Multi-level converter power unit

The multi-level converter power unit presented here offers the possibility to feed energy into the grid, even standing alone and supplying an isolated grid. Thus, the power unit works according to a novel "plug and generate" principle. This is possible because of the self-synchronization of the units to the frequency of the existing electricity grid. So it is possible to have an isolated grid supplied by two independent power units. By using multi-level converters instead of 2-level converters a better power quality can be achieved. In addition, it is possible to supply asymmetrical grids or consumers. In the case of an asymmetrical load, a symmetrical three-phase voltage can be made available by such a "power unit"