Method for controlling thermal management system of electric vehicle, data processing device, computer program, computer readable storage medium and use

Abstract

The present disclosure relates to a method for controlling a thermal management system (30) of an electric vehicle. The thermal management system (30) includes a cabin air conditioning system (22) configured to control a temperature in a passenger cabin (24) of the electric vehicle and a traction battery thermal management system (16) configured to control a temperature of a traction battery (12) of the electric vehicle. The method includes causing a heat transfer (H) from the cabin air conditioning system (22) to the traction battery thermal management system (16). In addition, a data processing apparatus (32), a computer program (40) and a computer readable storage medium (38) are described. Furthermore, the use of a traction battery (12) of an electric vehicle as a heat sink for a cabin air conditioning system (22) and the use of a heat exchanger (20) forming part of a traction battery thermal management system (16) of an electric vehicle for cooling a passenger cabin (24) of an electric vehicle are proposed.

Description

Technical Field

[0001] The present disclosure relates to a method for controlling a thermal management system of an electric vehicle. The thermal management system includes a cabin air-conditioning system configured to control the temperature in the passenger cabin of the electric vehicle, and a traction battery thermal management system configured to control the temperature of the traction battery of the electric vehicle.

[0002] Furthermore, the present disclosure relates to a data processing device, a computer program, and a computer-readable storage medium.

[0003] In addition, the present disclosure relates to the use of a traction battery of an electric vehicle and the use of a heat exchanger forming part of a traction battery thermal management system of the electric vehicle. Summary of the Invention

[0004] In this case, the cabin air-conditioning system is used to keep the temperature in the passenger cabin of the electric vehicle within a range that is comfortable or at least acceptable for passengers. This means that if the electric vehicle is used in a relatively warm environment, the cabin air-conditioning system is configured to cool the passenger cabin. In addition, if the electric vehicle is used in a relatively cold environment, the cabin air-conditioning system is configured to heat the passenger cabin.

[0005] The traction battery thermal management system is used to keep the temperature of the traction battery within a range that allows for efficient and reliable operation of the traction battery. In this case, the reliable operation of the traction battery includes ensuring a relatively long service life of the traction battery. This means that the traction battery is kept within a certain temperature range in order to extend the service life of the traction battery, or at least ensure that the traction battery reaches a predefined target service life.

[0006] Modifying and maintaining the desired temperature levels in the passenger cabin and the traction battery requires a certain amount of energy, which is typically provided by the traction battery in an electric vehicle. Therefore, the energy used by the cabin air-conditioning system and / or the traction battery thermal management system may not be used to propel the electric vehicle. This means that an energy-efficient (energy-saving) operation of the cabin air-conditioning system and / or the traction battery thermal management system may result in an increased driving range of the electric vehicle. This is generally desirable.

[0007] Therefore, the object of the present disclosure is to further improve the energy efficiency of a thermal management system including a cabin air-conditioning system and a traction battery thermal management system.

[0008] This problem is solved or alleviated at least in part by the subject matter of the independent claims of the present disclosure, with further examples being incorporated into the dependent claims.

[0009] According to a first aspect, a method for controlling a thermal management system of an electric vehicle is provided. The thermal management system includes a cabin air conditioning system configured to control the temperature in the passenger cabin of the electric vehicle, and a traction battery thermal management system configured to control the temperature of the traction battery of the electric vehicle. The method includes causing heat transfer from the cabin air conditioning system to the traction battery thermal management system. At a component level, this means that the cabin air conditioning system and the traction battery thermal management system are at least coupled to such an extent that this heat transfer is made possible. This heat transfer is particularly useful in the operating case where the passenger cabin is cooled by the cabin air conditioning system (i.e., in the operating case where heat needs to be extracted from the passenger cabin). By transferring heat from the cabin air conditioning system to the traction battery thermal management system, both the cabin air conditioning system and the traction battery thermal management system can be used jointly or synergistically to perform the task of cooling the passenger cabin. In other words, the traction battery thermal management system can support the cabin air conditioning system when cooling the passenger cabin. In doing so, the cooling capacity provided by the cabin air conditioning system can be expanded as appropriate through this heat transfer and the use of the traction battery thermal management system. This means that the cooling performance of the cabin air conditioning system can be expanded without making hardware changes in the cabin air conditioning system. In addition, the heat transfer from the cabin air conditioning system to the traction battery thermal management system can improve the efficiency of cooling the passenger cabin. This may even be the case when the cooling capacity of the cabin air conditioning system alone is sufficient to cool the passenger cabin in a desired manner. This is due to the fact that the efficiency of the cabin air conditioning system may be different at different operating points associated with different levels of cooling performance. Here, it has been observed that the efficiency is particularly reduced if the cabin air conditioning system needs to provide a relatively high level of cooling performance. Therefore, if heat is transferred to the traction battery thermal management system, the cabin air conditioning system can operate at a lower or relatively low performance level. This improves the overall efficiency of the thermal management system of the electric vehicle.

[0010] In one example, the traction battery thermal management system may additionally be configured to control the temperature of one or more other components of an electric powertrain including the traction battery (e.g., an electric motor or a control unit of the electric powertrain).

[0011] According to one example, the method further includes reducing or lowering the temperature of the traction battery of the electric vehicle. This is accomplished using a traction battery thermal management system. For example, the reference temperature of the vehicle's traction battery can be reduced. This also applies to one or more other components of the electric drivetrain that includes the traction battery (e.g., the motor or control unit of the electric drivetrain) in cases where the traction battery thermal management system is additionally configured to control the temperature of these components, i.e., the method includes also reducing or lowering the temperature of these components. Before causing heat transfer from the cabin air conditioning system to the traction battery thermal management system, the temperature of the traction battery of the electric vehicle and / or the components of the electric drivetrain is reduced or lowered. In short, before causing heat transfer from the cabin air conditioning system to the traction battery thermal management system, the traction battery of the electric vehicle and / or the components of the electric drivetrain are cooled or precooled. This improves the support that the traction battery thermal management system can provide to the cabin air conditioning system when cooling the passenger cabin. In other words, cooling or precooling the traction battery and / or the components of the electric drivetrain further expands the cooling capacity of the cabin air conditioning system because the heat transfer and utilization of the traction battery thermal management system can be increased. This means that the cooling performance of the cabin air conditioning system can be further expanded without making hardware changes to the cabin air conditioning system. Additionally, as previously described, heat transfer from the cabin air conditioning system to the traction battery thermal management system can improve the efficiency of cooling the passenger cabin. Reducing or lowering the temperature of the traction battery of the electric vehicle and / or the components of the electric drivetrain may be affected by an expectation, prediction, or forecast that heat transfer from the cabin air conditioning system to the traction battery thermal management system will occur in the relatively near future. Such an expectation, prediction, or forecast can be based on the driving situation of the electric vehicle. For example, if the electric vehicle is parked in a relatively warm environment and the user of the electric vehicle is approaching the vehicle, it can be expected that heat transfer from the cabin air conditioning system to the traction battery thermal management system will occur. More generally, the expectation, prediction, or forecast can be based on the temperature in the cabin of the electric vehicle, the temperature in the environment of the electric vehicle, the temperature of the traction battery of the electric vehicle and / or the components of the electric drivetrain, and / or the state of charge of the traction battery. In summary, precooling the traction battery and / or the components of the electric drivetrain can, as the case may be, improve the ability to cause heat transfer from the cabin air conditioning system to the traction battery thermal management system, thereby facilitating the cooling of the cabin.

[0012] In one example, causing heat transfer from the passenger compartment air conditioning system to the traction battery thermal management system includes selectively causing thermal coupling of the passenger compartment air conditioning system and the traction battery thermal management system. This means that the thermal coupling of the passenger compartment air conditioning system and the traction battery thermal management system can be controlled, i.e., the presence or absence of such thermal coupling and / or at least the degree of thermal coupling can be controlled. Thus, heat does not always transfer from the passenger compartment air conditioning system to the traction battery thermal system, but only transfers from the passenger compartment air conditioning system to the traction battery thermal system when such heat transfer is desired. This allows selectively increasing the cooling capacity of the passenger compartment and / or selectively increasing the operating efficiency of the thermal management system of the electric vehicle. However, when it is advantageous for there to be no heat transfer between the passenger compartment air conditioning system and the traction battery thermal system, the thermal coupling between the passenger compartment air conditioning system and the traction battery thermal management system can be interrupted. In summary, the overall efficiency of the thermal management system of the electric vehicle is increased.

[0013] According to one example, the passenger compartment air conditioning system and the traction battery thermal management system can be thermally coupled using a heat exchanger. This is a simple and reliable way to allow thermal coupling of the passenger compartment air conditioning system at the traction battery thermal management system.

[0014] According to one example, causing heat transfer from the passenger compartment air conditioning system to the traction battery thermal management system includes selectively opening a coolant flow path within the passenger compartment air conditioning system that extends through the heat exchanger. The heat exchanger thermally couples the passenger compartment air conditioning system and the traction battery thermal management system. Additionally or alternatively, causing heat transfer from the passenger compartment air conditioning system to the traction battery thermal management system includes selectively opening a coolant flow path within the traction battery thermal management system that extends through the heat exchanger. The heat exchanger thermally couples the passenger compartment air conditioning system and the traction battery thermal management system. The selective opening of the coolant flow path can be accomplished by correspondingly operating one or more valves. Selectively opening the coolant flow path to establish heat transfer between the passenger compartment air conditioning system and the traction battery thermal management system is a relatively simple and precise way to control the heat transfer between the passenger compartment air conditioning system and the traction battery thermal management system. Additionally, this allows heat transfer to be established or eliminated within a relatively short time span.

[0015] It should be noted that in the context of the present disclosure, the term coolant should be understood in its most general form. Thus, coolant describes any fluid used to transfer heat, i.e., a gas or a liquid. In one example, the coolant is a liquid. In this context, the coolant can have a constant state of aggregation when performing heat transfer. In this case, the coolant can be water or can include water. Alternatively, the coolant can change its state of aggregation when performing heat transfer. In this case, the coolant can also be described as a refrigerant. In one example, the refrigerant includes R134 or CO2.

[0016] In one example, causing heat transfer from the passenger compartment air conditioning system to the traction battery thermal management system includes selectively opening a coolant flow path within the traction battery thermal management system. The coolant flow path extends through or is disposed adjacent to the traction battery. Thus, heat can be transferred into the traction battery. In other words, heat from the coolant traveling along the coolant flow path can be dissipated in the traction battery. This heat can originate from the passenger compartment air conditioning system. Thus, the traction battery serves as a radiator, more precisely, as a radiator for heat originating from the passenger compartment air conditioning system and thus from the passenger compartment. Thus, heat originating from the passenger compartment and provided by the passenger compartment air conditioning system is not wasted but is further utilized within the electric vehicle. This improves overall efficiency.

[0017] According to one example, causing heat transfer from the passenger compartment air conditioning system to the traction battery thermal management system includes selectively causing a fluid coupling between the passenger compartment air conditioning system and the traction battery thermal management system. Thus, in this example, coolant is effectively transferred from the passenger compartment air conditioning system to the traction battery thermal management system. This means that the coolant that absorbs heat in the passenger compartment air conditioning system is transferred to the traction battery thermal management system and dissipates heat within the traction battery thermal management system. Optionally, the coolant can be circulated back to the passenger compartment air conditioning system from the traction battery thermal management system after having dissipated at least a portion of the heat. The fluid coupling between the passenger compartment air conditioning system and the traction battery thermal management system is a direct and effective way to transfer heat from the passenger compartment air conditioning system to the traction battery thermal management system.

[0018] In one example, the method further includes obtaining first data indicative of an operating condition of the passenger compartment air conditioning system. Additionally, the method includes causing heat transfer from the passenger compartment air conditioning system to the traction battery thermal management system if the first data exceeds a first data threshold indicative of an operating condition limit. Note that the term "first" is chosen for ease of explanation and does not imply any quantity. Thus, the term "first data" is considered a name. In this example, if the first data exceeds the first data threshold, i.e., if the passenger compartment air conditioning system is operating at an operating condition that exceeds the operating condition limit, then heat is transferred only from the passenger compartment air conditioning system to the traction battery thermal management system. The operating condition limit can correspond to a predefined percentage of maximum performance, such as 80% to 100% of maximum performance. By doing so, heat transfer from the passenger compartment air conditioning system to the traction battery thermal management system can be established only under operating conditions of the passenger compartment air conditioning system in which such heat transfer is useful in order to improve cooling performance and / or in order to improve efficiency. This further improves the overall efficiency of the thermal management system of the electric vehicle.

[0019] In one example, the operating conditions may be described by operating parameters. The operating parameters may indicate one or more of the following: user settings of the vehicle cabin air conditioning system, coolant temperature of the coolant in the vehicle cabin air conditioning system, temperature difference measured within the vehicle cabin air conditioning system, pressure measured within the vehicle cabin air conditioning system, pressure difference measured within the vehicle cabin air conditioning system, rotational speed of a pumping device (such as a pump or compressor) of the vehicle cabin air conditioning system, and rotational speed of a ventilation device (such as a fan) of the vehicle cabin air conditioning system. The operating condition limits may be described by corresponding threshold parameters.

[0020] In one example, the method further includes: obtaining second data indicative of the temperature of the passenger compartment; and obtaining third data indicative of the temperature of the traction battery. Additionally, the method includes: causing heat transfer from the vehicle cabin air conditioning system to the traction battery thermal management system if the second data and the third data indicate that the temperature of the traction battery is lower than the temperature of the passenger compartment. In other words, this condition relates to the fact that the temperature indicated by the third data is lower than the temperature indicated by the second data. It should be noted that the terms "second" and "third" are chosen for ease of explanation and do not imply any quantity. Thus, the terms "second data" and "third data" are considered as names. If the temperature of the traction battery is lower than the temperature of the passenger compartment, it is particularly easy to transfer heat from the passenger compartment (i.e., from the vehicle cabin air conditioning system) to the traction battery (i.e., to the traction battery thermal management system). In such a case, the heat transfer can be carried out in a particularly efficient manner. Additionally, the case where the temperature of the traction battery is lower than the temperature of the passenger compartment can be considered as a case indicating that the temperature of the traction battery is lower than the desired operating temperature or within the desired range of the temperature of the traction battery but with a certain margin to the upper end of the desired range. In summary, in such a case, further heating of the traction battery is beneficial or at least harmless.

[0021] Note that if the second data and the third data indicate that the temperature of the traction battery is higher than the temperature of the passenger compartment, heat transfer from the vehicle cabin air conditioning system to the traction battery thermal management system may also be caused. In other words, if the temperature indicated by the third data is higher than the temperature indicated by the second data, heat transfer may also be caused. As mentioned above, the terms "second" and "third" are chosen for ease of explanation and do not imply any quantity. Thus, the terms "second data" and "third data" are considered as names. In the case where the temperature of the traction battery is higher than the temperature of the passenger compartment, the heat pump effect needs to be used in order to be able to transfer heat from the passenger compartment (i.e., from the vehicle cabin air conditioning system) to the traction battery (i.e., to the traction battery thermal management system). In such a case, it is beneficial to use a refrigerant.

[0022] According to one example, the method further includes causing heat transfer from the traction battery thermal management system to the environment of the electric vehicle. Thus, in this example, heat can be transferred from the cabin air conditioning system to the traction battery thermal management system and from the traction battery thermal management system to the environment of the electric vehicle. This allows heat to be transferred from the cabin air conditioning system (and thus from the passenger cabin) into the traction battery thermal management system, even in cases where the traction battery thermal management system cannot provide a proper radiator as a result. Accordingly, the cooling capacity of the cabin air conditioning system can be further increased. In the same way, the efficiency of the combination of the cabin air conditioning system and the traction battery thermal management system can be increased.

[0023] In one example, causing heat transfer from the traction battery thermal management system to the environment includes selectively causing thermal coupling of the traction battery thermal management system and the environment. This means that the thermal coupling of the traction battery thermal management system and the environment can be controlled, i.e., the presence or absence of such thermal coupling and / or at least the degree of thermal coupling can be controlled. Thus, heat is not always transferred from the traction battery thermal system to the environment, but only from the traction battery thermal system to the environment when such heat transfer is desired. This allows selectively increasing the cooling capacity of the passenger cabin and / or selectively increasing the operating efficiency of the thermal management system of the electric vehicle. However, in cases where no heat transfer between the traction battery thermal system and the environment is advantageous, the thermal coupling of the traction battery thermal management system and the environment can be interrupted. In summary, the overall efficiency of the thermal management system of the electric vehicle is increased.

[0024] According to one example, the traction battery thermal management system and the environment can be thermally coupled using a heat exchanger (e.g., a liquid - gas heat exchanger or a gas - gas heat exchanger). Such a heat exchanger is sometimes referred to as a radiator. The environment essentially consists of air, i.e., the environment is always gaseous. The coolant can be a liquid or a gas. It is also possible that a part of the coolant is liquid and another part is gaseous. This is a simple and reliable way to allow thermal coupling of the traction battery thermal management system and the environment.

[0025] In one example, causing heat transfer from the traction battery thermal management system to the environment includes selectively opening a coolant flow path within the traction battery thermal management system that extends through the heat exchanger. The heat exchanger thermally couples the traction battery thermal management system and the environment. As mentioned before, such a heat exchanger can be configured as a liquid - gas heat exchanger, which is sometimes referred to as a radiator. The selective opening of the coolant flow path can be accomplished by operating one or more valves accordingly. Selectively opening the coolant flow path to establish heat transfer between the traction battery thermal management system and the environment is a relatively simple and precise way to control the heat transfer between the traction battery thermal management system and the environment. Additionally, this allows heat transfer to be established or eliminated within a relatively short time span.

[0026] The method can be at least partially computer-implemented and can be implemented in software or hardware or in a combination of software and hardware. Additionally, the method can be executed by computer program instructions running on a device that provides data processing capabilities. The data processing device can be a suitable computing device, such as an electronic control module, etc., and the computing device can also be a distributed computer system. The data processing device or computer can respectively include one or more of a processor, a memory, a data interface, etc.

[0027] According to a second aspect of the present disclosure, there is provided a data processing device that includes means for performing the method of the present disclosure. As previously mentioned, the heat transfer according to the method of the present disclosure is particularly useful in the operating situation where the passenger compartment is cooled by the vehicle air conditioning system (i.e., in the operating situation where heat needs to be extracted from the passenger compartment). By transferring heat from the vehicle air conditioning system to the traction battery thermal management system, both the vehicle air conditioning system and the traction battery thermal management system can be used jointly or cooperatively to perform the task of cooling the passenger compartment. In other words, the traction battery thermal management system can support the vehicle air conditioning system when cooling the passenger compartment. In doing so, the cooling capacity provided by the vehicle air conditioning system can be augmented by this heat transfer and the traction battery thermal management system as appropriate. This means that the cooling performance of the vehicle air conditioning system can be enhanced without making hardware changes in the vehicle air conditioning system. Additionally, the heat transfer from the vehicle air conditioning system to the traction battery thermal management system can improve the efficiency of cooling the passenger compartment. This may even be the case when the cooling capacity of the vehicle air conditioning system alone is sufficient to cool the passenger compartment in a desired manner. This is due to the fact that the efficiency of the vehicle air conditioning system may vary at different operating points associated with different levels of cooling performance. Here, it has been observed that if the vehicle air conditioning system needs to provide a relatively high level of cooling performance, the efficiency will be particularly reduced. Therefore, if heat is transferred to the traction battery thermal management system, the vehicle air conditioning system can operate at a lower or relatively low performance level. This improves the overall efficiency of the thermal management system of the electric vehicle.

[0028] According to a third aspect of the present disclosure, there is provided a computer program including instructions which, when executed by a computer, cause the computer to perform the method of the present disclosure. As previously mentioned, the heat transfer according to the method of the present disclosure is particularly useful in the case of the operation of cooling the passenger compartment by the vehicle cabin air conditioning system (i.e., in the case of the operation of extracting heat from the passenger compartment). By transferring heat from the vehicle cabin air conditioning system to the traction battery thermal management system, both the vehicle cabin air conditioning system and the traction battery thermal management system can be used jointly or synergistically to perform the task of cooling the passenger compartment. In other words, the traction battery thermal management system can support the vehicle cabin air conditioning system when cooling the passenger compartment. In doing so, the cooling capacity provided by the vehicle cabin air conditioning system can be expanded by this heat transfer and the traction battery thermal management system as appropriate. This means that the cooling performance of the vehicle cabin air conditioning system can be expanded without making hardware changes in the vehicle cabin air conditioning system. In addition, the heat transfer from the vehicle cabin air conditioning system to the traction battery thermal management system can improve the efficiency of cooling the passenger compartment. This may even be the case when the cooling capacity of the vehicle cabin air conditioning system alone is sufficient to cool the passenger compartment in a desired manner. This is due to the fact that the efficiency of the vehicle cabin air conditioning system may be different at different operating points associated with different levels of cooling performance. Here, it has been observed that if the vehicle cabin air conditioning system needs to provide a relatively high level of cooling performance, the efficiency will be particularly reduced. Therefore, if heat is transferred to the traction battery thermal management system, the vehicle cabin air conditioning system can operate at a lower or relatively low performance level. This improves the overall efficiency of the thermal management system of the electric vehicle.

[0029] According to a fourth aspect of the present disclosure, there is provided a computer-readable storage medium including instructions that, when executed by a computer, cause the computer to perform the methods of the present disclosure. As previously described, the heat transfer according to the method of the present disclosure is particularly useful in the case of an operation in which the passenger compartment is cooled by the vehicle cabin air conditioning system (i.e., in the case of an operation in which heat needs to be extracted from the passenger compartment). By transferring heat from the vehicle cabin air conditioning system to the traction battery thermal management system, both the vehicle cabin air conditioning system and the traction battery thermal management system can be used jointly or synergistically to perform the task of cooling the passenger compartment. In other words, the traction battery thermal management system can support the vehicle cabin air conditioning system when cooling the passenger compartment. In doing so, the cooling capacity provided by the vehicle cabin air conditioning system can be augmented by this heat transfer and the traction battery thermal management system as appropriate. This means that the cooling performance of the vehicle cabin air conditioning system can be enhanced without making hardware changes to the vehicle cabin air conditioning system. Additionally, the heat transfer from the vehicle cabin air conditioning system to the traction battery thermal management system can improve the efficiency of cooling the passenger compartment. This may even be the case when the cooling capacity of the vehicle cabin air conditioning system alone is sufficient to cool the passenger compartment in a desired manner. This is due to the fact that the efficiency of the vehicle cabin air conditioning system may vary at different operating points associated with different levels of cooling performance. Here, it has been observed that if the vehicle cabin air conditioning system needs to provide a relatively high level of cooling performance, the efficiency is particularly reduced. Thus, if heat is transferred to the traction battery thermal management system, the vehicle cabin air conditioning system can operate at a lower or relatively low performance level. This improves the overall efficiency of the thermal management system of the electric vehicle.

[0030] According to a fifth aspect of the present disclosure, there is provided a use of a traction battery of an electric vehicle as a radiator for a cabin air conditioning system. Thus, the heat to be removed or extracted from the cabin air conditioning system and thus from the passenger compartment can be transferred to the traction battery. In other words, the heat from the cabin air conditioning system can be dissipated in the traction battery. As previously mentioned, the heat transfer according to the method of the present disclosure is particularly useful in the operating situation where the passenger compartment is cooled by the cabin air conditioning system (i.e., in the operating situation where heat needs to be extracted from the passenger compartment). By transferring heat from the cabin air conditioning system to the traction battery thermal management system, both the cabin air conditioning system and the traction battery thermal management system can be used jointly or synergistically in order to perform the task of cooling the passenger compartment. In other words, the traction battery thermal management system can support the cabin air conditioning system when cooling the passenger compartment. In doing so, the cooling capacity provided by the cabin air conditioning system can be augmented by this heat transfer and the traction battery thermal management system as appropriate. This means that the cooling performance of the cabin air conditioning system can be increased without making hardware changes to the cabin air conditioning system. In addition, the heat transfer from the cabin air conditioning system to the traction battery thermal management system can improve the efficiency of cooling the passenger compartment. This may even be the case where the cooling capacity of the cabin air conditioning system alone is sufficient to cool the passenger compartment in the desired manner. This is due to the fact that the efficiency of the cabin air conditioning system may vary at different operating points associated with different levels of cooling performance. Here, it has been observed that the efficiency is particularly reduced if the cabin air conditioning system needs to provide a relatively high level of cooling performance. Thus, if heat is transferred to the traction battery thermal management system, the cabin air conditioning system can operate at a lower or relatively low performance level. This increases the overall efficiency of the thermal management system of the electric vehicle.

[0031] According to a sixth aspect of the present disclosure, there is provided a use of a heat exchanger forming part of a traction battery thermal management system of an electric vehicle for cooling a passenger compartment of the electric vehicle. In one example, the heat exchanger is thermally coupled to the traction battery thermal management system and the environment of the electric vehicle. This is particularly useful in operating situations where the passenger compartment is to be cooled by the compartment air conditioning system (i.e., in operating situations where heat needs to be extracted from the passenger compartment). By transferring heat from the compartment air conditioning system to the traction battery thermal management system and by using the heat exchanger of the traction battery thermal management system, both the compartment air conditioning system and the traction battery thermal management system can be used jointly or synergistically to perform the task of cooling the passenger compartment. In other words, the traction battery thermal management system can support the compartment air conditioning system when cooling the passenger compartment. In doing so, the cooling capacity provided by the compartment air conditioning system can be augmented by such heat transfer and the traction battery thermal management system as appropriate. This means that the cooling performance of the compartment air conditioning system can be enhanced without making hardware changes to the compartment air conditioning system. In addition, the heat transfer from the compartment air conditioning system to the traction battery thermal management system can improve the efficiency of cooling the passenger compartment. This may even be the case where the cooling capacity of the compartment air conditioning system alone is sufficient to cool the passenger compartment in a desired manner. This is due to the fact that the efficiency of the compartment air conditioning system may vary at different operating points associated with different levels of cooling performance. Here, it has been observed that the efficiency is particularly reduced if the compartment air conditioning system needs to provide a relatively high level of cooling performance. Thus, if heat is transferred to the traction battery thermal management system, the compartment air conditioning system can operate at a lower or relatively low performance level. This improves the overall efficiency of the thermal management system of the electric vehicle.

[0032] It should be noted that the above examples can be combined with each other regardless of the aspects involved.

[0033] These and other aspects of the present disclosure will become apparent and be elucidated with reference to the examples described hereinafter. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Examples of the present disclosure will be described hereinafter with reference to the following drawings.

[0035] Figure 1 An electric vehicle is shown, which has: a thermal management system including a compartment air conditioning system and a traction battery thermal management system; a data processing device according to the present disclosure; a computer program according to the present disclosure; and a computer-readable storage medium according to the present disclosure, such that a method for controlling the thermal management system according to the present disclosure can be executed,

[0036] Figure 2 is shown in more detailed schematic diagrams Figure 1 of the thermal management system, data processing device, computer program and computer-readable storage medium of the vehicle, and

[0037] Figure 3 In the view corresponding to Figure 2 a view of the alternative thermal management system is shown.

[0038] The drawings are only schematic representations and are only used to illustrate examples of the present disclosure. Identical or equivalent elements are in principle provided with the same reference signs. Detailed Description

[0039] Figure 1 An electric vehicle 10 is shown. The electric vehicle 10 is a battery electric vehicle and thus includes a traction battery 12 that is electrically connected to a traction motor unit 14 configured to drive the wheels of the vehicle 10.

[0040] To control the temperature of the traction battery 12, the electric vehicle 10 includes a traction battery thermal management system 16.

[0041] In Figure 1 the traction battery thermal management system 16 is represented by a traction battery side heat exchanger 18 and an ambient side heat exchanger 20. It should be understood that the traction battery side heat exchanger 18 and the ambient side heat exchanger 20 are thermally coupled. This detail and other details of the traction battery thermal management system 16 will be provided further below.

[0042] The vehicle 10 additionally includes a cabin air conditioning system 22 configured to control the temperature in the passenger cabin 24 of the electric vehicle 10.

[0043] In Figure 1 the cabin air conditioning system 22 is represented by a passenger cabin side heat exchanger 26 and an ambient side heat exchanger 28. It should be understood that the passenger cabin side heat exchanger 26 and the ambient side heat exchanger 28 are thermally coupled. This detail and other details of the cabin air conditioning system 22 will be provided further below.

[0044] The traction battery thermal management system 16 and the cabin air conditioning system 22 together form the thermal management system 30 of the electric vehicle 10.

[0045] The thermal management system 30 further includes a data processing device 32. The data processing device 32 is configured to control the remaining components of the thermal management system 30, in particular the traction battery thermal management system 16 and the cabin air conditioning system 22. Thus, the data processing device 32 can be referred to as a control unit.

[0046] The data processing device 32 includes a data processing unit 34 and a data storage unit 36.

[0047] The data storage unit 36 includes a computer-readable storage medium 38.

[0048] A computer program 40 is provided on a computer-readable storage medium 38 and thus also on the data storage unit 36.

[0049] The computer program 40 and thus also the computer-readable storage medium 38 include instructions which, when executed by the data processing unit 34 or more generally by a computer, cause the data processing unit 34 or the computer to execute a method for controlling the thermal management system of an electric vehicle.

[0050] Thus, the data processing unit 34 and the data storage unit 36 form a device 42 for executing the method for controlling the thermal management system of an electric vehicle.

[0051] Figure 2 The thermal management system 30 of the electric vehicle 10 is shown in more detail. For the sake of explanation, the passenger compartment 24 and the traction battery 12 are also shown schematically.

[0052] From Figure 2 It can be seen that the passenger compartment side heat exchanger 26 and the ambient side heat exchanger 28 of the passenger compartment air conditioning system 22 are fluidly coupled using two fluid connection lines 44, 46. The fluid connection lines 44, 46 allow the coolant to circulate between the passenger compartment side heat exchanger 26 and the ambient side heat exchanger 28. As will be seen from the following explanation, when circulating between the passenger compartment side heat exchanger 26 and the ambient side heat exchanger 28, the coolant undergoes a cyclic phase change. Thus, the coolant can be regarded as a refrigerant.

[0053] A compressor 48 is provided in the fluid connection line 46 so as to be able to selectively move the coolant provided in the passenger compartment air conditioning system 22 (i.e., in the fluid connection lines 44, 46, the passenger compartment side heat exchanger 26 and the ambient side heat exchanger 28).

[0054] In addition, an expansion valve 49 is provided in the fluid connection line 44.

[0055] In addition, the passenger compartment air conditioning system 22 includes a bypass line 50 which is fluidly coupled to the fluid connection lines 44, 46 via two bypass valves 52. The bypass line 50 is configured to bypass the ambient side heat exchanger 28 completely or partially.

[0056] From Figure 2 It can further be seen that the traction battery side heat exchanger 18 and the ambient side heat exchanger 20 of the traction battery thermal management system 16 are fluidly coupled using two fluid connection lines 54, 56. The fluid connection lines 54, 56 allow the coolant to circulate between the traction battery side heat exchanger 18 and the ambient side heat exchanger 20.

[0057] In this example, the coolant circulating between the traction battery side heat exchanger 18 and the ambient side heat exchanger 20 is a liquid and does not change its state of aggregation.

[0058] A pump 58 is provided in the fluid connection line 54 so as to be able to selectively move the coolant provided in the traction battery thermal management system 16 (i.e., in the fluid connection lines 54, 56, the traction battery side heat exchanger 18, and the ambient side heat exchanger 20).

[0059] In addition, the traction battery thermal management system 16 includes a bypass line 60 fluidly coupled to the fluid connection lines 54, 56 via two bypass valves 62. The bypass line 60 is configured to completely or partially bypass the ambient side heat exchanger 20.

[0060] The traction battery thermal management system 16 includes another bypass line 64 fluidly coupled to the fluid connection lines 54, 56 via two bypass valves 66. The bypass line 64 is configured to completely or partially bypass the traction battery side heat exchanger 18.

[0061] In Figure 2 the example of, the traction battery thermal management system 16 and the vehicle cabin air conditioning system 22 are thermally coupled using a coupled heat exchanger 68.

[0062] To allow such coupling, the vehicle cabin air conditioning system 22 includes a coolant flow path 70 connected to the fluid connection line 46 via a valve 72. The coolant flow path 70 extends through the coupled heat exchanger 68 and returns to the fluid connection line 46.

[0063] In a similar manner, the traction battery thermal management system 16 includes a coolant flow path 74 connected to the fluid connection line 56 via a valve 76. The coolant flow path 74 extends through the coupled heat exchanger 68 and returns to the fluid connection line 56.

[0064] A method for controlling the thermal management system of an electric vehicle can be used to control the thermal management system 30.

[0065] Hereinafter, the method will be explained in more detail.

[0066] In a first step S1 of the method, first data D1 indicating the operating conditions of the vehicle cabin air conditioning system 22 is obtained.

[0067] In Figure 2In the example, the operating conditions of the passenger compartment air conditioning system 22 are described by the rotational speed of the compressor 48. Thus, in the first step S1, data indicating the rotational speed of the compressor 48 is received. The rotational speed is used as an indicator of the heat load to be processed by the passenger compartment air conditioning system 22. This means that a high rotational speed of the compressor 48 is associated with a high heat load to be processed. Correspondingly, a relatively low rotational speed of the compressor 48 is associated with a relatively low heat load.

[0068] To be able to take the first data D1 into account in this method, the compressor 48 is communicatively connected to the data processing device 32.

[0069] Furthermore, in the second step S2, second data D2 indicating the temperature of the passenger compartment 24 and third data D3 indicating the temperature of the traction battery 12 are obtained.

[0070] For this purpose, a temperature sensor 78 is located near the traction battery 12. The temperature sensor 78 is communicatively connected to the data processing device 32. Furthermore, a temperature sensor 80 is located inside the passenger compartment 24. In addition, the temperature sensor 80 is communicatively connected to the data processing device 32.

[0071] In a subsequent third step S3, heat transfer H from the passenger compartment air conditioning system 22 to the traction battery thermal management system 16 is induced. However, the third step S3 is affected by two conditions.

[0072] The first condition relates to the fact that the first data D1 exceeds a first data threshold DT indicating an operating condition limit. This means that heat transfer H is only induced when the operating conditions of the passenger compartment air conditioning system 22 exceed the operating condition limit. The first data threshold DT is provided on the computer-readable storage medium 38.

[0073] The second condition relates to the second data D2 and the third data D3. Heat transfer is only induced when the second data D2 and the third data D3 indicate that the temperature of the traction battery 12 is lower than the temperature of the passenger compartment 24.

[0074] In this example, heat transfer from the passenger compartment air conditioning system 22 to the traction battery thermal management system 16 is accomplished by selectively inducing thermal coupling of the passenger compartment air conditioning system 22 and the traction battery thermal management system 16.

[0075] For this purpose, a coupling heat exchanger 68 is used.

[0076] This means that the coolant flow path 70 within the passenger compartment air conditioning system 22 is opened by correspondingly operating the valve 72.

[0077] Furthermore, the coolant flow path 74 is opened by correspondingly operating the valve 76.

[0078] Additionally, within the traction battery thermal management system 16, the coolant flow path is opened, which extends through or is arranged adjacent to the traction battery 12. In this example, this means that the coolant flow path extending through the traction battery side heat exchanger 18 is opened. Accordingly, the bypass line 64 is closed by operating the valve 66 accordingly.

[0079] Thus, the traction battery 12 can be used as a radiator for the cabin air conditioning system 22, because the heat transferred from the cabin air conditioning system 22 to the traction battery thermal management system 16 is dissipated into the traction battery 12.

[0080] According to an option of the method, an additional heat transfer E is caused. This additional heat transfer E extends from the traction battery thermal management system 16 to the environment of the electric vehicle 10.

[0081] For this purpose, the ambient side heat exchanger 20 of the traction battery thermal management system 16 is used. This means that the traction battery thermal management system 16 and the environment are selectively thermally coupled via this ambient side heat exchanger 20. More precisely, the coolant flow path extending through this ambient side heat exchanger 20 is selectively opened. This means that the bypass line 60 needs to be closed using the valve 62.

[0082] Note that even though the thermal management system 30 as Figure 1 and Figure 2 shown includes the ambient side heat exchanger 28, such a heat exchanger is also optional. In the case where the thermal management system 30 does not include the ambient side heat exchanger 28, the bypass valve 52 is not required. In this case, the bypass line 50 serves as a simple return line fluidly connecting the fluid connection line 44 and the fluid connection line 46.

[0083] Figure 3 An alternative thermal management system 30 is shown. Hereinafter, only the differences regarding the Figure 2 thermal management system 30 will be explained.

[0084] In Figure 3 the example, the cabin air conditioning system 22 consists of two sub-units. In the first sub-unit 22a, the coolant undergoes a phase change when circulated between the passenger compartment side heat exchanger 24 and the connected heat exchanger 81. For this purpose, a compressor 48 and an expansion valve 49 are provided. The first sub-unit 22a operates substantially in the same manner as the Figure 2 cabin air conditioning system 22 of the

[0085] example. In the second sub-unit 22b, the coolant is liquid and does not undergo a phase change when circulated between the connected heat exchanger 81 and the ambient side heat exchanger 28. The connected heat exchanger 81 and the ambient side heat exchanger 28 are fluidly connected via the fluid connection lines 44, 46. Additionally, a pump 83 is provided in the fluid connection line 44.

[0086] Heat from the passenger compartment 24 can be absorbed by the coolant in the first subunit 22a and transferred to the coolant in the second subunit 22b using the connected heat exchanger 81.

[0087] In Figure 3 the example, the vehicle air conditioning system 22 (more precisely, the second subunit 22b) and the traction battery thermal management system 16 can be fluidly coupled.

[0088] For this purpose, a first coupling line 82 is provided. The coupling line 82 is fluidly connected to the fluid line 46 via a first coupling valve 84.

[0089] Furthermore, a second coupling line 86 is provided, which is connected to the fluid line 56 via a second coupling valve 88.

[0090] Furthermore, Figure 3 the thermal management system 30 of

[0091] can be controlled using a method for controlling the thermal management system of an electric vehicle. Figure 2 Also in this context, only the differences with respect to the Figure 3 example will be explained. In the

[0092] example, causing heat transfer H from the vehicle air conditioning system 22 to the traction battery thermal management system 16 includes selectively causing fluid coupling of the vehicle air conditioning system 22 and the traction battery thermal management system 16.

[0093] In summary, in Figure 2 both examples, in Figure 3 the example, the traction battery 12 of the electric vehicle 10 can be used as a radiator for the vehicle air conditioning system 22.

[0094] Furthermore, according to the option described for the Figure 2 example (which is also valid for the Figure 3 example), a heat exchanger forming part of the traction battery thermal management system 16 (i.e., the ambient side heat exchanger 20) can be used to cool the passenger compartment 24 of the electric vehicle 10.

[0095] As used herein, the phrase "at least one" with respect to a list of one or more entities shall be understood to mean at least one entity selected from any one or more of the entities in the list of entities, but not necessarily including at least one of each entity specifically listed in the list of entities, and not excluding any combination of entities in the list of entities. This definition also allows that an entity may optionally exist outside of the entities specifically identified in the list of entities referred to by the phrase "at least one", whether or not related to those specifically identified entities. Thus, as a non-limiting example, "at least one of A and B" (or equivalently, "at least one of A or B", or equivalently, "at least one of A and / or B") can in one example mean at least one A, optionally including more than one A, with no B present (and optionally including entities other than B); in another example, it can mean at least one B, optionally including more than one B, with no A present (and optionally including entities other than A); in yet another example, it can mean at least one A, optionally including more than one A, and at least one B, optionally including more than one B (and optionally including other entities). In other words, the phrases "at least one", "one or more", and "and / or" are open-ended expressions that are both conjunctive and disjunctive in operation. For example, each of the expressions "at least one of A, B, and C", "at least one of A, B, or C", "one or more of A, B, and C", "one or more of A, B, or C", and "A, B, and / or C" can mean A alone, B alone, C alone, A and B together, A and C together, B and C together, A, B, and C together, and optionally any combination of any of the foregoing with at least one other entity.

[0096] From a study of the drawings, the disclosure, and the appended claims, other variations of the disclosed examples can be understood and effected by those skilled in the art in practicing the claimed disclosure. 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 implement 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 provided 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.

[0097] List of reference signs

[0098] 10. Electric vehicle

[0099] 12. Traction battery

[0100] 14. Traction motor unit

[0101] 16. Traction battery thermal management system

[0102] 18. Traction battery side heat exchanger of the traction battery thermal management system

[0103] 20. Ambient side heat exchanger of the traction battery thermal management system

[0104] 22. Compartment air conditioning system

[0105] 24. Passenger compartment

[0106] 26. Passenger compartment side heat exchanger of the compartment air conditioning system

[0107] 28. Ambient side heat exchanger of the compartment air conditioning system

[0108] 30. Thermal management system

[0109] 32. Data processing device

[0110] 34. Data processing unit

[0111] 36. Data storage unit

[0112] 38. Computer-readable storage medium

[0113] 40. Computer program

[0114] 42. Device for performing a method of controlling the thermal management system of an electric vehicle

[0115] 44. Fluid connection pipeline

[0116] 46. Fluid connection pipeline

[0117] 48. Compressor

[0118] 49. Expansion valve

[0119] 50. Bypass pipeline

[0120] 52. Bypass valve

[0121] 54. Fluid connection pipeline

[0122] 56. Fluid connection pipeline

[0123] 58. Pump

[0124] 60. Bypass pipeline

[0125] 62. Bypass valve

[0126] 64. Bypass pipeline

[0127] 66. Bypass valve

[0128] 68. Coupled heat exchanger

[0129] 70. Flow path

[0130] 72. Valve

[0131] 74. Flow path

[0132] 76. Valve

[0133] 78. Temperature sensor

[0134] 80. Temperature sensor

[0135] 81. Connected heat exchanger

[0136] 82. First coupling pipeline

[0137] 83. Pump

[0138] 84. First coupling valve

[0139] 86. Second coupling pipeline

[0140] 88. Second coupling valve

[0141] D1 First data

[0142] D2 Second data

[0143] D3 Third data

[0144] DT First data threshold

[0145] E Heat transfer

[0146] H Heat transfer

[0147] S1 First step

[0148] S2 Second step

[0149] S3. Third step.

Claims

1. A method for controlling a thermal management system (30) of an electric vehicle (10), wherein, The thermal management system (30) includes a cabin air conditioning system (22) configured to control the temperature in the passenger cabin (24) of the electric vehicle (10), and a traction battery thermal management system (16) configured to control the temperature of the traction battery (12) of the electric vehicle (10). The method includes: Causing heat transfer (H) from the cabin air conditioning system (22) to the traction battery thermal management system (16) (S3).

2. The method according to claim 1, wherein Causing the heat transfer (H) from the cabin air conditioning system (22) to the traction battery thermal management system (16) includes selectively causing thermal coupling of the cabin air conditioning system (22) and the traction battery thermal management system (16).

3. The method according to claim 1 or 2, wherein Causing the heat transfer (H) from the cabin air conditioning system (22) to the traction battery thermal management system (16) includes: Selectively opening a coolant flow path (70) extending through a heat exchanger (68) within the cabin air conditioning system (22), the heat exchanger (68) being thermally coupled to the cabin air conditioning system (22) and the traction battery thermal management system (16), and / or Selectively opening a coolant flow path (74) extending through a heat exchanger (68) within the traction battery thermal management system (16), the heat exchanger (68) being thermally coupled to the cabin air conditioning system (22) and the traction battery thermal management system (16).

4. The method according to any one of the preceding claims, wherein, Causing the heat transfer (H) from the cabin air conditioning system (22) to the traction battery thermal management system (16) includes selectively opening a coolant flow path extending through the traction battery (12) or disposed adjacent to the traction battery (12) within the traction battery thermal management system (16).

5. The method according to any one of the preceding claims, wherein, Causing the heat transfer (H) from the cabin air conditioning system (22) to the traction battery thermal management system (16) includes selectively causing fluid coupling of the cabin air conditioning system (22) and the traction battery thermal management system (16).

6. The method according to any one of the preceding claims, the method further comprising: Obtaining first data (D1) indicative of the operating conditions of the cabin air conditioning system (22) (S1), and If the first data (D1) exceeds a first data threshold indicative of an operating condition limit, causing the heat transfer (H) from the cabin air conditioning system (22) to the traction battery thermal management system (16).

7. The method according to any one of the preceding claims, the method further comprising: Obtaining second data (D2) indicative of the temperature of the passenger cabin (24), Obtaining third data (D3) indicative of the temperature of the traction battery (12) (S2), and If the second data (D2) and the third data (D3) indicate that the temperature of the traction battery (12) is lower than the temperature of the passenger cabin (24), causing the heat transfer (H) from the cabin air conditioning system (22) to the traction battery thermal management system (16).

8. The method according to any one of the preceding claims, the method further comprising: Causes heat transfer (E) from the traction battery thermal management system (16) to the environment of the electric vehicle (10).

9. The method according to claim 8, wherein Causing the heat transfer (E) from the traction battery thermal management system (16) to the environment includes selectively causing thermal coupling of the traction battery thermal management system (16) with the environment.

10. The method according to claim 8 or 9, wherein, Causing the heat transfer (E) from the traction battery thermal management system (16) to the environment includes: Selectively opening a coolant flow path within the traction battery thermal management system (16) that extends through a heat exchanger (20) that thermally couples the traction battery thermal management system (16) and the environment.

11. A data processing device (32) comprising means (42) for performing the method according to any one of the preceding claims.

12. A computer program (40) comprising instructions which, when executed by a computer, cause the computer to perform the method according to claims 1 to 10.

13. A computer-readable storage medium (38) comprising instructions which, when executed by a computer, cause the computer to perform the method according to claims 1 to 10.

14. Use of a traction battery (12) of an electric vehicle (10) as a radiator for a cabin air conditioning system (22).

15. Use of a heat exchanger (20) forming part of a traction battery thermal management system (16) of an electric vehicle (10) for cooling a passenger compartment (24) of the electric vehicle (10).

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