Vehicle system with battery boost and bypass control

• US 9,682,671 B2
• Filed: 06/10/2014
• Issued: 06/20/2017
• Est. Priority Date: 06/10/2014
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Lovett, Karin, Ferrel, Mark J., Tistle, Cathleen, Symanow, David Anthony
• Primary Examiner(s): Gannon, Levi
• Application Number:
  US14/300,678
• Publication Number:
  US 20150353035A1
• Time in Patent Office: 1,106 Days
• Field of Search: 307 91, 307 101
• CPC Class Codes: B60L 1/00 Supplying electric power to auxiliary equipment of vehicles circuit arrangements for charging batteries H02J7/00
• CPC Class Codes: B60L 2210/10 DC to DC converters
• CPC Class Codes: B60L 58/20 having different nominal voltages
• CPC Class Codes: B60R 16/033 characterised by the use of electrical cells or batteries for propulsion puposes B60K1/04; supplying batteries to, or removing batteries from, vehicles B60S5/06; testing of charge state G01R31/36
• CPC Class Codes: H02M 1/007 Plural converter units in cascade push-pull DC/DC converters with pre-regulator H02M3/3374; DC-AC converters following a DC-DC stage including a high frequency transformer H02M7/4807; DC-AC converters following a DC-DC conversion stage generating periodically varying voltages H02M7/4826
• CPC Class Codes: H02M 3/04 by static converters
• CPC Class Codes: H02M 3/156 with automatic control of output voltage or current, e.g. switching regulators
• 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 10/72 Electric energy management in electromobility
• CPC Class Codes: Y02T 90/14 Plug-in electric vehicles

Abstract

A vehicle system according to an exemplary aspect of the present disclosure includes, among other things, a DC/DC converter bus adapted to operate at a first voltage set-point and a low voltage battery bus adapted to operate at a second voltage set-point different from the first voltage set-point.

Claims

1. A vehicle system, comprising:

a DC/DC converter bus adapted to operate at a first voltage set-point;

a low voltage battery bus adapted to operate at a second voltage set-point different from said first voltage set-point; and

a boost converter disposed between said DC/DC converter bus and said low voltage battery bus and configured to control current flow between said DC/DC converter bus and said low voltage battery bus.

2. The vehicle system as recited in claim 1, wherein said boost converter includes at least one switch operable to disconnect said DC/DC converter bus from said low voltage battery bus.

3. The vehicle system as recited in claim 1, wherein said boost converter includes a bypass switch, an energy storage device, a boost switch, and a diode.

4. The vehicle system as recited in claim 1, wherein said DC/DC converter bus includes a DC/DC converter and at least one module load.

5. The vehicle system as recited in claim 1, wherein said low voltage battery bus includes a battery.

6. The vehicle system as recited in claim 1, wherein said first voltage set-point includes a fixed voltage and said second voltage set-point includes a variable voltage.

7. The vehicle system as recited in claim 1, comprising a control unit in electrical communication with said DC/DC converter bus and said low voltage battery bus.

8. The vehicle system as recited in claim 7, wherein said control unit is configured to operate in a charging mode in which said DC/DC converter bus charges a battery of said low voltage battery bus and a support mode in which said low voltage battery bus supports module loads of said DC/DC converter bus.

9. The vehicle system as recited in claim 1, wherein said vehicle system is part of a low voltage bus of an electrified vehicle.

10. A vehicle system, comprising:

a low voltage battery;

a DC/DC converter configured to charge said battery;

a boost converter connected between said battery and said DC/DC converter and configured to boost voltages from said DC/DC converter; and

a control unit configured to operate in a charging mode where current flows in a first direction to charge said battery and a support mode where current flows in a second, opposite direction to support a module load.

11. The vehicle system as recited in claim 10, wherein said battery part of a low voltage battery bus and said DC/DC converter is part of a DC/DC converter bus.

12. The vehicle system as recited in claim 11, wherein said module load is part of said DC/DC converter bus.

13. The vehicle system as recited in claim 10, wherein said boost converter includes a bypass switch that is selectively closed to define a path of said current flow in said support mode.

14. The vehicle system as recited in claim 13, wherein said boost converter includes a boost switch that is selectively opened and closed to store energy within an energy storage device during said charging mode.

15. The vehicle system as recited in claim 10, wherein said low voltage battery is a 12V battery.

16. A method, comprising:

incorporating a boost converter into a vehicle system of an electrified vehicle;

operating the vehicle system in a charging mode in which a DC/DC converter charges a battery in response to a low state of charge condition of the battery; and

operating the vehicle system in a support mode in which the battery supports at least one module load in response to an overload condition of the DC/DC converter.

17. The method as recited in claim 16, wherein the DC/DC converter is part of a DC/DC converter bus and the battery is part of a low voltage battery bus.

18. The method as recited in claim 17, comprising:

operating the DC/DC converter bus at a fixed voltage set-point; and

operating the low voltage battery bus at a variable voltage set-point.

19. The method as recited in claim 16, comprising disconnecting the DC/DC converter from the battery in response to a third condition.

20. A vehicle system, comprising:

a battery;

a DC/DC converter configured to charge said battery; and

a boost converter connected between said battery and said DC/DC converter and configured to boost voltages from said DC/DC converter, said boost converter including at least one switch operable to selectively disconnect said DC/DC converter from said battery.