Design of a Large battery pack for a hybrid locomotive

• US 20050269995A1
• Filed: 05/17/2005
• Published: 12/08/2005
• Est. Priority Date: 05/17/2004
• Status: Active Grant

• Current Assignee: Railpower, LLC
• Original Assignee: Railpower Technologies Corp.
• Inventors: Swan, David Herman, Donnelly, Frank Wegner, Watson, John David
• Granted Patent: US 7,507,500 B2
• Time in Patent Office: Days
• US Class Current: 320/150
• CPC Class Codes: B60L 2200/26 Rail vehicles
• 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 3/0046 relating to electric energy storage systems, e.g. batteries or capacitors
• CPC Class Codes: B60L 50/64 Constructional details of batteries specially adapted for electric vehicles
• CPC Class Codes: B60L 53/80 Exchanging energy storage elements, e.g. removable batteries
• CPC Class Codes: B60L 58/13 Maintaining the SoC within a determined range
• CPC Class Codes: B60L 58/14 Preventing excessive discharging
• CPC Class Codes: B60L 58/15 Preventing overcharging
• CPC Class Codes: B60L 58/22 Balancing the charge of battery modules
• CPC Class Codes: B60L 58/25 by controlling the electric load
• CPC Class Codes: B60L 58/26 by cooling
• CPC Class Codes: H01M 10/06 Lead-acid accumulators semi-lead accumulators H01M10/20
• CPC Class Codes: H01M 10/4207 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: H01M 10/486 for measuring temperature
• CPC Class Codes: H01M 10/613 Cooling or keeping cold
• CPC Class Codes: H01M 10/625 Vehicles
• CPC Class Codes: H01M 10/635 based on ambient temperature
• CPC Class Codes: H01M 10/647 : Prismatic or flat cells, e.g. pouch cells
• CPC Class Codes: H01M 10/6557 : arranged between the cells
• CPC Class Codes: H01M 10/6563 : with forced flow, e.g. by blowers
• CPC Class Codes: H01M 50/574 : Devices or arrangements for the interruption of current
• CPC Class Codes: H01M 50/578 : in response to pressure
• CPC Class Codes: H01M 50/581 : in response to temperature
• CPC Class Codes: H02J 7/0016 : using shunting, discharge or bypass circuits
• CPC Class Codes: H02J 7/007192 : in response to temperature
• CPC Class Codes: Y02E 60/10 : Energy storage using batteries
• 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

The present invention is directed to systems for prolonging battery life, such as maintaining battery cell temperatures in battery packs within specified limits, providing vibration and shock resistance, and/or electrically isolating groups of batteries from nearby conductive surfaces.

Claims

1. A method for operating a battery pack, comprising:

providing a battery pack, the battery pack comprising a plurality of battery cells, the battery cells being electrically connected in series; and

during battery pack charging and energy removal, maintaining an internal temperature in each of the battery cells within about 5°

C. of one another.

2. The method of claim 1, wherein the maintaining step comprises:

passing a cooling gas through the battery pack to remove thermal energy from the battery cells.

3. The method of claim 2, wherein the cooling gas is forced by at least one fan through an enclosure containing at least a portion of the battery pack.

4. The method of claim 3, wherein the cooling gas is passed through the enclosure along a first flow path and wherein the cooling gas is passed through an isolation container along a second different flow path and wherein the isolation container contains a plurality of battery cells.

5. The method of claim 4, wherein the isolation container comprises at least one fan positioned in an air passage, the air passage being in communication with the first and second flow paths.

6. The method of claim 3, wherein the isolation container comprises at least first and second passageways along opposing first and second surfaces of the battery cells.

7. The method of claim 3, wherein the opposing sides of the battery cells are spaced from adjacent sides of the isolation container.

8. The method of claim 1, further comprising:

inhibiting a flow of thermal energy from top and bottom surfaces of the battery cells and/or from opposing ends of the battery cells while allowing a flow of thermal energy from opposing side surfaces of the battery cells.

9. In a battery pack comprising a plurality of battery cells, the battery pack being in an enclosure having at least one air input for drawing in air at a first flow rate, comprising:

(a) determining an ambient air temperature outside of the enclosure; and

(b) performing at least one of the following steps;

(b1) when the ambient air temperature is above a first temperature set point, reducing, relative to the first flow rate, an amount of air being drawn into the enclosure; and

(b2) when the ambient air temperature is below a second temperature set point, reducing, relative to the first flow rate, an amount of air being drawn into the enclosure.

10. The method of claim 9, wherein step (b1) is performed.

11. The method of claim 10, wherein a shutter is closed over the at least one air input.

12. The method of claim 10, wherein a fan positioned in the at least one air input is turned off.

13. The method of claim 9, wherein step (b2) is performed.

14. The method of claim 13, wherein a shutter is closed over the at least one air input.

15. The method of claim 13, wherein a fan positioned in the at least one air input is turned off.

16. In a battery pack comprising a plurality of battery cells, the battery pack being in an enclosure having at least one air input for drawing in air at a first flow rate, comprising:

(a) determining a temperature at a point within the enclosure; and

(b) when the determined temperature is above a temperature set point, performing at least one of the following steps;

(b1) reducing, relative to the first flow rate, an amount of air being drawn into at least a portion of the enclosure;

(b2) controlling a molecular oxygen level in at least a portion of the enclosure; and

(b3) introducing an inert and/or non flammable gas or a liquid into at least a portion of the enclosure to lower the temperature in the at least a portion of the enclosure.

17. The method of claim 16, wherein step (b1) is performed.

18. The method of claim 17, wherein a shutter is closed over the at least one air input.

19. The method of claim 17, wherein a fan positioned in the at least one air input is turned off.

20. The method of claim 16, wherein step (b2) is performed.

21. The method of claim 20, wherein the molecular oxygen is removed by combustion of a fire suppressant material and/or fire retardant material.

22. The method of claim 20, wherein an inert gas is introduced into the at least a portion of the enclosure.

23. The method of claim 20, wherein a fire retardant material is introduced into the at least a portion of the enclosure.

24. The method of claim 16, wherein step (b3) is performed.

25. The method of claim 24, wherein the liquid is vaporizable.

26. The method of claim 24, wherein the liquid is water.

27. A battery pack assembly, comprising:

a plurality of battery cells, the plurality of battery cells being connected in series;

an enclosure enclosing the plurality of battery cells;

at least one air input and at least one air output in the enclosure; and

a fan positioned in at least one of the at least one air input and at least one air output.

28. The battery pack assembly of claim 27, wherein a shutter operatively engages each of the air input and air output, wherein the shutter is positionable between an open position in which air passes freely through the respective one of the air input and output and a closed position in which air does not pass freely through the respective one of the air input and output.

29. The battery pack assembly of claim 27, wherein the enclosure is an isolation container.

30. The battery pack assembly of claim 29, wherein isolation container comprises first and second passageways for the air, the first and second passageways being positioned along opposing sides of the battery cells.

31. The battery pack assembly of claim 30, wherein each battery cell comprises a plurality of plate pairs and wherein the plate pairs are at least substantially normal to the direction of air flow in the passageways.

32. The battery pack assembly of claim 29, wherein the isolation container is movably positioned on a module frame.

33. The battery pack assembly of claim 29, wherein the battery cells operatively engage first and second clamps, the first and second clamps engaging the isolation container and centering the battery cells in the isolation container and substantially isolating the battery cells from shock and vibration and inhibiting shorting of battery cells with a conductive surface of the isolation container.

34. The battery pack assembly of claim 33, wherein at least one of the first and second clamps comprise an electrically insulating, fire resistant, and/or fire suppressant material.

35. The battery pack assembly of claim 33, wherein an end of at least some of the battery cells are in contact with a thermally insulating material.

36. The battery pack assembly of claim 27, further comprising a hood surrounding the isolation container, the hood comprising at least one air input and at least one air output, the at least one air input and at least one air output of the hood being in fluid communication with the at least one air input and at least one air output of the isolation container.

37. A battery pack assembly, comprising:

a plurality of battery cells, the plurality of battery cells being connected in series;

an enclosure enclosing the plurality of battery cells;

at least one air input and at least one air output in the enclosure; and

a shutter operatively engaging each of the at least one air input and at least one air output, wherein the shutter is positionable between an open position in which air passes freely through the respective at least one air input and air output and a closed position in which air does not pass freely through the respective at least one air input and air output.

38. The battery pack assembly of claim 37, further comprising:

a fan positioned in at least one of the air input and air output.

39. The battery pack assembly of claim 38, wherein, when the fan is off, the shutter in the at least one of the air input and air output is closed and, when the fan is on, the shutter in the at least one of the air input and air output is open.

40. A battery pack assembly, comprising:

a plurality of battery cells;

a battery rack; and

a plurality of isolation containers supportably mounted on and movably engaging the battery rack, each isolation container comprising a number of battery cells.

41. The battery pack assembly of claim 40, wherein each isolation container comprises at least one of the following features:

(i) an airflow path passing through the isolation container to remove thermal energy from the enclosed battery cells;

(ii) a shock and vibration absorption assembly to substantially maintain shock and vibration levels within predetermined maximum values; and

(iii) an electrical isolation assembly to substantially inhibit contact of at least a portion of each battery cell with a conductive surface of at least one of the isolation container and battery rack.

42. The battery pack of claim 41, wherein each isolation container includes feature (i) and a surface of the airflow path is provided by a surface of the outer casings of the enclosed battery cells.

43. The battery park of claim 42, wherein each isolation container includes an air input and output and wherein the air input and output are located on differing surfaces of the isolation container to provide the airflow path.

44. The battery pack of claim 43, wherein the isolation container comprises a fan positioned in the airflow path.

45. The battery pack of claim 43, wherein in each battery cell the outer case casings house a plurality of plate pairs and wherein the airflow path is defined by a plurality of interlocking ducts molded into the outer casings of a number of adjacent plate pairs.

46. The battery pack of claim 41, wherein each isolation container includes feature (ii).

47. The battery pack of claim 46, wherein the shock and vibration absorption assembly is a vibration resistant clamp engaging at least one surface of a battery cell.

48. The battery pack of claim 46, wherein the clamp comprises a gas flow channel in fluid communication with at least one gas vent of the battery cell to direct vented gas into the isolation container and wherein the clamp is configured to center each of the battery cells in the isolation container.

49. The battery pack of claim 41, wherein each isolation container includes feature (iii).

50. The battery pack of claim 49, wherein the electrical isolation assembly is an electrically insulative clamp engaging at least one surface of a battery cell.

51. The battery pack of claim 49, wherein the clamp comprises at least one of polyurethane, polyethylene, nylon, teflon, and mixtures thereof.

52. The battery pack of claim 40, wherein each isolation container is an enclosure comprising end surfaces, top and bottom surfaces, and side surfaces, wherein each isolation container moves outwardly in a drawer-like manner, and wherein the top surfaces comprise at least one inspection door for accessing the enclosed battery cells when the isolation container is displaced outwardly from the battery rack.