POWER SYSTEM TRANSIENT CONTROL BY CAPACITOR SWITCHING

Inserting and removing a series capacitor in a transmission line can remove the oscillatory transients due to a fault. The capacitor should be inserted in the remaining transmission lines when the fault is detected and removed by short circuiting when the time rate of change of power flow through the capacitor is zero or the rate of change of phase angle between line terminations is zero. The capacitor should be reinserted when the kinetic energy due to speed deviations equals the amount of kinetic energy that can be removed during the remaining swing to the target state independent of whether or not the line is restored to service. A multimachine multiline network can be satisfactorily stabilized by inserting each capacitor in each line when the derivative of power flow in that line exceeds a small positive amount and removing the capacitor when the power derivative is less than a small positive amount. To energize a line capacitance can be inserted in the existing lines and at the maximum of the angle swing; the new line is energized simultaneously with the removal of the capacitance. Copyright © 1969 by The Institute of Electrical and Electronics Engineers, Inc.