BATTERY CELL BALANCING CIRCUIT USING LC SERIAL RESONANCE

• US 20150340886A1
• Filed: 03/20/2013
• Published: 11/26/2015
• Est. Priority Date: 01/18/2013
• Status: Active Grant

• Current Assignee: Postech Academy-Industry Foundation
• Original Assignee: Postech Academy-Industry Foundation
• Inventors: SUNG, Chang Hyeon, LEE, Kyung Min, CHUNG, Yoo Chae, KANG, Bong Koo
• Granted Patent: US 9,793,725 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01M 10/441 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 2010/4271 Battery management systems including electronic circuits, e.g. control of current or voltage to keep battery in healthy state, cell balancing
• 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 to a technology capable of improving the use time of a battery cell by generally or individually controlling charge or discharge with respect to a multi-battery cell by using LC serial resonance in a module with a multi-battery cell structure. To this end, the present invention includes a battery module including a plurality of serially connected battery cells, a serial resonant circuit including serially connected inductor and capacitor and performing a serial resonant function, and first to third switch units that set an electric energy collection path and an electric energy supply path between the battery module and the serial resonant circuit.

Claims

1. A battery cell balancing circuit using LC serial resonance and performing battery cell balancing, comprising:

a battery module including a plurality of serially connected battery cells;

a serial resonant circuit including serially connected inductor and capacitor and performing a serial resonant function;

a first switch unit including a plurality of switches each connected between each terminal of the plurality of battery cells and a first common node in order to provide a path for collecting electric energy charged in one or more battery cells of the plurality of battery cells and storing the electric energy in the capacitor, or for supplying the electric energy collected and stored in the capacitor to the one or more battery cells;

a second switch unit including a plurality of switches each connected between each terminal of the plurality of battery cells and a second common node in order to provide the path for supplying the electric energy collected and stored in the capacitor to the one or more battery cells, or for collecting the electric energy charged in the one or more battery cells; and

a third switch unit including a plurality of switches connected between the first common node and both terminals of the serial resonant circuit and switches connected between the second common node and both terminals of the serial resonant circuit in order to provide the path for collecting the electric energy charged in the one or more battery cells of the plurality of battery cells, or for supplying the electric energy collected and stored in the capacitor to the one or more battery cells.

2. The battery cell balancing circuit using LC serial resonance according to claim 1, wherein each switch of the first to third switch units includes one or more of a SPST (Single Pole Single Throw) and a MOS transistor.

3. The battery cell balancing circuit using LC serial resonance according to claim 2, wherein the MOS transistor is decided as an N channel MOS transistor or a P channel MOS transistor according to a direction of a current flowing through the MOS transistor.

4. The battery cell balancing circuit using LC serial resonance according to claim 1, wherein the plurality of switches included in the first switch unit include switches each having one side terminal connected to each terminal of the plurality of battery cells and the other side terminal commonly connected to the first common node.

5. The battery cell balancing circuit using LC serial resonance according to claim 1, wherein the plurality of switches included in the second switch unit include switches each having one side terminal connected to each terminal of the plurality of battery cells and the other side terminal commonly connected to the second common node.

6. The battery cell balancing circuit using LC serial resonance according to claim 1, wherein the plurality of switches included in the third switch unit include switches connected in parallel to one another between the first common node and both end terminals of the serial resonant circuit and switches connected in parallel to one another between the second common node and both end terminals of the serial resonant circuit.

7. The battery cell balancing circuit using LC serial resonance according to claim 1, wherein capacity of each of the plurality of battery cells is larger than capacity of the capacitor of the serial resonant circuit by a predetermined value or more.

8. A battery cell balancing circuit using LC serial resonance, comprising:

a battery module including a plurality of serially connected battery cells;

a serial resonant circuit including serially connected inductor and capacitor and performing a serial resonant function;

a first switch unit including a plurality of MOS transistors and reverse current blocking diodes connected between each terminal of the plurality of battery cells and a first common node in order to provide the path for collecting electric energy charged in one or more battery cells of the plurality of battery cells and storing the electric energy in the capacitor, or for supplying the electric energy collected and stored in the capacitor to the one or more battery cells, each MOS transistor and each diode being connected in parallel to each other;

a second switch unit including a plurality of MOS transistors and reverse current blocking diodes connected between each terminal of the plurality of battery cells and a second common node in order to provide a path for supplying the electric energy collected and stored in the capacitor to the one or more battery cells, or for collecting the electric energy charged in the one or more battery cells, each MOS transistor and each diode being connected in parallel to each other; and

a third switch unit including MOS transistors and reverse current blocking diodes connected between the first common node and both terminals of the serial resonant circuit and MOS transistors and reverse current blocking diodes connected between the second common node and both terminals of the serial resonant circuit in order to provide the path for collecting the electric energy charged in the one or more battery cells of the plurality of battery cells, or for supplying the electric energy collected and stored in the capacitor to the one or more battery cells, each MOS transistor and each diode being connected in parallel to each other.

9. The battery cell balancing circuit using LC serial resonance according to claim 8, wherein each reverse current blocking diode is connected between one side terminal and the other side terminal of each MOS transistor.

10. A battery cell balancing circuit using LC serial resonance and performing battery cell balancing, comprising:

a battery module including a plurality of serially connected battery cells;

a serial resonant circuit including serially connected inductor and capacitor and performing a serial resonant function;

a first switch unit including a plurality of switch paths connected between some of terminals of the plurality of battery cells and a first common node in order to provide a path for collecting electric energy charged in an arbitrary cell of the plurality of battery cells, or for supplying the electric energy collected and stored in the capacitor to the arbitrary cell battery cell, the plurality of switch paths each including two serially connected MOS transistors each connected in parallel to diodes;

a second switch unit including a plurality of switch paths connected between remaining terminals, other than some of terminals of the plurality of battery cells, and a second common node in order to provide the path for supplying the electric energy collected and stored in the capacitor to the arbitrary cell, or for collecting the electric energy charged in the arbitrary cell, the plurality of switch paths each including two serially connected MOS transistors each connected in parallel to diodes; and

a third switch unit including switch paths connected between the first common node and both terminals of the serial resonant circuit and switch paths connected between the second common node and both terminals of the serial resonant circuit in order to provide the path for collecting the electric energy charged in the arbitrary cell of the plurality of battery cells, or for supplying the electric energy collected and stored in the capacitor to the arbitrary cell, the plurality of switch paths each including two serially connected MOS transistors each connected in parallel to diodes.

11. The battery cell balancing circuit using LC serial resonance according to claim 10, wherein the plurality of switch paths of the first switch unit comprise:

a first switch path connected between one side terminal of a first battery cell and the first common node;

a third switch path connected between one side terminal of a third battery cell and the first common node; and

a fifth switch path connected between the other side terminal of a fourth battery cell and the first common node.

12. The battery cell balancing circuit using LC serial resonance according to claim 10, wherein the plurality of switch paths of the second switch unit comprise:

a second switch path connected between one side terminal of a second battery cell and the second common node;

a fourth switch path connected between one side terminal of a fourth battery cell and the second common node.

13. A battery cell balancing circuit using LC serial resonance and performing battery cell balancing, comprising:

a battery module including a plurality of serially connected battery cells;

a serial resonant circuit including an inductor and a capacitor serially connected between a first common node and a second common node and performing a serial resonant function;

a first switch unit including a plurality of switches each connected between each terminal of the plurality of battery cells and a first common node in order to provide a path for collecting electric energy charged in one or more battery cells of the plurality of battery cells and storing the electric energy in the capacitor, or for supplying the electric energy collected and stored in the capacitor to the one or more battery cells; and

a second switch unit including a plurality of switches each connected between each terminal of the plurality of battery cells and a second common node in order to provide the path for supplying the electric energy collected and stored in the capacitor to the one or more battery cells, or for collecting the electric energy charged in the one or more battery cells.

14. The battery cell balancing circuit using LC serial resonance according to claim 13, wherein the plurality of switch paths of the first switch unit each include two serially connected MOS transistors, and the two MOS transistors each are connected in parallel to diodes.

15. The battery cell balancing circuit using LC serial resonance according to claim 13, wherein the plurality of switch paths of the second switch unit each include two serially connected MOS transistors, and the two MOS transistors each are connected in parallel to diodes.

16. The battery cell balancing circuit using LC serial resonance according to claim 13, wherein a switch is connected in parallel to the capacitor of the serial resonant circuit in order to reset charge remaining in the capacitor after a resonance operation of the serial resonant circuit.