Methods and systems for battery charging management

• US 7,893,658 B2
• Filed: 06/25/2007
• Issued: 02/22/2011
• Est. Priority Date: 06/25/2007
• Status: Active Grant

• Current Assignee: Westinghouse Air Brake Technologies Corporation
• Original Assignee: General Electric Company
• Inventors: Bhardwaj, Ramesh Chandra
• Primary Examiner(s): Tso; Edward
• Assistant Examiner(s): Berhanu; Samuel
• Application Number:
  US11/767,971
• Publication Number:
  US 20080315843A1
• Time in Patent Office: 1,338 Days
• Field of Search: 320/147, 320/150, 320/152
• US Class Current: 320/147
• CPC Class Codes: B60L 2200/26 Rail vehicles
• CPC Class Codes: B60L 3/0046 relating to electric energy storage systems, e.g. batteries or capacitors
• CPC Class Codes: B60L 58/15 Preventing overcharging
• CPC Class Codes: B60L 58/25 by controlling the electric load
• CPC Class Codes: H02J 7/0029 with safety or protection devices or circuits
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: H02J 7/00719 in response to degree of gas development in the battery
• CPC Class Codes: H02J 7/007194 of the battery
• CPC Class Codes: H02J 7/04 Regulation of charging current or voltage
• CPC Class Codes: H02J 7/14 for charging batteries from dynamo-electric generators driven at varying speed, e.g. on vehicle
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

Methods and systems for battery charging are provided. A system includes a battery charger electrically coupled to at least one battery and a plurality of sensors configured to measure a voltage of the battery, a charging current supplied to the battery, and a temperature of the battery wherein the battery charger is configured to determine a state of charge of the battery using at least one of the plurality of sensors to control gassing of the battery during charging.

Claims

1. A battery charging system for a vehicle, said system comprising:

a battery charger electrically coupled to at least one battery; and

a plurality of sensors including at least one sensor configured to measure a voltage of the battery, at least one sensor configured to measure a charging current supplied to the battery, and at least one sensor configured to measure a temperature of the battery;

wherein said battery charger is configured to;

to provide charging current to the battery at a substantially constant voltage;

determine a state of charge of the battery using at least one of the plurality of sensors;

determine a rate of gassing of the battery using the temperature and the charging current; and

reduce a charging rate of the battery when the determined rate of gassing exceeds a predetermined rate of gassing.

2. A system in accordance with claim 1 wherein said battery charger is configured to provide charging current to the battery at a substantially constant voltage wherein the voltage is corrected using the measured temperature of the battery.

3. A system in accordance with claim 1 wherein said battery charger is further configured to:

determine a state of charge of the battery using the charging current; and

stop the battery charge when the determined state of charge substantially equals a predetermined state of charge.

4. A system in accordance with claim 1 wherein said battery charger further comprises a battery voltage sensor configured to measure the open circuit voltage of the battery and wherein said battery charger is further configured to determine a state of charge of the battery using the battery voltage sensor.

5. A system in accordance with claim 4 wherein said battery charger is configured to:

temporarily suspend the battery charge;

measure the open circuit voltage of the battery after a predetermined amount of time;

determine the state of charge of the battery using the measured open circuit voltage;

if the state of charge is less than a predetermined state of charge, resume the battery charge for a predetermined period of time;

iteratively determine the state of charge of the battery until the state of charge is equal to of greater than the predetermined state of charge.

6. A system in accordance with claim 1 wherein said battery charger is configured to determine a state of charge using a change of charging current over a predetermined period of time.

7. A system in accordance with claim 1 wherein said battery charger is configured to measure the temperature of a surface of the battery using a temperature sensor in contact with the surface of the battery.

8. A method of charging a battery, said method comprising:

providing a charging current to the battery from a battery charger at a substantially constant voltage determined by a measured temperature of the battery;

determining a state of charge of the battery using the provided charging current;

determining a rate of gassing of the battery using the temperature and the charging current; and

reducing a charging rate of the battery when the determined rate of gassing exceeds a predetermined rate of gassing; and

stopping charging of the battery when the determined state of charge of the battery substantially equals a predetermined state of charge of the battery.

9. A method in accordance with claim 8 wherein determining a state of charge of the battery using the charging current comprises determining a change of charging current over a predetermined period of time.

10. A method in accordance with claim 8 wherein providing charging current to the battery comprises adjusting a voltage output level of the battery charger to deliver a charging current to the battery wherein the level of charging current is at least partially determined by the state of charge of the battery.

11. A method in accordance with claim 8 further comprising measuring the temperature of a surface of the battery.

12. A method in accordance with claim 8 further comprising measuring the temperature of an internal surface of the battery.

13. A method in accordance with claim 8 further comprising:

temporarily suspending the battery charge;

measuring the open circuit voltage of the battery;

determining a state of charge of the battery using the measured open circuit voltage;

if the state of charge is less than a predetermined state of charge, resuming the battery charge for a predetermined period of time;

iteratively determining the state of charge of the battery until the state of charge is equal to or greater than the predetermined state of charge.