CHARGING DEVICE AND METHOD OF DETECTING A CONNECTION TO GROUND

• US 20120091960A1
• Filed: 11/11/2011
• Published: 04/19/2012
• Est. Priority Date: 11/11/2011
• Status: Active Grant

• Current Assignee: ABB BV (ABB Limited)
• Original Assignee: General Electric Company
• Inventors: Hooker, John Kenneth, Alagic, Denis, Khattab, Mazen Mohamad
• Granted Patent: US 9,413,178 B2
• Time in Patent Office: Days
• US Class Current: 320/109
• CPC Class Codes: B60L 3/0069 relating to the isolation, e.g. ground fault or leak current
• CPC Class Codes: H02J 2310/48 for electric vehicles [EV] or hybrid vehicles [HEV]
• CPC Class Codes: H02J 7/0029 with safety or protection devices or circuits

Abstract

A charging device includes a current control device configured to receive a first amount of current from a power source. The charging device also includes a ground detection module including a leakage circuit configured to direct a second amount of current to ground to generate a leakage voltage and a comparison circuit configured to detect a connection to ground of the charging device based on the leakage voltage generated. The charging device also includes a controller coupled to the ground detection module and to the current control device. The controller is configured to enable the first amount of current to be supplied to a power storage device of an electric vehicle when the connection to ground is detected.

Claims

1. A charging device comprising:

a current control device configured to receive a first amount of current from a power source;

a ground detection module comprising;

a leakage circuit configured to direct a second amount of current to ground to generate a leakage voltage; and

a comparison circuit configured to detect a connection to ground of said charging device based on the leakage voltage generated; and

a controller coupled to said ground detection module and to said current control device, said controller configured to enable the first amount of current to be supplied to a power storage device of an electric vehicle when the connection to ground is detected.

2. A charging device in accordance with claim 1, further comprising a reference circuit configured to provide a reference voltage to said comparison circuit.

3. A charging device in accordance with claim 2, wherein said comparison circuit is configured to detect the connection to ground by comparing the reference voltage to the leakage voltage.

4. A charging device in accordance with claim 3, wherein said comparison circuit is configured to detect the connection to ground when the leakage voltage is not less than the reference voltage.

5. A charging device in accordance with claim 1, further comprising a switching circuit configured to transmit a control signal to said controller to one of disable and enable the first amount of current to be supplied to the power storage device based on a status of the connection to ground.

6. A charging device in accordance with claim 5, wherein said controller operates said current control device to one of disable and enable the first amount of current to be supplied to the power storage device.

7. A charging device in accordance with claim 1, wherein said comparison circuit is a first comparison circuit, said ground detection module comprises a second comparison circuit, wherein said controller is configured to enable the first amount of current to be supplied to the power storage device when each of said first comparison circuit and said second comparison circuit detects a connection to ground.

8. A ground detection module for use with a charging device, said ground detection module comprising:

a ground detection circuit comprising;

a leakage circuit configured to direct a first amount of current to ground to generate a leakage voltage; and

a comparison circuit configured to detect a connection to ground of the charging device based on the leakage voltage generated; and

an output connector configured to enable a second amount of current to be supplied to a power storage device when the connection to ground is detected.

9. A ground detection module in accordance with claim 8, further comprising a reference circuit configured to provide a reference voltage to said comparison circuit.

10. A ground detection module in accordance with claim 9, wherein said comparison circuit is configured to detect the connection to ground by comparing the reference voltage to the leakage voltage.

11. A ground detection module in accordance with claim 10, wherein said comparison circuit is configured to detect the connection to ground if the leakage voltage is not less than the reference voltage.

12. A ground detection module in accordance with claim 8, further comprising a switching circuit configured to one of disable and enable the second amount of current to be supplied to the power storage device based on a status of the connection to ground.

13. A ground detection module in accordance with claim 12, wherein said switching circuit transmits a signal to said output connector to one of disable and enable the second amount of current to be supplied to the power storage device.

14. A ground detection module in accordance with claim 8, wherein said ground detection circuit is a first ground detection circuit comprising a first comparison circuit, said ground detection module comprises a second ground detection circuit comprising a second comparison circuit, wherein said output connector is configured to enable the second amount of current to be supplied to the power storage device when each of said first comparison circuit and said second comparison circuit detects a connection to ground.

15. A method of detecting a grounding state of a charging device, said method comprising:

receiving a first amount of current from a power source;

directing a second amount of current to ground to generate a leakage voltage;

receiving a reference voltage;

comparing the leakage voltage to the reference voltage; and

detecting a connection to ground based on the comparison of the leakage voltage and the reference voltage.

16. A method in accordance with claim 15, wherein said detecting a connection to ground comprises detecting a connection to ground if the leakage voltage is not less than the reference voltage.

17. A method in accordance with claim 15, further comprising enabling the first amount of current to be supplied to a power storage device when the connection to ground is detected.

18. A method in accordance with claim 17, further comprising preventing the second amount of current from being supplied to the power storage device when the connection to ground is not detected.

19. A method in accordance with claim 15, wherein the charging device includes a first detection circuit and a second detection circuit, said detecting a connection to ground comprises detecting a connection to ground by each of the first detection circuit and the second detection circuit.

20. A method in accordance with claim 19, wherein the first amount of current is enabled to be supplied to a power storage device when each of the first detection circuit and the second detection circuit detect a connection to ground.