An electric power source assembly for a vehicle, the power source assembly comprising a plurality of converter unit groups (GC, EC1, MC), each one of which comprises at least one converter unit, each converter unit comprising a plurality of controllable switches (S1 to S6), a first terminal group and a second terminal group, the first terminal group comprising two first terminals (T11, T12) and the second terminal group comprising three second terminals (T21, T22, T23), and control means (CTRL) for controlling the plurality of controllable switches (S1 to S6) in at least one converter unit of each converter unit group, the plurality of converter unit groups comprising at least one converter unit group (MC, MVC) in which at least one converter unit is arranged to operate as an inverter. The plurality of converter unit groups further comprise at least one converter unit group (EC1, EC2, HR), in which at least one converter unit is adapted to operate as a direct-voltage converter, the converter units in the plurality of converter unit groups (GC, MC, EC1, EC2, HR) being identical with one another.
