A power conversion device (1S, 2S) for use in an electric rolling stock to convert alternating-current power taken from a contact line system and decreased in voltage by a transformer to direct-current power by controlling switching of multiple power semiconductor elements (111-114, 201-208) in which a parasitic diode is used as a circulation diode, the power conversion device (1S, 2S) comprising: a control unit to control driving of the multiple power semiconductor elements (111-114, 201-208); and a DC stage capacitor (230, 231, 423) connected between a positive DC terminal and a negative DC terminal for output of DC power to which the AC power is converted; characterized in that: the power conversion device (1S, 2S) is operable in a converter mode in which AC power is converted to DC power by pulse width modulation and a rectification mode in which AC power is converted to DC power by bridge rectification; wherein, in the rectification mode the control unit is configured to apply a predetermined voltage pulse causing the power semiconductor elements (111-114, 201-208) to conduct current in a reverse direction for conversion of the AC current to DC current to the power semiconductor elements (111-114, 201-208), without exerting PWM control of the switching; when the power conversion device (1S, 2S) is operated in the rectification mode, the control unit is configured to apply the predetermined voltage pulse to the power semiconductor elements (111-114, 201-208) when the absolute value of the voltage of the AC power from the transformer exceeds the amplitude of the voltage of the DC stage capacitor (230, 231, 423); and the power conversion device (1S, 2S) is configured to operate in the rectification mode when the electric rolling stock is at a stop and in the converter mode when the electric rolling stock is moving. a control unit to control driving of the multiple power semiconductor elements (111-114, 201-208); and a DC stage capacitor (230, 231, 423) connected between a positive DC terminal and a negative DC terminal for output of DC power to which the AC power is converted; the power conversion device (1S, 2S) is operable in a converter mode in which AC power is converted to DC power by pulse width modulation and a rectification mode in which AC power is converted to DC power by bridge rectification; wherein, in the rectification mode the control unit is configured to apply a predetermined voltage pulse causing the power semiconductor elements (111-114, 201-208) to conduct current in a reverse direction for conversion of the AC current to DC current to the power semiconductor elements (111-114, 201-208), without exerting PWM control of the switching; when the power conversion device (1S, 2S) is operated in the rectification mode, the control unit is configured to apply the predetermined voltage pulse to the power semiconductor elements (111-114, 201-208) when the absolute value of the voltage of the AC power from the transformer exceeds the amplitude of the voltage of the DC stage capacitor (230, 231, 423); and the power conversion device (1S, 2S) is configured to operate in the rectification mode when the electric rolling stock is at a stop and in the converter mode when the electric rolling stock is moving.