1. Lesnicar A, Marquardt R (2003) An innovative modular multilevel converter topology suitable for a wide power range. In: 2003 IEEE Bologna power tech conference proceedings, vol 3, pp 1–6
2. Allebrod S, Hamerski R, Marquardt R (2011) New transformerless, scalable modular multilevel converters for HVDC-transmission. In: Proceedings of the 2011 14th European conference on power electronics and applications, pp 174–179
3. Knaak H (2008) Modular multilevel converters and HVDC/FACTS: a success story. In: 2008 IEEE power electronics specialists conference, pp 1–6
4. Rodriguez J, Bernet S, Wu B, Pontt JO, Kouro S (2007) Multilevel voltage-source-converter topologies for industrial medium-voltage drives. IEEE Trans Indus Electron 54(6):2930–2945
5. Hiller M, Krug D, Sommer R, Rohner S (2009) A new highly modular medium voltage converter topology for industrial drive applications. In: 2009 13th European conference on power electronics and applications, pp 1–10