Modular multilevel converter based on current source H-bridge cells implemented with low cost reversing conducting IGCT

Modular multilevel converters are used in HVDC transmission systems because the attractive features they offer which include independent control of the reactive power, easy control of bidirectional power flow and reduced filter requirements. The main disadvantage of these converters is the low power range compared to standard HVDC based on thyristors because the use of IGBT semiconductors. This paper proposes to replace the standard cells by inductor based cells implemented with IGCT instead of IGBT which will lead to an increase of the power range. Additionally, the proposed cell restricts the semiconductor voltages to be only positive allowing the use low cost IGCT technology.