Stability-Constrained Optimal Power Flow Based on a Novel Transient Stability Margin

A new approach to solve stability-constrained optimal power flow (SCOPF) based on a novel transient stability margin and its sensitivities is proposed. The transient stability constraints originally represented by the differential-algebraic equations are converted to the inequality constraints of the transient stability margin and its sensitivities with respect to the control variables in this approach. Furthermore the transient stability margin is based on the implicit expression for the stability region boundary related to the controlling unstable equilibrium point (CUEP), and this boundary can be approximated by the quadratic approximation of the stability region. The converted SCOPF problem can be easily solved by any standard nonlinear programming technique as the conventional OPF with the similar computation complexity. Simulation results in the New England 10-generator 39-bus system show the effectiveness of the proposed approach.