A power distribution system including first and second ac busbars connected to ac generators. A first active rectifier/inverter has ac input terminals electrically connected to the first ac busbar. A second active rectifier/inverter has ac input terminals electrically connected to the second ac busbar. A first dc interface is electrically connected to dc output terminals of the first active rectifier/inverter and a second dc interface is electrically connected to dc output terminals of the second active rectifier/inverter. The dc interfaces include reverse blocking means. A third active rectifier/inverter operates as a drive and has dc input terminals electrically connected in the parallel to dc output terminals of the first and second dc interfaces by means of an interposing dc busbar. An electric motor, that can optionally form part of a marine thruster T1, is electrically connected to ac output terminals of the third active rectifier/inverter.