New Method for Calculating Optimal Switching Time of Bang-Bang Controlled Series Capacitor Based on Direct Method

Controllable series capacitors have been utilized to damp swings resulted from large transient disturbances in power systems, and the switching time of the capacitors has distinct influence on the swings of the machines. The reason that different switching time of the series capacitor brings out different stability of the system is analyzed in this paper, a method for calculating the optimal switching time is also proposed. The optimal switching time satisfies the following condition: the transient energy of the system is minimum after the capacitor is switched. Simulation results with a 9-machines power system show the effectiveness of the method.