PRE-CHARGING VEHICLE BUS USING PARALLEL BATTERY PACKS

• US 20130175857A1
• Filed: 12/12/2012
• Published: 07/11/2013
• Est. Priority Date: 01/09/2012
• Status: Active Grant

• Current Assignee: CPS Technology Holdings, LLC
• Original Assignee: Johnson Controls Technology Company (Johnson Controls International plc)
• Inventors: Elberson, Matthew D., Shreevani, Kogatam, Norppa, Nicholas H.
• Granted Patent: US 9,350,187 B2
• Time in Patent Office: Days
• US Class Current: 307/9.1
• CPC Class Codes: B60L 2200/12 Bikes
• CPC Class Codes: B60L 2200/18 Buses
• CPC Class Codes: B60L 2200/32 Waterborne vessels
• CPC Class Codes: B60L 2200/36 Vehicles designed to transport cargo, e.g. trucks
• CPC Class Codes: B60L 2200/40 Working vehicles
• CPC Class Codes: B60L 2240/12 Speed
• CPC Class Codes: B60L 2240/34 Cabin temperature
• CPC Class Codes: B60L 2240/36 Temperature of vehicle components or parts
• CPC Class Codes: B60L 2240/421 Speed
• 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 2240/662 Temperature
• CPC Class Codes: B60L 2250/16 by display
• CPC Class Codes: B60L 3/0023 Detecting, eliminating, remedying or compensating for drive train abnormalities, e.g. failures within the drive train
• CPC Class Codes: B60L 3/0046 relating to electric energy storage systems, e.g. batteries or capacitors
• CPC Class Codes: B60L 3/0069 relating to the isolation, e.g. ground fault or leak current
• CPC Class Codes: B60L 3/0084 relating to control modules
• CPC Class Codes: B60L 3/04 Cutting off the power supply under fault conditions protective devices and circuit arrangements in general H01H; H02H
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 50/40 : using propulsion power supplied by capacitors
• CPC Class Codes: B60L 50/50 : using propulsion power supplied by batteries or fuel cells
• CPC Class Codes: B60L 50/61 : by batteries charged by engine-driven generators, e.g. series hybrid electric vehicles
• CPC Class Codes: B60L 50/66 : Arrangements of batteries
• CPC Class Codes: B60L 58/15 : Preventing overcharging
• CPC Class Codes: B60L 58/19 : Switching between serial connection and parallel connection of battery modules
• CPC Class Codes: H02J 7/345 : using capacitors as storage or buffering devices
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y02T 10/64 : Electric machine technologies in electromobility
• 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 10/72 : Electric energy management in electromobility
• CPC Class Codes: Y02T 90/16 : Information or communication technologies improving the operation of electric vehicles

Abstract

Systems and methods for pre-charging a bus capacitance in vehicles that receive at least a portion of their motive power from electricity generated from a battery are provided. By way of example, an embodiment includes a vehicle control unit (VCU) that receives battery pack data from a battery management unit (BMU) of each of a plurality of battery packs and determines, based on the battery pack data, which battery packs may be used to pre-charge the bus capacitance in parallel. The VCU issues commands to each of the BMUs to connect pre-charge circuits between each of the plurality of battery packs and the bus capacitance and receives status information from each of the BMUs to determine whether or not the bus capacitance was successfully pre-charged by the battery packs.

Claims

1. A vehicle control system comprising:

a vehicle control unit; and

a plurality of battery packs disposed in parallel and configured to power a bus capacitance of a vehicle deriving at least a portion of its motive power from the plurality of battery packs, wherein each battery pack comprises;

a pre-charge circuit coupled to the battery pack and configured to limit a current flowing from the battery pack;

main contactors configured to electrically couple and decouple the battery pack with the bus capacitance upon receiving an electric signal;

a pre-charge contactor configured to electrically couple and decouple the battery pack with the pre-charge circuit upon receiving an electric signal; and

a battery management unit configured to send data about the battery pack to a vehicle control unit, receive commands from the vehicle control unit, and send signals to the main contactors and the pre-charge contactor based on the commands from the vehicle control unit;

wherein the vehicle control unit is configured to receive battery pack data from the battery management units of the plurality of battery packs and send commands to each battery management unit to pre-charge the bus capacitance with each of the plurality of battery packs at the same time.

2. The vehicle control system of claim 1, wherein the battery management unit of each battery pack operates independently of every other battery management unit of other battery packs.

3. The vehicle control system of claim 1, wherein the vehicle control unit is configured to pre-charge the plurality of battery packs in parallel if a difference in terminal voltages of the battery packs less than or equal to a voltage threshold.

4. The vehicle control system of claim 3, wherein the vehicle control unit is configured to pre-charge with a subset of non-failing battery packs if pre-charging the plurality of battery packs in parallel fails for one or more battery packs.

5. The vehicle control system of claim 1, wherein the vehicle control unit is configured to pre-charge the bus capacitance with each of the plurality of battery packs sequentially if a difference in terminal voltages of the battery packs is greater than a voltage threshold.

6. The vehicle control system of claim 5, wherein the vehicle control unit is configured to pre-charge the bus capacitance with the battery pack that has a highest terminal voltage before pre-charging the bus capacitance with the battery packs with lower terminal voltages when the vehicle is in a mode enabling discharge of the battery packs.

7. The vehicle control system of claim 6, wherein the vehicle control unit is configured to pre-charge with the battery packs with lower terminal voltages if the pre-charge sequence fails for the battery pack that has the highest terminal voltage.

8. The vehicle control system of claim 6, wherein the vehicle control unit is configured to indicate to the driver of the vehicle that the battery packs with the lower terminal voltages need to be charged if the pre-charge sequence succeeds for the battery pack that has the highest terminal voltage and the difference in terminal voltages of the battery packs is still greater than a voltage threshold.

9. The vehicle control system of claim 6, wherein the vehicle control unit is configured to pre-charge with the battery packs with the lower terminal voltages if the pre-charge sequence succeeds for the battery pack that has the highest terminal voltage and the difference in terminal voltages of the battery packs is less than or equal to a voltage threshold.

10. The vehicle control system of claim 5, wherein the vehicle control unit is configured to pre-charge the bus capacitance with the battery pack that has a lowest terminal voltage before pre-charging the bus capacitance with the battery packs with higher terminal voltages when the vehicle is in a charge mode.

11. The vehicle control system of claim 10, wherein the vehicle control unit is configured to pre-charge with the battery packs with higher terminal voltages if the pre-charge sequence fails for the battery pack that has the lowest terminal voltage.

12. The vehicle control system of claim 10, wherein the vehicle control unit is configured to charge the battery pack with the lowest terminal voltage until the difference in terminal voltages of the plurality of battery packs is less than or equal to a voltage threshold if the pre-charge sequence succeeds for the battery pack with the lowest terminal voltage.

13. The vehicle control system of claim 12, wherein the vehicle control unit is configured to perform a pre-charge routine on the battery packs with the higher terminal voltages when the voltage difference of the plurality of battery packs is less than or equal to a voltage threshold.

14. The vehicle control system of claim 1, wherein the vehicle control unit is configured to charge battery packs that have successfully completed a pre-charge routine.

15. The vehicle control system of claim 1, wherein the battery management unit of each battery pack operate independently of every other battery management unit of other battery packs.

16. The vehicle control system of claim 1, wherein the battery management unit determines the pre-charge sequence is complete if the voltage of the bus capacitance is within a percentage range of the battery pack pre-charging the bus capacitance.

17. A method for pre-charging a bus capacitance of a vehicle that receives at least a portion of its motive power from electricity generated from a battery system using a plurality of battery packs disposed in parallel comprising:

receiving battery pack data from a battery management unit of each of the battery packs;

determining, based on the battery pack data, which battery packs may pre-charge the bus capacitance in parallel;

sending commands to the battery management units to begin pre-charging the bus capacitance by closing a pre-charge contactor in each battery pack to electrically couple the battery pack to a pre-charge circuit configured to limit a current flowing from each battery pack to the bus capacitance;

receiving status information from each of the battery management units; and

determining, based on the status information, whether the bus capacitance was successfully pre-charged by the battery packs.

18. The method of claim 17 comprising pre-charging the bus capacitance with the battery packs in parallel if a difference in terminal voltages of the battery packs is less than or equal to a voltage threshold.

19. The method of claim 17 comprising pre-charging the bus capacitance with the battery packs sequentially if a difference in terminal voltages of the battery packs is greater than a voltage threshold.

20. A non-transitory tangible computer-readable medium comprising executable code, the executable code comprising instructions for:

receiving battery pack data from a battery management unit of each of the battery packs;

determining, based on the battery pack data, which battery packs may pre-charge the bus capacitance in parallel;

sending commands to the battery management units to begin pre-charging the bus capacitance by closing a pre-charge contactor in each battery pack to electrically couple the battery pack to a pre-charge circuit configured to limit a current flowing from each battery pack to the bus capacitance;

receiving status information from each of the battery management units; and

determining, based on the status information, whether the bus capacitance was successfully pre-charged by the battery packs.