Optimal transmission switching in power system operation and planning

Transmission networks are traditionally considered as fixed assets where market-based changes in transmission states are not considered by power system operators. However, system operators consider changes in transmission states by adjusting the network topology for security purposes. The adjustment in transmission state, known as transmission switching (TS), could mitigate transmission flow violations, manage congestion, enhance power system security and adjust bus voltage levels. TS, as a market tool, could potentially affect power generation dispatch and commitment and improve power system economics.;This dissertation presents the formulations and the methodologies for combining the security as well as the economic features of TS. The TS applications are incorporated into the DC model of security-constrained unit commitment (SCUC) for the day-ahead power system scheduling. The dissertation will also consider the AC solution of SCUC for TS applications. The TS application to the AC network solution will enhance the reactive power flow for mitigating any bus voltage violations. The power system operation results are compared based on the AC and the DC power network solutions and the results are discussed. TS applications are also considered in the security-constrained power system planning in which various network planning options are considered for improving the short-term TS solutions. The TS solutions will improve the real power flow and provide security and the economic feedbacks to the planning module on how the long-term planning alternatives can be improved. The results are discussed and additional recommendations are made for future TS studies in power systems.