Charge equalization apparatus

• US 8,008,890 B2
• Filed: 02/05/2008
• Issued: 08/30/2011
• Est. Priority Date: 02/09/2007
• Status: Active Grant

• Current Assignee: Korea Advanced Institute of Science and Technology, SK On Company Limited (SK Innovation Company Limited)
• Original Assignee: Korea Advanced Institute of Science and Technology, SK Energy Co Ltd (SK Innovation Company Limited)
• Inventors: Kim, Chol Ho, Oh, Jeon Keun, Kim, Chong Eun, Jang, Soo Yeup, Lee, Joong Hui, Moon, Gun Woo, Park, Hong Sun
• Primary Examiner(s): Tso; Edward
• Assistant Examiner(s): RAMADAN, RAMY O
• Application Number:
  US12/449,312
• Publication Number:
  US 20100007308A1
• Time in Patent Office: 1,302 Days
• Field of Search: None
• US Class Current: 320/118
• CPC Class Codes: H02J 7/0018 using separate charge circuits

Abstract

The present invention relates to a charge equalization apparatus, which can enable the primary windings and the secondary windings of transformers to be easily manufactured, can control the flow of charges into batteries depending on the charged states of series-connected batteries, and can prevent overcurrent from flowing into batteries that are currently being charged.

Claims

1. A charge equalization apparatus, comprising:

N transformers respectively connected in parallel with N series-connected batteries, and configured to store energy, discharged from overcharged batteries, among the N batteries, and to charge batteries other than the overcharged batteries with the stored energy;

N charge/discharge control switching units respectively connected between first ends of primary windings of the N transformers and an anode of a first battery of the N batteries so as to supply a charge, supplied by the N series-connected batteries, to the primary windings of the N transformers;

a redistribution switch connected between a common node of second ends of the primary windings of the N transformers and a ground so as to supply the charge, supplied by the N series-connected batteries, to the primary windings of the N transformers;

N first semiconductor switching devices respectively connected between first ends of secondary windings of the N transformers and anodes of the batteries; and

a voltage detection and drive signal generation unit configured to detect voltages of respective N series-connected batteries, to generate a drive signal, required to drive the charge/discharge control switching units and the redistribution switch, depending on detected voltages, and to control driving of the charge/discharge control switching units and the redistribution switch.

2. The charge equalization apparatus according to claim 1, wherein, in each of the N transformers, a turns ratio of the primary winding to the secondary winding is N1:

N2.

3. The charge equalization apparatus according to claim 2, wherein N1 is greater than N2.

4. The charge equalization apparatus according to claim 3, further comprising:

N inductors respectively connected between the N first semiconductor switching devices and the anodes of the N batteries; and

second semiconductor switching devices connected between cathodes of the N batteries and common nodes of the first semiconductor switching devices and the inductors.

5. The charge equalization apparatus according to claim 4, wherein each of the charge/discharge control switching units comprises:

a charge/discharge control switch driven to prevent a charge supplied by the N series-connected batteries from being supplied to primary windings of transformers connected in parallel with the overcharged batteries and to supply the charge, supplied by the N series-connected batteries, to the batteries other than the overcharged batteries; and

a third semiconductor switching device configured to prevent a charge supplied by the primary windings of the transformers from being supplied to the N series-connected batteries.

6. The charge equalization apparatus according to claim 5, wherein the third semiconductor switching devices are connected between the charge/discharge control switches and the first ends of the primary windings of the transformers, or between the anode of the first battery of the N series-connected batteries and the charge/discharge control switches.

7. The charge equalization apparatus according to claim 6, wherein the transformers are each implemented such that a dot formed on the primary winding and a dot formed on the secondary winding are placed on different sides.

8. The charge equalization apparatus according to claim 6, wherein the transformers are implemented such that a dot formed on the primary winding and a dot formed on the secondary winding are placed on a same side.

9. The charge equalization apparatus according to claim 6, wherein the first semiconductor switching devices, the second semiconductor switching devices, and the third semiconductor switching device are one of Metal Oxide Semiconductor Field Effect Transistors (MOSFETs), Bipolar Junction Transistors (BJTs), relays, and diodes.

10. The charge equalization apparatus according to claim 9, wherein the first semiconductor switching devices, the second semiconductor switching devices and the third semiconductor switching devices are diodes.

11. The charge equalization apparatus according to claim 6, wherein the charge/discharge control switches and the redistribution switch are one of MOSFETs, BJTs, and relays.

12. The charge equalization apparatus according to claim 11, wherein the charge/discharge control switches and the redistribution switch are N-type MOSFETs.

13. The charge equalization apparatus according to claim 1, wherein the voltage detection and drive signal generation unit comprises:

a sensing unit for detecting voltages of the N batteries;

a microprocessor for setting ON/OFF times of the charge/discharge control switches and the redistribution switch depending on the voltages detected by the sensing unit; and

a switch driving circuit unit for generating the drive signal, required to drive both the charge/discharge control switches and the redistribution switch, in response to a signal input from the microprocessor.

14. A charge equalization apparatus, comprising:

N transformers, each having a single primary winding and two secondary windings, the N transformers being respectively connected in parallel with N series-connected batteries so as to charge batteries other than overcharged batteries with energy discharged from the overcharged batteries;

first and second charging devices connected in parallel with the N series-connected batteries;

first and second redistribution switches connected in parallel with the N series-connected batteries, and configured to supply a charge, supplied by the N series-connected batteries, to primary windings of the N transformers;

N charge/discharge control switching units connected between a common node of the first and second redistribution switches and first ends of the primary windings of the transformers so as to supply the charge, supplied by the N series-connected batteries, to the primary windings of the N transformers;

N first semiconductor switching devices respectively connected between first secondary windings of the N transformers and anodes of the batteries;

N second semiconductor switching devices respectively connected between second secondary windings of the N transformers and the anodes of the batteries; and

a voltage detection and drive signal generation unit configured to detect voltages of respective N series-connected batteries, to generate a drive signal, required to drive the charge/discharge control switching units and the redistribution switches, depending on detected voltages and to control driving of the charge/discharge control switching units and the redistribution switches.

15. The charge equalization apparatus according to claim 14, wherein, in each of the N transformers, a turns ratio of the primary winding to the secondary winding is N1:

N2, and the first secondary winding and the second secondary winding have a same number of turns.

16. The charge equalization apparatus according to claim 15, wherein N1 is greater than N2.

17. The charge equalization apparatus according to claim 16, wherein the transformers are each implemented such that a dot formed on the primary winding and dots formed on the first and second secondary windings are placed on a same side.

18. The charge equalization apparatus according to claim 14, wherein the first semiconductor switching devices and the second semiconductor switching devices are one of MOSFETs, BJTs, relays, and diodes.

19. The charge equalization apparatus according to claim 18, wherein the first semiconductor switching devices and the second semiconductor switching devices are diodes.

20. The charge equalization apparatus according to claim 19, wherein the redistribution switches are one of MOSFETs, BJTs, and relays.

21. The charge equalization apparatus according to claim 14, wherein the voltage detection and drive signal generation unit comprises:

a sensing unit for detecting voltages of the N batteries;

a microprocessor for setting ON/OFF times of the charge/discharge control switches and the redistribution switches depending on the voltages detected by the sensing unit; and

a switch driving circuit unit for generating the drive signal, required to drive the charge/discharge control switches and the redistribution switches, in response to a signal input from the microprocessor.