Patent ID: 8909406

Claim:
An electric vehicle comprising: a motor unit configured to drive a wheel; an ECU which is an electronic control unit configured to perform general control of the vehicle; an inverter unit, the inverter unit including: a power circuitry including an inverter configured to convert a DC power from a battery unit into an AC power used to drive the motor unit; and a motor control circuitry configured to control the power circuitry in accordance with a torque command from the ECU; a mechanical brake configured to brake the wheel; a malfunction detector configured to continuously monitor the torque command from the ECU as well as one of the following: signals indicating a rotational frequency of the motor unit; signals indicating a rotational frequency of the wheel driven by the motor unit; signals indicating a rotational direction of the motor unit; signals indicating a rotational direction of the wheel driven by the motor unit; and a motor current, and detect, according to a predefined rule, a malfunction of the motor unit, based on the monitoring information; and a malfunction-responsive controller configured to cause at least one of shut-off of a drive current to the motor unit and braking with the mechanical brake, if the malfunction detector detects a malfunction, wherein the motor unit comprises a plurality of motor units configured to drive respective different wheels and the malfunction-responsive controller is configured to cause, if a malfunction of one of the motor units is detected, not only shut-off of a drive current to the motor unit whose malfunction is detected but also shut-off of a drive current to one or more of the other motor units.