Systems and methods for controlling charging of electrified vehicle auxiliary batteries

Patent metadata

Field	Value
Publication number	US-10696181-B2
Application number	US-201816055219-A
Country	US
Kind code	B2
Filing date	Aug 6, 2018
Priority date	Aug 6, 2018
Publication date	Jun 30, 2020
Grant date	Jun 30, 2020

Abstract

This disclosure describes vehicle systems and methods for controlling charging of an auxiliary (i.e., low voltage) battery of an electrified vehicle. Exemplary charging methods may dynamically adjust a low voltage setpoint of a power converter during the low voltage support. The proposed systems and methods therefore achieve constrained low voltage support by controlling the power drawn by the power converter at an appropriate level during the low voltage support.

First claim

What is claimed is:

1. A method, comprising:
controlling charging of a low voltage battery of an electrified vehicle with a vehicle charging system, wherein controlling the charging includes dynamically adjusting a low voltage setpoint of a power converter of the electrified vehicle during a charging event,
wherein dynamically adjusting the low voltage setpoint includes:
decreasing the low voltage setpoint when a power draw of the power converter exceeds a power output of an electric vehicle supply equipment assembly.

2. The method as recited in claim 1 , wherein the low voltage setpoint establishes how much power is drawn by the power converter for charging the low voltage battery during the charging event.

3. The method as recited in claim 1 , wherein the controlling is performed when a state of charge (SOC) of the low voltage battery is below a predefined threshold.

4. The method as recited in claim 3 , wherein the controlling is performed when the electrified vehicle is on-plug.

5. The method as recited in claim 4 , wherein the controlling is performed when a predefined amount of time has elapsed since charging a high voltage battery pack of the electrified vehicle.

6. The method as recited in claim 1 , wherein dynamically adjusting the low voltage setpoint includes:
decreasing the low voltage setpoint when a charge acceptance of the low voltage battery is above a first predefined threshold and a power draw of the power converter is above a power output of an electric vehicle supply equipment assembly.

7. The method as recited in claim 6 , wherein decreasing the low voltage setpoint includes decreasing the low voltage setpoint by a calibrated value.

8. A method, comprising:
controlling charging of a low voltage battery of an electrified vehicle with a vehicle charging system, wherein controlling the charging includes dynamically adjusting a low voltage setpoint of a power converter of the electrified vehicle during a charging event,
wherein dynamically adjusting the low voltage setpoint includes:
increasing the low voltage setpoint when a charge acceptance of the low voltage battery is below a first predefined threshold and a state of charge of the low voltage battery is below a second predefined threshold.

9. The method as recited in claim 8 , wherein increasing the low voltage setpoint includes increasing the low voltage setpoint by a calibrated value.

10. A vehicle charging system for an electrified vehicle, comprising:
a low voltage battery for powering low voltage loads of the electrified vehicle;
a power converter; and
a control system configured to automatically decrease a low voltage setpoint of the power converter when a charge acceptance of the low voltage battery exceeds a first predefined threshold and automatically increase the low voltage setpoint when the charge acceptance is below the first predefined threshold and a state of charge of the low voltage battery is below a second predefined threshold.

11. The vehicle charging system as recited in claim 10 , wherein the low voltage setpoint establishes how much power is drawn by the power converter for charging the low voltage battery during a charging event.

12. The vehicle charging system as recited in claim 10 , wherein the power converter is a DC/DC converter.

13. The vehicle charging system as recited in claim 10 , comprising a high voltage battery for powering high voltage loads of the electrified vehicle.

14. The vehicle charging system as recited in claim 10 , wherein the control system is configured to decrease the low voltage setpoint of the power converter when a power draw of the power converter exceeds a power output of an electric vehicle supply equipment assembly.

15. The vehicle charging system as recited in claim 10 , wherein the control system is configured to either increase or decrease the low voltage setpoint by a calibrated value.

16. The vehicle charging system as recited in claim 15 , wherein the calibrated value is a fixed, incremental value.

Assignees

• Ford Global Tech Llc

Inventors

• Hu Changjian
• Lee Josephine S
• Keyse James Brian

Classifications

• B60L53/20 Primary

  characterised by converters located in the vehicle · CPC title

• B60L1/00 Primary

  Supplying electric power to auxiliary equipment of vehicles (circuit arrangements for charging batteries H02J7/00) · CPC title

• H02J2105/37

  exchanging power with electric vehicles [EV] or with hybrid electric vehicles [HEV] · CPC title

• H02J7/933

  the cycle being controlled or terminated in response to electric parameters · CPC title

• H02J7/96

  in response to battery voltage · CPC title