Effect of the single and three phase switching in the transient stability of an electric power system using the extended equal area criterion

In this paper the transient stability of a test power network is studied and analysed when a phase-to-ground fault occurs on a transmission line. A single and three phase reclosure of the tripped circuit breakers poles in the two ends of the faulted line were simulated. The software package TRANsySTEM that the authors developed for transient security assessment of a multimachine power system was used. These computer programs use the extended equal area criterion. This direct formulation reduces drastically the computing time, since it does not require numerical solution of the differential motion equations of the system. The results obtained with this direct approach were compared with the solutions produced by the Runge-Kutta method