A modular multipoint power converter (8) for converting an A.C. voltage into D.C. voltage or vice versa, and a method for operating the multipoint power converter are created. The multipoint power converter has a plurality of converter arms (9a-f), wherein two converter arms (9a-b, 9c-d, 9e-f) are each connected to one another in order to create a phase leg (11a-c) of the power converter (8). Each converter arm has a number of similar submodules (14), which are each configured by an H-bridge circuit (18) with power semiconductor switches. The branch currents through the converter arms (9a-f) are controlled or regulated during operation by increasing the DC component of the branch current or of the intermediate circuit direct current (Idc) such that one current having a single polarity, preferably a continuous unipolar sinusoidal current, flows through the converter arms (9a-f). As a result, with the same number of submodules (14) per converter arm (9a-f), the transmissible power can be increased, or the power semiconductor components can be better exploited or, with a constant transmissible power, the number of submodules (14) can be reduced.