A traction converter , comprising: a transformer for transforming an AC voltage at a primary side from an electric input of the traction converter into a different AC voltage at a secondary side ; a four quadrant converter for converting an AC voltage at an input side into a DC voltage at an output side connected to a DC link , wherein a negative input of the DC link is connected to a negative DC input (DC-) of the traction converter ; a choke arrangement comprising two chopper chokes (L3, L4) connected together in a midpoint ; a switch arrangement ; wherein, in an AC operation mode of the traction converter , the switch arrangement is adapted for connecting the primary side of the transformer to the electric input of the traction converter and for connecting the secondary side of the transformer to the input side of the four quadrant converter ; wherein, in a DC operation mode of the traction converter , the switch arrangement is adapted for connecting the electric input of the traction converter to a positive DC input (DC+) of the traction converter ; for connecting ends of the two chopper chokes (L3, L4) not connected to the midpoint to a first input and a second input of the input side of the four quadrant converter and for connecting the positive DC input (DC+) of the traction converter to the midpoint between the two chopper chokes (L3, L4); wherein the traction converter comprises a filter capacitor ; wherein, in the DC operation mode , the switch arrangement is adapted for connecting the filter capacitor to the midpoint between the two chopper chokes (L3, L4) and to the negative DC input (DC-) of the traction converter ; characterized in that in the AC operation mode , the switch arrangement is adapted for connecting the filter capacitor and one of the two chopper chokes (L3) in series and for connecting the series connection of the filter capacitor and the one of the two chopper chokes (L3) in parallel with the DC link . a transformer for transforming an AC voltage at a primary side from an electric input of the traction converter into a different AC voltage at a secondary side ; a four quadrant converter for converting an AC voltage at an input side into a DC voltage at an output side connected to a DC link , wherein a negative input of the DC link is connected to a negative DC input (DC-) of the traction converter ; a choke arrangement comprising two chopper chokes (L3, L4) connected together in a midpoint ; a switch arrangement ; wherein, in an AC operation mode of the traction converter , the switch arrangement is adapted for connecting the primary side of the transformer to the electric input of the traction converter and for connecting the secondary side of the transformer to the input side of the four quadrant converter ; wherein, in a DC operation mode of the traction converter , the switch arrangement is adapted for connecting the electric input of the traction converter to a positive DC input (DC+) of the traction converter ; for connecting ends of the two chopper chokes (L3, L4) not connected to the midpoint to a first input and a second input of the input side of the four quadrant converter and for connecting the positive DC input (DC+) of the traction converter to the midpoint between the two chopper chokes (L3, L4); wherein the traction converter comprises a filter capacitor ; wherein, in the DC operation mode , the switch arrangement is adapted for connecting the filter capacitor to the midpoint between the two chopper chokes (L3, L4) and to the negative DC input (DC-) of the traction converter ; characterized in that in the AC operation mode , the switch arrangement is adapted for connecting the filter capacitor and one of the two chopper chokes (L3) in series and for connecting the series connection of the filter capacitor and the one of the two chopper chokes (L3) in parallel with the DC link . <EOS>