System and method for evaluating vehicle charging circuits

• US 8,432,175 B2
• Filed: 12/27/2010
• Issued: 04/30/2013
• Est. Priority Date: 12/27/2010
• Status: Expired due to Fees

• Current Assignee: Lear Corporation
• Original Assignee: Lear Corporation
• Inventors: Hein, David A.
• Primary Examiner(s): Nguyen, Vincent Q
• Application Number:
  US12/979,015
• Publication Number:
  US 20120161797A1
• Time in Patent Office: 855 Days
• Field of Search: 324/705, 324/713
• US Class Current: 324/705
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 2240/549 Current
• CPC Class Codes: B60L 3/04 Cutting off the power supply under fault conditions protective devices and circuit arrangements in general H01H; H02H
• CPC Class Codes: B60L 53/18 Cables specially adapted for charging electric vehicles
• CPC Class Codes: B60L 53/65 involving identification of vehicles or their battery types
• CPC Class Codes: B60L 53/665 Methods related to measuring, billing or payment
• CPC Class Codes: G01R 31/42 AC power supplies
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 90/12 Electric charging stations
• CPC Class Codes: Y02T 90/14 Plug-in electric vehicles
• CPC Class Codes: Y02T 90/16 Information or communication technologies improving the operation of electric vehicles
• CPC Class Codes: Y02T 90/167 Systems integrating technologies related to power network operation and communication or information technologies for supporting the interoperability of electric or hybrid vehicles, i.e. smartgrids as interface for battery charging of electric vehicles [EV] or hybrid vehicles [HEV]
• CPC Class Codes: Y04S 30/14 Details associated with the interoperability, e.g. vehicle recognition, authentication, identification or billing

Abstract

A system and method is provided for evaluating performance of a supply circuit for electric vehicle charging. An electrical connection is established between a vehicle circuit and a supply circuit for an external Alternating Current (AC) power supply. The electrical connection includes a hot, neutral, and ground conductor. A control signal is transmitted to activate a switch disposed along the electrical connection for selectively initiating vehicle charging. Input signals are received including: a line current signal indicative of a current along at least one of the hot conductor and the neutral conductor, and at least one of a line voltage signal and a neutral voltage signal. The line voltage signal being indicative of a voltage potential between the hot conductor and the neutral conductor. The neutral voltage signal being indicative of a voltage potential between the neutral conductor and the ground conductor. At least one of the input signals is compared to predetermined resistance data for evaluating supply circuit performance.

Claims

1. A system for evaluating performance of a supply circuit for electric vehicle charging, the system comprising:

a charging cable for electrically connecting between a supply circuit and a vehicle circuit, the charging cable including a hot conductor, a neutral conductor and a ground conductor;

at least one voltage sensor for providing at least one of a line voltage signal and a neutral voltage signal, the line voltage signal being indicative of a voltage potential between the hot conductor and the neutral conductor, and the neutral voltage signal being indicative of a voltage potential between the neutral conductor and the ground conductor;

a current sensor for providing a line current signal indicative of a current along at least one of the hot conductor and the neutral conductor; and

a controller in electrical communication with the at least one voltage sensor, and the current sensor, the controller configured to;

receive the line current signal and at least one of the line voltage signal and the neutral voltage signal, and

compare at least one of the line voltage signal, the neutral voltage signal, and the line current signal to predetermined data to evaluate supply circuit performance.

2. The system of claim 1 wherein the predetermined data includes resistance values for residential wiring of the supply circuit.

3. The system of claim 1 further comprising a vehicle control in electrical communication with the controller for setting a charging current through the charging cable in response to a pilot signal.

4. The system of claim 3 wherein the controller is further configured to:

determine an allowable charge in response to the supply circuit performance; and

transmit the pilot signal indicative of the allowable charge to the vehicle control.

5. The system of claim 4 further comprising a switch in electrical communication with the controller for selectively disconnecting the vehicle circuit from the supply circuit in response to a control signal received from the controller and wherein the controller is further configured to:

monitor the line current signal; and

activate the switch to an opened position when the line current signal exceeds the allowable charge.

6. A system for evaluating performance of a supply circuit for electric vehicle charging, the system comprising:

a controller in electrical communication with a control circuit having electrical sensors in communication with a charging cable electrically connected to the supply circuit, wherein the charging cable has a hot conductor, a neutral conductor, and a ground conductor, the controller configured to;

receive input signals from the electrical sensors including a line current signal indicative of a current along at least one of the hot conductor and the neutral conductor, and at least one of a line voltage signal and a neutral voltage signal, the line voltage signal being indicative of a voltage potential between the hot conductor and the neutral conductor, and the neutral voltage signal being indicative of a voltage potential between the neutral conductor and the ground conductor, and

compare at least one of the line voltage signal, the neutral voltage signal, and the line current signal to predetermined data to evaluate supply circuit performance.

7. The system of claim 6 wherein the control circuit further comprises a switch configured to electrically disconnect the charging cable from the supply circuit and wherein the controller is further configured to:

activate the switch between an opened position in which the charging cable is electrically disconnected from the supply circuit and a closed position in which the charging cable is electrically connected to the supply circuit;

analyze the input signals to determine a no load line voltage and a no load neutral voltage after activating the switch to the opened position; and

compare the no load line voltage and the no load neutral voltage to predetermined data to evaluate a voltage range.

8. The system of claim 7 wherein the controller is further configured to:

receive a charge request signal from a vehicle control; and

activate the switch to the closed position in response to the voltage range and the vehicle cycle charge request.

9. The system of claim 8 wherein the controller is further configured to:

analyze the input signals received when the switch is in the closed position to determine a load line voltage, a load neutral voltage, and a load line current;

compare at least one of the no load line voltage, and the no load neutral voltage to at least one of the load line voltage, the load neutral voltage and the load line current to determine a resistance; and

compare the resistance to predetermined data to evaluate supply circuit performance.

10. The system of claim 6 wherein the controller is further configured to:

determine an allowable charge in response to the supply circuit performance; and

transmit a pilot signal to a vehicle control indicative of the allowable charge.

11. A method for evaluating performance of a supply circuit for electric vehicle charging, the method comprising:

establishing an electrical connection between a vehicle circuit and a supply circuit for an external Alternating Current (AC) power supply, wherein the electrical connection includes a hot, neutral, and ground conductor;

transmitting a control signal to activate a switch disposed along the electrical connection for selectively initiating vehicle charging;

receiving input signals including a line current signal indicative of a current along at least one of the hot conductor and the neutral conductor, and at least one of a line voltage signal and a neutral voltage signal, the line voltage signal being indicative of a voltage potential between the hot conductor and the neutral conductor, and the neutral voltage signal being indicative of a voltage potential between the neutral conductor and the ground conductor; and

comparing at least one of the input signals to predetermined resistance data for evaluating supply circuit performance.

12. The method of claim 11 wherein evaluating supply circuit performance further comprises comparing the line voltage signal taken when the switch is open to the line voltage signal and the line current signal taken when the switch is closed in order to determine a total line wiring resistance.

13. The method of claim 12 further comprising comparing the total line wiring resistance to predetermined resistance data to determine if the total line wiring resistance is within an acceptable range.

14. The method of claim 12 wherein evaluating supply circuit performance further comprises comparing the line current signal taken when the switch is closed to the total line wiring resistance in order to determine a total line power loss.

15. The method of claim 14 further comprising:

determining a second total line power loss after a predetermined time interval; and

comparing the second total line power loss to the total line power loss in order to determine a total line power loss drift.

16. The method of claim 15 further comprising:

determining a first allowable charge in response to the total line power loss;

transmitting a first pilot signal indicative of the first allowable charge to a vehicle control;

determining a second allowable charge in response to the total line power loss drift; and

transmitting a second pilot signal indicative of the second allowable charge to the vehicle control.

17. The method of claim 11 wherein evaluating supply circuit performance further comprises comparing the neutral voltage signal taken when the switch is open, to the neutral voltage signal and the line current signal taken when the switch is closed in order to determine a neutral wiring resistance.

18. The method of claim 11 wherein evaluating supply circuit performance further comprises:

comparing the line voltage signal taken when the switch is opened, to the line voltage signal and the line current signal taken when the switch is closed, to determine a total line wiring resistance;

comparing the neutral voltage signal taken when the switch is opened, to the neutral voltage signal and the line current signal taken when the switch is closed, to determine a neutral wiring resistance; and

comparing the total line wiring resistance to the neutral wiring resistance in order to determine a hot wiring resistance.

19. The method of claim 18 further comprising comparing the hot wiring resistance to the neutral wiring resistance in order to determine a resistance balance ratio.

20. The method of claim 11 wherein evaluating supply circuit performance further comprises:

comparing at least two of the line current signal, the line voltage signal, and the neutral voltage signal, to determine a first resistance;

comparing at least two of the line current signal, the line voltage signal, and the neutral voltage signal, taken after a predetermined time interval, to determine a second resistance; and

comparing the first resistance to the second resistance in order to determine a resistance drift.