Electric vehicle charging apparatus

1. An electric vehicle charging controller comprising:

a first sensor configured to measure a second voltage value between a first battery having a first voltage value and a relay in a high voltage line connected to electric vehicle supply equipment;

a second sensor configured to measure a third voltage value between the electric vehicle supply equipment and the relay in the high voltage line; and

a control unit configured to control turning the relay on and to control turning the relay off,

wherein if a difference between the second voltage value and the third voltage value is less than a preset fourth voltage value when the control unit applies a voltage of a second battery in the high voltage line between the relay and the electric vehicle supply equipment after controlling the relay to be turned off, the control unit determines that the relay is malfunctioning,

the electric vehicle charging controller further comprising:

a converter disposed between the high voltage line and the second battery; and

a switch disposed between the converter and the high voltage line,

wherein a fixed fifth voltage value is applied to the high voltage line through the converter.

2. The electric vehicle charging controller of claim 1 , wherein the malfunctioning of the relay is a state in which the relay is welded.

3. The electric vehicle charging controller of claim 1 , wherein the control unit includes a determination unit that determines whether the relay is malfunctioning.

4. The electric vehicle charging controller of claim 1 , wherein, when the relay is determined to be malfunctioning, the control unit transmits an off-signal to the relay again.

5. The electric vehicle charging controller of claim 1 , further comprising a communication unit configured to communicate with an electronic control unit (ECU) of an electric vehicle, wherein the communication unit receives state information related to a charging state, a standby state, and a driving state of the electric vehicle from the ECU.

6. The electric vehicle charging controller of claim 5 , wherein

the control unit transmits an off-signal to the switch when the electric vehicle is in the charging state, and

the control unit transmits an on-signal to the switch when the electric vehicle is in the standby state or the driving state.

7. The electric vehicle charging controller of claim 5 , wherein the ECU communicates with the electric vehicle supply equipment to transmit the state information related to the charging state, the standby state, and the driving state of the electric vehicle to the communication unit.

8. The electric vehicle charging controller of claim 1 , wherein the fixed fifth voltage value is set to a value in a range of ⅓ to ½ of the first voltage value.

9. The electric vehicle charging controller of claim 8 , wherein the fourth voltage value is set to a value of ⅓ of the first voltage value.

10. The electric vehicle charging controller of claim 1 , wherein the fixed fifth voltage value is set to a value of ½ of the first voltage value.

11. The electric vehicle charging controller of claim 10 , wherein the fourth voltage value is set to be equal to the fixed fifth voltage value.

12. The electric vehicle charging controller of claim 1 , further comprising a fuse installed between the electric vehicle supply equipment and a contact to which a voltage having the fixed fifth voltage value is applied in the high voltage line.

13. The electric vehicle charging controller of claim 12 , further comprising a third sensor configured to measure a sixth voltage value between the electric vehicle supply equipment and the fuse in the high voltage line, wherein when a difference between the third voltage value and the sixth voltage value is measured to be greater than or equal to a preset seventh voltage value, the control unit determines that the fuse is blown.