Optimal Reclosing Time of Transmission Lines and its Application in Real Power System

The study of various stability-control methods for a transmission system indicates that the reclosing time of a transmission line has a distinct influence on system stability. And there is an optimal reclosing time (ORT) for all transmission line faults. Utilizing the transient energy function (TEF) with classical models considered, the ORT setting computation method is proposed. This paper shows the validity and practicability of ORT. Based on analyzing the characteristic and influencing factors of the ORT, the setting criteria of reclosing time for transmission line is presented. It will conduct simulations with a complex real system in Northwest of China. Simulation studies show that this technique can significantly increase the security margin and damp the oscillation of the power system. It is indicated that the variation of optimal reclosing time of a certain transmission line is insensitive to these influencing factors: the fault location, fault clearing time and pre-fault power flow of this line. Finally, the setting strategy is drawn to optimize the reclosing time of the key transmission lines in NingXia network under current technological conditions.