Electric Vehicle with Thermal Management System

Abstract

An electric vehicle includes a thermal management system, an electric drive, a traction battery electrically coupled to the electric drive and a thermal energy source thermally coupled to the traction battery. Thermally coupling the thermal energy source and traction battery makes it possible to keep the area surrounding the traction battery and the traction battery itself at a temperature level where the traction battery can be efficiently operated. The waste heat of the thermal energy source may be used directly for heating up the vehicle interior and/or for controlling the temperature of the traction battery. Making direct use of provided waste heat that might arise in the motor vehicle anyway proves to be particularly energy efficient.

Claims

1-13. (canceled)

14. A motor vehicle comprising: at least one electric drive; a traction battery electrically coupled with the electric drive; and a thermal energy source thermally coupled with the traction battery.

15. The motor vehicle according to claim 14, wherein the thermal energy source comprises a fuel cell for generating electric energy.

16. The motor vehicle according to claim 14, further comprising a heat exchanger having a thermal energy bus thermally coupled between the thermal energy source and the traction battery.

17. The motor vehicle according to claim 16, further comprising a heater thermally coupled with the thermal energy bus.

18. The motor vehicle according to claim 16, further comprising an air conditioner thermally coupled with the thermal energy bus.

19. The motor vehicle according to claim 16, wherein the heat exchanger is thermally coupled with an interior of the motor vehicle.

20. The motor vehicle according to claim 16, further comprising: at least one sensor arranged in an area of the traction battery; and a regulator coupled with the sensor to receive temperature data and operable to maintain a prescribed temperature for the thermal energy bus based on the temperature data.

21. The motor vehicle according to claim 20, wherein the regulator is configured to operate at least one of a heater, an air conditioner and a circulation member.

22. The motor vehicle according to claim 16, wherein the thermal energy bus comprises a circulation member configured to convey a heat exchanger medium between the thermal energy source and the traction battery.

23. The motor vehicle according to claim 14, further comprising a vehicle electric system electrically coupled with the thermal energy source and the traction battery.

24. The motor vehicle according to claim 23, wherein the vehicle electric system is electrically coupled with at least one of an air conditioner and a heater.

25. A motor vehicle comprising: at least one electric drive; a traction battery electrically coupled with the electric drive; at least one sensor arranged in an area of the traction battery for measuring temperature data; a thermal energy source thermally coupled with the traction battery a heat exchanger having a thermal energy bus thermally coupled between the thermal energy source and the traction battery; and a regulator coupled with the sensor to receive temperature data and operable to maintain a prescribed temperature for the thermal energy bus based on the temperature data.

26. A method for controlling the temperature of a traction battery in a motor vehicle comprising: measuring an actual temperature prevailing in an area of the traction battery; comparing the actual temperature with a prescribed desired temperature; and transferring thermal energy to and from the area of the traction battery based on the comparison for maintaining the prescribed desired temperature in the area of the traction battery.

27. The method according to claim 25, further comprising directing a heating fluid having a temperature greater than the actual temperature to the area of the traction battery.

28. The method according to claim 25, further comprising directing a cooling fluid having a temperature less than the actual temperature to the area of the traction battery.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present disclosure will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements.

[0029] FIG. 1 is a schematic side view of a motor vehicle,

[0030] FIG. 2 is a block diagram of a thermal management system of the motor vehicle,

[0031] FIG. 3 is another block diagram to illustrate the temperature control of the traction battery and/or a thermal energy bus, and

[0032] FIG. 4 is a flowchart of the method for controlling the temperature of the traction battery.

DETAILED DESCRIPTION

[0033] The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Furthermore, there is no intention to be bound by any theory presented in the preceding background of the invention or the following detailed description.

[0034] The motor vehicle 1 shown schematically in FIG. 1 in a side view has a motor vehicle body 2 with an interior 3 acting as a passenger compartment. The motor vehicle 1 is equipped with a thermal management system 10, the function of which is explained in more detail based on the block diagram in FIG. 2.

[0035] The motor vehicle 1 is equipped with at least one electric drive 28. For example, three electric drives 28 are denoted in FIG. 2 in the form of electric motors. These are coupled by power electronics 26 with a vehicle electric system 24 of the motor vehicle 1. The vehicle electric system 24 can further be connected with the traction battery 12 or is permanently connected with the traction battery 12. The traction battery 12 can provide the electric energy required for operating the drives 28 as appropriate.

[0036] Apart from the traction battery 12 and electric drive 28, the motor vehicle 1 is equipped with a thermal energy source 14. The thermal energy source may be configured as an electric generator. In the present exemplary embodiment, it has a fuel cell 15. The fuel cell 15 can be connected with the vehicle electric system 24 of the motor vehicle 1 by a converter 34. During operation of the fuel cell 15, electric energy generated by the fuel cell 15 can be fed into the vehicle electric system 24 of the motor vehicle 1 via the converter 34. The vehicle electric system 24 may be configured as a high-voltage vehicle electric system.

[0037] The vehicle electric system 24 can further be connected to another battery 30 via another converter 32. For example, the battery 30 may be configured as a low-voltage battery. For example, it may be configured as a 12 V, 24 V or 48 V battery, so as to supply energy to additional electrical consumers of the motor vehicle 1.

[0038] The thermal energy source 14 can further be thermally coupled with a thermal energy bus 16 via a heat exchanger 18. The thermal energy bus 16 is further thermally coupled at least with the traction battery 12. Waste heat that arises in the area of the thermal energy source 14, for example due to operation of the fuel cell 15, can be provided via the heat exchanger 18 and via the thermal energy bus 16 in the area of the traction battery 12, so that, in particular in a start phase of the motor vehicle, the traction battery 12 can be operated in a temperature range in which the traction battery 12 optimally operates. The temperature of the traction battery 12 can typically be controlled by thermal coupling with the thermal energy source 14 to a temperature range in roughly the room temperature range, for example about 72 F. (22 C.).

[0039] For extreme weather conditions, given especially low or high outside temperatures, the thermal energy bus 16 can be thermally coupled with an air conditioner 20 and/or with a heater 22. The air conditioner 20 may be configured as an electric air conditioner 20, and can be connected to the vehicle electric system 24 of the motor vehicle 1. In like manner, the heater 22 can be implemented as an electric heater, which is also connected to the vehicle electric system 24 of the motor vehicle 1. If necessary, the air conditioner 20 can be used to remove thermal energy from the thermal energy bus 16 or couple a cooling capacity into the thermal energy bus 16. In like manner, additional thermal energy can be fed into the thermal energy bus 16 via the heater if need be, so as to set and maintain a prescribed desired temperature in the area of the thermal energy bus 16 and/or in the area of the traction battery 12 thermally coupled thereto.

[0040] As further denoted in FIGS. 2 and 3, the heat exchanger 18 can be coupled not just with the thermal energy bus 16, but also directly with the interior 3 of the motor vehicle 1. The thermal coupling between the heat exchanger 18, interior 3 and thermal energy bus 18 can be established by a closed cycle, in which a heat exchanger medium, for example a heat exchanger gas or a heat exchanger liquid, circulates. In particular, air is possible as the gaseous heat exchanger. One example for the heat exchanger liquid would be water, if necessary mixed with an antifreeze additive to achieve freezing-point depression.

[0041] As schematically illustrated in particular in FIG. 3, the thermal management system 10 has at least one regulator 40 and one sensor 42. The sensor 42 is typically configured as a temperature sensor. It is arranged in the area of the traction battery 12. For example, the prevailing actual temperature in the area of the traction battery 12 can be measured with the sensor 42. The data processing coupling between the regulator 40 and sensor 42 makes it possible to determine the respective prevailing actual temperature of the traction battery 12. In addition to the sensor 42 in the area of the traction battery 12, additional sensors, in particular temperature sensors, can be provided, for example in the area of the heat exchanger 18, in the area of the thermal energy source 14, and also in the area of the air conditioner 20 and/or heater 22.

[0042] All sensors can here be coupled with one and the same regulator 40 in terms of data processing. In this regard, the regulator 40 can receive information about the current thermal state of all components of the thermal management system 10. The thermal management system 10 can further be provided with a circulation member 46. The circulation member is typically embedded in the thermal energy bus 16, which may be configured as a closed or, in particular given a gaseous heat exchanger medium, also as an open cycle in which the heat exchanger medium described above circulates. The circulation or circulation rate of the heat exchanger medium in the thermal energy bus 16 can be controlled as needed by means of the circulation member 46. The circulation member 46, for example which is configured as a circulating pump or fan, can be controlled by means of the regulator 40.

[0043] For example, if a large temperature difference is measured between an actual temperature measured in the area of the traction battery 12 and a prescribed desired temperature, increasing the flow rate of the heat exchanger medium using the circulation member makes it possible to more quickly harmonize the actual temperature to the prescribed desired temperature.

[0044] The process of thermally coupling the heat exchanger 18, air conditioner 20, heater 22 and traction battery 12 to the thermal energy bus 16 can be respectively controlled by at least one valve 44. The valves 44 are typically control valves, which can be actuated from the regulator 40. The valves 44 can be control valves for liquids or throttle valves or butterfly valves for a gas flow. The thermal energy bus 16 can further also be coupled with the interior 3 of the motor vehicle by way of a valve 44. The latter can also be actuated via the regulator 40.

[0045] Finally, FIG. 4 shows the method proposed for operating the thermal management system 10 described herein. A prevailing actual temperature is measured in the area of the traction battery 12 at block 100. The measured actual temperature is compared with a prescribed desired temperature at block 102. Based on the comparison, the regulator 40 can initiate corresponding measures for controlling the temperature of the traction battery 12 as needed. If the actual temperature is too low, for example, the heater 22 can be activated at block 104, and the heat additionally provided by the heater 22 can be supplied to the traction battery 12 via the thermal energy bus 16.

[0046] Once a prescribed desired temperature has been reached in the area of the traction battery 12, the heater 22 can again be throttled or deactivated, for example. In like manner, the thermal energy continuously emitted by the thermal energy source 14, in particular by its fuel cell 15, can be made available to the traction battery 12 through activation of the circulation member 46 and via the thermal energy bus 16. Should the measured actual temperature in the area of the traction battery 12 clearly exceed the desired temperature in another instance, a thermal energy supply to the thermal energy bus 16 can be throttled, for example through decoupling from the thermal energy source 14. As a result, thermal energy can be drawn from the thermal energy bus 16, for example by activating and thermally coupling the air conditioner 20 with it.

[0047] While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment as contemplated herein. It should be understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the invention as set forth in the appended claims.