Sensitivity-based Optimal Remedial Actions to Damp Oscillatory Modes Considering Security Constraints.

• Calculating sensitivity factors of electromechanical modes, generators reactive power, transmission lines apparent power and bus voltage magnitudes by a systematic method. • Determine cost-effective proactive remedial actions to damp critical oscillatory modes considering security constraints. • Proposing an iterative MINLP optimization model to determine the best set of remedial actions. • Specifying the effective generators to change voltage set point and active power by the proposed damping ratio sensitivity index. This paper proposes a comprehensive analytic method for applying various optimal remedial actions to improve critical electromechanical modes damping without jeopardizing damping of non-critical modes and violating security constraints of power system. Generators and reactive power sources redisptach, demand side management and the generators voltage reference tuning are remedial actions that are considered here. Dynamic equations of the flux-decay dynamic model of generators, standard dynamic models of excitation system and power system stabilizer and algebraic equations of active and reactive powers balance are formulated in the quadratic eigenvalue problem framework. With simultaneous use of system parameters and online measured data, sensitivity factors of electromechanical modes, generators reactive power, transmission lines apparent power and the buses voltage amplitude with respect to the mentioned remedial actions are calculated. Consumers, generators and reactive power sources are independent agents that offer their price bid to contribute in remedial action schemes. Finally, using sensitivity factors, the best remedial action is determined by mixed-integer nonlinear optimization subject to the minimum required damping ratio and security constraints of transmission lines congestion, generators reactive power capability and buses voltage amplitude. The proposed method is demonstrated on the IEEE 39-bus power system and the results highlight its efficacy. [ABSTRACT FROM AUTHOR]