Converter level modeling and control of quasi multi-pulse static synchronous series compensator

In this study, converter-level model of static synchronous series compensator (SSSC) has been proposed in PSCAD/EMTDC^® for the dynamic control of real power flow in a transmission line of WSCC 3-machine 9-bus test system. SSSC is modeled by a quasi multi-pulse voltage source converter (VSC) formed by two 24-pulse VSCs whose phase-shifted outputs are summed up using a magnetic interface. The switching frequency is 60 Hz so commutating device loss is minimized as low as possible. The real power flow is controlled by employing conventional PI regulator whose parameters are optimized by non-liner and non-gradient Simplex method. The real power flow controller in the SSSC control system provides satisfactory dynamic performance during both transient and steady-state conditions.