MODULAR MULTILEVEL CONVERTER AND CELL FOR REDUCING CURRENT CONDUCTION LOSSES

摘要

A multilevel converter for forming an alternating current waveform includes at least one cell (HBA) comprising at least one energy storage element (C) and a first branch of series-connected switching units in parallel with the energy storage element (C). The first branch comprises a first and a second switching unit (S1, S2), where one (S1) of the switching units that is operative to bypass the energy storage element (C) has a current conduction area that is larger than the current conduction area of the other switching unit (S2). This cell structure has the advantage of reducing the conduction losses through the cell with a limited increase of the cell size.