Optimal Preventive Control of Transient Instabilities of Rotor Angles and Nodal Voltage Magnitudes

This paper addresses the fundamental issue regarding how to perform the preventive control of transient dynamics associated with rotor angles and nodal voltage magnitudes to obtain a transiently stable operating point for a given contingency scenario. The problem is formulated as a single contingency transient stability-constrained optimal power flow (TSC-OPF) model, in which the optimization and the transient stability problems are sequentially solved until a suitable generation dispatch that provides a transiently stable equilibrium point is assessed. A relevant feature of the proposed approach is its formulation in the form of a conventional OPF problem, which includes two power re-dispatch constraints that are only a function of the steady state active power output of generators. Hence, the control objective is achieved by constraining the direction and magnitude of the steady-state active power re-dispatch of the generators. The effectiveness of the proposed approach is demonstrated on the WSCC 3machine-9 bus test system.