A full-scale converter system for converting active power produced by a generator of a variable speed wind turbine to be fed to an electricity-grid, the converter system comprising: a converter system controller, a grid-side inverter unit, a generator-side inverter unit, both the grid-side inverter unit and the generator-side inverter unit comprising a series connection of parallel inverters, wherein at least two inverters (4a, 4b) of the generator-side inverter unit are connected to each other in parallel, wherein these parallel-connected inverters are connected in series to at least two other generator-side inverters (4c, 4d) of the generator-side inverter unit that are connected to each other in parallel and, wherein at least two inverters (5a, 5b) by the grid-side inverter unit are connected to each other in parallel, wherein these parallel-connected grid-side inverters are connected in series to at least two other grid-side inverters (5c, 5d) by the grid-side inverter unit that are connected to each other in parallel, the inverters of the grid-side inverter unit and the generator-side inverter unit at a same voltage level of the series connections together forming first and second converter strings, wherein the grid-side inverter unit and the generator-side inverter unit are connected back to back on their DC sides by a positive potential conductor and a negative potential conductor to form a common DC link, the positive and negative potential conductors having cross-sections, wherein the generator-side and grid-side inverter form a generator-side and grid-side voltage-center-point, respectively, at a voltage level between the inverters connected in series, wherein the voltage-center points are electrically connected by a center-line conductor, wherein the center-line conductor has a cross-section between 30% and 70% of the cross-section of either the positive potential conductor or the negative potential conductor, whichever has the smaller cross-section, wherein the converter system controller is programmed to continue conversion operation, in the event of a fault of an inverter of the first converter-string, with non-faulty inverters of the first and second converter strings, causing unbalanced active power-output between the first and second converter-strings, as the center-line conductor is dimensioned by said cross-section to carry a compensation current resulting from the unbalanced active power-output caused by the fault. a converter system controller, a grid-side inverter unit, a generator-side inverter unit, both the grid-side inverter unit and the generator-side inverter unit comprising a series connection of parallel inverters, wherein at least two inverters (4a, 4b) of the generator-side inverter unit are connected to each other in parallel, wherein these parallel-connected inverters are connected in series to at least two other generator-side inverters (4c, 4d) of the generator-side inverter unit that are connected to each other in parallel and, wherein at least two inverters (5a, 5b) by the grid-side inverter unit are connected to each other in parallel, wherein these parallel-connected grid-side inverters are connected in series to at least two other grid-side inverters (5c, 5d) by the grid-side inverter unit that are connected to each other in parallel, the inverters of the grid-side inverter unit and the generator-side inverter unit at a same voltage level of the series connections together forming first and second converter strings, wherein the grid-side inverter unit and the generator-side inverter unit are connected back to back on their DC sides by a positive potential conductor and a negative potential conductor to form a common DC link, the positive and negative potential conductors having cross-sections, wherein the generator-side and grid-side inverter form a generator-side and grid-side voltage-center-point, respectively, at a voltage level between the inverters connected in series, wherein the voltage-center points are electrically connected by a center-line conductor, wherein the center-line conductor has a cross-section between 30% and 70% of the cross-section of either the positive potential conductor or the negative potential conductor, whichever has the smaller cross-section, wherein the converter system controller is programmed to continue conversion operation, in the event of a fault of an inverter of the first converter-string, with non-faulty inverters of the first and second converter strings, causing unbalanced active power-output between the first and second converter-strings, as the center-line conductor is dimensioned by said cross-section to carry a compensation current resulting from the unbalanced active power-output caused by the fault.