Circuit current balancing method and apparatus for battery apparatus

1. A circuit current balancing apparatus of a battery device provided with a plurality of cell stacks respectively composed of at least one cell, the apparatus balancing a circuit current flowing in a circuit connected to each of the plurality of cell stacks, the apparatus comprising:

a comparator for comparing an output voltage of the corresponding cell stack with a voltage of the circuit connected to the corresponding cell stack; and

a current source for adding or subtracting a dummy current to/from a circuit current flowing in the circuit in correspondence with the output of the comparator such that the circuit current is balanced with a circuit current flowing in an adjacent control circuit.

2. The circuit current balancing apparatus of a battery device according to claim 1 , further comprising:

an adder for adding a predetermined offset voltage to the output of the comparator and then providing the added result to the current source.

3. The circuit current balancing apparatus of a battery device according to claim 1 , wherein the comparator includes:

a first comparator for comparing any one of voltages at both ends of the cell stack with any one of voltages at both ends of the circuit;

a second comparator for comparing the other one of voltages at both ends of the cell stack with the other one of voltages at both ends of the circuit; and

an adder for adding outputs of the first and second comparators and then providing the added result to the current source.

4. The circuit current balancing apparatus of a battery device according to claim 3 , wherein the adder executes:

adding a predetermined offset voltage to the output of the first comparator;

adding a predetermined offset voltage to the output of the second comparator; and

adding the added results again.

5. The circuit current balancing apparatus of a battery device according to claim 3 , wherein the adder adds the output of the first comparator, the output of the second comparator, and a predetermined offset voltage.

6. A circuit current balancing method of a battery device provided with a plurality of cell stacks respectively composed of at least one cell, the apparatus balancing a circuit current flowing in a circuit connected to each of the plurality of cell stacks, the method comprising:

comparing an output voltage of the corresponding cell stack with a voltage of the circuit connected to the corresponding cell stack; and

adding or subtracting a dummy current to/from a circuit current flowing in the circuit in correspondence with the output such that the circuit current is balanced with a circuit current flowing in an adjacent control circuit.

7. The circuit current balancing method of a battery device according to claim 6 , further comprising:

adding a predetermined offset voltage to the output to adjust an operation point at which the dummy current is generated.

8. The circuit current balancing method of a battery device according to claim 6 , wherein the comparing step includes:

comparing any one of voltages at both ends of the cell stack with any one of voltages at both ends of the circuit;

comparing the other one of voltages at both ends of the cell stack with the other one of voltages at both ends of the circuit; and

adding both comparison results and then outputting the added result as a final comparison result.

9. The circuit current balancing method of a battery device according to claim 8 , wherein the comparing step adds a predetermined offset voltage to each of the comparison results, adds both added results, and then outputs the re-added result as a final comparison result.

10. The circuit current balancing method of a battery device according to claim 8 , wherein the comparing step adds both comparison results and a predetermined offset voltage and outputs the added result as a final comparison result.