Energy supply device for a motor vehicle

Abstract

An energy supply device for a motor vehicle has a high-voltage energy storage device and a control device for controlling the charging and discharging operations of the high-voltage energy storage device. The control device is designed to determine a temperature of the high-voltage energy storage device and to adjust a predetermined working range of the high-voltage energy storage device, which is defined by an upper limit and a lower limit, as a function of the determined temperature.

Claims

1. An energy supply device for a motor vehicle, the energy supply device comprising: a high-voltage energy storage device; and a control device for controlling charging and discharging processes of the high-voltage energy storage device, wherein the control device is configured to: receive a present temperature of the high-voltage energy storage device from a temperature sensor after a predefined period of time after switch-off of the motor vehicle, and adapt a predetermined working range of the high-voltage energy storage device based on the present temperature of the high-voltage energy storage device, said working range being defined by an upper limit and a lower limit.

2. The energy supply device according to claim 1, wherein the predefined period of time is greater than or equal to 6 hours.

3. The energy supply device according to claim 1, wherein the control device is further configured to adapt the lower limit and/or the predefined period of time depending on at least one operating parameter of the motor vehicle.

4. The energy supply device according to claim 1, wherein the control device is further configured to adapt the working range by adapting the lower limit whilst maintaining the upper limit.

5. The energy supply device according to claim 1, wherein the control device is further configured to adapt the lower limit to a first value if the present temperature of the high-voltage energy storage device is less than or equal to a predefined temperature threshold value.

6. The energy supply device according to claim 5, wherein the control device is further configured to adapt the lower limit to a second value if the present temperature of the high-voltage energy storage device is greater than the predefined temperature threshold value, wherein the first value is higher than the second value.

7. A motor vehicle comprising an energy supply device according to claim 1.

8. The motor vehicle according to claim 7, wherein the motor vehicle is an automobile.

9. A method for supplying a motor vehicle with energy, wherein the motor vehicle comprises an energy supply device with a high-voltage energy storage device and a control device for controlling charging and discharging processes of the high-voltage energy storage device, the method comprising: receiving a present temperature of the high-voltage energy storage device from a temperature sensor after a predefined period of time after switch-off of the motor vehicle; and adapting a predetermined working range of the high-voltage energy storage device based on the present temperature of the high-voltage energy storage device, said working range being defined by an upper limit and a lower limit.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic block diagram of a motor vehicle comprising an energy supply device.

(2) FIG. 2 shows an exemplary sequence of charging of the energy supply device from FIG. 1.

(3) FIG. 3 is a schematic flow diagram of a method for supplying a motor vehicle with energy.

DETAILED DESCRIPTION OF THE DRAWINGS

(4) In the figures, identical or functionally identical elements have been provided with the same reference signs, unless indicated otherwise.

(5) FIG. 1 shows a motor vehicle 1 comprising an energy supply device 10. The energy supply device 10 comprises a high-voltage energy storage device 11 for supplying the motor vehicle 1 with energy and a control device 12 for controlling the charging and discharging processes of the high-voltage energy storage device 11.

(6) In order to ensure a reliable cold start of the motor vehicle 1 in all cases, even at low outside temperatures, the control device 12 can adapt the working range of the high-voltage energy storage device 11. For this purpose, the control device 12 firstly determines the present temperature of the high-voltage energy storage device 11. The temperature can be provided by a temperature sensor 13.

(7) The high-voltage energy storage device 11 is operated in a working or operating range that is chosen in such a way that, on the one hand, a defined cold start (e.g. start of the internal combustion engine at −25° C.) must be possible at any time (lower state of charge limit/minimum storage capacity, lower limit hereinafter) and that, on the other hand, there is (upward) enough storage capacity (upper state of charge limit/maximum storage capacity) to be able to utilize the energy store for braking energy recovery.

(8) In order optimally to utilize the working range of the high-voltage energy storage device 11, the control device 12 adapts the working range of the high-voltage energy storage device 11 on the basis of the temperature of the high-voltage energy storage device 11 itself. For the purpose of adapting the working range, a lower limit of the working range of the high-voltage energy storage device 11 is shifted upward or downward.

(9) An exemplary sequence of the charging and the shifting of the lower limit is shown in FIG. 2. In this case, the dotted arrows indicate the temperature profile of the high-voltage energy storage device 11 when the vehicle 1 is parked, and the solid arrows indicate the temperature profile of the high-voltage energy storage device 11 during driving.

(10) Firstly, the high-voltage energy storage device 11 is operated with a lower limit of the working range at a value W. In the case of the value W, the lower limit of the working range of the high-voltage energy storage device 11 is set to its minimum value, for example to an energy content of 13%.

(11) If the motor vehicle 1 is parked, the temperature of the high-voltage energy storage device 11 drops. If the temperature here falls below a temperature threshold value 201, the lower limit W is still used in the case of this parking process, but a different lower limit K is then used in the case of the next parking process. After parking, the high-voltage energy storage device 11 is heated up again during driving.

(12) The lower limit K is then used in the case of the next parking process. This lower limit is suitable for lower temperatures since here the lower limit of the working range of the high-voltage energy storage device 11 is set to a higher value, for example to an energy content of 18%. This lower limit K is then used as long as the temperature of the high-voltage energy storage device 11 after parking is in a temperature range 202 lying below the temperature threshold value 201. A different value for the lower limit is used only if the temperature of the high-voltage energy storage device 11 no longer drops to a temperature threshold value 201, but rather is in a higher temperature range 203 above the temperature threshold value. In other words, if a temperature above the temperature threshold value 201 is established after a parking process, the lower limit W is used again for future parking processes until the temperature of the high-voltage energy storage device 11 below the temperature threshold value 201 is established again.

(13) FIG. 3 shows a method for supplying a motor vehicle 1 in accordance with FIG. 1 with energy. The method comprises the following steps.

(14) A first step 301 involves determining a temperature of the high-voltage energy storage device 11.

(15) Afterward, a second step 302 involves adapting a predetermined working range of the high-voltage energy storage device 11, said working range being defined by an upper limit and a lower limit, depending on the determined temperature of the high-voltage energy storage device 11.

(16) The proposed apparatus makes it possible optimally to utilize the working range of a high-voltage energy storage device since, rather than a—possibly irrelevant—outside temperature, the actual temperature of the high-voltage energy storage device is used to adapt a working range of the high-voltage energy storage device.

(17) Although the present invention has been described on the basis of exemplary embodiments, it is modifiable in diverse ways.

REFERENCE SIGNS

(18) 1 Motor vehicle 10 Energy supply device 11 High-voltage energy storage device 12 Control device 13 Temperature sensor 201 Temperature threshold value 202, 203 Temperature ranges 301-302 Method steps K, W Lower limits

(19) The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.