obvious how to remove symmetry by remodeling pairs of identical lines as one line without potentially affecting the quality of the solution. In this letter, we conclude that how one deals with symmetry can drastically affect computation times.