System and method for charging electrified vehicle low-voltage battery

Patent metadata

Field	Value
Publication number	US-10457155-B2
Application number	US-201615261268-A
Country	US
Kind code	B2
Filing date	Sep 9, 2016
Priority date	Sep 9, 2016
Publication date	Oct 29, 2019
Grant date	Oct 29, 2019

Abstract

A vehicle charging system includes a controller programmed to, in response to a charger being coupled to a power source and parameters being indicative of a low charge level of an auxiliary battery and a full charge level of a traction battery, decouple the traction battery from the power converter and the charger and charge the auxiliary battery from the charger.

First claim

What is claimed is:

1. A charging system for a vehicle comprising:
a controller programmed to, responsive to receiving parameters indicative of a full charge level of a traction battery and a depleted charge level of an auxiliary battery coupled to a power converter while a charger is coupled to a power source, decouple the traction battery from the power converter and the charger and reduce a charger output voltage supplied to the power converter to charge the auxiliary battery.

2. The charging system of claim 1 wherein parameters indicative of a full charge level of the traction battery include a state of charge of the traction battery being greater than a predetermined threshold.

3. The charging system of claim 1 wherein parameters indicative of a full charge level of the traction battery include a voltage of the traction battery being greater than a predetermined threshold.

4. The charging system of claim 1 wherein parameters indicative of a depleted charge level of the auxiliary battery include a state of charge of the auxiliary battery being less than a predetermined threshold.

5. The charging system of claim 1 wherein parameters indicative of a depleted charge level of the auxiliary battery include a voltage of the auxiliary battery being less than a predetermined threshold.

6. The charging system of claim 1 wherein the controller is further programmed to charge the auxiliary battery at a power level that does not exceed a power limit of the charger.

7. The charging system of claim 1 wherein the controller is further programmed to command the charger at an output voltage that is independent from a voltage level of the traction battery.

8. The charging system of claim 1 wherein the controller is further programmed to command the charger at a power level that maximizes a conversion efficiency of the power converter.

9. The charging system of claim 1 wherein the controller is further programmed to command the charger at a power level that maximizes a conversion efficiency of the charger.

10. A vehicle comprising:
a power converter configured to transfer power from a charger and a traction battery to an auxiliary battery; and
a controller programmed to, responsive to an auxiliary battery voltage falling below a predetermined threshold while a traction battery parameter indicates a full charge and the charger is coupled to a power source, isolate the traction battery from the power converter and the charger, and reduce an output voltage of the charger.

11. The vehicle of claim 10 further comprising contactors coupled between terminals of the traction battery and the power converter and wherein the controller is further programmed to open at least one of the contactors to isolate the traction battery from the power converter and the charger.

12. The vehicle of claim 10 wherein the controller is further programmed to charge the auxiliary battery at a power level that does not exceed a power limit of the charger.

13. The vehicle of claim 10 wherein the controller is further programmed to command the charger at a power level that maximizes a conversion efficiency of the power converter.

14. The vehicle of claim 10 wherein the controller is further programmed to command the charger at a power level that maximizes a conversion efficiency of the charger.

15. The vehicle of claim 10 wherein the traction battery parameter is a state of charge of the traction battery.

16. The vehicle of claim 10 wherein the traction battery parameter is a voltage of the traction battery.

17. A method comprising:
decoupling, by a controller, a traction battery from a power converter and a charger responsive to receiving parameters indicative of a full charge level of the traction battery and a depleted charge level of an auxiliary battery coupled to the power converter while the charger is coupled to a power source; and
commanding, by the controller, the charger to reduce a voltage supplied to the power converter to charge the auxiliary battery.

18. The method of claim 17 further comprising commanding, by the controller, the charger to a power level that does not exceed a power limit of the charger.

19. The method of claim 17 further comprising commanding, by the controller, the charger to an output power level that maximizes a conversion efficiency of the power converter.

20. The method of claim 17 further comprising commanding, by the controller, the charge to an output power level that maximizes a conversion efficiency of the charger.

Assignees

• Ford Global Tech Llc

Inventors

• Wu Bo
• Ferrel Mark J
• Lee Josephine S

Classifications

• H02J7/02

  for charging batteries from AC mains by converters · CPC title

• H02J2105/37

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

• H02J7/825

  Detection of fully charged condition · CPC title

• H02J7/50

  acting upon multiple batteries simultaneously or sequentially · CPC title

• B60L58/22

  Balancing the charge of battery modules · CPC title