Dynamic performance of a STATCON at an HVDC inverter feeding a very weak AC system

This paper investigates the dynamic performance of the advanced static VAr compensator or STATCON at a high voltage direct current (HVDC) converter terminal where the AC system has a very low short circuit ratio (SCR). The STATCON is based on a nine-level GTO thyristor inverter. The studies include operating characteristics of the STATCON under various AC and DC disturbances. The simulation results are compared with other types of reactive power compensation options available for such applications. It is shown that the STATCON has clear advantages over the other compensators, in areas such as: fault response time; voltage support ability; and DC recovery, while operating with very weak AC systems.