Online Calculation for the Optimal Reclosing Time of Transmission Lines

Circuit breakers should be reclosed at the optimal reclosing time in order to enhance the transient stability of a power system after disturbances. This article proposes an online optimal reclosing time calculation based on the extended equal area criterion of transmission lines. A multi-machine system is first clustered into an equivalent two-machine system with a fuzzy c-means algorithm. Then a transient kinetic energy function of system oscillation magnitudes is used to determine the optimal reclosing time in an online manner. The performance of the proposed online calculation method for optimal reclosing time is evaluated on multi-machine power system benchmarks with comparison to the conventional optimal reclosing method. The results have shown that the stability of the system is enhanced by the proposed optimal reclosing time in different case studies. Moreover, the value of optimal reclosing time is smaller with the proposed method compared to the conventional optimal reclosing method. An accurate predictive reclosing time can be obtained by the proposed method