A modular switching cell of a high voltage direct current power converter has a modular switching cell that includes a base module, which has: a first switching unit; a second switching unit; a first capacitor; and a second capacitor. The first switching unit, the second switching unit, the first capacitor, and the second capacitor are mounted on a chassis. The base module is configured to receive at least three different busbar sets, each of the busbar sets having a plurality of busbars for interconnecting the first switching unit, the second switching unit, the first capacitor, and the second capacitor to form one of: two parallel half bridge circuits between a first cell terminal and a second cell terminal; two serial half bridge circuits between the first cell terminal and the second cell terminal; or a full bridge circuit between the first cell terminal and the second cell terminal.