Method of operating an AC electric vehicle comprising: a motor configured to generate propulsion power; a first converter configured to convert AC power that is supplied from a train line to DC power; a first inverter configured to convert DC power converted by the first converter to AC power, and that supplies inverted AC power to the motor; a first DC link for mutual connection of respective DC sides of the first converter and the first inverter; a first contactor for electrically connecting and disconnecting the first DC link and a battery; an auxiliary equipment, wherein the auxiliary equipment is illumination or air conditioning devices within a passenger vehicle compartment; a second converter configured to convert AC power that is supplied from the train line to DC power; a second inverter configured to convert DC power converted by the second converter to AC power and that supplies inverted AC power to the auxiliary equipment; a second DC link for mutual connection of respective DC sides of the second converter and the second inverter; a second contactor for electrically connecting and disconnecting the battery and the second DC link through a DC/DC converter; the DC/DC converter configured to convert DC power supplied from the second contactor to DC voltage suitable for the second DC link and supplies converted DC power to the second DC link; a first operating means for operating the first contactor manually; and a second operating means for operating the second contactor manually, wherein a secondary circuit includes the first converter, the first inverter, and the motor, wherein a tertiary circuit includes the second converter, the second inverter, and the auxiliary equipment, and wherein the method comprises: when current supply from the train line is stopped, if priority is to move the AC electric vehicle to a location where power supply can be obtained from the train line, an operator turns the first contactor on and turns the second contactor off, whereby power is supplied by the battery exclusively to the secondary circuit, and in case the operator prioritizes continuance of operation of the auxiliary equipment, the operator turns the first contactor off and turns the second contactor on, whereby the battery supplies power exclusively to the tertiary circuit, through the DC/DC converter. a motor configured to generate propulsion power; a first converter configured to convert AC power that is supplied from a train line to DC power; a first inverter configured to convert DC power converted by the first converter to AC power, and that supplies inverted AC power to the motor; a first DC link for mutual connection of respective DC sides of the first converter and the first inverter; a first contactor for electrically connecting and disconnecting the first DC link and a battery; an auxiliary equipment, wherein the auxiliary equipment is illumination or air conditioning devices within a passenger vehicle compartment; a second converter configured to convert AC power that is supplied from the train line to DC power; a second inverter configured to convert DC power converted by the second converter to AC power and that supplies inverted AC power to the auxiliary equipment; a second DC link for mutual connection of respective DC sides of the second converter and the second inverter; a second contactor for electrically connecting and disconnecting the battery and the second DC link through a DC/DC converter; the DC/DC converter configured to convert DC power supplied from the second contactor to DC voltage suitable for the second DC link and supplies converted DC power to the second DC link; a first operating means for operating the first contactor manually; and a second operating means for operating the second contactor manually, wherein a secondary circuit includes the first converter, the first inverter, and the motor, wherein a tertiary circuit includes the second converter, the second inverter, and the auxiliary equipment, and wherein the method comprises: when current supply from the train line is stopped, if priority is to move the AC electric vehicle to a location where power supply can be obtained from the train line, an operator turns the first contactor on and turns the second contactor off, whereby power is supplied by the battery exclusively to the secondary circuit, and in case the operator prioritizes continuance of operation of the auxiliary equipment, the operator turns the first contactor off and turns the second contactor on, when current supply from the train line is stopped, if priority is to move the AC electric vehicle to a location where power supply can be obtained from the train line, an operator turns the first contactor on and turns the second contactor off, whereby power is supplied by the battery exclusively to the secondary circuit, and in case the operator prioritizes continuance of operation of the auxiliary equipment, the operator turns the first contactor off and turns the second contactor on, whereby the battery supplies power exclusively to the tertiary circuit, through the DC/DC converter.