Bidirectional current pump for battery charge balancing

• US 5,631,534 A
• Filed: 08/21/1995
• Issued: 05/20/1997
• Est. Priority Date: 08/21/1995
• Status: Expired due to Fees

• Current Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Original Assignee: Delco Electronics Corporation (Motors Liquidation Co. GUC Trust)
• Inventors: Lewis, Dave
• Primary Examiner(s): TSO, EDWARD H
• Application Number:
  US08/517,886
• Time in Patent Office: 638 Days
• Field of Search: 320/6, 320/7, 320/15, 320/16, 320/17, 320/18, 320/14, 320/21, 320/30, 320/43
• US Class Current: 320/103
• CPC Class Codes: H01M 10/441 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 10/482 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H02J 7/0016 using shunting, discharge or bypass circuits
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A battery balancing system for balancing charge among series connected batteries. The battery balancing system includes a series connected battery array having a predetermined number of series connected batteries. A predetermined number of bidirectional charge balancing modules are provided and each respective module is coupled across two consecutive batteries. A controller is connected to each of the batteries for sensing the state of charge of each of the batteries and for providing control output signals that turn on and off and control the current direction flow of the modules to balance charge among batteries. Each module includes first and second series connected switches coupled across two consecutive batteries. Each of the series connected switches have control inputs connected to control outputs of the controller. First and second diodes are respectively coupled across the first and second series connected switches. An inductor is coupled from a point between the first and second series connected switches and a point between the batteries.

Claims

1. A battery balancing system comprising:

a series connected battery array comprising a predetermined number (N) of batteries connected in series;

a predetermined number (N-1) of bidirectional charge balancing modules, each charge balancing module being connected across two consecutive batteries for transferring charge from either of the respective two consecutive batteries to the other; and

a controller connected to each of the bidirectional charge balancing modules for providing control output signals to the bidirectional charge balancing modules to equalize the charge among batteries.

2. A battery balancing system comprising:

a series connected battery array comprising a predetermined number (N) of batteries connected in series;

a predetermined number (N-1) of bidirectional charge balancing modules, and wherein each bidirectional charge balancing module comprises first and second series connected switches coupled across two consecutive batteries, each of the series connected switches having control inputs connected to control outputs of the controller, first and second diodes coupled across respective ones of the first and second series connected switches and an inductor coupled from a point between the first and second series connected switches and a point between the two consecutive batteries;

a controller connected to each of the bidirectional charge balancing modules for providing control output signals that turn on and off and control selected bidirectional charge balancing modules to balance charge among batteries.

3. A battery balancing system comprising:

a series connected battery array comprising a predetermined number (N) of batteries connected in series;

a predetermined number (N-1) of bidirectional charge balancing modules, and wherein each charge balancing module is connected across two consecutive batteries; and

a controller connected to each of the bidirectional charge balancing modules for providing control output signals that turn on and off and control selected bidirectional charge balancing modules to balance charge among batteries, wherein the control output signals provided by the controller comprise pulse width modulated control signals.

4. A charge balancing system for use in balancing charge among series connected batteries, said system comprising:

a controller coupled to each of the batteries for sensing the relative state of charge thereof; and

a predetermined number of bidirectional charge balancing modules coupled to the controller that each comprise;

first and second series connected switches coupled across two consecutive batteries, and wherein each of the series connected switches have control inputs connected to control outputs of the controller;

first and second diodes coupled across respective ones of the first and second series connected switches; and

an inductor coupled from a point between the first and second series connected switches and a point between the batteries; and

wherein the controller turns on and off selected ones of the switches of selected ones of the predetermined number of bidirectional charge balancing modules to transfer charge from relatively high charge batteries to relatively low charge batteries to thereby balance charge among the series connected batteries.

5. The system of claim 4 wherein the control output signals provided by the controller comprise pulse width modulated control signals.

6. A battery balancing module capable of transferring power bidirectionally from one battery to another in response to control signals provided by a controller coupled to each of the batteries that senses the relative state of charge thereof, said module comprising:

first and second series connected switches coupled across two consecutive batteries, and wherein each of the series connected switches have control inputs connected to control outputs of the controller;

first and second diodes coupled across respective ones of the first and second series connected switches; and

an inductor coupled from a point between the first and second series connected switches and a point between the batteries.

7. A battery balancing system comprising:

a series connected battery array comprising a predetermined number (N) of batteries connected in series;

a predetermined number (N-1) of bidirectional charge balancing modules, each charge balancing module being connected across two consecutive batteries and having two switching devices and an intermediate charge storage device, the switching devices being adapted to be turned on and off for transferring charge from either of the respective two consecutive batteries to the other; and

a controller connected to each of the bidirectional charge balancing modules for providing control output signals that turn on and off the switching devices of selected bidirectional charge balancing modules to balance charge among batteries.