Battery assembly system and electric-motor vehicle system using the same

• US 20030146737A1
• Filed: 01/16/2003
• Published: 08/07/2003
• Est. Priority Date: 01/17/2002
• Status: Active Grant

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Takada, Kanji, Kadouchi, Eiji
• Granted Patent: US 6,984,961 B2
• Time in Patent Office: Days
• US Class Current: 320/132
• CPC Class Codes: B60L 2240/545 Temperature
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 2240/549 Current
• CPC Class Codes: B60L 3/0046 relating to electric energy storage systems, e.g. batteries or capacitors
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 58/14 Preventing excessive discharging
• CPC Class Codes: B60L 58/15 Preventing overcharging
• CPC Class Codes: B60L 58/18 of two or more battery modules
• CPC Class Codes: B60L 58/22 Balancing the charge of battery modules
• CPC Class Codes: H02J 7/0019 using switched or multiplexed charge circuits
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors

Abstract

The battery assembly system 100 includes a battery assembly including a plurality of storage batteries C1 to Cn connected in series, a voltage detector 3 for detecting respectively voltages generated in the storage batteries, a current detector 4 for detecting a current flowing in the plurality of storage batteries, a state-of-charge (SOC) calculator 2 for calculating the state of charge (SOC) of the storage batteries, respectively, based on the voltages detected respectively by the voltage detectors 3 and the current detected by the current detector 4, and a charging/discharging unit 1 for charging or discharging at least one of the plurality of storage batteries so as to equalize the SOC of the storage batteries calculated respectively by the SOC calculator 2.

Claims

1. A battery assembly system comprising

a battery assembly comprising a plurality of storage batteries connected in series,

a voltage detector for detecting respective voltages generated in the storage batteries constituting the battery assembly,

a current detector for detecting a current flowing in the plurality of storage batteries,

a state-of-charge (SOC) calculator for calculating the state of charge (SOC) of the storage batteries, respectively, based on the voltages detected by the voltage detectors, respectively and the current detected by the current detector, and

a charging/discharging unit for charging or discharging at least one of the plurality of storage batteries so as to equalize the SOC of the storage batteries calculated by the SOC calculator, respectively.

2. The battery assembly system according to claim 1, further comprising a multiplexer for connecting any one of the plurality of storage batteries to the voltage detector.

3. The battery assembly system according to claim 2, wherein the voltage detector detects a voltage of each storage battery by switching the multiplexer in succession.

4. The battery assembly system according to claim 2, wherein the multiplexer connects any one of the plurality of storage batteries to the charging/discharging unit.

5. The battery assembly system according to claim 2, wherein the charging/discharging unit charges or discharges each storage battery by switching the multiplexer in succession.

6. The battery assembly system according to claim 1, further comprising a deviation judging unit for judging whether the maximum value of the deviation of the SOC of each storage battery calculated by the SOC calculator exceeds the predetermined value, wherein

when the deviation judging unit judges that the maximum value of the deviation of the SOC of each storage battery exceeds the predetermined value, the charging/discharging unit charges or discharges at least one of the plurality of storage batteries.

7. The battery assembly system according to claim 6, wherein the charging/discharging unit charges or discharges a storage battery in which the deviation of the SOC exceeds the predetermined value.

8. The battery assembly system according to claim 6, wherein the charging/discharging unit charges a storage battery in which the deviation of the SOC is deviated to the negative side and discharges a storage battery in which the deviation of the SOC is deviated to the positive side.

9. The battery assembly system according to claim 6, wherein the predetermined value is 5%.

10. The battery assembly system according to claim 6, wherein the deviation is a deviation with respect to the median value of the SOC of the plurality of storage batteries.

11. The battery assembly system according to claim 1, wherein the charging/discharging unit has {fraction (1/100)} C to {fraction (1/10000)} C of charging/discharging capacity with respect to the capacity of the battery assembly.

12. The battery assembly system according to claim 1, further comprising a deterioration detector for detecting a storage battery with deteriorated performance among the plurality of storage batteries.

13. The battery assembly system according to claim 12, wherein the deterioration detector detects the deteriorated storage battery based on the quantity of charged/discharged electricity that is an accumulation of the quantity of electricity for each storage battery being charged or discharged.

14. The battery assembly system according to claim 13, wherein the deterioration detector detects the deteriorated storage battery based on an elapsed time until the deviation of the SOC exceeds the predetermined value.

15. An electric-motor vehicle system comprising

a battery assembly system according to claim 1,

an engine for generating power to be transmitted to wheels,

a motor provided for assisting the power generated by the engine to be transmitted to the wheels at the time of acceleration of the engine, and

an inverter for supplying the motor with electric power obtained by discharging the battery assembly of the battery assembly system at the time of acceleration of the engine.

16. The electric-motor vehicle system according to claim 15, wherein the motor generates electric power while generating a braking power of the engine at the time of the deceleration of the engine, and the inverter charges the battery assembly with the electric power generated by the motor.

17. The electric-motor vehicle system according to claim 15, wherein the voltage detector detects the voltages while the wheels are moving by the power of engine.

18. The electric-motor vehicle system according to claim 15, further comprising a multiplexer for connecting any one of the plurality of storage batteries to the voltage detector, wherein

the voltage detector detects the voltages by switching the multiplexer at a speed of several millisecond/channel or less when the wheels are moving by the power of engine.

19. The electric-motor vehicle system according to claim 15, wherein the voltage detector finishes detecting voltages of the plurality of storage batteries for such a short time that the load fluctuation of the storage battery falls within 5% or less.

20. The electric motor vehicle system according to claim 15, wherein the voltage detector detects the voltages, respectively, when the wheels are stopping.