Robust optimal transmission switching with the consideration of corrective actions for N - k contingencies

In order to achieve a better economic dispatch decision of the electricity generation while guaranteeing system security, the optimal transmission switching (OTS) has been proposed with the well-known N-k contingency security criterion. However, the challenge for treating the OTS problem considering N-k contingencies lie in that it may lead to a conservative result, since the optimal solution should simultaneously satisfy all the sets of N-k constraints. To address this problem, the corrective control with respect to different contingencies is utilised during the period when the transmission topology remains unchanged, which can be formulated as a two-stage problem. Consequently, a two-stage robust optimisation is employed to optimise the objective value under the worst contingency, so as to hedge against the contingency uncertainties. Comparison of the traditional N-1 OTS and the proposed robust N-1 OTS models on IEEE 30-bus test system shows that the robust OTS model has less conservatism than the traditional OTS model with the help of corrective actions. Moreover, it illustrates that the proposed method can be fairly applicable to cases with even N-k contingencies, which can facilitate the complexity of contingency analysis.