Advanced static VAr compensator using multimodules of multilevel converters with equalization control of DC voltage levels

This paper describes a high MVA static VAr compensator based on four modules of a diode-clamped, five-level power converter operating under the fundamental frequency method of control. By designing the switching instants of GTOs in the four modules, it is possible to achieve a high quality voltage waveform (THD /spl ap/4%) and at the same time assure even current loading in the parallel connected modules. Equalization feedback control balances the GTO voltage stresses.