Vehicle motor control apparatus and method

1. A vehicle motor control apparatus comprising:

a motor failure sensor configured to determine whether a failure has occurred in a motor provided in a vehicle steering system based on information about a current flowing in each phase of the motor; and

a motor controller configured to apply a demagnetization current to the motor for permanently demagnetizing the magnet in the motor when the failure has occurred in the motor.

2. The vehicle motor control apparatus of claim 1 , wherein the motor failure sensor is configured to:

determine a failure type of the motor based on the information about the current, and

wherein the failure type of the motor is classified into disconnection of at least one of respective phases of the motor, a short circuit of at least two of respective phases of the motor, or non-identification of the failure type.

3. The vehicle motor control apparatus of claim 1 , wherein the motor controller is configured to:

apply, when any one phase of the motor has been disconnected, a current such that a demagnetization current flows in remaining phases, which have not been disconnected.

4. The vehicle motor control apparatus of claim 3 , wherein the motor controller is configured to:

apply, when the motor has been disconnected in a U phase, the demagnetization current from a V phase to a W phase; apply, when the motor has been disconnected in the V phase, the demagnetization current from the W phase to the U phase; and

apply, when the motor has been disconnected in the W phase, the demagnetization current from the U phase to the V phase.

5. The vehicle motor control apparatus of claim 1 , wherein the motor controller is configured to:

apply, when any two phases of the motor have been short-circuited, a current such that the demagnetization current flows from a remaining non-short-circuited phase to the two short-circuited phases.

6. The vehicle motor control apparatus of claim 5 , wherein the motor controller is configured to:

apply, when a U phase and a V phase of the motor have been short-circuited, the demagnetization current from a W phase to the U and V phases;

apply, when the V phase and the W phase of the motor have been short-circuited, apply the demagnetization current from the U phase to the V and W phases; and

apply, when the W phase and the U phase of the motor have been short-circuited, the demagnetization current from the V phase to the U and W phases.

7. The vehicle motor control apparatus of claim 1 , wherein the motor controller is configured to:

sequentially apply, when the failure type of the motor is not identified, a current to respective phases such that the demagnetization current flows from each phase of the motor to other two phases; and

sequentially apply a current to respective two phases such that the demagnetization current flows in the two phases among the respective phases of the motor.

8. A vehicle motor control method comprising:

a motor failure detection step of determining whether a failure has occurred in a motor provided in a vehicle steering system based on information about a current flowing in each phase of the motor; and

a motor control step of applying a demagnetization current to the motor for permanently demagnetizing the magnet in the motor when the failure has occurred in the motor.

9. The vehicle motor control method of claim 8 , wherein, in the motor failure detection step,

a failure type of the motor is determined based on the information about the current, and

the failure type of the motor is classified into disconnection of at least one of respective phases of the motor, a short circuit of at least two of respective phases of the motor, or non-identification of the failure type.

10. The vehicle motor control method of claim 8 , wherein, in the motor control step,

when any one phase of the motor has been disconnected, a current is applied such that a demagnetization current flows in remaining phases, which have not been disconnected.

11. The vehicle motor control method of claim 10 , wherein, in the motor control step,

when the motor has been disconnected in a U phase, the demagnetization current is applied from a V phase to a W phase, when the motor has been disconnected in the V phase, the demagnetization current is applied from the W phase to the U phase; and when the motor has been disconnected in the W phase, the demagnetization current is applied from the U phase to the V phase.

12. The vehicle motor control method of claim 8 , wherein, in the motor control step,

when any two phases of the motor have been short-circuited, a current is applied such that the demagnetization current flows from a remaining non-short-circuited phase to the two short-circuited phases.

13. The vehicle motor control method of claim 12 , wherein, in the motor control step,

when a U phase and a V phase of the motor have been short-circuited, the demagnetization current is applied from a W phase of the motor to U and V phases, when the V phase and the W phase of the motor have been short-circuited, the demagnetization current is applied from the U phase to the V and W phases, and when the W phase and the U phase of the motor have been short-circuited, the demagnetization current is applied from the V phase to the U and W phases.

14. The vehicle motor control method of claim 8 , wherein, in the motor control step,

when the failure type of the motor is not identified, a current is sequentially applied to respective phases such that the demagnetization current flows from each phase to other two phases, and a current is sequentially applied to respective two phases such that the demagnetization current flows in the two phases among the respective phases of the motor.