Method and charging system for selecting charging mode of electric vehicle

1. A method for determining a charging mode of an electric vehicle, the method comprising:

measuring a duty ratio of a control signal applied to a communication line of a charger connector by a first controller for controlling slow charging and a second controller for controlling quick charging;

transmitting measurement results obtained from each of the first controller and the second controller to a third controller for managing a battery;

determining a final duty ratio using the measurement results by the third controller;

transmitting the determined final duty ratio to the first controller and the second controller; and

starting charging in a mode corresponding to the determined final duty ratio.

2. The method according to claim 1 , wherein the control signal is a pulse width modulation (PWM) signal.

3. The method according to claim 1 , wherein:

the first controller comprises an on-board charger (OBC) controller, and

the second controller comprises an electric vehicle communication controller (EVCC).

4. The method according to claim 1 , wherein the third controller comprises a battery management system (BMS).

5. The method according to claim 1 , wherein the first controller, the second controller, and the third controller are connected via controller area network (CAN) communication.

6. The method according to claim 1 , wherein the third controller determines the final duty ratio to be a predetermined duty ratio when any one of the measurement results is equal to the predetermined duty ratio.

7. The method according to claim 1 , wherein the starting comprises:

starting charging in a quick charging mode when the final duty ratio is equal to a predetermined duty ratio, and

starting the charging in a slow charging mode when the final duty ratio exceeds the predetermined duty ratio.

8. A charging system of an electric vehicle, the charging system comprising:

an inlet connected to a charging connector;

a first controller for controlling slow charging and first-measuring a duty ratio of a control signal of a communication line first-branched from the inlet;

a second controller for controlling quick charging and second-measuring a duty ratio of a communication line second-branched from the inlet; and

a third controller in charge of battery management, for acquiring a first measurement result of the first-measuring and a second measurement result of the second-measuring, determining a final measurement result using each of the first measurement result and the second measurement result, and transmitting the final measurement result to the first controller and the second controller,

wherein the first controller and the second controller perform controlling to start charging in a mode corresponding to a final duty ratio from a quick charging mode and a slow charging mode.

9. The charging system according to claim 8 , wherein the control signal is a pulse width modulation (PWM) signal.

10. The charging system according to claim 8 , wherein:

the first controller comprises an on-board charger (OBC) controller, and

the second controller comprises an electric vehicle communication controller (EVCC).

11. The charging system according to claim 8 , wherein the third controller comprises a battery management system (BMS).

12. The charging system according to claim 8 , wherein the first controller, the second controller, and the third controller are connected via controller area network (CAN) communication.

13. The charging system according to claim 8 , wherein the third controller determines the final duty ratio to be a predetermined duty ratio when any one of measurement results is equal to the predetermined duty ratio.

14. The charging system according to claim 8 , wherein:

the charging is started in a quick charging mode when the final duty ratio is a predetermined duty ratio, and

the charging is started in a slow charging mode when the final duty ratio exceeds the predetermined duty ratio.