An Analysis of Optimal Reclosing for Enhancement of Transient Stability

In a power system, the auto-reclosing schemes are applied in order to enhance the transient stability. However, conventional auto-reclosing techniques adopt fixed time interval reclosing, that is, the circuit breakers reclose after a prescribed dead time. Since the transient stability is dependent on the generator state of reclosing instance, this method may cause an unstable state when unsuccessful reclosing occurs. Therefore, the method to determine the optimal reclosing time is needed in order to enhance the transient stability of power system effectively.This paper proposes the method to determine an optimal reclosing time by using the kinetic energy of synchronous generators. The significance of this method is that it uses the kinetic energy of each generator which can be obtained easily. Consequently, this technique may be implemented for the on-line application. The proposed method is verified by simulation study using EMTP/ATP