Auxiliary winding of a multibody traction transformer for filtering psophometric currents produced by interlaced modulation of PWM rectifiers

The paper deals with the problem of interferences produced by equipments utilized in railway traction systems; in particular the electrical traction drives are considered. A method for filtering harmonic currents produced by modulation of interlaced PWM rectifiers (V.S.R.) is described. An additional winding is introduced in the multibody traction transformer; it is properly sized together with a capacitance in order to minimize the interference level, reducing the psophometric current in the feeding network.