Apparatus for power conversion and method for operating the apparatus

An apparatus for power conversion comprising:

• at least one of a first partial power converter (PPC) string and a second PPC string, wherein the first PPC string comprising more than one series-connected PPCs, wherein an output of each PPC of the more than one series-connected PPCs is connected in series;
• and
• wherein the second PPC string comprising at least one series-connected PPC and at least one PPC set, wherein each PPC set comprises more than one parallel-connected PPCs, the respective outputs of the more than one parallel-connected PPCs are connected in parallel and further connected to the output of the PPC set, and respective outputs of the at least one series-connected PPC and the at least one PPC set are connected in series,
• wherein, for each PPC in the apparatus, the respective input of the PPC is connected to a corresponding power source, and the input of the PPC and the output of the PPC have one common terminal, and the PPC comprises at least one controllable switch, and
• wherein the at least one of the first PPC string and the second PPC string is connected in parallel with a direct current (DC) bus, and
• a circuit protector, comprising at least one of:
• one PPC protector corresponding to each PPC in the apparatus;
• one set protector corresponding to each PPC set in the apparatus;
• and
• one string protector corresponding to each of the first PPC string and the second PPC string.