Buck Boost Converter Cell for MMC

The present disclosure relates to a converter cell () for an MMC. The cell comprises a primary energy storage (C), an inductor (Lf), and a secondary energy storage (C); and first and second converter valves (T, T). The secondary energy storage (C) is connected in series with the first converter valve (T1), and together with said first converter valve in parallel with the inductor (L), and the primary energy storage (C) is connected in series with the second converter valve (T), and together with said second converter valve (T) in parallel with the inductor (L).