System and method for balancing states of charge of energy storage modules in hybrid vehicles

• US 9,932,029 B2
• Filed: 08/28/2015
• Issued: 04/03/2018
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: Allison Transmission Incorporated (Allison Transmission Holdings Incorporated)
• Original Assignee: Allison Transmission Incorporated (Allison Transmission Holdings Incorporated)
• Inventors: Pruitt, Perry, Biehl, Kurt, Langford, Justin, Kellerman, Jonathan
• Primary Examiner(s): Black, Thomas G
• Assistant Examiner(s): PAIGE, TYLER D
• Application Number:
  US14/838,441
• Publication Number:
  US 20150367836A1
• Time in Patent Office: 949 Days
• Field of Search: 701 22, 320118
• CPC Class Codes: B60L 1/003 to auxiliary motors, e.g. for pumps, compressors
• CPC Class Codes: B60L 15/20 for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed
• CPC Class Codes: B60L 2210/10 DC to DC converters
• CPC Class Codes: B60L 2210/40 DC to AC converters
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2240/423 Torque
• 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 2250/16 by display
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 58/13 Maintaining the SoC within a determined range
• CPC Class Codes: B60L 58/20 having different nominal voltages
• CPC Class Codes: B60L 58/22 Balancing the charge of battery modules
• CPC Class Codes: B60W 10/26 for electrical energy, e.g. batteries or capacitors
• CPC Class Codes: B60W 20/13 in order to stay within battery power input or output limits; in order to prevent overcharging or battery depletion
• CPC Class Codes: H02J 7/0014 Circuits for equalisation of charge between batteries
• CPC Class Codes: H02J 7/0019 using switched or multiplexed charge circuits
• 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: Y10S 903/907 : Electricity storage, e.g. battery, capacitor

Abstract

A system and method for balancing the states of charge between a plurality of energy storage modules in a hybrid vehicle is disclosed. The method comprises determining states of charge of individual energy storage modules in said plurality of energy storage modules operatively connected to a power source in the hybrid electric vehicle. The vehicle is operated using a subset of the plurality of energy storage modules when the states of charge of said subset the plurality of energy storage modules is outside of a tolerances relative to the remaining energy storage modules of said plurality of said energy storage modules. The energy storage modules may be charged or discharged using the method in order to equalize the states of charge of the energy storage modules.

Claims

1. A method, comprising:

using a controller to determine the states of charge of individual energy storage modules of a plurality of energy storage modules, wherein said energy storage modules include multiple individual battery cells electrically connected together, and wherein said energy storage modules include switching devices configured to selectively electrically connect the individual energy storage module to a motor generator in a hybrid electric vehicle;

using the controller to determine states of charge differentials for the individual energy storage modules, wherein the states of charge differentials correspond to differences between the states of charge of the individual energy storage modules;

determining one or more first and one or more second energy storage modules of the plurality of energy storage modules, wherein the first energy storage modules have a corresponding state of charge differential that is greater than a predetermined tolerance;

engaging the switching devices for the first energy storage modules to electrically connect them to the motor generator using the controller;

engaging the switching devices for the second energy storage modules to electrically disconnect them to the motor generator using the controller; and

supplying power to the motor generator by discharging the first energy storage modules and not the second energy storage modules.

2. The method of claim 1, wherein power is supplied to the motor generator using the first one of said energy storage modules until the state of charge of the first energy storage module is within said tolerance relative to the remaining energy storage modules of the plurality of energy storage modules.

3. The method of claim 1, further comprising:

determining that the state of charge of said first energy storage modules have reached a level substantially equal to a second one of said energy storage modules;

supplying power to the motor generator by engaging the switching devices for the second energy storage modules to electrically connect them to the motor generator; and

operating the vehicle using the first and second energy storage modules.

4. The method of claim 3, wherein the hybrid vehicle is operated using the first and second energy storage modules until the states of charge of said first and second energy storage modules is within said tolerance relative to the remaining energy storage modules of the plurality of energy storage modules.

5. The method of claim 1, wherein said vehicle operation uses energy stored in the first energy storage modules to assist in propulsion of the vehicle.

6. The method of claim 1, wherein said vehicle operation at least partially charges the first energy storage modules at a different time than the discharging of the first energy storage modules.

7. The method of claim 6, wherein said vehicle operation comprises using energy collected during regenerative braking to charge the first energy storage modules.

8. The method of claim 1, further comprising:

determining the states of charge of the individual energy storage modules after the vehicle has been operating using said first energy storage modules;

verifying that the states of charge of the first energy storage modules is within the tolerance using the controller; and

operating the vehicle using the first energy storage modules in addition to at least one additional energy storage module.

9. The method of claim 1, wherein an energy storage module controller operatively communicates with a hybrid controller to signal that the subset of the plurality of energy storage modules are ready to be charged or discharged.

10. The method of claim 9, wherein the hybrid controller performs said vehicle operation.

11. The method of claim 1, further comprising:

closing at least one high voltage contactor between the motor generator and at least one of the first energy storage modules using the controller, wherein the switching devices are high voltage contactors responsive to the controller.

12. The method of claim 11, wherein said at least one high voltage contactor is located within the at least one of the first energy storage modules.

13. The method of claim 1, wherein the plurality of energy storage modules are electrically connected to an inverter that is electrically connected to the motor generator.

14. A system for balancing a state of charge of energy storage modules in a hybrid vehicle, comprising:

a plurality of energy storage modules having multiple separate battery cells adapted to store and provide electrical energy to the hybrid electric vehicle;

a motor generator electrically connected to the energy storage modules;

a switching device electrically connected between the motor generator and an energy storage module; and

a controller operatively connected to the energy storage modules, wherein the controller is configured to;

determine states of charge differentials for the individual energy storage modules, wherein the states of charge differentials represent corresponding differences between the states of charge of the individual energy storage modules;

determine one or more first and one or more second energy storage modules of the plurality of energy storage modules, wherein the first energy storage modules have a corresponding state of charge differential that is greater than a predetermined tolerance;

command the switching devices for the first energy storage modules to electrically connect the motor generator to the first energy storage modules; and

command the switching devices for the second energy storage modules to electrically disconnect the motor generator from the second energy storage modules.

15. The system of claim 14, wherein the controller is further configured to operate the hybrid vehicle using the first energy storage modules of said plurality of energy storage modules until the state of charge of the first energy storage modules is within said tolerance relative to the remaining said energy storage modules of said plurality of energy storage modules.

16. The system of claim 14, wherein the controller is further configured to:

determine that the state of charge of said first energy storage modules has reached a level substantially equal to the second energy storage modules; and

command the switching devices for the first and second energy storage modules to electrically connect the motor generator to the first and second energy storage modules.

17. The system of claim 16, wherein the controller is further configured to supply power to the motor generator using the first and second energy storage modules until the states of charge of said first and second energy storage modules is within said tolerance relative to the remaining energy storage modules of said plurality of energy storage modules.

18. The system of claim 14, wherein said vehicle operation uses energy stored in the first energy storage modules to assist in propulsion of the vehicle.

19. The system of claim 14, wherein said vehicle operation at least partially charges the first energy storage modules at a different time than the discharging of the first energy storage modules.

20. The system of any one of claim 19, wherein said vehicle operation comprises using energy collected during regenerative braking to charge the first energy storage modules.

21. The system of claim 14, wherein the controller is further configured to:

determine the states of charge of the individual energy storage modules after the vehicle has been operating using said first energy storage modules;

verify that the states of charge of the first energy storage modules is within the tolerance; and

operate the vehicle using the first energy storage modules in addition to at least one additional energy storage module of the plurality of energy storage modules.

22. The system of claim 14, wherein an energy storage module controller operatively communicates with a hybrid controller to signal that the first energy storage modules are ready to be charged or discharged.

23. The system of claim 22, wherein the hybrid controller performs said vehicle operation.

24. The system of claim 14, wherein the switching devices are high voltage contactors responsive to the controller;

and wherein the controller is further configured to;

close at least one high voltage contactor between the vehicle power source and at least one of the first energy storage modules.

25. The system of claim 24, wherein said at least one high voltage contactor is located within the at least one of the first energy storage modules.

26. The system of claim 14, wherein the plurality of energy storage modules are electrically connected to an inverter that is electrically connected to the motor generator.