BATTERY ASSEMBLY FOR AN ELECTRIC VEHICLE, VEHICLE AND METHOD FOR OPERATING AN ELECTRIC VEHICLE

Abstract

A battery assembly for an electric vehicle including a first battery unit, a DC/DC converter, and a battery receptacle for selectively receiving a second battery unit. The first battery unit is electrically connected to the DC/DC converter. Moreover, a first electric connection interface is positioned in the battery receptacle and is electrically connected to the DC/DC converter. Additionally, a vehicle including such a battery assembly is presented. Furthermore, a method for operating an electric vehicle is explained. A first operational mode includes electrically connecting the first battery unit to an electric traction machine and electrically connecting the second battery unit to the first battery unit. A second operational mode includes electrically connecting the second battery unit to the electric traction machine.

Claims

1. A battery assembly for an electric vehicle, the battery assembly comprising: a first battery unit; a DC/DC converter; a battery receptacle for selectively receiving a second battery unit; and a first electric connection interface for electrically connecting the second battery unit; the first battery unit being electrically connected to the DC/DC converter; the first electric connection interface being positioned in the battery receptacle; and the first electric connection interface being electrically connected to the DC/DC converter.

2. The battery assembly according to claim 1, further comprising a second electric connection interface being configured for electrically connecting the battery assembly to an inverter unit, the first electric connection interface being electrically connected to the second electric connection interface.

3. The battery assembly according to claim 2, further comprising a control unit being communicatively connected to the first electric connection interface, the control unit being configured for selectively enabling and selectively disabling at least one of the electric connection between the first electric connection interface and the DC/DC converter and the electric connection between the first electric connection interface and the second electric connection interface.

4. The battery assembly according to claim 2, further comprising a third electric connection interface being configured for electrically connecting the battery assembly to an inverter unit, the third electric connection interface being electrically connected to the first battery unit.

5. The battery assembly according to claim 4, wherein the second electric connection interface and the third electric connection interface are formed by a common electric connection interface.

6. The battery assembly according to claim 1, further comprising the second battery unit, the second battery unit being located in the battery receptacle and being electrically connected to the first electric connection interface.

7. The battery assembly according to claim 1, further comprising a cooling system having at least one cooling channel and a cooling interface being fluidically connected to the cooling channel, the cooling interface being arranged in the battery receptacle.

8. A vehicle comprising the battery assembly according to claim 1, an inverter unit and an electric traction machine, the battery assembly being electrically connected to the inverter unit and the inverter unit being electrically connected to the electric traction machine such that the electric traction machine can be powered by the battery assembly.

9. A method for operating an electric vehicle having a battery assembly comprising a first battery unit and a second battery unit, the battery assembly being electrically connected to an electric traction machine, the method comprising: in a first operational mode (M1), electrically connecting the first battery unit to the electric traction machine such that electric power flows from the first battery unit to the electric traction machine, and electrically connecting the second battery unit to the first battery unit such that electric power flows from the second battery unit to the first battery unit; and in a second operational mode (M2), electrically connecting the second battery unit to the electric traction machine such that electric power flows from the second battery unit to the electric traction machine.

10. The method according to claim 9, wherein the second operational mode (M2) comprises electrically disconnecting the first battery unit from the electric traction machine and electrically disconnected the first battery unit from the second battery unit.

11. The method according to claim 9, wherein the second operational mode (M2) comprises electrically connecting the first battery unit to the electric traction machine such that electric power flows from the first battery unit to the electric traction machine.

12. The method according to claim 9, wherein the second operational mode (M2) comprises electrically connecting the first battery unit to the second battery unit such that electric power flows from the first battery unit to the second battery unit.

13. The method according to claim 9, further comprising assessing a desired energy capacity of the second battery unit based on a planned drive cycle.

14. The method according to claim 13, wherein assessing a desired energy capacity comprises selecting one out of a number of predefined energy capacities.

15. The method according to claim 13, further comprising inserting the second battery unit into the battery assembly.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Examples of the disclosure will be described in the following with reference to the following drawings.

[0032] FIG. 1 shows a vehicle according to the present disclosure including a battery assembly according to the present disclosure being operable by a method according to the present disclosure,

[0033] FIG. 2 shows a drivetrain of the vehicle of FIG. 1 in a schematic, more detailed representation,

[0034] FIG. 3 shows operational modes of the method according to the present disclosure, and

[0035] FIG. 4 illustrates an aspect of the method of FIG. 3.

[0036] The figures are merely schematic representations and serve only to illustrate examples of the disclosure. Identical or equivalent elements are in principle provided with the same reference signs.

DETAILED DESCRIPTION

[0037] FIG. 1 shows a vehicle 10 including a battery assembly 12. The battery assembly 12 is used for propelling the vehicle 10. Thus, the vehicle 10 is an electric vehicle.

[0038] FIG. 2 shows a drivetrain 14 of the vehicle 10 in more detail. The drivetrain 14 includes the battery assembly 12. Moreover, the drivetrain has an electric traction machine 16 and an inverter unit 18.

[0039] The battery assembly 12 is electrically connected to the inverter unit 18 and the inverter unit 18 is electrically connected to the electric traction machine 16. Consequently, the electric traction machine 16 can be powered by the battery assembly 12. The battery assembly 12 includes a first battery unit 20. The first battery unit 20 is fixedly built into the battery assembly 12 and thus in the vehicle 10. The battery assembly 12 also includes a battery receptacle 22 for selectively receiving a second battery unit 24. In the representation of FIG. 2, the second battery unit 24 is located in the battery receptacle 22. However, it has to be noted that the drivetrain 14 is also fully operational without the second battery unit 24, i.e. with the battery receptacle 22 being empty. The battery assembly 12 includes a first electric connection interface 26 for electrically connecting the second battery unit 24. The first electric connection interface 26 is positioned in the battery receptacle 22. Since in the example shown in FIG. 2, the second battery unit 24 is provided, the second battery unit 24 is electrically connected to the first electric connection interface 26. The battery assembly also includes a DC/DC converter 28 which is fixedly built into the battery assembly 12. The DC/DC converter is electrically connected to the first electric connection interface 26 and to the first battery unit 20. Thus, the second battery unit 24 and the first battery unit 20 are electrically connected via the DC/DC converter 28.

[0040] The battery assembly 12 also including a second electric connection interface 30. The second electric connection interface 30 is configured for electrically connecting the battery assembly 12 to the inverter unit 18, i.e. for making the connection between the battery assembly 12 and the electric traction machine 16. Moreover, the first electric connection interface 26 and the second electric connection interface 30 are electrically connected.

[0041] Furthermore, the battery assembly 12 includes a third electric connection interface 32. The third electric connection interface 32 is also configured for electrically connecting the battery assembly 12 to the inverter unit 18. Moreover, the third electric connection interface 32 is electrically connected to the first battery unit 20. It is noted that the second electric connection interface 30 and the third electric connection interface 32 may also be formed as a common electric connection interface. However, in the representation of FIG. 2 they are configured as separate electric connection interfaces.

[0042] Considering the electric connections as described above, the second battery unit 24 can be connected to the inverter unit 18 via the first electric connection interface 26 and the second electric connection interface 30, thereby bypassing the first battery unit 20 and the DC/DC converter 28, or via the first electric connection interface 26, the DC/DC converter 28, the first battery unit 20 and the third electric connection interface 32.

[0043] In order to select one of these alternatives, the battery assembly 12 includes a control unit 34 being communicatively connected to the first electric connection interface 26.

[0044] The control unit 34 is configured for selectively enabling and selectively disabling at least one of the electric connection between the first electric connection interface 26 and the DC/DC converter 28 and the electric connection between the first electric connection interface 26 and the second electric connection interface 30.

[0045] The battery assembly 12 additionally includes a cooling system 36 includes a cooling channel 38. Moreover, the cooling system 36 includes a cooling interface 40. The cooling interface 40 is fluidically connected to the cooling channel 38. The cooling interface 40 is arranged in the battery receptacle 22 such that the second battery unit 24 may be fluidically connected thereto. Since in the example of FIG. 2 the second battery unit 24 is located in the battery receptacle, it is fluidically connected to the cooling system 36 via cooling interface 40. Consequently, using the cooling system 36 both, the first battery unit 20 and the second battery unit 24 can be maintained within a desired temperature range.

[0046] The electric vehicle 10 can be operated by a method for operating an electric vehicle 10 as shown in FIG. 3. The steps of the method may at least partially be implemented as executable computer program elements on a data processing device of the control unit 34.

[0047] The method includes a first operational mode M1. In this first operational mode the first battery unit 20 is electrically connected to the electric traction machine 16 such that electric power flows from the first battery unit 20 to the electric traction machine 16. Of course, this is done via the inverter unit 18 which is necessary for converting the DC provided by the first battery unit 20 into AC. At the same time, according to the first operational mode M1, the second battery unit 24 is connected to the first battery unit 20 such that electric power flows from the second battery unit to the first battery unit 20. In more detail, the second battery unit 24 is connected to the first battery unit 20 via the first electric connection interface 26 and the DC/DC converter 28. In other words, in the first operational mode M1, the second battery unit 24 is charging the first battery unit 20 and the first battery unit 20 is used for powering the electric traction machine 16.

[0048] The method also includes a second operational mode M2. The second operational mode M2 includes electrically connecting the second battery unit 24 to the electric traction machine 16 such that electric power flows from the second battery unit to the electric traction machine 16. In more detail, the second battery unit 24 is connected to the electric traction machine 16 via the first electric connection interface 26, the second electric connection interface 30 and the inverter unit 18. In other words, in the second operational mode M2, the electric connection of the second battery unit 24 to the electric traction machine 16 bypasses the first battery unit 20 and the DC/DC converter 28.

[0049] In a variant of the second operational mode M21, the first battery unit 20 is electrically disconnected from the electric traction machine 16 and also electrically disconnected from the second battery unit 24. Thus, in this variant, the first battery unit 20 is not used.

[0050] In another variant of the second operational mode M22, the first battery unit 20 is electrically connected to the electric traction machine 16 such that electric power flows from the first battery unit 20 to the electric traction machine 16.

[0051] In more detail, the first battery unit 20 is connected to the electric traction machine 16 via the third electric connection interface 32 and the inverter unit 18.

[0052] In a further variant M23 of the second operational mode M2 the first battery unit 20 is electrically connected to the second battery unit 24 such that electric power flows from the first battery unit 20 to the second battery unit 24. This electric connection is realized via the DC/DC converter 28 and the first electric connection interface 26. In other words, in the variant M23 the first battery unit 20 is used for charging the second battery unit 24 and the electric traction machine 16 is powered by the second battery unit 24.

[0053] It is understood that while operating the electric vehicle 10, the operational modes M1, M2 as described above may be changed depending on a state of the battery assembly 12 and environmental driving conditions. It is additionally noted that performing the above described method only is useful if the second battery unit 24 is used.

[0054] Prior to the execution of the method steps as described above and relating to the operational modes M1, M2, the method also includes assessing a desired energy capacity of the second battery unit 24 based on a planned drive cycle. The planned drive cycle may for example be provided by a navigation unit. The planned drive cycle especially includes an information about a travel distance. Based on this information, a desired energy capacity of the second battery unit 24 may be assessed, in doing so, also preferences of a driver may be respected which for example relate to the fact that charging stops shall be avoided or that the driving time shall be minimized. Assessing the desired energy capacity also include selecting one out of a number of predefined energy capacities which the second battery unit 24 may have. Once this has been decided, an appropriate second battery unit 24 may be inserted into the battery assembly 12, i.e. into the battery receptacle 22.

[0055] In this respect, FIG. 4 shows three alternatives. It is assumed that a second battery unit 24 having a comparatively high electric capacity and a second battery unit 24 having a comparatively low electric capacity are provided as options.

[0056] The alternative a) may be chosen if the planned drive cycle is associated with a long distance. In this alternative, the second battery unit 24 having the comparatively high electric capacity is arranged in the battery receptacle 22. In this context, the built-in first battery unit 20 may have an electric capacity of 40 kWh and the second battery unit 24 may have an electric capacity of 80 kWh.

[0057] In the alternative b) the second battery unit 24 having the comparatively low electric capacity may be considered to be appropriate. Thus, this second electric battery unit 24 is arranged in the battery receptacle 22. Again, the built-in first battery unit 20 may have an electric capacity of 40 kWh. In this alternative, the second battery unit 24 may have an electric capacity of 40 kWh.

[0058] In the alternative c) it may be determined that the built-in first battery unit 20 is enough, i.e. that the desired electric capacity of the second battery unit is 0 kWh.

[0059] Thus, in any of the above alternatives, the vehicle 10 is equipped with a battery assembly 12 having an appropriate electric capacity.

[0060] Other variations to the disclosed examples can be understood and effected by those skilled in the art in practicing the claimed disclosure, from the study of the drawings, the disclosure, and the appended claims. In the claims the word “comprising” does not exclude other elements or steps and the indefinite article “a” or “an” does not exclude a plurality. A single processor or other unit may fulfill the functions of several items or steps recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. A computer program may be stored/distributed on a suitable medium such as an optical storage medium or a solid-state medium supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems. Any reference signs in the claims should not be construed as limiting the scope of the claims.