This invention relates to a power supply system comprising at least two drive units (3) having two power inputs and at least one power generator (G) providing electric power at a chosen system frequency and voltage. The system comprising a transformer unit (LLC) having a first and a second connection points (1,2), at least one of which being connected to a power generator (G), wherein the two inputs of each drive unit is connected to the first and the second connection point (1,2) of the transformer unit (LLC), and the transformer unit being adapted to provide a chosen phase shift between said inputs at the chosen system frequency and voltage.