Modeling of Transmission Line Faults for Transient Stability Analysis

This paper presents a novel approach to model faults on transmission lines for power system transient stability studies. Typically such faults, incident at a certain distance along a transmission line, are modeled by the introduction of dummy or fictitious buses. This dummy bus is placed at the length along the transmission line at which the fault is incident and the fault is applied on it. The introduction of dummy buses introduces inefficiencies in the solution process, particularly from a computational view point due to the need of resizing of the vectors and matrices. In this paper, we present a direct approach for modeling that avoids the need of dummy buses. We derive the necessary equations representing the impact of transmission line faults on the buses connected to the transmission line. The impact of such a fault is then modeled by mere modification of the elements of system admittance matrix. Numerical results on test systems are presented comparing its accuracy with a commercial software.