Power distribution systems

The present invention provides a power distribution system such as a marine power distribution and propulsion system (20). The system includes an ac busbar (2) and a plurality of active front end (AFE) power converters (4, 22). Each AFE power converter (4, 22) includes a first active rectifier/inverter (6) connected to the busbar (2) and a second active rectifier/inverter (8) connected to an electrical load such as an electric propulsion motor (M1...M4). Power sources (PS1...PS3) are connected to the dc link (24) of the AFE power converters (22) and can be operated under the control of a power management controller or power management system (PMS).