Method and control arrangement for operating an electric motor of a vehicle

Abstract

Method (200) for operating (230) an electric motor system (101) of a vehicle (100), the method (200) comprising: Predetermining (210) a set of temperature profiles (T1, T2, ..., T n ) for the electric motor system (101) in an upcoming road section (510) based on a set of speed profiles (v1, v2, ..., v n ) for the upcoming road section (510) and information linked to the upcoming road section (510), wherein each temperature profile (T1, T2, ..., T n ) in the set of temperature profiles (T1, T2, ..., T n ) is linked to a speed profile (v1, v2, ..., v n ) in the set of velocity profiles (v1, v2, ..., v n ) and with an operating temperature (T) of the electric motor system (101); Determining (220) a power consumption for the electric motor system (101) based on a temperature profile (T1, T2, ..., T n) in the set of temperature profiles (T1, T2, ..., T n ) based on its threshold temperature (Th) in the upcoming road section (510); and Operating (230) the electric motor system (101) in the upcoming road section (510) according to the determined power consumption.

Description

TECHNICAL FIELD

[0001] The invention relates to a method and a control arrangement for operating an electric motor system of a vehicle, which enable preferential power extraction from the electric motor system.

[0002] The invention also relates to a computer program and a computer-readable medium as well as a vehicle with such a control arrangement. BACKGROUND

[0003] The following description of technical principles concerns the background of the invention and does not necessarily include prior art.

[0004] One of the main global challenges today is the reduction of the negative impacts of road traffic on the environment due to environmentally harmful gas emissions. For motor vehicles, such as passenger cars, trucks, and buses, the cost of fuel is a significant expense for the vehicle owner or user. This has led to increased efforts in vehicle electrification. The powertrain of vehicles powered at least partially by electric energy, i.e., electric vehicles and hybrid vehicles, has an electric motor system with a battery for energy storage and at least one electric motor. Electric vehicles are expected to efficiently and reliably provide motive power and energy to propel the vehicle at a required speed, as well as braking power and energy to brake the vehicle efficiently and safely.Driving performance and distance can be improved through efficient use of the drive train.

[0005] The performance of an electric motor system is limited for one or more reasons, such as thermal performance. The electric motor system in a vehicle operates efficiently and safely at a safe operating temperature. A safe operating temperature is often limited by a maximum operating temperature in one or more components of the system. At temperatures above the maximum operating temperature, the service life of the electric motor system components is reduced. Excessively high temperatures can also lead to component failure.

[0006] Electric vehicles powered exclusively by electric energy must be dimensioned to meet high power requirements. Under normal conditions, the energy requirements of an electric vehicle can be relatively low. However, to cope with long periods of high energy demands and temperature stresses, electric motor systems are often oversized, heavy, large, and expensive. On the other hand, undersized electric motor systems are unable to provide the required power in situations where the power output is limited by some parts of the electric motor system. This is particularly a problem for vehicles with relatively small powertrains.

[0007] In modern vehicles, the operating temperature of various components of an electric motor system is often monitored. If an operating temperature exceeds a target temperature limit, a common solution to the problem is to reduce the load on the motor, e.g., by electronically limiting the motor's power output. This reduces the torque generated by the motor, which in turn leads to reduced vehicle speed or even braking the vehicle to a standstill. This reduces the overall performance of the vehicle.

[0008] In hybrid vehicles, the power provided by the electric motor system does not have to limit the vehicle's propulsion, as propulsion power can be generated by the vehicle's internal combustion engine. However, an efficient and lightweight electric motor system can reduce a hybrid vehicle's fuel consumption.

[0009] DE 10 2013 016 569 A1 describes an operating method for a hybrid drive of a motor vehicle, in particular a plug-in hybrid or range extender vehicle that can be operated with multiple operating modes. DE 10 2013 016 569 A1 describes, in particular, an operating method for selecting optimal operating modes of the hybrid drive along a route. The operating method comprises the steps of dividing a route into a sequence of route sections; determining at least one predicted target variable for each of the operating modes of the hybrid drive on each route section along the route; determining an optimal path for the route, wherein a path is a sequence of operating modes along the route such that each route section is assigned an operating mode and the optimal path is the path that has an optimal value for the at least one target variable.

[0010] DE 10 2015 113 699 A1 generally describes a system, a device, a method, and a process for creating a route-based energy consumption estimate based on physical models. In particular, DE 10 2015 113 699 A1 describes the creation of the route-based energy consumption estimate based on physical models for a vehicle traveling on a specific road section. The energy consumption estimate can be based on information related to historical energy consumption information for the vehicle, external information that can influence energy consumption by the vehicle, vehicle system information that can influence energy consumption by the vehicle, and / or selected road section information that can be used to predict energy consumption by the vehicle.

[0011] DE 10 2019 118 415 A1 describes a method for predicting an expected charging time of an HV battery of a motor vehicle, comprising the following steps: - determining a route to be traveled by means of a route determination system of the motor vehicle, - detecting an actual temperature of the HV battery by means of a detection device of the motor vehicle, - determining an expected temperature development of the HV battery as a function of the determined route by means of a determination device of the motor vehicle, - determining an expected battery temperature of the HV battery at a charging station by means of the determination device, - determining an expected state of charge of the HV battery at the charging station by means of the determination device, and - determining an expected charging time of the HV battery at the charging station by means of the determination device.

[0012] DE 10 2018 216 091 A1 describes a controller for controlling the operation of at least a first and a second traction machine in a vehicle. The controller includes a processor configured to predict an operating temperature of each of the at least first and second traction machines for at least a portion of a current route. The processor determines at least first and second torque requests for the at least first and second traction machines. The at least first and second torque requests are determined as a function of the predicted operating temperatures of the at least first and second traction machines. The processor generates at least a first and a second traction motor control signal as a function of the determined at least first and second torque requests. SHORT DESCRIPTION

[0013] It is an object of the present invention to provide a method and a control arrangement for mitigating or overcoming disadvantages of conventional solutions. In particular, it is an object of the present invention to provide a solution regarding the operation of an electric motor system of a vehicle that prevents the limits of the design components of the electric motor system from being reached.

[0014] According to a first embodiment of the invention, the above and other objects are achieved by a method for operating an electric motor system of a vehicle, the method comprising: Predicting a set of temperature profiles for the electric motor system in an upcoming road section based on a set of speed profiles for the upcoming road section and information regarding the upcoming road section, each temperature profile in the set of temperature profiles being linked to a speed profile in the set of speed profiles and an operating temperature of the electric motor system; Determining a power draw for the electric motor system based on a temperature profile in the set of temperature profiles based on its threshold temperature in the upcoming road segment; and Operating the electric motor system in the road section according to the specific power consumption.

[0015] An electric motor system may comprise an electric motor, power electronics, and associated battery systems. The temperature in the components of the electric motor system changes over time, primarily depending on the power drawn from the electric motor system when delivering motive power or braking force from the electric motor in the vehicle to the drive wheels of the vehicle when the vehicle is in motion. Such temperature fluctuation corresponds to the temperature profile mentioned above.

[0016] Each temperature profile from the set of predetermined temperature profiles can be linked to a speed profile such that each temperature profile corresponds to a specific speed profile. Each temperature profile from the set of predetermined temperature profiles can further be linked to an operating temperature of the electric motor system such that each temperature profile represents a temperature change in one or more components of the electric motor system as a function of time when the electric motor provides drive or braking power for propelling or braking the vehicle in the road section according to the associated speed profile. The operating temperature of the one or more components can be different for each component.

[0017] Information related to an upcoming road section for the vehicle may include conditions that, for example, influence the power and thermal requirements for the vehicle's electric motor system when the vehicle travels on that road section. Such conditions may include the upcoming road topology, expected speed requirements, ambient temperatures, etc.

[0018] By predicting a set of temperature profiles for the electric motor system in an upcoming road section based on a set of speed profiles for the upcoming road section and information related to the upcoming road section, temperature changes in various components of the electric motor system can be estimated when a power draw from the electric motor system corresponds to the power required to propel the vehicle in the upcoming road section according to the associated speed profile.

[0019] By determining a power consumption for the electric motor system in the upcoming road section based on the temperature profile of the electric motor system and by operating the electric motor system in the road section according to the power consumption for the electric motor system, the risk of the electric motor system reaching its thermal limit is significantly reduced.

[0020] This allows the electric motor system to be used with increased efficiency, improves performance across the driving range, and extends its service life. The driver of the vehicle feels more power available compared to the size of the vehicle's engine. The need for undersizing, development costs, and the weight of the system are reduced, thus improving sustainability. Furthermore, by using the solution according to the invention in hybrid vehicles, the fuel efficiency of the vehicle can be improved due to the lower vehicle weight and the improved efficiency of the electric motor system.

[0021] In one embodiment of the invention, each speed profile in the set of speed profiles has an average speed, and the determination of the power draw for the electric motor system is further based on the average speed of each individual speed profile.

[0022] By determining the power consumption for the electric motor system based on the average speed of each individual speed profile, the speed of the vehicle can be adjusted as desired.

[0023] In one embodiment of the invention, the average speed of the speed profile is the highest average speed in the upcoming road section.

[0024] This reduces the risk of unwanted speed loss due to thermal limitations in the electric motor system.

[0025] In one embodiment of the invention, the determination of the power consumption for the electric motor system takes into account the energy consumption of the electric motor system in the upcoming road section.

[0026] By determining the power consumption for the electric motor system, taking into account the energy consumption of the electric motor system in the upcoming road section, the energy consumption for the vehicle can be controlled and limited.

[0027] This can also increase the driving range of the vehicle.

[0028] In one embodiment of the invention, the wear of the electric motor system in the upcoming road section is taken into account when determining the power consumption for the electric motor system.

[0029] This allows the electric motor system to be controlled safely while limiting the wear of the components of the electric motor system and reducing the risk of a reduced service life of the electric motor system.

[0030] In one embodiment of the invention, the method further includes: a predetermination of the set of temperature profiles additionally based on vehicle configuration data for the vehicle.

[0031] By predetermining the set of temperature profiles, additionally based on vehicle configuration data, the temperature profiles can be modeled and precisely predicted for different vehicle types. Inadequate modeling of the thermal limitations in the electric motor system can lead to improper control of the vehicle's electric motor system.

[0032] This allows the electric motor system to be controlled in a precisely adapted manner and reduces the risk of premature aging of a component as well as the risk of premature reduction in the efficiency of the electric motor system and the risk of reduced drivability of the vehicle.

[0033] In one embodiment of the invention, the vehicle configuration data is one or more of the following: a current weight, a vehicle model, a transmission type, a drivetrain configuration, an axle configuration, and the type of tires.

[0034] This allows the temperature profiles to be precisely predicted, taking into account the vehicle configuration data, which may influence the thermal properties of the electric motor system.

[0035] In one embodiment of the invention, the information regarding the upcoming road section is one or more of the following: topographical data, cartographical data, traffic data and vehicle-to-everything interaction data.

[0036] This means that the information regarding the upcoming road section can include any information that could influence the thermal properties of the electric motor system. This allows the electric motor system to be controlled reliably and accurately, reducing the risk of premature component aging and reducing the risk of reduced efficiency of the electric motor system and the quality of the vehicle's handling.

[0037] In one embodiment of the invention, the method further includes predetermining the set of temperature profiles on an additional set of power loss profiles for the electric motor system in the upcoming road section.

[0038] By predetermining the set of temperature profiles also based on a set of power loss profiles for the electric motor system in the upcoming road section, a reliable and accurate temperature prediction is ensured taking into account the efficiency of the electric motor system under different load conditions.

[0039] This allows the electric motor system to be controlled in a reliable and precise manner, reducing the risk of premature aging of components and the risk of a reduction in the efficiency of the electric motor system as well as the risk of deteriorated driving characteristics of the vehicle.

[0040] In one embodiment of the invention, the operating temperature is one or more of the following: a temperature of a winding, a temperature of power electronics, a temperature of a permanent magnet of the electric motor system, a temperature of a battery cell in the battery system, and a temperature of a battery pack in the battery system.

[0041] This reduces the risk of wear, shortened service life or failure of components in the electric motor system.

[0042] According to a second embodiment, the invention relates to a control arrangement for controlling an electric motor system of a vehicle, wherein the control arrangement is designed to Predicting a set of temperature profiles for the electric motor system in an upcoming road section based on a set of speed profiles for the upcoming road section and information associated with the upcoming road section, each temperature profile in the set of temperature profiles being linked to a speed profile in the set of speed profiles and an operating temperature of the electric motor system; Determining a power draw for the electric motor system based on a temperature profile in the set of temperature profiles based on its threshold temperature in the upcoming road section; and Operating the electric motor system in the road section according to the specific power consumption.

[0043] It is understood that all features of the exemplary embodiments of the invention described in connection with the method also apply to at least one embodiment of the control arrangement according to the invention. Thus, all exemplary embodiments described in connection with the method features of the invention can also be implemented by the control arrangement, i.e., a device that can also be a control device. The control arrangement of these exemplary embodiments has advantages corresponding to those described above in connection with the methods and their embodiments.

[0044] According to a third embodiment of the invention, the above and other objects are achieved with a vehicle having the control arrangement according to the second embodiment of the invention. The vehicle may be, for example, a bus, a truck, or a passenger car.

[0045] According to a fourth embodiment, the invention relates to a computer program with instructions which, when the program is executed by a computer, cause the computer to carry out the method according to the first embodiment.

[0046] According to a fifth embodiment of the invention, it relates to a computer-readable medium with instructions which, when executed by a computer, cause the computer to carry out the method according to the first embodiment.

[0047] Further advantageous embodiments of the method, the control arrangement, the vehicle, the computer program and the computer-readable medium according to the present invention as well as further advantages of the embodiments of the present invention emerge from the detailed description of embodiments. BRIEF DESCRIPTION OF THE CHARACTERS

[0048] Embodiments of the invention will now be described in more detail in conjunction with the accompanying figures, wherein corresponding reference numerals are used for corresponding components: Fig. 1 schematically shows an exemplary vehicle in which embodiments of the present invention may be implemented; Fig. 2 shows a flowchart for a method for operating an electric motor system of a vehicle according to an embodiment of the invention; Fig. 3 illustrates the travel of a vehicle over a route according to an embodiment of the invention; Fig. 4 shows a control arrangement in which a method according to one of the embodiments described here can be implemented. DESCRIPTION OF DETAILS

[0049] Typically, an electric motor system designed to consistently meet high performance and temperature requirements is unnecessarily heavy, large, and expensive.

[0050] On the other hand, an electric motor system that is not properly dimensioned may fail to deliver the required power in situations where the power draw is thermally limited with respect to some components of the electric motor system.

[0051] It is an object of the present invention to provide a method and a control arrangement with which a power output from an electric motor system is enabled to overcome or at least partially overcome the above problems.

[0052] Fig. Figure 1 schematically shows a vehicle 100 and is used below to explain the exemplary embodiments presented here. The vehicle 100 can be, for example, a passenger car, a bus, or a truck. The vehicle 100 according to Fig. 1 has an electric motor system 101 with at least one electric motor 102, which is configured to drive drive wheels 111, 112 of the vehicle 100. In the illustrated embodiment, the vehicle 100 has two drive wheels 111, 112, but it is understood that the vehicle 100 may also be provided with one or more drive wheels. The at least one electric motor 102 may, as in Fig. 1, may be connected to a transmission 104 via an input shaft 106. The vehicle 100 may have a drive shaft 107 of the transmission 104, which drives the drive wheels 111, 112 via a central gear 105, for example, a conventional differential, as well as two drive shafts 108, 109 of the vehicle 100. The vehicle 100 may be configured in any known manner, for example, without a transmission 104 or even without a conventional differential, which does not limit the scope of the invention.

[0053] The at least one electric motor 102 can be located essentially anywhere as long as it provides torque to the one or more wheels 111, 112, for example, it can be located adjacent to one or more wheels or it can be located in other conventional manner, as will be appreciated by those skilled in the art. The at least one electric motor 102 can be supplied with electrical energy from a battery system 103 via an electronic power module 110, the latter two components being part of the electric motor system 101 of the vehicle 100. The battery system 103, in one embodiment, can comprise one electric battery unit or it can include multiple electric battery units. In another embodiment, the battery system 103 can comprise a fuel cell, optionally in combination with a battery unit.The electronic power module 110 converts the DC voltage of the battery unit into a voltage required by the electric motor, typically a three-phase AC voltage.

[0054] The vehicle 100 may be a purely electric vehicle, which only has electric motors 102 for driving the drive wheels 111, 112 of the vehicle 100. However, the vehicle 100 may also be a so-called hybrid vehicle and also have an internal combustion engine (not in Fig. 1), such as an internal combustion engine or any other internal combustion engine, which are connected in a conventional manner to the transmission 104 via a clutch (not shown in Fig. 1).

[0055] The electric motor system 101 is controlled by a vehicle control system via a control arrangement 120. The control arrangement 120 can be implemented distributed across several individual control units, wherein the individual units are configured to control different components of the vehicle 100. The control arrangement 120 can, for example, contain: a predetermination unit 121, a determination unit 122, and an operating unit 123, which are configured to carry out the method steps of the invention described here, as will be explained in more detail below. The control arrangement 120 and / or another control arrangement can further be configured to control any other unit / device / feature of the vehicle 100. Fig. 1, however, only those units / devices / conditions of the vehicle are shown that are helpful for understanding the present invention. The control arrangement 120 is described in further detail in Fig. 4 described.

[0056] The vehicle 100 may further include one or more sensors 130, e.g., at least one camera, arranged at a suitable location on or in the vehicle 100.

[0057] Furthermore, the vehicle 100 may include a positioning system / positioning unit 140. The positioning unit 140 may be based on a satellite navigation system, such as Navigation Signal Timing and Ranging (Navstar), a Global Positioning System (GPS), a Differential GPS (DGPS), Galileo, GLONASS, or the like. Thus, the positioning unit 140 may include a GPS receiver.

[0058] The vehicle 100 may further comprise at least one communication device 150 configured for communication with at least one device 160 external to the vehicle 100, such as at least one communication device of another vehicle. Accordingly, the communication device 150 may be: a vehicle-to-vehicle (V2V) communication device, a vehicle-to-infrastructure (V2I) communication device, a vehicle-to-everything (V2X) communication device, and / or a wireless communication device, such that communication between the vehicle and at least one external device 120 is enabled.

[0059] The proposed invention will now be described in more detail with reference to a method 200 which is Fig. 2, for operating an electric motor system 101 of a vehicle, such as the vehicle 100 according to Fig. 1. Procedure 200 includes: in step 210 according to Fig. 2, a set of temperature profiles for an electric motor system 101 in an upcoming road section 510 is predetermined based on a set of speed profiles for the upcoming road section 510 and information associated with the upcoming road section 510, wherein each temperature profile in the set of temperature profiles is associated with a speed profile in the set of speed profiles and an operating temperature T of the electric motor system 101; in step 220 according to Fig. 2, a power consumption for the electric motor system 101 is determined based on a temperature profile in the set of temperature profiles based on its threshold temperature Th in the upcoming road section 510; and in step 230 according to Fig. 2, the electric motor system 101 is operated in the road section 510 according to the determined power consumption.

[0060] As previously explained, the electric motor system 101 may include at least one electric motor 102, an associated battery system 103, and an electronic power module 110.

[0061] The method 200 can be carried out when the vehicle 100 is driven by the electric motor system 101, wherein the traction forces and the braking forces for propulsion and braking of the vehicle are generated by one or more electric motors 102.

[0062] The speed of the vehicle 100 can be automatically controlled by a control arrangement 120 which repeatedly executes the method steps 210-230 based on, for example, information regarding the road section in front of the vehicle 100 such that the power extraction from the electric motor system 101 is optimized taking into account its thermal limitations.

[0063] The method 200 and further embodiments of the invention will now be explained in further detail and with regard to Fig. 3. Fig. 3 shows a driving scenario in which the execution of the method 200 according to Fig. 2 and further embodiments of the method are implemented. Fig. 3 shows a vehicle, such as the vehicle 100 according to Fig. 1, which has an instantaneous speed v ctravels over a route, wherein the reference number 510 refers to an upcoming road section.

[0064] As explained above, the speed of the vehicle 100 may be automatically controlled. In one example, such automatic speed control may be provided by a cruise control function. The cruise control function may be of a type that uses additional information in controlling the vehicle. For example, the cruise control may include a so-called "look-ahead" function, e.g., an active look-ahead function. Look-ahead control (LACC) has a cruise control function using knowledge of the upcoming section 510 of road, i.e., knowledge of the topography of the road ahead of the vehicle, to adjust the vehicle speed according to changes in the road on which the vehicle is traveling.

[0065] In another example, the speed of the vehicle 100 may be controlled in the vehicle's powertrain control system according to the sequence of steps 210-230 by changing the driver's actions on the accelerator pedal.

[0066] The speed of the vehicle 100 can be controlled by determining at least one speed profile v1 v2, ..., v n regarding the upcoming road section 510 accordingly Fig. 3. The at least one speed profile may include an expected speed variation of the vehicle 100 when the vehicle is guided over the upcoming road section 510. In other words, a speed profile may represent an expected speed variation of the vehicle in the upcoming road section 510. The expected speed variation may be derived in a conventional manner from the current speed of the vehicle v cdepend on speed limits on the upcoming road section 510, traffic conditions, driver wishes, etc., to name just a few relevant parameters.

[0067] The travel of vehicle 100 along the upcoming road section 510 according to the speed profile requires the electric motor 102 of vehicle 100 to provide a certain amount of power, whether for traction or braking, to the vehicle's drive wheels, with the power corresponding at any given time to the speed of the speed profile. The load on the electric motor system 101 thus varies depending on the power variation, and thus also the temperature of the components.

[0068] If appropriate Fig. 3 the vehicle 100 travels at a speed corresponding to one of the speed profiles v1, v2, ..., v n, then the load on the electric motor system 101 and the corresponding components causes a temperature variation in the components of the electric motor system 101. The temperature variation caused is in Fig. 3 example with the temperature profiles T1, T2, ..., T n Thus, each of the velocity profiles (there may also be a single velocity profile) corresponds to v1, v2, ..., v n a temperature profile, ie an expected temperature development per unit of time T1, T2, ..., T n in the various components of the electric motor system 101 of the vehicle 100 when the vehicle speed corresponds to a speed profile in the road section 510. The temperature development here can affect the temperature of components of the electric motor 102, the electronic power module 110, and the battery system 103, which will be explained further.

[0069] In step 210 accordingly Fig. 2, the set of temperature profiles, ie the expected temperature evolution T1, T2, ..., T n per unit of time of the electric motor system 101 in an upcoming road section 510.

[0070] The predetermination of a set of temperature profiles in the electric motor system 101 in an upcoming road section 510 according to step 210 in Fig. 2 may include that for each velocity profile v1, v2, ..., v n based on information linked to the upcoming road section 510, at least one corresponding temperature variation T1, T2, ..., T n per unit of time.

[0071] The predetermined set of temperature profiles T1, T2, ..., T nmay include one or more temperature profiles, each temperature profile relating to a temperature variation in a component of the electric motor system 101. Each temperature profile for a specific component may thus indicate the temperature of the component during the load on the component, which occurs when the vehicle speed varies according to one of the specific speed profiles v1, v2, ..., v n in the upcoming road section 510 varies.

[0072] The prediction of the set of temperature profiles can be achieved here according to conventional methods based on thermal models for each component, in which a temperature change (temperature variation) in the component is represented as a function of the load on the component.

[0073] The load acting on each of the components during travel according to each of the determined speed profiles v1, v2, ..., v nin the upcoming road section 510 can be obtained by modelling the travel time dynamics and / or by extrapolation from measured load values.

[0074] As with any modeling, the load on the electric motor system 101 can be modeled at different levels of detail, which affects the accuracy of the load predictions. In other words, the prediction of the set of temperature profiles in step 210 according to Fig. 2 can be based on a number of factors that influence the temperature of the components of the electric motor system 101, such as road topology, ambient temperature, and various internal energy losses within the vehicle. Some of these factors will now be explained in more detail.

[0075] The set of temperature profiles T1, T2, ..., T n for the electric motor system 101 can be based on the determined set of speed profiles v1, v2, ..., v nfor the upcoming road section 510 and information associated with the upcoming road section 510.

[0076] In one embodiment, the information associated with the upcoming road segment 510 is one or more of the following: topographical data, cartographic data, traffic data, and vehicle-to-everything interaction data.

[0077] The information associated with the upcoming road section 510 may include, for example, topographical data, such as the road gradient and the amount of uphill and / or downhill sections. Such information may be obtained from digital maps and cartographic data in combination with position information, e.g., based on a global positioning system (GPS). The position information may be used to determine the location of the vehicle relative to map data, so that the information regarding the road section may be derived from the map data. Various modern cruise control systems utilize map data and position information. Such systems may then supply the system for the present invention with map data and position information.In one example, information regarding the upcoming road section 510 can be received as a communication from at least one other vehicle. Such communication can occur, for example, via V2V communication, V2I communication, V2X communication, or the like. In another example, topographical information can be stored in the vehicle and selected in combination with position information.

[0078] According to another example, information associated with the upcoming road section may be obtained in the vehicle using on-board sensors and cameras or a lidar device related to the upcoming road section. The collection of information may, for example, occur while the vehicle is traveling along a road section. Such collected information may be stored in the vehicle and used the next time the vehicle travels along the road section. In one example, corresponding vehicle data may also be obtained and stored in the vehicle. For example, the temperature of components of the electric motor system 101 may be measured while traveling along a particular road section and stored in the vehicle.

[0079] Such information may be used in predicting the set of temperature profiles for the electric motor system 101 in an upcoming road section 510 in step 210 of the method 200. Such prediction may thus be performed by, for example, a self-learning technique in the vehicle using the resulting temperature profile over a specific road section.

[0080] By taking into account the information associated with the upcoming road section 510 when predetermining the set of temperature profiles T1, T2, ..., T n an expected load on the electric motor system 101 of the vehicle 100 can be calculated according to the propulsion force required to drive the vehicle at a speed corresponding to the set of speed profiles v1, v2, ..., v nin the upcoming road section 510. If the upcoming road section 510 has an incline, the vehicle's dynamics are influenced by incline-induced forces. Since the vehicle 100 can travel uphill or downhill, the incline-induced forces either hinder or enhance the traction forces of the vehicle 100. When traveling uphill, the incline-induced force creates a resistance to the vehicle's traction forces, thus increasing the load acting on the electric motor system 101 and thus causing a rise in temperature. When traveling downhill, the incline-induced force increases the vehicle's traction force. The use of the electric motor system 101 and the drivetrain of the vehicle 100 for regenerative braking and also for braking the vehicle 100, which causes decelerating forces, should be considered when predicting the temperature profiles.Such calculations can be performed using conventional methods. By using Newton's laws of motion, the propulsive forces or braking forces corresponding to the load on the electric motor system 101 can be calculated based on parameters such as the vehicle mass, speed, and the gradient of the road ahead, to name a few. The temperatures of the components of the electric motor system 101, for example, can be calculated based on theoretical models for component temperature as a function of motor power.

[0081] The temperatures in the components of the electric motor system 101 may also depend on various internal losses within the vehicle when the traction force is transferred from the electric motor to the vehicle's drive wheels or from the wheels to the engine when the electric motor is used as a brake, i.e., as a generator. Such losses may depend on a number of resistive forces acting on the vehicle when it is in motion, such as pitch-induced forces, aerodynamic drag, rolling resistance, etc.

[0082] Thus, in one embodiment, the prediction 210 of the set of temperature profiles is further based on vehicle configuration data relating to the vehicle 100.

[0083] In one example, the prediction 210 of the set of temperature profiles may be based on a current weight of the vehicle 100. As described above, the weight of the vehicle may be used, along with topographical data, to predict the power required of the electric motor 102 to propel the vehicle 100 at a particular speed.

[0084] In another example, the prediction 210 of the set of temperature profiles is based on a vehicle model. For example, the cross-sectional area of ​​the vehicle, which depends on the size and shape of the vehicle, may influence the anticipated load on the electric motor system 101 and its components due to the aerodynamic drag the vehicle experiences while driving.

[0085] In another example, the prediction 210 of the set of temperature profiles may be further based on vehicle configuration data, such as the type of transmission, the configuration of the driveline, the axle, and / or the type of tires.

[0086] The load on the electric motor system 101 and its components can also be influenced by mechanical losses in the transmission and drivetrain, such as rolling losses and friction losses. Tire types, air pressure, etc., can influence the rolling resistance of the vehicle, which in turn contributes to the load on the electric motor system 101.

[0087] Vehicle configuration data can be obtained from a configuration file stored in the vehicle, or it can be obtained in a conventional manner. For example, the air pressure in the vehicle's tires can be obtained from sensor measurements.

[0088] This allows the temperature profiles to be precisely predicted taking into account the vehicle configuration data, which can influence the thermal conditions of the electric motor system.

[0089] As explained above, each temperature profile T1, T2, ..., T n in the set of temperature profiles are linked to a velocity profile in the set of velocity profiles v1, v2, ..., v n and an operating temperature T of the electric motor system 101.

[0090] The operating temperature T may here be a temperature relating to one or more components of the electric motor system 101, wherein the component in question must be kept at a safe operating temperature, ie below or significantly below a temperature threshold Th associated with the component, so that the service life of the component does not decrease or a failure of the component does not occur.

[0091] Thus, each velocity profile v1, v2, ..., v n correspond to one or more temperature profiles, each temperature profile representing a temperature variation in a component of the electric motor system 101, where due to various losses the temperature may rise and thus the service life of this component may be shortened or the component may fail.

[0092] According to embodiments, the operating temperature T may be one or more of the following: the temperature of a winding, the temperature of power electronics, the temperature of a permanent magnet of the electric motor system 101, the temperature of a battery cell in the battery system 103, and the temperature of a battery pack in the battery system 103.

[0093] In other words, the prediction of a set of temperature profiles in step 210 according to Fig. 2 may include predetermining a set of temperature profiles per component of the electric motor system 101, where the component may be one of the following: temperature of a winding, temperature of one or more power electronics, temperature of a permanent magnet of the electric motor system 101, temperature of a battery cell in the battery system 103, and temperature of a battery pack in the battery system 103.

[0094] An electric motor converts electrical energy into mechanical energy. The electric motor operates through the interaction between the motor's magnetic field and an electric current in a wire winding. High temperatures can impair the winding insulation or shorten the wire winding's service life, and excessive currents can even cause the winding to fail. Thus, in an example, any speed profile v1, v2, ..., v ncorrespond to a temperature profile of the wire winding in the electric motor 102.

[0095] A permanent magnet motor uses permanent magnets in addition to the winding, not just one winding. High temperatures in the permanent magnets can lead to demagnetization of the permanent magnets and thus motor failure. Thus, in an example, each speed profile corresponds to v1, v2, ..., v n a temperature profile of a permanent magnet in the electric motor 102.

[0096] The main losses in an electronic power module 110 can arise due to current conduction and switching in the transistors. Excessively high temperatures can lead to overheating of the transistors, which can shorten their lifetime or even cause failure. Thus, in an example, each speed profile v1, v2, ..., v na temperature profile of the transistors in the electronic power module 110.

[0097] The lifetime of the battery system may also decrease if the temperature of battery system components rises above a threshold. This is particularly important in hybrid vehicles, where the battery system is typically small compared to purely electric vehicles and where power output from each cell can contribute. Thus, in one example, each speed profile corresponds to v1, v2, ..., v n a temperature profile of the battery cell or battery pack in the battery system 103.

[0098] As described above, the temperatures in the components of the electric motor system 101 vary depending on the load on the system, i.e., the power drawn from the system, and the losses in the system. Each component in the electric motor system 101 can be linked to a corresponding power loss profile. A power loss profile of a component contains a relationship between the component temperature variation and the load acting on the component, which in turn depends on the speed of the vehicle. The prediction 210 of the set of temperature profiles can be further based on a set of power loss profiles relating to the electric motor system 101 in the upcoming road section 510, resulting in an even more accurate prediction of the temperature distribution in the electric motor system 101 at different vehicle speeds.

[0099] Thus, in one embodiment, the prediction 210 of the set of temperature profiles may be additionally based on a set of power loss profiles for the electric motor system 101 in the upcoming road section 510.

[0100] An electric motor system 101 in a motor vehicle 100 operates efficiently and safely when its operating temperature T is within its safe operating temperature range. A safe operating temperature is often limited by a temperature threshold Th, such as Fig. 3. The temperature threshold may depend on which component of the motor system is considered. The temperature threshold Th of a component or system may indicate a maximum permissible operating temperature of the component or system. When temperatures above the safe operating temperature are reached, wear on the electric motor system 101 and its components increases, which may lead to a shortened service life of the components or even their failure. The extent of wear or deterioration of the component when the temperature threshold is exceeded with respect to the component depends on the type of component, the extent to which the temperature threshold is exceeded, and the time for which the temperature threshold is exceeded.

[0101] For some components, the temperature threshold Th may never be exceeded, while for other components, a slight exceedance of the temperature threshold Th is possible for limited periods of time. In some cases, it may even be desirable to temporarily exceed the temperature threshold Th in order to increase the power output from the electric motor system 101 and thus the average speed.

[0102] T1 according to Fig. 3 is a temperature profile corresponding to the speed profile v1 with a temperature variation below the temperature threshold Th. T2 is a temperature profile corresponding to the speed profile v2 with a temperature variation that is substantially below the temperature threshold Th, with the temperature briefly exceeding the temperature threshold Th, and T n is a temperature profile corresponding to the velocity profile v n, where the temperature variation significantly exceeds the temperature threshold over a non-negligible period of time.

[0103] For an illustrative and highly simplified example, assume that a component of the electric motor system 101 can be operated at temperatures in the range of 1 to 10, where 1-7 corresponds to a normal range of temperatures with expected wear of the electrical component and the electric motor system 101. At a temperature of 8, which corresponds to a threshold value according to this description, the wear of the component increases significantly, even more so at temperature 9, and at temperature 10 the component fails. Furthermore, assume that in this simplified illustrative example, the duration of one minute at temperature 8 wears the component such that its overall service life is reduced by 1%; two minutes results in a service life reduction of 2.5%, and 10 minutes results in component failure.Similarly, a duration of one minute at temperature 9 increases the wear on the component such that its overall lifetime is reduced by 5%; two minutes would result in a 15% reduction in overall lifetime, and 5 minutes would result in component failure. From this highly simplified example, it is possible to exceed the threshold, but this comes at the cost of increased wear and a reduction in the overall lifetime of the component. Furthermore, assume that the vehicle 100 is driven uphill and that the temperature rises as the vehicle 100 drives uphill. Suppose that immediately before the top of the hill the temperature just reaches 8, so the vehicle 100 drives for 30 seconds at temperature 8.The uphill section is followed by a downhill section in which the vehicle 100 can coast / freeze, causing the component temperature to drop below 8 in 15 seconds. This means that the total time the component operates at a temperature of 8 is 45 seconds. This can be considered acceptable, although the question of what is acceptable should be decided either by the vehicle manufacturer or by the operator / owner. If the vehicle 100 does not coast / freeze on the subsequent downhill section, but instead uses the electric motor brake to reduce speed, this will result in an even greater temperature stress on the component. Such a temperature increase cannot be acceptable, and therefore a different speed profile must be selected.Furthermore, assume that in this simplified example, the uphill section is followed by a straight (flat) section where it takes one minute for the temperature to drop below 8, meaning that the total time the component operates at temperature 8 is 90 seconds. For this illustrative example, this can be considered too long a time period, resulting in an excessive reduction in the component's lifetime, so a different speed profile is chosen in which the temperature never reaches 8.

[0104] According to this highly simplified example, the thresholds and extent of wear of a component over time can be determined by the hardware itself and can be adjusted by the component manufacturer. On the other hand, the question of what constitutes "acceptable wear" during operation of the vehicle 100 and what should be considered a threshold for increased wear concerns either the manufacturer of the electric motor or the purchaser of the vehicle 100.

[0105] This description therefore does not provide exact values ​​for the thresholds and / or for acceptable periods during which such thresholds may be exceeded, as such settings must be made during implementation, taking into account decisions regarding what constitutes acceptable wear and tear and the corresponding reduction in the lifetime of the respective components. When reference is made to thresholds in this description, this corresponds, for example, to the threshold at temperature 8, i.e., a threshold at which increased wear of the component in question occurs.

[0106] In an example, several thresholds Th1, ..., Th χ-1 , Th χ for each component temperature profile, with the highest temperature value Th χ means a temperature that must never be exceeded, while the lower thresholds Th1, ..., Th χ-1one or more temperature values ​​which may be exceeded to a certain extent over a limited period of time.

[0107] A temperature threshold of a component may be determined based on requirements regarding the expected and / or desired lifetime of the component. The effect of temperature on the overall lifetime of the system must also be considered. This can be done by determining in step 220 according to Fig. 2, a power draw for the electric motor system 101 is determined. The determined power draw for the electric motor system 101 may be based on a temperature profile in the set of temperature profiles based on the respective threshold temperature Th in the upcoming road section 510. The temperature profile in the set of temperature profiles may here be a temperature profile for a lifetime-limiting component.

[0108] The power extraction can be determined by means of an optimization algorithm by selecting a power extraction corresponding to an optimized vehicle speed, a lowest wear with respect to the electric motor system 101 and / or a lowest energy consumption by the vehicle 100. Thus, the optimization algorithm aims at selecting an optimal speed profile from the set of speed profiles v1, v2, ...,v n, where the selected speed profile corresponds to a specific power draw. Each temperature profile associated with the selected speed profile must satisfy the temperature requirements regarding the temperature thresholds of the corresponding component, as described above, as well as at least one optimization criterion. To perform the optimization, the optimization algorithm can convert each set of temperature profiles into a prediction regarding the wear of a component and / or the system, i.e., how the temperature profile affects the lifetime of the electric motor system 101. The speed profile is selected to result in an optimal average speed, the least wear on the electric motor system 101, and / or the lowest energy consumption without compromising the requirements regarding a minimum or desired lifetime of the electric motor system 101.The power consumption is then adjusted accordingly.

[0109] In one embodiment, each speed profile in the set of speed profiles may have an average speed, and in step 220, a determination of the power draw from the electric motor system 101 is additionally made based on the average speed of each individual speed profile.

[0110] In one example, it may be advantageous to determine the power draw with respect to the electric motor system 101 based on a temperature profile corresponding to a speed profile with the highest average speed in the upcoming road section 510. Thus, in one embodiment, the average speed of the speed profile has the highest value in the upcoming road section 510.

[0111] In a further example, it may be advantageous to continue to set the power draw from the electric motor system 101 as a constant power draw and not to set it to a highest average speed in order to avoid jerky behavior of the vehicle 100.

[0112] In one embodiment, determining the power draw for the electric motor system 101 may take into account the energy consumption of the electric motor system 101 in the upcoming road section 510. For example, the power draw may be based on the temperature profile that meets the temperature requirements described above and that corresponds to the speed profile that requires the least energy consumption in the electric motor system 101 when the vehicle 100 travels in the upcoming road section 510 at a speed corresponding to the speed profile.

[0113] The energy consumption of the electric motor system 101 can be determined by a so-called efficiency map of the electric motor in conjunction with the predetermined power consumption and losses of other components.

[0114] In one embodiment, the determination of the power draw for the electric motor system 101 may take into account the wear and tear on the electric motor system 202 in the upcoming road section 510.

[0115] As described above, wear on the electric motor system 101 increases as the temperature of its components exceeds the safe operating temperature range. In one example, the power draw may be based on the temperature profile that increases the temperature requirements described above and that corresponds to the speed profile at which the least wear on the electric motor system 101 occurs when the vehicle is traveling over the upcoming road section 510 at a speed according to the speed profile.

[0116] By operating the electric motor system 101 in the upcoming road section 510 according to the determined power consumption according to step 230 in Fig. 2, the electric motor system 101 may be controlled to provide power such that the vehicle 100 is moved according to the speed profile corresponding to the selected temperature profile.

[0117] According to one embodiment of the invention, a control arrangement 120 is provided for controlling an electric motor system 101 of a vehicle 100. The control arrangement 120 includes a device 121 configured to predict a set of temperature profiles for the electric motor system 101 in an upcoming road section 510 based on a set of speed profiles for the upcoming road section 510 and information associated with the upcoming road section 510, wherein each temperature profile in the set of temperature profiles is associated with a speed profile in the set of speed profiles and an operating temperature T of the electric motor system 101.

[0118] The control arrangement 120 further includes a device 122 configured to determine a power draw for the electric motor system 101 based on a temperature profile in the set of temperature profiles corresponding to its threshold temperature Th in the upcoming road section 510.

[0119] The control arrangement 120 further comprises a device 123 which is configured to operate the electric motor system 101 in the upcoming road section 510 in accordance with the determined power consumption.

[0120] The control arrangement 120, e.g., a device or a control device, according to the invention can be configured to perform all the steps provided for in the claims and in the exemplary embodiments described here for the method. The control arrangement 120 thus has the advantages described above according to the respective exemplary embodiment.

[0121] The invention also relates to a vehicle 100 with the control arrangement 120. Fig. 4 shows the control arrangement 600 / 120, which may correspond to or contain one or more of the above-mentioned control units 121-123, i.e., control units that carry out the method steps of the invention described here. The control arrangement 600 / 120 has a computing unit 601, which may be formed by any suitable processor or microcomputer, e.g., a circuit for digital signal processing (Digital Signal Processor, DSP), or a circuit with a predetermined specific function (Application Specific Integrated Circuit, ASIC). The computing unit 601 is connected to a memory unit 602 arranged in the control arrangement 600 / 120, wherein the memory unit supplies the computing unit 601 with, for example, stored program code and / or stored data, which the computing unit 601 needs to execute the calculations.The calculation unit 601 is also configured to store partial results or final results of the calculations in the storage unit 602.

[0122] The control arrangement 600 / 120 is further provided with devices 611, 612, 613, 614 for receiving and transmitting input and output signals. These input and output signals can take waveforms, pulse forms, or other forms that can be detected as information by the devices 611, 613 for receiving input signals and converted into signals that can be processed by the computing unit 601. These signals are then input to the computing unit 601. The devices 612, 614 for transmitting the output signals are configured to convert signals received by the computing unit 601 to generate output signals, e.g., modulated signals, that can be transmitted to other components and / or systems in the vehicle 100.

[0123] Each of the connections to the devices for receiving and transmitting input and output signals can be formed by one or more cables, a data bus, such as a CAN bus (Controller Area Network), a MOST bus (Media Oriented Systems Transport bus), or another bus configuration; in particular, also by wireless transmission. A person skilled in the art will recognize that the computer described above can be formed by the computing unit 601 and that the memory described above can be formed by the storage unit 602.

[0124] Control systems in modern vehicles typically have communication bus systems with one or more communication buses for linking a number of electronic control units (ECUs) or controllers, as well as various components located in the vehicle. Such a control system may have a large number of control units, and the respective responsibility for a specific function may be divided between several control units. Vehicles of this type often have a significantly larger number of control units than is the case in Fig. 1 and Fig. 4 shows what is well known to a specialist.

[0125] In the embodiment shown, the invention can be implemented by one or more of the above-mentioned control units 121, 122 and 123. However, the invention can also be implemented, either in whole or in part, in one or more other control units that are already present in the vehicle 100, or in a control unit that is specifically designed for the invention.

[0126] Here and in this document, units are sometimes described as "configured to perform steps of the method according to the invention." This also implies that the units are designed and / or configured to perform these method steps.

[0127] The one or more control units 121, 122 and 123 are in Fig.1 as separate units. However, these units can also be merely logically separated and physically implemented in the same unit, or they can be arranged logically and physically together. For example, these units can each be assigned to groups of instructions in the form of program code that is input into a processor / processing unit 601 when the respective unit is active and / or they can be used to execute specific method steps.

[0128] Those skilled in the art will recognize that the embodiments described herein for controlling a motor can also be implemented with a computer program which, when executed in a computer, instructs the computer to carry out the method. The computer program is typically provided in the form of a computer program product 603 in a permanent / non-volatile digital storage medium, in which the computer program is implemented in the computer-readable medium of the computer program product. The computer-readable medium has a suitable memory, such as a ROM (read only memory), a PROM (programmable read only memory), an EPROM (erasable PROM), a flash memory, an EEPROM (electrically erasable PROM), a hard disk, etc. The invention is not limited to the above embodiments. Rather, the invention relates to and includes all various embodiments as included within the scope of the independent claims.

Claims

[1] Method (200) for operating (230) an electric motor system (101) of a vehicle (100), the method (200) comprising: Predetermining (210) a set of temperature profiles (T1, T2, ..., T n ) for the electric motor system (101) in an upcoming road section (510) based on a set of speed profiles (v1, v2, ..., v n ) for the upcoming road section (510) and information linked to the upcoming road section (510), wherein each temperature profile (T1, T2, ..., T n ) in the set of temperature profiles (T1, T2, ..., T n ) is linked to a speed profile (v1, v2, ..., v n ) in the set of velocity profiles (v1, v2, ..., v n ) and with an operating temperature (T) of the electric motor system (101); Determining (220) a power consumption for the electric motor system (101) based on a temperature profile (T1, T2, ..., T n) in the set of temperature profiles (T1, T2, ..., T n ) based on its threshold temperature (Th) in the upcoming road section (510); and Operating (230) the electric motor system (101) in the upcoming road section (510) according to the determined power consumption. [2] Method (200) according to claim 1, wherein each velocity profile (v1, v2, ..., v n ) in the set of velocity profiles (v1, v2, ..., v n ) has an average speed, and wherein the determination (220) of the power consumption for the electric motor system (101) is further based on the average speed of each individual speed profile (v1, v2, ..., v n ). [3] Method (200) according to claim 2, wherein the average speed of the speed profile (v1, v2, ..., v n ) is a highest average speed in the upcoming road section (510). [4] Method (200) according to one of claims 1-3, wherein the determination (220) of the power consumption for the electric motor system (101) takes into account the energy consumption of the electric motor system (101) in the upcoming road section (510). [5] Method (200) according to one of claims 1-4, wherein the determination (220) of the power consumption for the electric motor system (101) takes into account wear on the electric motor system (101) in the upcoming road section (510). [6] Method (200) according to one of the preceding claims, further comprising: Predetermining (210) the set of temperature profiles (T1, T2, ..., T n ) still based on vehicle configuration data for the vehicle (100). [7] Method (200) according to claim 6, wherein the vehicle configuration data relates to one or more of the following: a current weight, a vehicle model, a transmission type, a drivetrain configuration, an axle configuration and the type of tires. [8] Method (200) according to one of the preceding claims, wherein the information associated with the upcoming road section (510) relates to one or more of the following: topographical data, cartographic data, traffic data and vehicle-to-everything exchange data. [9] Method (200) according to one of the preceding claims, further comprising: Predetermining (210) the set of temperature profiles (T1, T2, ..., T n ) further based on a set of power loss profiles for the electric motor system (101) in the upcoming road section (510). [10] Method (200) according to one of the preceding claims, wherein the operating temperature (T) is one or more of the following: a temperature of a winding, a temperature of power electronics, a temperature of a permanent magnet of the electric motor system (101), a temperature of a battery cell in the battery system (103) and a temperature of a battery pack in the battery system (103). [11] Control arrangement (120) for controlling an electric motor system (101) of a vehicle (100), wherein the control arrangement (120) is arranged to Predetermining (210) a set of temperature profiles (T1, T2, ..., T n ) for the electric motor system (101) in an upcoming road section (510) based on a set of speed profiles (v1, v2, ..., v n ) for the upcoming road section (510) and information linked to the upcoming road section (510), wherein each temperature profile (T1, T2, ..., Tn ) in the set of temperature profiles (T1, T2, ..., T n ) is linked to a speed profile (v1, v2, ..., v n ) in the set of velocity profiles (v1, v2, ..., v n ) and an operating temperature (T) of the electric motor system (101); Determining (220) a power consumption for the electric motor system (101) based on a temperature profile (T1, T2, ..., T n ) in the set of temperature profiles (T1, T2, ..., T n ) based on its temperature threshold value (Th) in the upcoming road section (510); and Operating (230) the electric motor system (101) in the upcoming road section (510) according to the determined power consumption. [12] Vehicle (100) with a control arrangement (120) according to claim 11. [13] A computer program comprising instructions which, when executed by a computer, cause the computer to carry out the method (200) according to any one of claims 1 to 10. [14] A computer-readable medium having instructions which, when executed by a computer, cause the computer to perform the method (200) according to any one of claims 1 to 10.

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