CHARGE EQUALIZATION APPARATUS

• US 20090237030A1
• Filed: 06/13/2007
• Published: 09/24/2009
• Est. Priority Date: 06/15/2006
• 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 Corporation (SK Innovation Company Limited)
• Inventors: Oh, Jeon Keun, Kim, Chong Eun, Jang, Soo Yeup, Lee, Joong Hui, Moon, Gun Woo, Park, Hong Sun
• Granted Patent: US 7,880,433 B2
• Time in Patent Office: Days
• US Class Current: 320/108
• CPC Class Codes: H02J 7/0016 using shunting, discharge or bypass circuits
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

The present invention relates to a charge equalization apparatus, which allows the primary and secondary windings of a transformer to be easily fabricated, can control the flow of charge to batteries depending on the charged states of series-connected batteries, and can prevent overcurrent from flowing into a battery currently being charged.

Claims

1. A charge equalization apparatus, comprising:

N transformers connected in parallel to N respective 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 control switches each connected between both ends of each of the N transformers;

a redistribution switch connected between a common node of a primary winding of an Nth of the transformers and an Nth of the charge control switches and a ground;

N first semiconductor switching elements connected in series to respective secondary windings of the N transformers; and

a voltage detection and drive signal generation unit configured to detect respective voltages of the N series-connected batteries, and to generate a first drive signal and a second drive signal for driving the charge control switches and the redistribution switch based on the detected voltages.

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

N2, which is identical for the N transformers.

3. The charge equalization apparatus as set forth in claim 2, further comprising:

N inductors each connected between each of the N first semiconductor switching elements and a positive electrode of each of the N batteries; and

N second semiconductor switching elements each connected between a negative electrode of each of the N batteries and a common node of each of the first semiconductor switching elements and each of the inductors.

4. The charge equalization apparatus as set forth in claim 3, wherein the first semiconductor switching elements and the second semiconductor switching elements are each any one of a MOSFET, a BJT, a relay and a diode.

5. The charge equalization apparatus as set forth in claim 4, wherein the first semiconductor switching elements and the second semiconductor switching elements are diodes.

6. The charge equalization apparatus as set forth in claim 5, wherein the charge control switches and the redistribution switch are each any one of a MOSFET, a BJT and a relay.

7. The charge equalization apparatus as set forth in claim 6, wherein the charge control switches and the redistribution switch are N-type MOSFETs.

8. The charge equalization apparatus as set forth in claim 7, 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 time of the charge control switches and the redistribution switch based on the voltages detected by the sensing unit; and

a switch driving circuit unit for generating a first drive signal and a second drive signal for driving the charge control switches and the redistribution switch in response to signals input from the microprocessor.

9. The charge equalization apparatus as set forth in claim 8, wherein the transformers are configured such that a dot formed on each of the primary windings and a dot formed on each of the secondary windings are located on different sides.

10. The charge equalization apparatus as set forth in claim 8, wherein the transformers are configured such that a dot formed on each of the primary windings and a dot formed on each of the secondary windings are located on a same side.

11. A charge equalization apparatus, comprising:

N transformers connected in parallel to N respective series-connected batteries, and configured to each include one primary winding and two secondary windings and to charge batteries, other than the overcharged batteries, with energy discharged from the overcharged batteries;

a first charge storage device and a second charge storage device each connected in parallel to the N series-connected battery and the N transformer;

a first redistribution switch and a second redistribution switch connected in series between the first and second charge storage devices and the N transformers;

charge control switches each connected to both ends of a primary winding of each of the N transformers;

N first semiconductor switching elements each connected to a first secondary winding of each of the N transformers and a positive electrode of each of the N batteries; and

N second semiconductor switching elements each connected to a second secondary winding of each of the N transformers and a positive electrode of each of the N batteries.

12. The charge equalization apparatus as set forth in claim 11, wherein the first semiconductor switching elements and the second semiconductor switching elements are each any one of a MOSFET, a BJT, a relay and a diode.

13. The charge equalization apparatus as set forth in claim 12, wherein the first semiconductor switching elements and the second semiconductor switching elements are diodes.

14. The charge equalization apparatus as set forth in claim 13, wherein the charge control switches, the first redistribution switch and the second redistribution switch are each any one of a MOSFET, a BJT, and a relay.

15. The charge equalization apparatus as set forth in claim 14, wherein the charge control switches, the first redistribution switch and the second redistribution switch are and the redistribution switch are N-type MOSFETs.

16. The charge equalization apparatus as set forth in claim 15, wherein a turns ratio of a primary winding of each of the N transformers to a secondary winding thereof is N1:

N2, which is identical for the first secondary windings and the second secondary windings.

17. The charge equalization apparatus as set forth in claim 16, wherein polarities of the primary windings, the first secondary windings and the second secondary windings are identical to each other.

18. The charge equalization apparatus as set forth in claim 17, wherein a common node of each of the first secondary windings and each of the second secondary windings is connected to a negative electrode of each of the batteries.

19. The charge equalization apparatus as set forth in claim 18, 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 time of the charge control switches and the redistribution switch based on the voltages detected by the sensing unit; and

a switch driving circuit unit for generating a first drive signal and a second drive signal for driving the charge control switches and the redistribution switch in response to signals input from the microprocessor.

20. The charge equalization apparatus as set forth in claim 19, wherein the first charge storage device and the second charge storage device are each any one of a capacitor and a battery.

21. The charge equalization apparatus as set forth in claim 20, wherein the first charge storage device and the second charge storage device are capacitors.