The amount of power that can be transferred with long overhead transmission lines is limited by the impedance that can lead to voltage drops. For decades, fixed series compensation is the proven solution to maintain a minimum voltage profile and maximize utilization of transmission lines.
It works by connecting a capacitor bank in series with the transmission line to partially compensate the inductive impedance of the line while also increasing the voltage at the point of connection. The capacitors are protected by metal-oxide varistors (MOV) and – in case of a fault – by tripping the FSC and closing the bypass breaker. For instant protection, a triggered spark gap bypasses capacitors and MOVs within less than 1 ms. Even gap-less solutions are possible, provided that local requirements match. Due to this complexity Siemens Energy recommends and offers individually designed solutions with fixed series capacitors.
