System and method of maintaining high voltage battery charging with detected auxiliary battery fault

• US 10,112,487 B1
• Filed: 04/18/2017
• Issued: 10/30/2018
• Est. Priority Date: 04/18/2017
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Lee, Josephine S., Tistle, Cathleen, Mohr, Jeff Raymond, Keyse, James Brian, Russell, Jeremy L.
• Primary Examiner(s): Melton, Todd M
• Application Number:
  US15/490,448
• Publication Number:
  US 20180297474A1
• Time in Patent Office: 560 Days
• Field of Search: None
• 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 3/12 Recording operating variables ; Monitoring of operating variables
• CPC Class Codes: B60L 58/10 for monitoring or controlling batteries
• CPC Class Codes: G01R 31/007 using microprocessors or computers
• CPC Class Codes: G01R 31/3835 involving only voltage measurements
• CPC Class Codes: H01M 10/425 Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing printed circuits H05K1/00
• CPC Class Codes: H01M 10/48 Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569
• CPC Class Codes: H01M 10/486 for measuring temperature
• CPC Class Codes: H01M 2010/4278 Systems for data transfer from batteries, e.g. transfer of battery parameters to a controller, data transferred between battery controller and main controller
• CPC Class Codes: H01M 2220/20 Batteries in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: H02J 7/0047 with monitoring or indicating devices or circuits
• CPC Class Codes: H02J 7/14 for charging batteries from dynamo-electric generators driven at varying speed, e.g. on vehicle
• CPC Class Codes: H02J 7/342 The other DC source being a battery actively interacting with the first one, i.e. battery to battery charging with circuits for polarity protection H02J7/0034
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility
• 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

Abstract

A system using a computer to be configured to perform particular actions by virtue of having software, firmware, hardware, or a combination installed. One aspect includes a system, programmed to receive a fault signal from an auxiliary battery sensor. The system also determines if a low voltage set point is greater than the main battery voltage, and sends an open switch signal to a battery isolation switch if the low voltage set point is greater than the main battery voltage value. The system will send an auxiliary set point signal to an auxiliary battery charger to maintain a low voltage. The system will receive a current signal from an auxiliary battery sensor to indicate an auxiliary battery current value. The system also determines if the auxiliary battery current is above a maximum current value, and send a disable auxiliary battery maintenance signal to the auxiliary battery charger.

Claims

1. An electric vehicle (EV) auxiliary battery current fault system, comprising:

a battery maintenance electronic control unit (ECU);

an auxiliary battery sensor communicatively coupled to an auxiliary battery and the battery maintenance ECU;

a voltage sensor communicatively coupled to a main battery and the battery maintenance ECU;

a battery isolation switch;

a low voltage bus communicatively coupled to at least one of the main battery, the auxiliary battery, the battery isolation switch, and a DC to DC converter; and

an auxiliary battery sensor and controller communicatively coupled to the auxiliary battery and the battery maintenance ECU.

2. The system of claim 1, further including a diode communicatively coupled to the battery isolation switch to prevent the main battery from discharging when the battery isolation switch is open.

3. The system of claim 1, wherein the DC to DC converter converts a high voltage to a low voltage.

4. The system of claim 1, wherein the battery maintenance ECU further comprises a processor and a memory.

5. The system of claim 4, wherein the battery maintenance ECU is communicatively coupled to a network of the EV.

6. The system of claim 5, wherein the network is a Controller Area Network (CAN) bus.

7. The system of claim 1, wherein the auxiliary battery sensor and controller includes at least one of an ampere sensor, a temperature sensor, a voltage sensor and a timer sensor to determine a fault signal.

8. A system, comprising a computer having a processor and a memory, the memory storing instructions executable by the processor such that the computer is programmed to:

receive a fault signal from an auxiliary battery sensor and controller communicatively coupled to an auxiliary battery;

receive a voltage signal from a voltage sensor communicatively coupled to a main battery, wherein the voltage signal indicates a main battery voltage value;

determine if a low voltage set point value is greater than the main battery voltage value;

send an open switch signal to a battery isolation switch if the low voltage set point is greater than the main battery voltage value;

send an auxiliary set point signal to an auxiliary battery charger to maintain a low voltage value on a low voltage bus of an electric vehicle (EV);

receive a current signal from an auxiliary battery current sensor communicatively coupled to the auxiliary battery, wherein the current signal indicates an auxiliary battery current value;

determine if the auxiliary battery current value is above an auxiliary battery maximum current value; and

send a disable auxiliary battery maintenance signal to the auxiliary battery charger.

9. The system of claim 8, further including a diode communicatively coupled to the battery isolation switch to prevent the main battery from discharging when the battery isolation switch is open.

10. The system of claim 8, wherein a high voltage (HV) battery continues to charge when the auxiliary battery charger is disabled.

11. The system of claim 8, wherein the processor and the memory are located in a battery charging computer.

12. The system of claim 11, wherein the battery charging computer is communicatively coupled to a network of the EV.

13. The system of claim 12, wherein the network is a Controller Area Network (CAN) bus.

14. The system of claim 8, wherein the auxiliary battery sensor and controller includes at least one of an ampere sensor, a temperature sensor, a voltage sensor and a timer sensor to determine the fault signal.

15. A method, comprising:

receiving a fault signal from an auxiliary battery sensor and controller communicatively coupled to an auxiliary battery;

receiving a voltage signal from a voltage sensor communicatively coupled to a main battery, wherein the voltage signal indicates a main battery voltage value;

determining if a low voltage set point value is greater than the main battery voltage value;

sending an open switch signal to a battery isolation switch if the low voltage set point is greater than the main battery voltage value;

sending an auxiliary set point signal to an auxiliary battery charger to maintain a low voltage value on a low voltage bus of an electric vehicle (EV);

receiving a current signal from an auxiliary battery current sensor communicatively coupled to the auxiliary battery, wherein the current signal indicates an auxiliary battery current value;

determining if the auxiliary battery current value is above an auxiliary battery maximum current value; and

sending a disable auxiliary battery maintenance signal to the auxiliary battery charger.

16. The method of claim 15, further includes preventing the main battery from discharging when the battery isolation switch is open with a diode communicatively coupled to the battery isolation switch.

17. The method of claim 15, further includes continuing to charge a high voltage (HV) battery when the auxiliary battery charger is disabled.

18. The method of claim 15, wherein a processor and a memory are located in a battery charging computer.

19. The method of claim 18, wherein the battery charging computer is communicatively coupled to a Controller Area Network (CAN) bus of the EV.

20. The method of claim 15, further includes determining the fault signal from at least one of an ampere sensor, a temperature sensor, a voltage sensor and a timer sensor to determine the fault signal.