Advanced static compensation using a multilevel GTO thyristor inverter

This paper investigates the possibility of using the multilevel gate turn-off (GTO) thyristor inverter as an advanced static VAr compensator (STATCON). The studies have indicated that the design shows promise and that the fundamental frequency switching of the GTO thyristors is superior to various forms of pulse-width modulation. The main advantages of the multilevel STATCON over other types of STATCON is that each individual GTO thyristor is clamped to a DC voltage and can be switched independently. Hence a staircase type of output voltage can be used to reduce the harmonics, the filtering requirements and the switching losses