A converter station for connecting an AC system to a bipolar HVDC transmission line. A DC neutral arrangement includes first DC breakers enabling breaking of a first current path from the neutral bus of one pole to the neutral bus of the other pole at bipolar operation of the station for changing to monopolar operation thereof for isolation of a faulty section of the system while establishing a current path to electrode line connecting members for diverting the current from the one pole thereto. A separate connecting member is provided for each of the electrode lines. A connector is configured to connect each neutral bus to an optional of the two electrode line connecting members.