Patent ID: 7690453

Claim:
An electric vehicle comprising: a high-voltage power source at least including a first power source; a low-voltage battery that is supplied with electric power from the high-voltage power source through a converter; an auxiliary vehicle controller for controlling a high-voltage contactor with electric power supplied from the high-voltage power source through the converter or with electric power supplied from the low-voltage battery; the high-voltage contactor being connectedly provided between the high-voltage power source and the auxiliary vehicle controller; an electric motor driving with electric power supplied from the high-voltage power source, a vehicle speed sensor for detecting a traveling speed of the electric vehicle; and a low-voltage battery connection detector for detecting a connection state between the low-voltage battery and the electric vehicle, wherein using the electric power supplied from the high-voltage power source through the converter directly to the auxiliary vehicle controller, the auxiliary vehicle controller controls the high-voltage contactor in such a manner that the electric power supply from the high-voltage power source is shut off if: the electric power supply from the low-voltage battery to the auxiliary vehicle controller is cut off, the low-voltage battery connection detector detects a disconnection state between the low-voltage battery and the electric vehicle, and it is determined that the traveling speed value of the electric vehicle obtained on the vehicle speed shows at least that the vehicle is in a still state or in a low-speed state, and using the electric power supplied from the high-voltage power source through the converter directly to the auxiliary vehicle controller, the auxiliary vehicle controller further controls the high-voltage contactor in such a manner that the electric power supply from the high-voltage power source is not shut off if: the electric power supply from the low-voltage battery to the auxiliary vehicle controller is cut off, the low-voltage battery connection detector detects a disconnection state between the low-voltage battery and the electric vehicle, and it is determined that the traveling speed value of the electric vehicle obtained on the vehicle speed sensor shows at lest that the vehicle is not in a still state or in a low-speed state.