The increasing deployment of uncontrollable renewable energy resources requires additional flexibility during grid operation to decrease operational cost and increase resilience. As opposed to commonly employed redispatch or countertrading, switching actions reduce components’ lifespans but come at no additional monetary cost. This applies to tap ratios of phase shifting transformers and switchgear, alike.

Switching problems result in combinatorial, computationally expensive mixed-integer problems. As grid operators face real-time constraints, however, this thesis explores heuristic methods to make optimal transmission switching tractable for real-world grids.