Rapid deployment of renewable energy (RE) generation are resulting in level of uncertainty in power systems significantly increased and leading to severe issues related to the reliability of network operation. In general, RE outputs sometimes behave very fast and the uncertainty in their behavior considerably increases as a function of the prediction time for future issues. On the other hand, the available capacities of controllable generations and their ramp-rates are very limited. In this relation, the authors have proposed a new concept of “Robust Power System Security” by extending the conventional N-1 security criterion. This paper proposes a novel formulation using bi-level optimization scheme for evaluating the robust power system security region in controllable parameter space where the conventional N-1 security criterion suffices in the presence of uncertainties. Severe transmission line limits are imposed to power system for examining the robustness of the proposed method. The proposed method is solved by mixed integer linear programming (MILP). The effectiveness of the proposed method is demonstrated through numerical examination in 6-bus 3-generator system and satisfactory results are obtained.