Hybrid battery charger

• US 9,368,269 B2
• Filed: 10/24/2012
• Issued: 06/14/2016
• Est. Priority Date: 10/24/2012
• Status: Active Grant

• Current Assignee: Schumacher Electric Corporation
• Original Assignee: Schumacher Electric Corporation
• Inventors: Chen, Xiao Ping, Heins, Matthew, Zhu, Shenzhong
• Primary Examiner(s): Rodas, Richard Isla
• Assistant Examiner(s): Bui, Dung V
• Application Number:
  US13/659,412
• Publication Number:
  US 20140111139A1
• Time in Patent Office: 1,329 Days
• Field of Search: 320/107
• US Class Current: 1/1
• CPC Class Codes: B60L 53/00 Methods of charging batteries, specially adapted for electric vehicles; Charging stations or on-board charging equipment therefor; Exchange of energy storage elements in electric vehicles
• CPC Class Codes: B60L 58/15 Preventing overcharging
• CPC Class Codes: H01F 27/28 Coils; Windings; Conductive connections
• CPC Class Codes: H01F 38/42 Flyback transformers
• CPC Class Codes: H02J 2207/20 Charging or discharging characterised by the power electronics converter
• CPC Class Codes: H02J 7/00302 Overcharge protection
• CPC Class Codes: H02J 7/00714 in response to battery charging or discharging current
• CPC Class Codes: H02J 7/007182 in response to battery voltage
• CPC Class Codes: H02J 7/02 for charging batteries from ac mains by converters
• CPC Class Codes: H02J 7/04 Regulation of charging current or voltage
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A hybrid battery charger is disclosed that includes a linear battery charging circuit for providing vehicle starting current and battery charging and a high frequency battery charging circuit that provides battery charging current. The linear battery charging circuit and the high frequency battery charging circuits are selectively enabled to provide vehicle starting current, maximum charging current and optimum efficiency.

Claims

1. A hybrid battery charger comprising:

a control circuit;

a linear charger circuit for selectively charging a battery during one or more modes of operation;

a high frequency charger circuit for selectively charging the battery during one or more modes of operation;

a set of output terminals;

a first switch operatively coupled to said control circuit, the first switch being configured to selectively couple said linear charger circuit to a power source; and

a second switch operatively coupled to said control circuit, the second switch being configured to selectively couple said high frequency charger circuit to said set of output terminals,

wherein the control circuit is configured to control each of said linear battery charger circuit and said high frequency charger circuit to simultaneously supply a current to said set of output terminals.

2. The hybrid battery charger as recited in claim 1, wherein said linear battery charger circuit and said high frequency charger circuit simultaneously supply a current to said set of output terminals until a predetermined condition is met.

3. The hybrid battery charger as recited in claim 1, wherein said hybrid battery charger includes at least three modes of operation.

4. The hybrid battery charger as recited in claim 3, wherein, in a first mode of operation, said linear battery charger circuit provides a starting current to said set of output terminals.

5. The hybrid battery charger as recited in claim 4, wherein, in a second mode of operation, said linear battery charger circuit provides a charging current to said set of output terminals.

6. The hybrid battery charger as recited in claim 5, wherein, in a third mode of operation, said high frequency battery charger circuit provides a charging current to said set of output terminals.

7. The hybrid battery charger as recited in claim 6, further including a fourth mode of operation in which both the linear charger circuit and the high frequency charger circuit simultaneously provide a charging current to said set of output terminals.

8. The hybrid battery charger as recited in claim 1, wherein said linear battery charger circuit and said high frequency charger circuit simultaneously supply a current to said set of output terminals until a predetermined condition is met, whereby said control circuit then disables said high frequency charger circuit.

9. The hybrid battery charger as recited in claim 8, wherein said predetermined condition relates to a battery voltage of a battery coupled to said set of output terminals.

10. The hybrid battery charger as recited in claim 9, wherein said predetermined condition is met when the battery voltage meets or exceeds 13.2 volts.

11. The hybrid battery charger as recited in claim 8, wherein said predetermined condition relates to a rate of change of a battery voltage, dV/dt, of a battery coupled to said set of output terminals.

12. The hybrid battery charger as recited in claim 11, wherein said predetermined condition is met when the rate of change is at or below 0.1 volt/hour.

13. The hybrid battery charger as recited in claim 8, wherein said predetermined condition relates to a charging current.

14. The hybrid battery charger as recited in claim 13, wherein said predetermined condition is met when the charging current is at or below 7 amps DC.

15. The hybrid battery charger as recited in claim 1, wherein said control circuit includes a microcontroller and the control circuit is configured to provide a nominal power to the microcontroller in low voltage conditions down to a battery voltage of 1.0 volts DC.

16. The hybrid battery charger as recited in claim 1, wherein said high frequency charging circuit includes a flyback transformer and said control circuit includes a set of bias windings on a primary and secondary windings of said transformer configured to provide power to said control circuit and said microcontroller during a low voltage condition.

17. A flyback transformer comprising:

a core;

a bobbin disposed relative to said core;

a primary winding wound onto said bobbin;

a pair of bias windings wound onto said bobbin in opposite polarities relative to one another, said pair of bias windings being insulated from said primary winding; and

a pair of secondary windings in opposite polarities relative to one another.

18. The flyback transformer as recited in claim 17, wherein one of said pair of bias windings is wound on said bobbin to cover a full winding width of the bobbin as one or more layers.

19. The flyback transformer as recited in claim 17, wherein said primary winding and said pair of bias windings each comprise magnetic wire.

20. The flyback transformer as recited in claim 17, wherein said pair of secondary windings comprises triple insulated wire.

21. An efficient method for charging a battery, the method comprising:

simultaneously charging a battery with a linear battery charger circuit and a high frequency battery charger circuit;

monitoring one or more parameters associated with the charging of the battery; and

turning off the high frequency battery charging circuit and continuing charging of the battery by way of the linear battery charger circuit, as a function of said one or more parameters.

22. The method as recited in claim 21, wherein said one or more parameters include a charging current.

23. The method as recited in claim 21, wherein said one or more parameters include a rate of change of a battery voltage, dV/dt, of a battery coupled across a set of output terminals.

24. The method as recited in claim 21, wherein said one or more parameters include a rate of change of charging current, dI/dt.

25. A hybrid battery charger comprising:

a control circuit;

a linear charger circuit;

a first switch operatively coupled to said control circuit, the first switch being configured to selectively couple said linear charger circuit to a power source;

a high frequency charger circuit; and

a second switch operatively coupled to said control circuit, the second switch being configured to selectively couple said high frequency charger circuit to a set of output terminals,

wherein the control circuit is configured to independently control said first switch and said second switch to, when a predetermined condition is met, simultaneously connect (1) said linear battery charger circuit to said power supply and (2) said high frequency charger circuit to said set of output terminals.

26. A hybrid battery charging apparatus comprising:

a linear charger circuit;

a high frequency charger circuit;

a set of output terminals operably connected to said linear charger circuit and said high frequency charger circuit, said output terminals being configured to couple with a battery; and

a control circuit configured to selectively enable said linear battery charger circuit and said high frequency charger circuit,

wherein said control circuit is configured to enable both of said linear battery charger circuit and said high frequency charger circuit until a predetermined condition is met, whereby each of said linear battery charger circuit and said high frequency charger circuit simultaneously supplies a current to said set of output terminals.

27. The hybrid battery charging apparatus as recited in claim 26, wherein said hybrid battery charger is configured to disable said linear charging circuit when the predetermined condition is met.

28. The hybrid battery charging apparatus as recited in claim 26, wherein said hybrid battery charger is configured to disable said high frequency battery charger circuit when the predetermined condition is met.

29. The hybrid battery charging apparatus as recited in claim 28, wherein said predetermined condition is met when the battery'"'"'s voltage meets or exceeds 13.2 volts.

30. The hybrid battery charging apparatus as recited in claim 28, wherein said predetermined condition is met when the battery'"'"'s load current is at or below 7 amps DC.

31. The hybrid battery charging apparatus as recited in claim 26, wherein said high frequency charging circuit includes a flyback transformer and said control circuit includes a set of bias windings on the primary and secondary of said transformer configured to provide power to a pulse-width modulation (PWM) controller and a microcontroller during a low voltage condition.