FUEL CELL HYBRID SYSTEM AND METHOD FOR CHARGING RECHARGEABLE BATTERY THEREOF

• US 20130241464A1
• Filed: 12/19/2012
• Published: 09/19/2013
• Est. Priority Date: 03/14/2012
• Status: Abandoned Application

• Current Assignee: Samsung SDI Company Limited
• Original Assignee: Samsung SDI Company Limited
• Inventors: KIM, Dong-Rak, SONG, In-Seob, CHOI, Jong-Rock, CHO, Hye-Jung, PARK, Jeong-Kurn
• Application Number:
  US13/719,365
• Publication Number:
  US 20130241464A1
• Time in Patent Office: Days
• US Class Current: 320/101
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/34 Parallel operation in networks using both storage and other dc sources, e.g. providing buffering H02J7/14 takes precedence
• 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

Abstract

A fuel cell hybrid system extends a cycle-life of a rechargeable battery by charging the rechargeable battery with voltage lower than the maximum charging voltage of the rechargeable battery by a predetermined level.

Claims

1. A fuel cell hybrid system, comprising:

a fuel cell stack to generate an electrical current;

a rechargeable battery;

a direct current to direct current(dc/dc) converter electrically connected to the fuel cell stack and the rechargeable battery; and

a control unit electrically connected to the dc/dc converter to control the charging of the rechargeable battery by causing the dc/dc converter to output the electrical current received from the fuel cell stack at a voltage level that is less than a maximum charging voltage of the rechargeable battery.

2. The fuel cell hybrid system recited in claim 1, wherein the dc/dc converter further comprises:

a first distributed resistance electrically connected to the fuel cell stack and the rechargeable battery; and

a second distributed resistance electrically connected to the first distributed resistance and the control unit,

wherein the control unit alters the voltage level to the rechargeable battery by altering a resistance level in at least one of either the first distributed resistance or the second distributed resistance.

3. The fuel cell hybrid system recited in claim 2, wherein the control unit alters the voltage level to the rechargeable battery by altering the resistance level in both the first distributed resistance and the second distributed resistance.

4. The fuel cell hybrid system recited in claim 2, further comprising:

a current measurement unit electrically connected to the fuel cell stack, the dc/dc converter and the control unit to measure the electrical voltage from the fuel cell stack and transmit a current amount signal to the control unit indicative of an amount electrical current being generated by the fuel cell stack.

5. The fuel cell hybrid system recited in claim 4, wherein the dc/dc converter further comprises:

a power converter electrically connected between the fuel cell stack and the rechargeable battery;

a first amplifier electrically connected between the control unit and the power converter; and

a second amplifier electrically connected between the first amplifier and the power converter;

wherein a first end of the first distributed resistor is connected to a first node located between the power converter and the rechargeable battery;

a second end of the first distributed resistor is connected to a second node located between an output of the first amplifier and an input of the second amplifier;

a first end of the second distributed resistor is connected to the second node; and

a second end of the second distributed resistor is connected to the output of the first amplifier.

6. The fuel cell hybrid system recited in claim 1, wherein the dc/dc converter includes a power converter, said power converter, further comprising:

a first switch;

a second switch;

an inductor; and

a capacitor,

wherein the first switch includes a gate connected to a switch controller included in the dc/dc controller, a first end of the first switch connected to the current measurement unit and a second end connected to a first end of the inductor;

the second switch includes a gate connected to the switch controller, a first end connected to the second end of the first switch and a second end connected to a first terminal of the fuel cell stack;

a second end of the inductor is connected to a first end of the capacitor; and

a second end of the capacitor is connected to a second terminal of the fuel cell stack.

7. The fuel cell hybrid system recited in claim 6, wherein the switch controller varies an on-duty cycle of the first switch and the second switch on the basis of the current amount signal.

8. The fuel cell hybrid system recited in claim 6, wherein the control unit transfers an analog control signal based upon the performance of the fuel cell stack as indicated by the current amount signal to the dc/dc converter, and

wherein upon receipt of the analog control signal the power conversion efficiency of the dc/dc converter is altered.

9. The fuel cell hybrid system recited in claim 7, wherein the switch controller varies the on-duty cycle of the first switch and the second switch on the basis of the analog control signal.

10. The fuel cell hybrid system recited in claim 9, wherein the control unit changes a voltage value of the analog control signal to set the charging voltage of the rechargeable battery.

11. The fuel cell hybrid system recited in claim 2, wherein at least one of the first distributed resistance and the second distributed resistance is a variable resistance resistor.

12. The fuel cell hybrid system recited in claim 2, wherein both the first distributed resistance and the second distributed resistance are variable resistance resistors.

13. The fuel cell hybrid system recited in claim 1, wherein the rechargeable battery is a lithium-ion rechargeable battery.

14. The fuel cell hybrid system recited in claim 13, wherein the charging voltage of the rechargeable battery is in a range of equal to or less than 4.1 volts and equal to or greater than 4.0 volts.

15. The fuel cell hybrid system recited in claim 13, wherein the lithium-ion rechargeable battery is charged and discharged in a high temperature environment.

16. The fuel cell hybrid system recited in claim 15, wherein the charging voltage of rechargeable battery is in a range of equal to or less than 4.0 volts and equal to or greater than 3.8 volts.

17. The fuel cell hybrid system recited in claim 14, wherein the rechargeable battery is utilized in a cellular phone.

18. The fuel cell hybrid system recited in claim 16, wherein the rechargeable battery is utilized in a navigation system.

19. The fuel cell hybrid system recited in claim 1, wherein the rechargeable battery is a lithium iron phosphate (LFP) rechargeable battery.

20. The fuel cell hybrid system recited in claim 19, wherein the charging voltage of rechargeable battery is in a range of equal to or less than charging voltage 3.6 volts and equal to or greater than 3.4 volts.