التفاصيل البيبلوغرافية
| العنوان: |
POWER SUPPLY SYSTEM AND CONTROL METHOD OF ASSEMBLED BATTERY |
| Document Number: |
20100253284 |
| تاريخ النشر: |
October 7, 2010 |
| Appl. No: |
12/663630 |
| Application Filed: |
October 01, 2007 |
| مستخلص: |
A power supply system comprises: an assembled battery in which a plurality of cells are connected in series and which supplies power from a series circuit of the cells to a device; a power generator that parallely supplies generated power to the assembled battery and the device connected in parallel; a plurality of forced discharge units that cause the plurality of cells to forcibly discharge individually; a cell state detector that detects a state of each cell; and a controller which, when the cell state detector detects that at least one of the plurality of cells is in a first state showing that the cell is not fully charged, causes the cell detected to be in the first state to discharge by means of the forced discharge units until the cell state detector detects that the cell enters a second state having a lower state of charge than the first state. |
| Inventors: |
Aoki, Mamoru (Osaka, JP); Sugiyama, Shigeyuki (Kanagawa, JP); Suzuki, Kohei (Osaka, JP) |
| Claim: |
1. A power supply system, comprising: an assembled battery in which a plurality of cells are connected in series and which supplies power from a series circuit of the cells to a device; a power generator that parallely supplies generated power to the assembled battery and the device connected in parallel; a plurality of forced discharge units that cause the plurality of cells to forcibly discharge individually; a cell state detector that detects a state of each cell; and a controller which, when the cell state detector detects that at least one of the plurality of cells is in a first state showing that the cell is not fully charged, causes the cell detected to be in the first state to discharge by means of the forced discharge units until the cell state detector detects that the cell enters a second state having a lower state of charge than the first state. |
| Claim: |
2. The power supply system according to claim 1, wherein each of the forced discharge units has: a forced discharge circuit in which a series circuit of a resistor and diode is connected with each cell in parallel, wherein the diode is connected in a direction such that discharging current of each cell flows in a forward direction of the diode; and a switch that is connected with the forced discharge circuit in series and opens/closes the connection between the forced discharge circuit and the cell on the basis of a command from the controller. |
| Claim: |
3. The power supply system according to claim 1, wherein the first state is a state where the state of charge of the cell is within the range of 86.5% to 95.5%, and the second state is a state where the state of charge of the cell is within the range of 68.5% to 77.5%. |
| Claim: |
4. The power supply system according to claim 1, wherein the cell state detector detects voltage of each cell as the state of the cell, the first state is a state where the voltage of the cell becomes forced discharge start voltage Va that is set in advance to be lower than voltage obtained when the cell is fully charged, and the second state is a state where the voltage of the cell becomes forced discharge end voltage Vb that is set in advance to be lower than the forced discharge start voltage Va. |
| Claim: |
5. The power supply system according to claim 4, wherein, when the voltage of at least one of the plurality of cells detected by the cell state detector becomes the forced discharge start voltage Va, the controller uses the forced discharge units to cause the cell, whose voltage becomes the forced discharge start voltage Va, to discharge a previously set amount of discharge electricity with a previously set constant current value for a previously set constant period of time, the set amount of discharge electricity being set as an amount of discharge electricity for reducing the voltage of the cell from the forced discharge start voltage Va to the forced discharge end voltage Vb. |
| Claim: |
6. The power supply system according to claim 2, wherein the cell state detector detects voltage of each cell as the state of the cell, the first state is a state where the voltage of the cell becomes forced discharge start voltage Va that is set in advance to be lower than voltage obtained when the cell is fully charged, the second state is a state where the voltage of the cell becomes forced discharge end voltage Vb that is set in advance to be lower than the forced discharge start voltage Va, and, when the voltage of at least one of the plurality of cells detected by the cell state detector becomes the forced discharge start voltage Va, the controller turns on the switch connected with the forced discharge circuit that is connected in parallel with the cell having the forced discharge start voltage Va, during a set time period that is set in advance as a time period for reducing the voltage of the cell from the forced discharge start voltage Va to the forced discharge end voltage Vb by turning the switch on. |
| Claim: |
7. The power supply system according to claim 4, wherein a nonaqueous electrolyte secondary battery is used as the cell. |
| Claim: |
8. The power supply system according to claim 7, wherein a lithium composite oxide that contains cobalt is used as a positive-electrode active material of the nonaqueous electrolyte secondary battery. |
| Claim: |
9. The power supply system according to claim 7, wherein the forced discharge start voltage Va is set within the range of 4.05V to 4.15V per cell. |
| Claim: |
10. The power supply system according to claim 7, wherein the forced discharge end voltage Vb is set within the range of 3.85V to 3.95V per cell. |
| Claim: |
11. The power supply system according to claim 1, wherein the cell state detector detects the state of charge of each cell as the state of the cell, the first state is a state where the state of charge of the cell becomes forced discharge start state Ca that is set in advance to a state of charge at which the cell is not fully charged, and the second state is a state where the state of charge of the cell becomes forced discharge end state Cb that is set in advance to be less than the forced discharge start state Ca. |
| Claim: |
12. The power supply system according to claim 11, wherein, when the state of charge of at least one of the cells detected by the cell state detector becomes the forced discharge start state Ca, the controller uses the forced discharge units to cause the cell, whose state of charge becomes the forced discharge start state Ca, to discharge a previously set amount of discharge electricity with a previously set constant current value for a previously set constant period of time, the set amount of discharge electricity being set as an amount of discharge electricity for reducing the state of charge of the cell from the forced discharge start state Ca to the forced discharge end state Cb. |
| Claim: |
13. The power supply system according to claim 2, wherein the cell state detector detects the state of charge of each cell as the state of the cell, the first state is a state where the state of charge of the cell becomes forced discharge start state Ca that is set in advance to a state of charge at which the cell is not fully charged, the second state is a state where the state of charge of the cell becomes forced discharge end state Cb that is set in advance to be less than the forced discharge start state Ca, and, when the state of charge of at least one of the plurality of cells detected by the cell state detector becomes the forced discharge start state Ca, the controller turns on the switch connected with the forced discharge circuit that is connected in parallel with the cell having the forced discharge start state Ca, during a set time period that is set in advance as a time period for reducing the state of charge of the cell from the forced discharge start state Ca to the forced discharge end state Cb by turning the switch on. |
| Claim: |
14. The power supply system according to claim 13, wherein the cell state detector has: a current detector for detecting charging/discharging current flowing through each cell; and a charge state calculator for calculating the state of charge of the cell by cumulatively adding the charging current and subtracting the discharging current for each of the cells, the charging current and the discharging current being detected by the current detector. |
| Claim: |
15. The power supply system according to claim 14, wherein the current detector has: a plurality of current detection resistors that are connected with the plurality of cells in series; and a current signal detector that acquires voltage between both ends of each of the current detection resistors as a signal indicating the charging/discharging current flowing to the cell, and that the forced discharge circuits are respectively connected in parallel to a plurality of series circuits configured by the cell and the current detection resistor. |
| Claim: |
16. The power supply system according to claim 11, wherein the forced discharge start state Ca is set within the range of 86.5% to 95.5% per cell. |
| Claim: |
17. The power supply system according to claim 11, wherein the forced discharge end state Cb is set within the range of 68.5% to 77.5% per cell. |
| Claim: |
18. A control method of an assembled battery for supplying power to a device from an assembled battery having a plurality of cells connected in series, the control method comprising: a step in which a power generator parallely supplies generated power to the assembled battery and the device; a step in which a cell state detector detects a state of each cell; and a step in which, when the cell state detector detects that at least one of the plurality of cells is in a first state showing that the cell is not fully charged, a controller causes the cell detected to be in the first state to discharge by means of a forced discharge unit until the cell state detector detects that the cell enters a second state having a lower state of charge than the first state. |
| Current U.S. Class: |
320/118 |
| Current International Class: |
02 |
| رقم الانضمام: |
edspap.20100253284 |
| قاعدة البيانات: |
USPTO Patent Applications |