A traction power converter for a multisystem rail vehicle, the traction power converter comprising: a current collector (P) capable of collecting current from two different DC feeder system sections, one having a higher DC voltage than the other; an inverter configured to drive an AC motor ; an inverter configured to perform constant voltage constant frequency control, wherein said inverter uses a semiconductor device with a withstand voltage lower than that of the inverter configured to drive the AC motor; a step-up/down chopper capable of outputting a step-up/down DC voltage from an input DC; and first circuit switching means (S4-S6) capable of switching a current path selectively, wherein the first circuit switching means is configured to switch the current path such that, in a case in which the current collector collects DC from a DC feeder system section under the higher DC voltage, said DC voltage is stepped down by the step-up/down chopper and supplied to the inverter configured to perform the constant voltage constant frequency control, in a case in which the current collector collects DC from a DC feeder system section under the lower DC voltage, said DC voltage is stepped up by the step-up/down chopper and supplied to the inverter configured to drive the AC motor, and in the case in which the current collector collects the higher voltage DC of the two DCs, the higher voltage DC is supplied to the inverter configured to drive the AC motor, characterized in that in the case in which the current collector collects the lower voltage DC of the two DCs, the lower voltage DC is directly supplied to the inverter configured to perform the constant voltage constant frequency control. a current collector (P) capable of collecting current from two different DC feeder system sections, one having a higher DC voltage than the other; an inverter configured to drive an AC motor ; an inverter configured to perform constant voltage constant frequency control, wherein said inverter uses a semiconductor device with a withstand voltage lower than that of the inverter configured to drive the AC motor; a step-up/down chopper capable of outputting a step-up/down DC voltage from an input DC; and first circuit switching means (S4-S6) capable of switching a current path selectively, wherein the first circuit switching means is configured to switch the current path such that, in a case in which the current collector collects DC from a DC feeder system section under the higher DC voltage, said DC voltage is stepped down by the step-up/down chopper and supplied to the inverter configured to perform the constant voltage constant frequency control, in a case in which the current collector collects DC from a DC feeder system section under the lower DC voltage, said DC voltage is stepped up by the step-up/down chopper and supplied to the inverter configured to drive the AC motor, and in the case in which the current collector collects the higher voltage DC of the two DCs, the higher voltage DC is supplied to the inverter configured to drive the AC motor, characterized in that in the case in which the current collector collects the lower voltage DC of the two DCs, the lower voltage DC is directly supplied to the inverter configured to perform the constant voltage constant frequency control. <EOS>