Method for controlling a converter assembly which comprises at least one AC voltage terminal (L1, L2, L3) at which an alternating current may be fed or drawn, and at least two DC voltage terminals (L+, L-) at which a direct current may be fed or drawn, - wherein the converter assembly comprises at least one series circuit (R1, R2, R3) of which the external terminals form the DC voltage terminals (L+, L-) of the converter assembly , the series circuit (R1, R2, R3) comprises two subcircuits (TS) connected in series, of which the electrical connecting point forms the AC voltage terminal or one of the AC voltage terminals (L1, L2, L3) of the converter assembly , and the subcircuits (TS) respectively comprise at least two submodules (SM) connected in series, which respectively comprise at least two switches and one capacitor (C), and - wherein in the method, the control of the submodules (SM), and thus the connection or disconnection of the respective capacitors (C) of the submodules (SM), takes place at least also as a function of the capacitor voltage of the respective capacitor (C), characterized in that - in at least one of the subcircuits (TS), at least one capacitor (C) is operated exclusively in unipolar mode, and at least one capacitor (C) is operated in bipolar mode, - wherein in a time range (ZB) in which the temporal average value (MW) of the current (I) flowing through the subcircuit (TS) has a sign which is different from that of the respective instantaneous current (I) flowing through the subcircuit (TS), the capacitor or capacitors (C) operated in unipolar mode are given preference over the capacitor or capacitors (C) operated in bipolar mode, in particular, are preferably connected or preferably remain connected. - wherein the converter assembly comprises at least one series circuit (R1, R2, R3) of which the external terminals form the DC voltage terminals (L+, L-) of the converter assembly , the series circuit (R1, R2, R3) comprises two subcircuits (TS) connected in series, of which the electrical connecting point forms the AC voltage terminal or one of the AC voltage terminals (L1, L2, L3) of the converter assembly , and the subcircuits (TS) respectively comprise at least two submodules (SM) connected in series, which respectively comprise at least two switches and one capacitor (C), and - wherein in the method, the control of the submodules (SM), and thus the connection or disconnection of the respective capacitors (C) of the submodules (SM), takes place at least also as a function of the capacitor voltage of the respective capacitor (C), characterized in that - in at least one of the subcircuits (TS), at least one capacitor (C) is operated exclusively in unipolar mode, and at least one capacitor (C) is operated in bipolar mode, - wherein in a time range (ZB) in which the temporal average value (MW) of the current (I) flowing through the subcircuit (TS) has a sign which is different from that of the respective instantaneous current (I) flowing through the subcircuit (TS), the capacitor or capacitors (C) operated in unipolar mode are given preference over the capacitor or capacitors (C) operated in bipolar mode, in particular, are preferably connected or preferably remain connected. <EOS>