Overvoltage Protection of Series Capacitor Banks

The series capacitor bank is mainly composed of a capacitor and its protection system and increases the power flow on the existing system by reducing the line impedance. Their first application dates back to 1928 when GE installed such energy storage (rated 1.2 MVar) at the Ballston Spa substation of the New York Power and Lighting Company’s 33 kV grid. Since then, series capacitor banks have been installed in systems around the world. Metal oxide varistors (MOV) provide overvoltage protection and are therefore an important part of these groups.