CELL BALANCE DEVICE AND BATTERY SYSTEM

• US 20120139493A1
• Filed: 11/09/2011
• Published: 06/07/2012
• Est. Priority Date: 12/06/2010
• Status: Active Grant

• Current Assignee: Ablic Inc. (MinebeaMitsumi Inc.)
• Original Assignee: SII Semiconductor Corporation
• Inventors: Sakurai, Atsushi, Sano, Kazuaki, Saito, Hiroshi
• Granted Patent: US 9,577,442 B2
• Time in Patent Office: Days
• US Class Current: 320/118
• CPC Class Codes: H02J 7/0016 using shunting, discharge or bypass circuits

Abstract

Provided are a cell balance device with high cell balance performance and high cell balance speed and requiring no high voltage process, and a battery system including the cell balance devices. The cell balance device includes: three terminals to be connected to secondary batteries; one terminal to be connected to a voltage hold device; three switches provided between the three terminals and the one terminal; and a receiving terminal and a transmitting terminal for a synchronization signal. Alternatively, the cell balance device includes: four terminals to be connected to secondary batteries; two terminals to be connected to a voltage hold device; six switches provided between the four terminals and the two terminals; and a receiving terminal and a transmitting terminal for a synchronization signal. The battery system includes: a plurality of secondary batteries; a plurality of voltage hold devices; a plurality of cell balance devices; and a clock generation circuit.

Claims

1. A cell balance device for a battery system for adjusting a cell balance of a plurality of electric accumulators connected in series, the cell balance device comprising:

a plurality of electric accumulator connection terminals to be each connected to one of a node and two terminals of the plurality of electric accumulators connected in series;

a voltage hold device connection terminal to be connected to a voltage hold device;

a plurality of switch circuits provided between the plurality of electric accumulator connection terminals and the voltage hold device;

a receiving terminal for receiving a synchronization signal;

a transmitting terminal for transmitting the synchronization signal; and

a control circuit for controlling ON/OFF of the plurality of switch circuits based on the synchronization signal,

wherein, when receiving the synchronization signal, the control circuit sequentially controls the ON/OFF of the plurality of switch circuits.

2. A cell balance device according to claim 1, wherein:

the plurality of electric accumulator connection terminals comprise a first electric accumulator connection terminal, a second electric accumulator connection terminal, and a third electric accumulator connection terminal;

the plurality of switch circuits comprise a first switch circuit, a second switch circuit, and a third switch circuit;

the first switch circuit is connected between the first electric accumulator connection terminal and the voltage hold device connection terminal;

the second switch circuit is connected between the second electric accumulator connection terminal and the voltage hold device connection terminal;

the third switch circuit is connected between the third electric accumulator connection terminal and the voltage hold device connection terminal; and

the first switch circuit, the second switch circuit, and the third switch circuit are sequentially ON/OFF based on the synchronization signal.

3. A cell balance device according to claim 2, wherein:

the plurality of electric accumulator connection terminals further comprise a fourth electric accumulator connection terminal;

the plurality of switch circuits further comprise a fourth switch circuit, a fifth switch circuit, and a sixth switch circuit;

the voltage hold device connection terminal further comprises a second voltage hold device connection terminal;

the fourth switch circuit is connected between the second electric accumulator connection terminal and the second voltage hold device connection terminal;

the fifth switch circuit is connected between the third electric accumulator connection terminal and the second voltage hold device connection terminal;

the sixth switch circuit is connected between the fourth electric accumulator connection terminal and the second voltage hold device connection terminal; and

the first switch circuit and the fourth switch circuit, the second switch circuit and the fifth switch circuit, and the third switch circuit and the sixth switch circuit are turned ON/OFF sequentially based on the synchronization signal.

4. A cell balance device according to claim 1, wherein the synchronization signal comprises a clock signal.

5. A cell balance device according to claim 1, further comprising:

a reset signal receiving terminal for receiving a first reset signal; and

a reset signal transmitting terminal for transmitting a second reset signal.

6. A cell balance device according to claim 5, wherein the control circuit is further configured to one of transmit, when the receiving terminal receives the synchronization signal, the second reset signal from the reset signal transmitting terminal after a predetermined number of counts of the synchronization signal and transmit, when the reset signal receiving terminal receives the first reset signal, the second reset signal from the reset signal transmitting terminal.

7. A battery system, comprising:

a plurality of electric accumulators connected in series;

a plurality of the cell balance devices according to claim 1 connected in series;

a plurality of voltage hold devices connected in series; and

a clock generation circuit for outputting the synchronization signal,

wherein the plurality of the cell balance devices each comprise electric accumulator connection terminals connected to both terminals of a corresponding one of the plurality of electric accumulators, and the voltage hold device connection terminal connected to one of one terminal and both terminals of a corresponding one of the plurality of voltage hold devices.

8. A battery system according to claim 7, wherein:

the cell balance device at a first stage comprises the receiving terminal connected to an output terminal of the clock generation circuit; and

the cell balance devices at second and subsequent stages each comprise the transmitting terminal connected to the receiving terminal of the cell balance device at a next stage.

9. A battery system according to claim 7, wherein the plurality of the cell balance devices each comprise the receiving terminal connected to an output terminal of the clock generation circuit.

10. A battery system according to claim 7, wherein the clock generation circuit outputs the synchronization signal upon detection that a charger has been connected to external terminals of the battery system.