A railway vehicle traction system comprising: an engine; a generator configured to be driven by the engine; a first power converter configured to convert alternating-current power output from the generator into direct-current power; a smoothing capacitor configured to smooth the direct-current power output from the first power converter; a second power converter configured to convert the direct-current power output from the smoothing capacitor serving as a direct-current voltage source into alternating-current power; storage battery means for supplying power to an on-vehicle control device; and a contactor that is connected between the storage battery means and the smoothing capacitor, characterized in that: the generator is an induction generator; the second power converter is configured to drive an electric motor for driving the railway vehicle; the railway vehicle traction system being configured to, when the contactor is closed, the smoothing capacitor is charged by the storage battery means; when the voltage of the smoothing capacitor reaches or becomes higher than a voltage sufficient to excite the induction generator, the contactor is opened and insulation between the storage battery means and the smoothing capacitor is ensured; supply a current to the induction generator in order to start an operation of generating power using power charged in the smoothing capacitor after the contactor is opened; and the on-vehicle control device includes at least any of a control circuit for the first power converter, a control circuit for the second power converter, an on-vehicle signal device, a driver's board, a central control unit for communicating with devices within the railway vehicle and a brake control device. an engine; a generator configured to be driven by the engine; a first power converter configured to convert alternating-current power output from the generator into direct-current power; a smoothing capacitor configured to smooth the direct-current power output from the first power converter; a second power converter configured to convert the direct-current power output from the smoothing capacitor serving as a direct-current voltage source into alternating-current power; storage battery means for supplying power to an on-vehicle control device; and a contactor that is connected between the storage battery means and the smoothing capacitor, the generator is an induction generator; the second power converter is configured to drive an electric motor for driving the railway vehicle; the railway vehicle traction system being configured to, when the contactor is closed, the smoothing capacitor is charged by the storage battery means; when the voltage of the smoothing capacitor reaches or becomes higher than a voltage sufficient to excite the induction generator, the contactor is opened and insulation between the storage battery means and the smoothing capacitor is ensured; supply a current to the induction generator in order to start an operation of generating power using power charged in the smoothing capacitor after the contactor is opened; and the on-vehicle control device includes at least any of a control circuit for the first power converter, a control circuit for the second power converter, an on-vehicle signal device, a driver's board, a central control unit for communicating with devices within the railway vehicle and a brake control device.