Optimal power system steady-state security regions with fuzzy constraints

This paper proposes a new approach to compute the maximal power system steady-state security regions using optimization approach. The maximal steady-state security region-hyperbox-is directly computed through a linear programming (LP) model, in which the upper and lower limits of each component forming a hyperbox are taken as unknown variables, and the objective is to maximize the sum of the generators' power adjustment ranges. For the first time, both fuzzy branch power flow constraints and the N-1 security constraints are introduced into the study of the steady-state security regions. A new idea of "N-1 constrained zone" is also adopted to calculate the all N-1 security constraints so as to reduce the computation burden. The steady-state security regions with fuzzy power constraints are successfully calculated on the IEEE 6-bus system.