Battery charging device having time shared charging cycle

• US 5,726,551 A
• Filed: 10/21/1996
• Issued: 03/10/1998
• Est. Priority Date: 10/19/1995
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Kaneko, Satoru, Masaki, Ryoso, Horiba, Tatsuo, Miyazaki, Taizou
• Primary Examiner(s): TSO, EDWARD H
• Application Number:
  US08/734,072
• Time in Patent Office: 505 Days
• Field of Search: 320/6, 320/8, 320/12, 320/13, 320/15, 320/21, 320/22, 320/30, 320/61, 320/65, 320/64
• US Class Current: 320/124
• CPC Class Codes: B60L 50/51 characterised by AC-motors
• CPC Class Codes: B60L 53/11 DC charging controlled by the charging station, e.g. mode 4
• CPC Class Codes: B60L 53/12 Inductive energy transfer
• CPC Class Codes: B60L 53/57 Charging stations without connection to power networks
• CPC Class Codes: H02J 7/0018 using separate 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
• CPC Class Codes: Y02T 90/12 Electric charging stations
• CPC Class Codes: Y02T 90/14 Plug-in electric vehicles

Abstract

A battery charging unit is provided with a charge controlling unit which is designed to perform at least one of rest mode operating function which causes to rest charging for respective battery, groups and discharge mode operating function which causes to discharge electric power from the respective battery groups in addition to charge mode operating function for the respective battery groups, the battery charging unit controls charging for the respective battery groups through the charge controlling unit while repeating at least two modes including the charging mode among the charging mode, rest mode and discharge mode in a predetermined time cycle and further performs a mutual control between the respective battery groups so that at least one battery group is placed in the rest mode in a predetermined sequence during the operation thereof, thereby, drawbacks of a conventional pulse like charging and burp charging, which are suitable for a quick charging but requires a large instantaneous charging current which causes the size increse of the charging unit and the electric circuit concerned, are eliminated.

Claims

1. A battery charging device for a plurality of battery groups connected in series, the series connection of the plurality of battery groups being connected across an electric load, comprising:

a plurality of battery charging units, each being coupled to one of said plurality of battery groups for charging the same; and

a common battery charging control unit which controls said plurality of battery charging units to effect a charge cycle having a charging mode, short discharge mode and rest mode in a time sharing manner, wherein at least any one of said plurality of battery groups is placed in the rest mode in every moment of the charging operation for said plurality of battery groups.

2. A battery charging device of the type in which a battery arrangement comprising a plurality of battery groups which are electrically connected to each other is charged by repeating a charge cycle comprising at least a charging mode, in which a charging current flows to said battery arrangement, and a rest period in which no current flows, said charging device comprising:

a plurality of charging circuits, each of which is coupled to charge a different battery group of said battery arrangement; and

a charge controlling unit for controlling each of said charging circuits to charge the battery group to which it is coupled, according to said charge cycle, said charge cycles for said respective charging circuits being time staggered, whereby each of said charging circuits is sequentially placed in said rest mode while other charging circuits are in said charging mode, according to a predetermined operating sequence.

3. A battery charging device for charging a plurality of battery groups connected in series, the series connection of said plurality of battery groups being connected across an electric load, comprising:

a plurality of battery charging units, each being coupled to one of said plurality of battery groups for charging the same; and

a charge controlling unit having an output coupled to each of said battery charging units;

wherein said charge controlling unit causes each of said charging units to perform a charge cycle comprising at least a charging phase and rest phase for said plurality of battery charging units, in a time sharing manner in which the rest phase is implemented successively and sequentially in said plurality of battery charging units.

4. A battery charging device according to claim 3, wherein said charge controlling unit controls the charging quantity for said respective battery groups depending on the charged condition thereof.

5. A battery charging device according to claim 3 further comprising:

a transformer having a primary winding and a plurality of secondary windings and a changing-over means which independently connects and disconnects outputs of the respective secondary windings for the corresponding battery groups.

6. A battery charging device according to claim 5 further comprising a frequency converter connected to the primary winding of said transformer.

7. Battery charging device, according to claim 3 wherein said charge cycle comprises a charging phase, a relatively shorter discharge phase and a rest phase.

8. Battery charging device, according to claim 3 wherein said electric load comprises a unit for driving an electric vehicle.

9. An electric vehicle comprising:

a transformer having a primary winding coupled to an energy source and a plurality of secondary windings;

a plurality of battery groups connected in series, each being coupled to a respective one of the plurality of secondary windings and the series connection of said plurality of battery groups being connected across an electric load for driving the electric vehicle; and

a battery charging device which charges said plurality of battery groups, and includes

a plurality of battery charging units, each being coupled to one of said plurality of battery groups for charging the same; and

a charge controlling unit having an output coupled to each of said battery charging units;

wherein said charge controlling unit causes each of said charging units to perform a charge cycle comprising a charging phase and a rest phase for said plurality of battery charging units, in a time sharing manner in which the rest phase is implemented successively and sequentially in said plurality of battery charging units.

10. An electric vehicle according to claim 9, wherein said charge controlling unit controls the charging quantity for said respective battery groups depending on the charged condition thereof.

11. Electric vehicle according to claim 9 wherein said charge cycle comprises a charging phase, a relatively shorter discharge phase and a rest phase.

12. A fuel cell-battery hybrid type electric vehicle comprising:

a fuel cell;

a plurality of battery groups connected in series, the series connection of said plurality of battery groups being connected across an electric load for driving the electric vehicle;

a battery charging device which is fed from said fuel cell, charges said plurality of battery groups, and includes

a plurality of battery charging units, each being coupled to one of said plurality of battery groups for charging the same; and

a charge controlling unit having an output coupled to each of said battery charging units;

wherein said charge controlling unit causes each of said charging units to perform a charge cycle comprising a charging phase and a rest phase for said plurality of battery charging units, in a time sharing manner in which the rest phase is implemented successively and sequentially in said plurality of battery charging units.

13. An electric vehicle according to claim 12, wherein said charge controlling unit controls the charging quantity for said respective battery groups depending on the charged condition thereof.

14. An electric vehicle according to claim 12 wherein said battery charging unit further includes a transformer having a primary winding and a plurality of secondary windings and a changing-over means which independently connects and disconnects outputs of the respective secondary windings for the corresponding battery groups.

15. Electric vehicle according to claim 12 wherein said charge cycle comprises a charging phase, a relatively shorter discharge phase and a rest phase.

16. An engine-battery hybrid type electric vehicle comprising:

an engine generator;

a plurality of battery groups connected in series, the series connection of said plurality of battery groups being connected across an electric load for driving the electric vehicle; and

a battery charging device which is fed from said engine generator, charges said plurality of battery groups and includes

a plurality of battery charging units, each being coupled to one of said plurality of battery groups for charging the same; and

a charge controlling unit having an output coupled to each of said battery charging units;

wherein said charge controlling unit causes each of said charging units to perform a charge cycle comprising a charging phase and a rest phase for said plurality of battery charging units, in a time sharing manner in which the rest phase is implemented successively and sequentially in said plurality of battery charging units.

17. An engine-battery hybrid type electric vehicle according to claim 16, wherein said charge controlling unit controls the charging quantity for said respective battery groups depending on the charged condition thereof.

18. Electric vehicle according to claim 16 wherein said charge cycle comprises a charging phase, a relatively shorter discharge phase and a rest phase.