Charge of equalization apparatus with parallel connection of secondary windings of multiple transformers
View Patent ↗The present invention relates, in general, to a charge equalization apparatus with series-connected battery cells and, more particularly, to a charge equalization apparatus, in which series-connected battery cells (B 1 to BN) are connected in parallel with the primary windings (Mi 1 to M 1 N) of transformers (T 1 to TN), switches (S 1 to SN) for controlling the flow of current of the primary windings are connected in series with the primary windings (M 1 1 to M 1 N), and multiple secondary windings (M 21 to M 2 N) corresponding to the primary windings are connected in parallel with each other.
1. A charge equalization apparatus, comprising:
a plurality of transformers having primary windings and secondary windings wound around the transformers, the primary windings being connected in parallel with batteries, the secondary windings being connected in parallel with each other;
a plurality of first switches respectively connected in series with the primary windings of the transformers and adapted to control flow of current of the primary windings in a first direction or a second direction; a plurality of battery cells connected in series with each other, the battery cells being connected in parallel with the primary windings of the transformers; and
a voltage sensing and switch drive signal generation unit for sensing voltages of the plurality of battery cells, thus turning on/off the plurality of first switches, wherein the charge equalization apparatus is operated such that, when one or more of the first switches are turned on, current flows into one or more primary windings connected to the turned-on first switches in the first direction, so that current is induced in the second windings, and current is induced in the primary windings because of the current induced in the secondary windings, thus enabling equalized charge to be distributed to the plurality of battery cells.
2. The charge equalization apparatus according to claim 1 , wherein the primary windings and secondary windings of the transformers form structures of respective flyback converters.
3. The charge equalization apparatus according to claim 1 , wherein the plurality of transformers have a same turns ratio.
4. The charge equalization apparatus according to claim 1 , wherein the first switches are implemented as one type selected from among Metal-Oxide Semiconductor Field-Effect Transistor (MOSFET) switches, Bipolar Junction Transistor (BJT) switches, and relay switches, and have bidirectionality.
5. The charge equalization apparatus according to claim 1 , further comprising:
a charging means connected in parallel with the parallel-connected secondary windings; and
a second switch interposed between first ends of the parallel-connected secondary windings and the battery, and adapted to control flow of current from the secondary windings to the battery and flow of current from the battery to the secondary windings.
6. The charge equalization apparatus according to claim 1 , further comprising:
a charging means connected in parallel with the parallel-connected secondary windings; and
a current transfer device interposed between first ends of the parallel-connected secondary windings and the battery, and adapted to provide flow of current from the secondary windings to the battery.
7. The charge equalization apparatus according to claim 6 , further comprising:
a second transformer having a primary winding connected to the charging means;
a secondary winding connected to the series-connected battery cells;
a third switch connected in series with the primary winding of the second transformer; and
a second current transfer device interposed between the secondary winding of the second transformer and the battery cells.
8. The charge equalization apparatus according to claim 1 , further comprising a second switch interposed between first ends of the parallel-connected secondary windings and a first end of the series-connected battery cells, and adapted to control flow of current from the secondary windings to the battery cells and flow of current from the battery cells to the secondary windings.
9. The charge equalization apparatus according to claim 1 , further comprising a current transfer device interposed between first ends of the parallel-connected secondary windings and a first end of the series-connected battery cells, and adapted to control flow of current from the secondary windings to the battery cells.
10. A charge equalization apparatus, comprising:
a plurality of transformers, each having a plurality of primary windings and a single secondary winding wound around a single core, the primary windings being connected in parallel with respective battery cells, the secondary windings of the transformers being connected in parallel with each other;
a plurality of first switches connected in series with the primary windings of the transformers and adapted to control flow of current of the primary windings in a first direction or a second direction;
a plurality of battery cells connected in series with each other, the battery cells being connected in parallel with the primary windings of the transformers; and
a voltage sensing and switch drive signal generation unit for sensing voltages of the plurality of battery cells, thus turning on/off the first switches, wherein the charge equalization apparatus is operated such that, when one or more of the first switches are turned on, current flows into one or more primary windings connected to the turned-on first switches in the first direction, so that current is induced in the second windings, and current is induced in the primary windings because of the current induced in the secondary windings, thus enabling equalized charge to be distributed to the plurality of battery cells.
11. The charge equalization apparatus according to claim 10 , wherein the primary windings and secondary windings of the plurality of transformers form structures of respective flyback converters.
12. The charge equalization apparatus according to claim 10 , further comprising:
a charging means connected in parallel with the parallel-connected secondary windings; and
a second switch interposed between first ends of the parallel-connected secondary windings and the battery, and adapted to control flow of current from the secondary windings to the battery and flow of current from the battery to the secondary windings.
13. The charge equalization apparatus according to claim 10 , further comprising:
a charging means connected in parallel with the parallel-connected secondary windings; and
a current transfer device interposed between first ends of the parallel-connected secondary windings and the battery, and adapted to provide flow of current from the secondary windings to the battery.
14. The charge equalization apparatus according to claim 10 , further comprising:
a second transformer having a primary winding connected to the charging means and a secondary winding connected to the series-connected battery cells;
a third switch connected in series with the primary winding of the second transformer; and
a second current transfer device interposed between the secondary winding of the second transformer and the battery cells.
15. The charge equalization apparatus according to claim 10 , further comprising a second switch interposed between first ends of the parallel-connected secondary windings and a first end of the series-connected battery cells, and adapted to control flow of current from the secondary windings to the battery cells and flow of current from the battery cells to the secondary windings.
16. The charge equalization apparatus according to claim 10 , further comprising a current transfer device interposed between first ends of the parallel-connected secondary windings and a first end of the series-connected battery cells, and adapted to control flow of current from the secondary windings to the battery cells.