| CPC H02J 7/0014 (2013.01) [H01M 10/425 (2013.01); H01M 10/441 (2013.01); H02J 1/08 (2013.01); H02J 7/0063 (2013.01); H02M 1/007 (2021.05); H02M 7/53871 (2013.01); H01M 2010/4271 (2013.01); H02J 2207/20 (2020.01)] | 15 Claims |

|
1. A method for generating a polyphase alternating current, in particular a three-phase alternating current, by interconnecting a plurality of DC voltage sources, having at least the following method steps:
providing a configurable DC voltage string for each phase (L1, L2, L3) of the polyphase alternating current, wherein each configurable DC voltage string is formed from a plurality of the DC voltage sources which can be interconnected in a configurable series circuit;
arranging the configurable DC voltage strings in a polygon circuit, in particular in a delta circuit;
providing a neutral grounding transformer for the purpose of achieving a common neutral point (N) of all configurable DC voltage strings; and
configuring the configurable DC voltage strings such that the polyphase alternating current is provided and a zero phase-sequence system current is also formed for charge equalization between the configurable DC voltage strings,
wherein a q component of the zero phase-sequence system current is minimized and/or a target value of a d component of the zero phase-sequence system current is determined taking into account a charge difference between the DC voltage sources of the DC voltage strings.
|