Power converter circuit with AC output

Disclosed is a power converter circuit, a power supply system, a power converter unit, and a method for operating a power converter circuit. The power converter circuit comprises: output terminals (11, 12); a plurality of converter units (2) each comprising input terminals (21, 22) configured to be coupled to a DC power source (3), and output terminals (23, 24) for providing an AC output voltage (v2) and an AC output current (i1), the plurality of converter units (2) being connected in series between the output terminals (11, 12) of the power converter circuit, wherein at least one of the converter units (2) is configured to detect its AC output (v2) voltage and its AC output current (i1) and is configured to regulate a generation of the AC output current (i1) such that a phase difference between the AC output current (i1) and the AC output voltage (v2) assumes a given set value.