Representation of series capacitors in electric power system stability studies

Series capacitor compensation applied to long-distance power transmission systems is addressed. Series capacitors reduce the effective transmission line inductive reactance, resulting in a larger capacity for stable power transfer. It is important to mention the effect of series capacitors on increased short-circuit current levels, as compared with the corresponding currents for noncompensated systems. These currents may reach very high values, especially for faults electrically near capacitor bank terminals, depending on their location, on network electric characteristics, and also on how series compensation is distributed. The authors analyze the representation of bypassed capacitors in stability studies of one-phase-to-ground short circuit, during and after short-circuit occurrence. The short-circuit and bypass periods are also discussed, leading to the adoption of a conservative modeling