The converter includes a plurality of input lines and one or more output lines. Each input line is connected to a group of supply circuits and the supply circuits of each group are connected to different output lines. The electric generator comprises a stator and a rotor. The stator has a plurality of windings. Each winding has a plurality of phases. Each phase comprises bars connected in series. The phases have a first connection at one end, a second connection at the other end and a third connection in an intermediate position between the first and the second connection.