CHARGE EQUALIZATION APPARATUS WITH PARALLEL CONNECTION OF PRIMARY WINDINGS OF MULTIPLE TRANSFORMERS

• US 20100283433A1
• Filed: 06/12/2007
• Published: 11/11/2010
• 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 8,766,598 B2
• Time in Patent Office: Days
• US Class Current: 320/162
• CPC Class Codes: H02J 7/0016 using shunting, discharge or bypass circuits
• CPC Class Codes: H02J 7/0019 using switched or multiplexed charge circuits
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

The present invention relates, in general, to a charge equalization apparatus for batteries and, more particularly, to a charge equalization apparatus, in which the primary windings (M11 to M1N) of a number of transformers (T1 to TN) corresponding to the number of battery cells are connected in parallel with each other, a switch (S) for controlling the flow of current of the primary windings (M11 to M1N) of the parallel-connected transformers is connected in series with the parallel-connected primary windings, respective secondary windings (M21 to M2N) corresponding to the primary windings are connected in parallel with the battery cells, and the battery cells are connected in series with each other.

Claims

1. A charge equalization apparatus, comprising:

N transformers, each having a primary winding and a secondary winding wound around the transformer, the primary windings of the transformers being connected in parallel with each other, the secondary windings of the transformers being connected in parallel with battery cells;

N first current transfer devices connected in series with the secondary windings of the N transformers, respectively;

N battery cells connected in series with each other, and connected in parallel with the secondary windings of the N transformers, the battery cells being constructed so that a first end of the N series-connected battery cells is connected to first ends of the parallel-connected primary windings of the N transformers;

a first switch connected to the first ends of the parallel-connected primary windings of the N transformers, thus controlling flow of current of the primary windings in a first direction or a second direction; and

a voltage sensing and switch drive signal generation unit for sensing voltages of the N battery cells and turning on/off the first switch,

wherein the charge equalization apparatus is operated such that, when the first switch is turned on, current flows through the primary windings in the first direction, and current is induced in the secondary windings, thus enabling equalized charge to be distributed to the N battery cells.

2. The charge equalization apparatus according to claim 1, wherein the primary windings and the secondary windings of the N transformers form flyback converters.

3. The charge equalization apparatus according to claim 1, wherein the N transformers have a same turns ratio.

4. The charge equalization apparatus according to claim 1, wherein the first switch is a semiconductor switching device.

5. The charge equalization apparatus according to claim 1, wherein the primary windings and the secondary windings of the N transformers are coupled to each other in structures of forward converters, the charge equalization apparatus further comprising N second current transfer devices connected in parallel with the secondary windings of the N transformers, and provided with cathodes connected to cathodes of the first current transfer devices.

6. The charge equalization apparatus according to claim 5, further comprising N inductors interposed between the cathodes of the first current transfer devices and the battery cells, respectively.

7. The charge equalization apparatus according to claim 1, wherein the primary windings and the secondary windings of the N transformers are implemented in structures of half-bridge converters.

8. The charge equalization apparatus according to claim 7, wherein:

the primary windings of the N transformers are respectively wound around first portions of N cores of the N transformers,

the secondary windings of the N transformers are implemented using respective pairs of secondary windings, wound around second portions of the N cores of the N transformers so that the pairs of the secondary windings are connected in parallel with respective battery cells,

the first current transfer devices are implemented using respective pairs of first current transfer devices, connected in series with the pairs of secondary windings, and

the first switch is implemented using a pair of first switches required to control respective pairs of secondary windings.

9. The charge equalization apparatus according to claim 8, wherein the pair of first switches is constructed such that one is connected to first ends of the primary windings connected in parallel with the battery cells, and a remaining one is connected to second ends of the primary windings connected in parallel with the battery cells.