Vehicle Charging Diagnostic

1 . A vehicle charging diagnostic apparatus comprising:

a voltage sensor configured for determining a voltage on a control pilot line; and

a diagnostic controller configured for identifying a first fault in response to detecting, using the voltage sensor, a negative voltage at or below a threshold.

2 . The vehicle charging diagnostic apparatus according to claim 1 , wherein the negative voltage corresponds to a charging station having a negative potential.

3 . The vehicle charging diagnostic apparatus according to claim 1 , wherein the diagnostic controller outputs a first fault indicator in response to identifying a first fault.

4 . The vehicle charging diagnostic apparatus according to claim 3 , wherein the first fault indicator is associated with a permanent earth disconnection fault between at least one of:

(i) a charging station and its coupler,

(ii) the charging station and a vehicle inlet, where an inlet proximity pilot resistor is damaged, or

(iii) the vehicle inlet and a vehicle charge controller, where an inlet proximity pilot resistor is damaged, and a coupler proximity pilot resistor is damaged.

5 . The vehicle charging diagnostic apparatus according to claim 1 , further comprising:

a current sensor for sensing the current on the proximity pilot line, and wherein the diagnostic controller is further configured to monitor characteristics in the current sensed by the current sensor and identify a further fault in response to detecting the detected characteristics.

6 . The vehicle charging diagnostic apparatus according to claim 5 , wherein the characteristics in the current comprise amplitude fluctuations.

7 . The vehicle charging diagnostic apparatus according to claim 6 , wherein the fluctuations in the current have a signal frequency of between 900 Hz and 1.1 kHz.

8 . The vehicle charging diagnostic apparatus according to claim 7 , wherein the diagnostic controller is configured to output a further fault indicator in response to identifying a further fault.

9 . The vehicle charging diagnostic apparatus according to claim 8 , wherein the diagnostic controller categorises the further fault based on a peak to trough amplitude being within a predetermined range.

10 . The vehicle charging diagnostic apparatus according to claim 1 , wherein the diagnostic controller is configured to stop a charging operation in response to identifying a first fault or a further fault.

11 . The vehicle charging diagnostic apparatus according to claim 1 , wherein the threshold is between −13V and −30V.

12 . A vehicle charging diagnostic method comprising:

determining, using a voltage sensor, a voltage on a control pilot line; and

identifying, by a diagnostic controller, a first fault in response to detecting, using the voltage sensor, a negative voltage at or below a threshold.

13 . The vehicle charging diagnostic method according to claim 12 , further comprising:

outputting, by the diagnostic controller, a first fault indicator in response to identifying a first fault.

14 . The vehicle charging diagnostic method according to claim 12 , further comprising:

sensing, using a current sensor, the current on a proximity pilot line; and

identifying, by the diagnostic controller, characteristics in the sensed current and identifying a further fault in response to the detected characteristics.

15 . The vehicle charging diagnostic method according to claim 14 , further comprising:

outputting a further fault indicator in response to identifying the further fault.

16 . The method according to claim 15 , further comprising:

stopping a charging operation in response to identifying the first fault or in response to identifying the further fault.

17 . The method according to claim 12 , wherein the negative voltage corresponds to a charging station having a negative potential.

18 . A non-transient computer readable medium comprising instructions which, when executed by a processor, causes the processor to:

determine, using a voltage sensor, a voltage on a control pilot line; and

identify, by a diagnostic controller, a first fault in response to detecting, using the voltage sensor, a negative voltage at or below a threshold.

19 . The non-transient computer readable medium of claim 18 , further comprising instructions, which when executed by the processor, further cause the processor to:

sense a current on a proximity pilot line; and

identify a further fault based on characteristics in the current.

20 . The non-transient computer readable medium of claim 19 , further comprising instructions, which when executed by the processor, further cause the processor to:

output a further fault indicator in response to the identification of the further fault; and

stopping a charging operation in response to the identification of the first fault or the identification of the further fault.