Method for temperature control of a high-voltage storage device taking into account a selected driving mode, device and vehicle

Abstract

Method for temperature control of a high-voltage storage device (3) of a vehicle (1) driven by an electric machine (2), in which a power requirement for the high-voltage storage device (3) is determined for a journey of the vehicle (1), an operating temperature range for the high-voltage storage device (3) is determined depending on the determined power requirement, and the high-voltage storage device (3) is temperature controlled such that a temperature of the high-voltage storage device (3) lies within the determined operating temperature range, characterized in that a driving mode selected by a driver of the vehicle (1) from different driving modes provided for selection for the journey is determined for the journey of the vehicle (1) by means of an operating input, and the power requirement is determined depending on the selected driving mode and depending on whether the vehicle (1) is connected to a trailer.

Description

[0001] The present invention relates to a method for temperature control of a high-voltage battery in a vehicle powered by an electric motor. In this method, a power requirement for the high-voltage battery is determined for a given driving situation, and an operating temperature range for the high-voltage battery is determined based on this power requirement. Furthermore, the high-voltage battery is temperature-controlled such that its temperature remains within the determined temperature range. The present invention also relates to a device for temperature control of a high-voltage battery in a vehicle powered by an electric motor. Finally, the present invention relates to a vehicle equipped with such a device.

[0002] High-voltage storage systems are typically used to store electrical energy in electrically powered vehicles, such as electric vehicles or hybrid vehicles. For optimal operation, these high-voltage storage systems require cooling and / or auxiliary heating of the battery cells, depending on the ambient temperature and operating point. It is known from the prior art that a high-voltage storage system, or the individual battery cells from which the high-voltage storage system is manufactured, is temperature-controlled by a suitable temperature control device. This device can be used for both cooling and heating the high-voltage storage system. The high-voltage storage system is maintained within a predefined operating temperature range.This operating temperature range is defined to ensure the most efficient operation of the electric vehicle while simultaneously minimizing damage to or aging of the high-voltage battery. However, the cooling and heating levels of the battery cells are not typically optimized for this optimal operating state. During vehicle operation, the battery cells often operate within this fixed temperature window or range, regardless of the power demand. This results in limitations in both performance and lifespan.

[0003] DE 10 2007 045 182 A1 describes the use of at least one vehicle battery of a type whose operating temperature range exceeds and / or falls below the temperature range occurring in vehicle technology. To maintain the operating temperature of the vehicle battery, it is cooled.

[0004] Furthermore, DE 10 2013 009 561 A1 discloses that, in the case of a traction battery, demand-based cooling is initiated when a traction battery temperature threshold is exceeded. This traction battery temperature threshold cannot be fixed at a predetermined value. Rather, its specific value can depend on the current performance requirements of the traction battery.

[0005] Furthermore, a method for operating a battery arrangement of a motor vehicle is known from DE 10 2012 204 410 A1. In this method, expected environmental conditions and / or operating parameters of the motor vehicle are determined.

[0006] DE 10 2012 205 852 A1 discloses a method for heating a vehicle battery used for vehicle propulsion as known.

[0007] Furthermore, DE 10 2010 031 414 A1 discloses a cooling system for demand-based temperature control of a high-performance battery. DE 103 36 743 A1 discloses a system for coordinated torque control for a vehicle.

[0008] The object of the present invention is to provide a solution for how a high-voltage storage device of a vehicle can be temperature-controlled during operation of the vehicle in such a way that the high-voltage storage device can be operated more efficiently and aging is reduced.

[0009] This problem is solved according to the invention by a method, a device, and a vehicle having the features according to the independent claims. Advantageous embodiments of the present invention are specified in the dependent claims.

[0010] A method according to the invention serves to regulate the temperature of a high-voltage battery in a vehicle powered by an electric motor. In this method, a power requirement for the high-voltage battery is determined for each vehicle journey. Furthermore, an operating temperature range for the high-voltage battery is determined based on this power requirement. The high-voltage battery is then regulated such that its temperature remains within the specified temperature range. The method also provides that a driving mode, selected by the vehicle's driver from among various available driving modes, is determined for the journey, and the power requirement is determined based on the selected driving mode and whether the vehicle is connected to a trailer.

[0011] This method is used to control the temperature of the vehicle's high-voltage storage system or battery. The high-voltage storage system can be used, in particular, to supply electrical energy to the vehicle's electric motor. Furthermore, electrical energy can be transferred from the electric motor to the high-voltage storage system during recuperation. The vehicle can be an electric vehicle or a purely electric vehicle. It can also be a hybrid vehicle, especially a plug-in hybrid. The high-voltage storage system can comprise multiple battery cells, which can be connected electrically in series and / or parallel. These battery cells can, in turn, be connected to form individual battery modules. The high-voltage storage system or the individual battery cells can be temperature-controlled by means of a temperature control unit.This temperature control unit serves both to cool and to heat the battery cells. The unit is controlled in such a way that the current temperature of the high-voltage storage system or the battery cells remains within a specific operating temperature range. This includes first heating the high-voltage storage system from its initial temperature until it reaches the operating temperature range. Subsequently, the high-voltage storage system can be cooled and / or heated to maintain its temperature within this range. Specifically, the temperature of the high-voltage storage system can be regulated to remain within this operating temperature range. This operating temperature range can, for example, also include a target operating temperature to which the high-voltage storage system is controlled.

[0012] According to a key aspect of the present invention, a power requirement for the high-voltage storage device is determined, and the operating temperature range is defined based on this power requirement. The power requirement is determined based on a selected driving mode. This driving mode describes the vehicle's driving style during operation. For example, this driving mode can be assigned to a sporty, comfortable, or fuel-efficient driving style. This driving mode can be selected by the driver before starting the journey or during the journey. The selected driving mode is recognized, and the power requirement, and thus the operating temperature range, is adjusted accordingly.In the simplest case, this can mean that different operating temperature ranges are provided or selected for the different driving modes. For example, if a sporty driving mode is selected, the operating temperature range can be higher than in a comfortable driving mode. The higher operating temperature range in the sporty driving mode increases the efficiency of the high-voltage battery, thus enabling a more sporty driving experience. In particular, the temperature range is determined to minimize the aging of the high-voltage battery and its individual cells. This prevents aging and potential damage to the battery cells, thereby avoiding the need for a replacement of the high-voltage battery, which is typically very expensive.Overall, by taking the selected driving mode into account, the high-voltage storage system or the battery cells can be temperature-controlled in such a way that efficient operation of the vehicle is enabled and at the same time the aging of the battery cells is minimized.

[0013] As previously explained, the selected driving mode can be a fuel-efficient driving mode, a comfortable driving mode, or a sporty driving mode. These different driving modes are available for selection when operating or driving the vehicle. The driver or user can select these driving modes using a control input. Different accelerator pedal characteristics can be assigned to the different driving modes. For example, in a fuel-efficient driving mode, less power may be requested from the electric motor for the same accelerator pedal travel compared to a sporty driving mode. If the vehicle is a hybrid, the driving mode can also be assigned to purely electric operation. Furthermore, in a hybrid vehicle, the driving mode can describe the extent or proportion to which the electric motor is used.Based on the selected driving mode, the expected power requirement for the high-voltage storage system can be estimated, and the operating temperature range can be precisely determined from this.

[0014] In one embodiment, the power requirement is determined based on the electrical drive power supplied by the high-voltage storage system to the vehicle's electric motor and / or on the electrical recuperation power supplied by the electric motor to the high-voltage storage system during recuperation. Thus, the power requirement can differentiate between driving the electric motor and recuperation. To propel the vehicle while driving, the electrical power or the electrical drive power is transferred from the high-voltage storage system to the electric motor. In this case, the electric motor operates as a motor. Based on the selected driving mode, it is possible to estimate the drive power to be provided by the high-voltage storage system during vehicle operation and / or the range within which the drive power will fall.The operating temperature range can then be adjusted to this drive power to enable efficient and gentle operation of the high-voltage battery. During recuperation, the electric motor operates as a generator. In this process, the recuperation power is transferred from the electric motor to the high-voltage battery. This can cause the battery cells to heat up significantly. By taking into account the proportion of recuperation power and the resulting change in battery cell temperature, efficient and gentle operation of the high-voltage battery can be guaranteed.

[0015] This system specifically allows the power requirement to be determined based on a gradient of drive power and / or a gradient of recuperation power. This means that the change in drive power and / or recuperation power over time can be determined or estimated. For example, it can be taken into account that a high gradient of drive power and / or recuperation power can lead to a significant increase in the temperature of the battery cells. A high gradient of drive power can occur, for instance, in a sporty driving mode. Therefore, based on the selected driving mode, the gradient of drive power and / or recuperation power can be determined, and the operating temperature range can be reliably derived from this.

[0016] In another embodiment, the vehicle's driving behavior is continuously monitored during operation, and the power demand is determined based on this behavior. The driver's driving behavior can be continuously analyzed during operation. In particular, the driver's use of the accelerator pedals can be recorded. This allows the system to determine whether the driver prefers a sporty or relaxed driving style. The relevant data describing the driver's behavior can be continuously collected. In this way, a self-learning system can be provided that learns the driver's behavior over time. This approach takes into account that actual driving behavior can only be reliably determined based on measurements.A simple input method where the driver enters their personal driving behavior is often insufficient. This is because drivers frequently misjudge their own driving style. Based on the recorded driving behavior, the performance requirements for the journey can be precisely estimated. It may also be possible to determine the individual driving behavior for different drivers of the same vehicle.

[0017] In a further embodiment, route data describing a route for the vehicle's journey is determined, and the power requirement is calculated based on this route data. This route data can describe a route along which the vehicle will maneuver during its journey. This route data can be received, for example, from the vehicle's navigation system. In particular, this route data can be extracted from a digital map of the navigation system. It is preferably provided that the route data also includes topological information, i.e., information about the gradients of the route sections to be traveled. From this, it can be deduced, for example, that the drive power and thus the power requirement will increase on a route section with an incline.If sections of the route have a relatively steep gradient, it can be deduced that, for example, the recuperation power is relatively high there, and therefore a heating of the battery cells is to be expected. Thus, the power requirement for the route to be traveled in the future can be predicted precisely.

[0018] The route data can also be used to determine whether the vehicle will be traveling on a highway, a rural road, in an urban area, or similar terrain for each section of the route. This information can then be used to calculate future performance requirements. For example, the performance requirements for driving on a highway can be relatively high. In this context, speed limits imposed on the route sections can also be taken into account. Furthermore, traffic information relevant to the route can be received and considered when determining performance requirements. This allows, for instance, an estimation of whether the vehicle will encounter traffic jams or whether a predominantly constant speed is possible. Overall, this results in a precise prediction of performance requirements.

[0019] Furthermore, it is advantageous to determine the power requirement based on the vehicle's load. In addition to the vehicle's known unladen weight, the payload can also be considered when determining the power requirement. Increased payload also increases the power requirement. The vehicle's payload can be determined based on the number of occupants. For this purpose, data from corresponding seat occupancy sensors can be used, for example. The vehicle's payload can also be determined using appropriate chassis sensors. Additionally, it can be checked whether the vehicle is coupled to a trailer. If the vehicle is coupled to a trailer, caravan, or similar, the power requirement will also increase during driving. Thus, the power requirement, and consequently the operating temperature range, can be determined precisely.

[0020] Furthermore, it is advantageous if the high-voltage battery is pre-conditioned before the start of a journey. At the beginning of a journey, the current temperature of the high-voltage battery may deviate significantly from its operating temperature range. This can occur, for example, if the vehicle has been parked for an extended period, such as overnight. This also applies to both cold and warm ambient temperatures. In this case, it is recommended that the high-voltage battery be pre-conditioned so that its temperature reaches the operating temperature range as quickly as possible. This can be achieved by pre-conditioning a medium used to regulate the temperature of the high-voltage battery or its individual cells. Alternatively, the pre-conditioning process can be carried out before the journey even begins.This ensures that the electric motor or electric drive is reliably available. This applies to purely electric vehicles, where the desired power output from the electric motor or high-voltage battery is required from the moment the vehicle starts moving. It also applies to hybrid vehicles, where, for example, one axle is driven by a combustion engine and the other by the electric motor. In this case, the driver expects power to be available on both axles. If power is not available on the axle assigned to the electric motor, this can confuse the driver due to the altered driving behavior and, in the worst case, compromise safety. Pre-heating the high-voltage battery prevents this.

[0021] In a further embodiment, the operating temperature range is determined as a function of the electric motor's temperature. It is typically intended that the battery cells and the electric drive operate at different temperature points. Usually, the electric motor has a higher temperature than the battery cells during vehicle operation. The temperature of the electric motor can be taken into account when determining the operating temperature range. The aim is to ensure that the optimal system state is always maintained for the customer, regardless of the selected driving mode.

[0022] A device according to the invention serves to regulate the temperature of a high-voltage battery in a vehicle powered by an electric motor. The device comprises a computing unit for determining a power requirement for the high-voltage battery and for determining an operating temperature range for the high-voltage battery depending on the determined power requirement. Furthermore, the device comprises a temperature control unit configured to regulate the temperature of the high-voltage battery such that its temperature remains within the determined temperature range.The computing unit is designed to determine the driving mode selected by the driver from among the various driving modes available for selection, and to determine the power requirement depending on the selected driving mode and whether the vehicle is connected to a trailer.

[0023] The temperature control unit can circulate a suitable medium, such as a liquid, which is used to regulate the temperature of the high-voltage storage system or the battery cells. The unit can both cool and heat the high-voltage storage system. Furthermore, the unit can include a temperature sensor to determine the current temperature of the high-voltage storage system or the individual battery cells. The computer can calculate the power requirements and derive the operating temperature range from this. The computer can also be configured to receive data describing the currently selected driving mode. Additionally, the computer can receive route data from a navigation system.Furthermore, the computing device can be designed to receive current traffic information for the route. Additionally, data regarding the vehicle's payload and / or the vehicle's connection to a trailer can be supplied to the computing device. The device is designed to carry out a method according to the invention and its advantageous embodiments.

[0024] A vehicle according to the invention comprises an electric machine and a high-voltage storage device for supplying the electric machine with electrical energy. Furthermore, the vehicle comprises a device according to the invention. The vehicle can be configured as an electric vehicle or as a purely electrically powered vehicle. Alternatively, the vehicle can be configured as a hybrid vehicle, in particular as a plug-in hybrid. In particular, the vehicle is configured as a passenger car. It can also be configured as a commercial vehicle.

[0025] The preferred embodiments and their advantages presented with regard to the method according to the invention apply accordingly to the device according to the invention as well as to the vehicle according to the invention.

[0026] Further features of the invention will become apparent from the claims, the figures, and the description of the figures. The features and combinations of features mentioned above in the description, as well as the features and combinations of features mentioned below in the description of the figures and / or shown in the figures alone, are not only usable in the combinations specified, but also in other combinations or on their own.

[0027] The invention will now be explained in more detail with reference to a preferred embodiment and the drawings. The drawings show: Fig. 1. A schematic representation of a vehicle comprising a high-voltage storage device and a device for temperature control of the high-voltage storage device; and Fig. 2 a schematic representation of the high-voltage storage device and the apparatus.

[0028] In the figures, identical or functionally equivalent elements are given the same reference symbols.

[0029] Fig. Figure 1 shows a schematic representation of a vehicle 1, which in this case is configured as a passenger car. The vehicle 1 is electrically powered. It comprises an electric motor 2 and a high-voltage storage device 3, by means of which electrical power or electrical energy can be transferred to the electric motor 2. Furthermore, during recuperation, electrical power can be transferred from the electric motor 2 to the high-voltage storage device 3. The vehicle 1 also includes a device 4 for temperature control of the high-voltage storage device 3. The vehicle 1 can be configured as an electric vehicle or as a hybrid vehicle.

[0030] Fig.Figure 2 shows a schematic representation of the high-voltage storage device 3 and the device 4 for temperature control of the high-voltage storage device 3. It can be seen that the high-voltage storage device 3 comprises a plurality of battery cells 5. These battery cells 5 can be electrically connected in series and / or parallel. The number and arrangement of the battery cells 5 shown here are purely illustrative. The device 4 includes a temperature control unit 6 by means of which the high-voltage storage device 3 and / or the battery cells 5 can be temperature-controlled. The temperature control unit 6, shown only schematically here, can be configured to pump a medium, for example, a suitable liquid, by means of which the battery cells 5 are temperature-controlled. The battery cells 5 can be both cooled and heated by means of the temperature control unit 6.

[0031] Furthermore, the device 4 includes a computing unit 7, by means of which the temperature control unit 6 can be controlled. Thus, the high-voltage storage device 3 can be temperature-controlled by the temperature control unit 6 so that its temperature remains within a specific operating temperature range. The device 4 also includes a detection unit 8, by means of which a currently set or selected driving mode can be determined. Finally, the device 4 includes at least one receiving unit 9. The receiving unit 9 can receive route data describing a route for the journey with the vehicle 1. In addition, the receiving unit 9 can receive traffic information. Furthermore, the receiving unit 9 can retrieve information or data regarding the payload of the vehicle 1 and / or the connection of the vehicle 1 to a trailer.Furthermore, the receiving device can receive 9 data sets that describe the driving behavior of a driver of vehicle 1.

[0032] To precisely determine the operating temperature range for the high-voltage storage device 3, a power requirement for the high-voltage storage device 3 is determined using the computing unit 7. This power requirement can describe, on the one hand, the electrical power or drive power that is transferred from the high-voltage storage device 3 to the electric machine 2 for propelling the vehicle 1. Furthermore, the power requirement can describe the electrical power or recuperation power that is transferred from the electric machine 2 to the high-voltage storage device 3 during recuperation. To determine the power requirement, the detection unit 8 records which driving mode has been selected by the driver. The selected driving mode can be a sporty driving mode, a fuel-efficient driving mode, or a comfortable driving mode.Depending on the selected driving mode, the expected power requirement for the journey can be determined using the computing unit 7. Based on this power requirement, the operating temperature range, within which the temperature of the high-voltage storage unit 3 is regulated by the temperature control unit 6, can then be determined.

[0033] To precisely determine the power requirement, a gradient of the drive power and / or the recuperation power can be determined using the computing unit 7. Additionally, the route data received by the receiver 9 can be used. This data can describe individual sections of the route that the vehicle 1 is to travel. In particular, the route data can be used to determine whether these sections have inclines or declines. If the route data indicates that the vehicle 1 is to be maneuvered up a mountain pass, a significant increase in the power requirement can be expected. Furthermore, traffic information can also be used to determine the power requirement. Additionally, data on the current payload of the vehicle 1 can be taken into account to determine the power requirement.This can also be used to check whether vehicle 1 is connected to a trailer or the like.

[0034] Furthermore, the device 4 can include a temperature sensor (not shown here) with which the current temperature of the high-voltage storage unit 3 or the battery cells 5 can be determined. Corresponding sensor data from the temperature sensor can be used to regulate the temperature of the high-voltage storage unit 3 to the operating temperature range. This information can also be used for pre-heating the high-voltage storage unit 3. For example, if it is determined that the current temperature of the high-voltage storage unit 3 is far outside the operating temperature range due to cold or hot ambient temperatures, pre-heating of the high-voltage storage unit 3 can be provided. This pre-heating of the high-voltage storage unit 3 can be carried out at the beginning of the journey or even before the journey.For example, if it is determined that the high-voltage battery 3 has a very low temperature because the vehicle 1 was left overnight in cold ambient conditions, the high-voltage battery 3 can first be warmed up by pre-heating or pre-conditioning. The route data can also be taken into account. If, for example, this data shows that the vehicle 1 is predominantly driven downhill or that a relatively low drive power is supplied by the high-voltage battery 3, it can be assumed that the high-voltage battery 3 will only heat up very slightly. In this case, the high-voltage battery 3 can be heated accordingly by pre-heating.

[0035] At the start of the journey and during the journey with vehicle 1, the power demand on the high-voltage storage device 3 can be continuously determined. Depending on this power demand, the high-voltage storage device 3 can then be temperature-controlled by the device 4 so that its temperature remains within the operating temperature range. This enables efficient operation of both the high-voltage storage device 3 and the vehicle 1. Furthermore, the aging and wear of the high-voltage storage device 3 can be reduced. This prevents damage and the potential need for replacement of the high-voltage storage device 3. Reference symbol list 1 vehicle 2 electric machine 3 high-voltage storage units 4 Device 5 battery cells 6 Temperature control unit 7 Computing equipment 8 Recording device 9 Receiving equipment

Claims

[1] Method for temperature control of a high-voltage storage device (3) of a vehicle (1) powered by an electric machine (2), in which a power requirement for the high-voltage storage device (3) is determined for a journey of the vehicle (1), an operating temperature range for the high-voltage storage device (3) is determined depending on the determined power requirement and the high-voltage storage device (3) is temperature controlled such that a temperature of the high-voltage storage device (3) lies within the determined operating temperature range, characterized by , that a driving mode selected by a driver of the vehicle (1) from different driving modes available for selection for the journey is determined for the journey of the vehicle (1) by means of an operating input and the power requirement is determined depending on the selected driving mode and depending on a connection of the vehicle (1) with a trailer. [2] Method according to claim 1, characterized bythat the selected driving mode is a fuel-efficient driving mode, a comfortable driving mode, or a sporty driving mode. [3] Method according to claim 1 or 2, characterized by , that the power requirement is determined depending on the electrical drive power supplied by the high-voltage storage (3) to the electric machine (2) of the vehicle (1) and / or depending on the electrical recuperation power supplied by the electric machine (2) to the high-voltage storage (3) during recuperation. [4] Method according to claim 3, characterized by , that the power requirement is determined depending on a gradient of the drive power and / or a gradient of the recuperation power. [5] Method according to any one of the preceding claims, characterized by, that during the operation of the vehicle (1) the driving behavior of the driver of the vehicle (1) is continuously determined and the power requirement is determined depending on the driving behavior of the driver (1). [6] Method according to any one of the preceding claims, characterized by , that route data describing a route for the journey of the vehicle (1) are determined and the power requirement is determined as a function of the route data. [7] Method according to any one of the preceding claims, characterized by , that the performance requirement is determined depending on the vehicle's load (1). [8] Method according to any one of the preceding claims, characterized by , that the high-voltage storage device (3) is pre-heated at the start of the journey. [9] Method according to any one of the preceding claims, characterized by, that the operating temperature range is determined as a function of the temperature of the electric machine (2) of the vehicle (1). [10] Device (4) for temperature control of a high-voltage storage device (3) of a vehicle (1) powered by an electric machine (2), comprising a computing device (7) for determining a power requirement for the high-voltage storage device (3) and for determining an operating temperature range for the high-voltage storage device (3) depending on the determined power requirement and comprising a temperature control device (6) which is configured to temperature control the high-voltage storage device (3) such that the temperature of the high-voltage storage device (3) is within the determined operating temperature range, characterized by, that the computing device (7) is designed to determine a driving mode selected by a driver of the vehicle (1) from different driving modes available for selection for the journey by means of an operating input for the journey of the vehicle (1) and to determine the power requirement depending on the selected driving mode and depending on a connection of the vehicle (1) with a trailer. [11] Vehicle (1) with an electric machine (2), with a high-voltage storage device (3) for supplying the electric machine (2) with electrical energy and with a device (4) according to claim 10.

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