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 respective second port of the more than one series-connected PPCs are connected in series to further connect to a direct current (DC) bus;
• 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 second ports of the more than one parallel-connected PPCs are connected in parallel and further connected to a port of the PPC set, and respective second ports of the at least one series-connected PPC and the port of the at least one PPC set are connected in series to further connect to the DC bus,
• wherein, for each PPC in the apparatus, a first port of the PPC and the second port of the PPC have one common terminal, and
• wherein the at least one of the first PPC string and the second PPC string is connected in parallel with a DC bus, and
• wherein, the first port of at least one PPC in the apparatus is connected to a load, while the respective first ports of other PPCs in the apparatus are connected to power sources, wherein at least one of the power sources is a power storage source.