Transfer capability computation considering steady-state and transient stability constraints

This paper presents a fast and accurate method to determine the available transfer capability. The Ralston´s method is used to predict the two trajectory points of voltage magnitude, power flow and maximum generator rotor angle difference. Then, the cubic-spline interpolation technique is used to accurately trace the P-V, P-S or P-Δδ curves between two points of trajectory. The P-V, P-S and P-Δδ curves represent as the variations of voltage magnitude, power flow and maximum generator rotor angle difference due to the increase of power transfer. The actual available transfer capability value is determined at the intersection point between the curve and the constraints limit. The effectiveness of the proposed method is verified utilizes 39-New England bus system. The proposed method gives satisfactorily accurate and fast computation of ATC compared to recursive AC power flow method.