Computation of Available Transfer Capability considering Transient Stability Constraints

This paper presents a methodology to calculate the available transfer capability in AC transmission links considering transient stability constraints. The problem is formulated and solved as an optimal power flow problem, which aims to maximize the active power flow through selected transmission links taking into account steady state and transient stability constraints. This model is formulated in the Euclidian space, where the transient stability limit is represented by a single stability constraint expressed only in terms of steady state variables. The stability constraint is derived from the sensitivity analysis carried out from the single machine equivalent method (SIME). Thus, the resulting optimization model is similar to the conventional optimal power flow model. The application of the proposal is numerically illustrated considering an equivalent model of the interconnected Mexican system composed by 190 bus, 46 generators and 265 transmission lines.