Method for determining a drive parameter for driving an oil pump of an electric drive unit for a vehicle

Abstract

The invention relates to a method for determining a drive parameter (Q) for driving an oil pump (35) of an electric drive unit (10) for a vehicle, wherein the drive parameter (Q) influences the delivery rate of the oil pump (npump) and wherein the electric drive unit (10) comprises components to be temperature-controlled, namely at least a rotor (12), a stator (14), and oil (16). The method comprises the steps of: - receiving data relating to temperatures (Tx, act) of the drive-unit components to be temperature-controlled, - determining temperature error signals (ex) as the difference between the temperatures of the components to be temperature-controlled (Tx, act) and temperature setpoint values (Tx, ref) individually assigned to the components to be temperature-controlled, - determining control variables (Kx) for the temperatures of the components to be temperature-controlled by processing the temperature error signals (ex) using predefined gain functions (fx), - selecting a maximum value (Kmax) from the control variables (Kx), and - calculating the drive parameter (Q) from the maximum value (Kmax) in accordance with a predefined calculation function. Selecting the maximum value (Kmax) from the control variables (Kx) maximises the delivery rate of the oil pump (35).

Description

[0001] R. 416719

[0002] - 1 -

[0003] Description

[0004] title

[0005] Method for determining a drive parameter for a drive of an oil pump of an electric drive unit for a vehicle

[0006] State of the art

[0007] From DE 102023 105235 A1, a method for controlling an oil pump is known, which is designed to pump oil as a coolant into a wet-running electric machine and into a transmission of a motor vehicle, wherein the oil pump can be operated in a first mode and in a second mode, wherein in the first mode of the oil pump the oil is pumped intermittently by means of the oil pump during operation of the electric machine and in the second mode of the oil pump the oil is pumped without interruption during operation of the electric machine, in which the mode is set depending on at least one criterion.

[0008] From DE 102022 214 389 A1, an arrangement for the demand-based distribution of cooling / lubricating oil flows in an electric traction drive is known, comprising an electrically controllable motor-pump unit and a hydraulic arrangement, wherein the motor-pump unit can be controlled in both directions of rotation. The motor-pump unit is connected via a heat exchanger to several fluid outlets for partial volume flows, which are connected for cooling and / or heating and / or lubrication at least to the stator of an electric machine, the rotor of an electric machine, and the gearbox. At least one fluid outlet is additionally opened via at least one hydraulically switchable valve when the direction of rotation of the motor-pump unit is reversed. R. 416719

[0009] - 2 -

[0010] From US Patent 2021 / 0095649 A1, a control device for a motor assembly in a vehicle is known, wherein the motor assembly comprises: a motor consisting of a plurality of coils arranged laterally around a motor shaft; a transmission mechanism that transmits the motor's power to a shaft; a housing that contains the motor and transmission mechanism components; an electric oil pump that draws oil from the housing; and a coil temperature sensor that detects the coil temperature. The control device includes: a motor controller that drives and controls the motor; and a pump controller that drives and controls the electric oil pump. The pump controller estimates an oil temperature based on the ambient temperature and the coil temperature and determines a start time for the electric oil pump according to the estimated oil temperature.

[0011] Disclosure of the invention

[0012] The invention relates to a method according to claim 1 as well as a control unit and an electric drive unit according to the dependent claims.

[0013] The underlying electric drive unit comprises an oil pump and components to be temperature-controlled, namely at least a rotor of an electric machine, a stator of the electric machine, and oil, which is circulated by the oil pump in an oil circuit within the electric drive unit to temperature-control the rotor and the stator. The oil itself can be temperature-controlled in other ways, for example, by exchanging heat with a fluid temperature-control medium (e.g., a liquid such as water or air) in a heat exchanger within the electric drive unit.

[0014] It is possible that the electric drive unit has one or more additional components requiring temperature control, which are also temperature-controlled by the oil pump circulating within the electric drive unit's oil circuit. These components could be, for example, a rolling bearing or multiple rolling bearings. R. 416719

[0015] - 3 -

[0016] The invention is further based on the fundamental desire to control the temperatures of the components to be tempered to individually assigned setpoints. However, this is made particularly difficult by the fact that the only available control variable is the oil pump's delivery rate, or rather the oil pump's drive parameter, which influences the oil pump's delivery rate. In other words, it is generally not possible to precisely control the temperatures of all components to be tempered to their individually assigned setpoints.

[0017] To nevertheless achieve optimal temperature control, the invention initially provides that, similar to conventional temperature control loops, temperature error signals are determined based on data relating to the temperatures of the drive unit components to be cooled and on the setpoint values. Control variables for the temperatures of the components to be cooled are then derived from these temperature error signals using predefined gain functions. This results in a control variable for the oil temperature, a control variable for the stator temperature, a control variable for the rotor temperature, and optionally, further control variables.

[0018] According to the invention, the selection of a maximum value from the control variables is provided, wherein the method provides for a calculation of the drive parameter from the maximum value according to a predetermined calculation function, and wherein the selection of the maximum value from the control variables is made according to the criterion that the delivery rate of the oil pump is maximized by the selection.

[0019] If the oil pump is controlled with the drive parameter determined by the method according to the invention, this results in it providing a delivery quantity that is sufficient for temperature control of the stator, the rotor, the oil and, if applicable, other components.

[0020] In the case of the component assigned to the control variable selected as the maximum, this is obvious, since the flow rate with respect to this component corresponds to the flow rate also found in R. 416719

[0021] - 4 - in a conventional control loop for the temperature of this component. With regard to the other components, the flow rate is higher than the flow rate that would have been set in a conventional control loop for the temperature control of this component. Within the scope of the present invention, this is considered uncritical, since this additional interaction of the oil with these other components to be temperature-controlled may result in efficiency losses but not in critical operating conditions of the other components to be temperature-controlled, such as overheating.

[0022] The same applies to the situation in which the oil itself is one of the other components to be temperature-controlled and circulates in excess in the oil circuit compared to a control loop exclusively for oil temperature.

[0023] In other words, the control variable assigned to a component being cooled defines the desired flow rate for that component. The selection of the maximum value from the control variables, as provided for in the invention, further ensures that the oil pump's flow rate for none of the components being cooled is lower than desired.

[0024] The electric drive shaft may have one or more rolling bearings, which, for example, support a rotor shaft of the electric drive unit or a gearbox shaft of the electric drive unit. This rolling bearing, or one or more of these rolling bearings, may also be a component(s) of the electric drive unit that require temperature control. In this case, the procedure includes the following additional steps:

[0025] - Receiving data representing the temperature of the rolling bearing, or receiving data representing the temperatures of the rolling bearings,

[0026] - Determining a rolling bearing temperature error signal as the difference between the temperature of the rolling bearing and a target value of the rolling bearing temperature, or determining rolling bearing temperature error signals as differences between the temperatures of the rolling bearings and the target values ​​of the rolling bearing temperatures, R. 416719

[0027] - 5 -

[0028] - Determining a control variable for the rolling bearing temperature as a result of calculating the rolling bearing temperature error signal with a predefined rolling bearing control amplification function, or determining control variables for the rolling bearing temperatures as a result of calculating the rolling bearing temperature error signals with predefined rolling bearing control amplification functions, wherein the control variables include the control variable for the rolling bearing temperature or the control variables for the rolling bearing temperatures.

[0029] The oil circuit may include a heat exchanger in which the oil can exchange heat with a fluid temperature control medium to maintain its temperature. This fluid temperature control medium could be, for example, air or a liquid, such as a water-glycol mixture.

[0030] The method can include receiving data representing the temperature of the fluid temperature control medium. This makes the temperature of the temperature control medium available and processable. For example, the temperature of the temperature control medium can be measured using a thermometer.

[0031] It is an advantageous further development that the temperature setpoints are determined dynamically as a function of the temperature of the temperature control medium.

[0032] For example, the oil temperature setpoint can be chosen to be identical to the temperature of the temperature control medium, or the oil temperature setpoint can be chosen as the sum of the temperature of the temperature control medium and a fixed positive offset, and / or the stator temperature setpoint can be chosen as the sum of the temperature of the temperature control medium and the fixed positive offset or another fixed positive offset; and / or the rotor temperature setpoint can be chosen as the sum of the temperature of the temperature control medium and the fixed positive offset or another fixed positive offset or yet another fixed positive offset. R. 416719

[0033] - 6 -

[0034] Especially when the positive offsets are small, for example, no greater than 20 K, this dynamic selection of setpoints corresponds to an operating strategy for the electric drive in which the components to be cooled are cooled as much as possible. With significant heat generation at the stator and rotor of the electric machine, this generally means that the components to be cooled are cooled as much as possible. Since strong cooling, or a lower temperature of its components, results in a higher instantaneous output power of the electric machine, this operating mode can also be described as a high-performance mode. On the other hand, in this operating mode, a high oil pump delivery rate, increased oil viscosity, and increased friction losses may reduce the overall efficiency of the electric drive.

[0035] Alternatively, the temperature setpoints can be fixed. For example, the fixed setpoint for the oil temperature could be 80°C, the fixed setpoint for the stator temperature could be 120°C, and the fixed setpoint for the rotor temperature could be 100°C. These fixed values ​​can be optimized to take into account the reduced friction losses of the electric drive at elevated temperatures, the increased electrical losses of the electric drive at elevated temperatures, and the energy consumption of the oil pump, which is generally reduced when higher temperature setpoints are selected. This optimization can then be applied to the overall efficiency of the electric drive.

[0036] An operating mode that specifies fixed temperature setpoints, in particular 70°C - 90°C for the oil temperature setpoint, 90°C to 110°C for the rotor temperature setpoint and / or 110°C to 130°C for the stator temperature setpoint, can therefore also be described as an efficient mode.

[0037] It may be provided that the procedure allows for a selection of the operating mode, whereby at least one operation in the high-performance mode and one operation in the efficient mode of the electric drive can be selected.

[0038] It may also be provided that at least two operating modes are provided R. 416719

[0039] - 7 - are, namely a first operating mode and a second operating mode.

[0040] In both operating modes, all temperature setpoints can be fixed, whereby the setpoints for oil temperature, stator temperature and rotor temperature in the first operating mode differ from the setpoints for oil temperature, stator temperature and rotor temperature in the second operating mode.

[0041] Alternatively, the setpoints for oil temperature, stator temperature and rotor temperature in the first operating mode can be determined by first calculation rules, and the setpoints for oil temperature, stator temperature and rotor temperature in the second operating mode can be determined by second calculation rules, the first calculation rules being different from the second calculation rules.

[0042] Alternatively, the setpoint values ​​for oil temperature, stator temperature and rotor temperature can be fixed in the first operating mode and determined by calculation rules in the second operating mode, and in particular be a function of the temperature of the temperature control medium.

[0043] It can be advantageous for the oil control gain function to have proportional and integral components, similar to a PI controller. This counteracts a persistent deviation in the oil temperature control.

[0044] The oil control amplification function may be designed to include anti-windup protection. Anti-windup, as understood by those skilled in the art, refers to the application of technical measures to limit the effects of integrators in control systems and to prevent undesirable effects during severe disturbances or limitations. This can be achieved through the implementation of anti-windup algorithms, saturation protection, or other methods to improve the stability and performance of the control system.

[0045] It may be provided that the stator control gain function and the rotor control gain function have proportional components, R. 416719

[0046] - 8 - corresponding to a P-controller, which is easy to implement and ensures stable operation.

[0047] It may be provided that the stator control gain function and the rotor control gain function have an output saturation to further make the controlled system more robust or to protect it.

[0048] It is possible to determine the stator temperature using a model that continuously incorporates at least the operating parameters of the electric machine (e.g., current, voltage, speed, torque, etc.) and the temperature of the oil and, if applicable, the temperature control medium. Such models provide data representing the stator temperature, thus eliminating the need for a physical thermometer measurement. This approach is also known as virtual sensing and can utilize artificial intelligence. The same principle applies to the rotor temperature.

[0049] The invention also relates to a control unit in which all steps of the method relating to data processing can be carried out.

[0050] The invention also relates to an electric drive unit for a vehicle, comprising an oil pump and the components to be tempered, namely at least a rotor of an electric machine, a stator of the electric machine and oil, which is driven by the oil pump in an oil circuit of the electric drive unit to temper the rotor and the stator; and with the control unit.

[0051] Exemplary embodiments of the invention are explained below with reference to the drawing. The drawing shows:

[0052] Figure 1 schematically shows an electric drive unit,

[0053] Figures 2 and 3 show an exemplary embodiment of the method according to the invention.

[0054] Figure 4 shows a stator control gain function. R. 416719

[0055] - 9 -

[0056] Figure 1 schematically and by way of example shows an electric drive unit 10 comprising an electric machine with a rotor 12 and a stator 14, a gearbox 15 mechanically coupled to the rotor 12, and an inverter 17 electrically connected to the electric machine. Rotating shafts of the rotor 12 and the gearbox 15 can be supported in rolling bearings. The electric drive unit 10 further comprises an oil sump 62, an oil filter 63, an oil pump 35, and a heat exchanger 18.

[0057] The electric drive unit 10 further comprises an oil circuit 25, in which oil 16 is drawn from the oil sump 62 via the oil filter 63 by the oil pump 35 and then conveyed via the heat exchanger 18, the rotor 12 and the stator 14 back to the oil sump 62. In this example, the rotor 12 and the stator 14 are arranged fluidically in parallel; however, a series arrangement is also conceivable.

[0058] In this example, the gearbox 15 is also arranged fluidically parallel to the rotor 12 and the stator 14 within the oil circuit 25. However, a series arrangement of the gearbox 15 with the rotor 12 and stator 14 is also conceivable, as are arrangements in which the gearbox 15 is located outside the oil circuit 25 described above, for example, by supplying oil 16 separately from the oil sump 62 to the gearbox 15 and from there back to the oil sump 62.

[0059] Due to the thermal interaction with the oil 16, the components rotor 12 and stator 14 can be temperature-controlled, i.e., cooled or heated depending on the temperature gradient.

[0060] In the heat exchanger 18, the oil 16 in the example comes into thermal contact with a fluid temperature control medium 20 (for example, water or a water / glycol mixture), which in turn is kept at a moderate temperature, for example, by ambient air and airflow. The oil 16 can therefore be temperature-controlled in the heat exchanger 18, in particular cooled or heated.

[0061] The oil pump 35 can be an electrically driven pump. The delivery rate n pU The oil pump 35's speed is determined by a drive parameter Q R. 416719

[0062] - 10 - controllable, e.g., adjustable. In the case of an electrically driven oil pump 35, the drive parameter Q can, for example, be a rotational speed or oscillation frequency of the oil pump 35 or of the electric drive of the oil pump 35. Alternatively, it can be an electrical voltage, an electrical current, or an electrical power of the oil pump 35 or of the electric drive of the oil pump 35.

[0063] Alternatively, it could also be a mechanically driven oil pump 35, for example an oil pump 35 that can be driven via the gearbox 15.

[0064] The drive parameter Q of the oil pump 35 can therefore also be a parameter with which devices, for example, electrically switchable valves of the oil pump 35 for the purpose of controlling the delivery rate n pU The oil pump 35 can be controlled.

[0065] In this example, temperature sensors 61 are provided for measuring the temperature of the stator 14, the rotor 12, and the oil 16. Furthermore, a temperature sensor 61 is provided for measuring the temperature of the temperature control medium 20. These can be physical sensors, such as NTC or PTC sensors, as in the example. Alternatively, however, the use of virtual sensors is also possible; that is, the use of models with which the relevant temperatures are reliably determined from other physical quantities, for example, operating parameters of the electric machine and / or other temperatures.

[0066] The electric drive unit 10 further comprises a control unit 50, which is configured to execute the method according to the invention, or to perform the data reception, calculation, and data output steps of an associated method for temperature control of an electric drive unit 10 for a vehicle. The control unit 50 can be integrated together with the inverter 17 in a housing.

[0067] In one example, the procedure comprises the following steps, see Figures 2 and 3: R. 416719

[0068] - 11 -

[0069] - S1: Receiving data indicating the oil temperature T O ii, ac t represent,

[0070] - S2: Receiving data representing the temperature of the stator TsTM.act,

[0071] - S3: Receiving data representing a temperature of the rotor TRTM^CI;

[0072] - S4: Determining an oil temperature fault signal e O ii as the difference between the temperature of the oil T O ii, ac t minus a target value of the oil temperature Toü.ref,

[0073] - S5: Determining a stator temperature error signal 6STM as the difference between the stator temperature TsTM.act and a setpoint stator temperature TsTM.ref,

[0074] - S6: Determining a rotor temperature error signal e RT M as the difference between the rotor temperature TRTM.act and a setpoint value of the rotor temperature TRTM.ret;

[0075] - S7: Determining a control variable for the oil temperature K0H as a result of processing the oil temperature error signal e O ii with a predefined oil control amplification function f oi i,

[0076] - S8: Determining a control variable for the stator temperature KSTM as a result of calculating the stator temperature error signal 6STM with a predefined stator control gain function fsTM,

[0077] - S9: Determining a control variable for the rotor temperature KRTM as a result of calculating the rotor temperature error signal e RT M with a predefined rotor control 11- amplification function RTM;

[0078] - S10: Selection of a maximum value K ma x from the control variable for oil temperature K0H, the control variable for stator temperature KSTM and the control variable for rotor temperature KRTM;

[0079] - S11: Calculation of the drive parameter Q from the maximum value K ma x according to a predefined calculation function.

[0080] The selection of the maximum value K ma x from the control variables is determined in S10 according to the criterion that the delivery quantity npU The oil pump's mp 35 is maximized by the selection.

[0081] In one operating mode of the example, the target value of the oil temperature T is O ii,ref 80°C, the setpoint for the stator temperature TsTM.ref 120°C, and the setpoint for the rotor temperature TRTM.ref 100°C. These values ​​may be values ​​determined to be optimal from an efficiency point of view. In the underlying R. 416719

[0082] - 12 -

[0083] Efficiency considerations can, for example, take into account that low target temperatures of the oil Toü.ref, the rotor TRTM.ref and the stator TsTM.ref, while enabling low electrical losses, are on the other hand associated with increased power consumption of the oil pump 35 and increased viscosity of the oil, which in turn results in friction losses.

[0084] In another operating mode of the example, the setpoint for the oil temperature Toü.ref is dynamically set to the current temperature of the temperature control medium, and the setpoints for the stator temperature TsTM.ref and the rotor temperature TRTM.ref can be dynamically chosen to be equal to the sum of the temperature of the temperature control medium plus an offset of, for example, a maximum of 10 K. This operating mode may be less efficient, but due to the lower temperature, it allows for fewer electrical losses and thus optimized performance of the electric drive.

[0085] In this example, appropriate limitations are in place to ensure that the control variables for the oil temperature K are not limited. oThe stator temperature KSTM and the rotor temperature KRTM can only assume values ​​between 0 and 1. The maximum value therefore lies within this range. Figure 4 shows an example of the stator control gain function fsTM in this case. It exhibits proportional behavior in the range of -20 K to 20 K and saturation behavior outside this range.

[0086] The example further provides that, based on the temperature of the oil Ton, act, a value of a minimum delivery Qßase of the oil pump 35 is determined and a value of a maximum additional delivery Qf. eas is determined.

[0087] From the sum of the minimum funding Qßase and the product of the maximum additional funding Qf eas and the maximum value K ma In this example, x is determined as the drive parameter Q for the drive of the oil pump 35.

[0088] The oil pump 35 is then controlled with this drive parameter Q, so that it delivers the delivery quantity n in a subsequent time interval. pU mp promotes.

[0089] The depicted control loop or the depicted process steps are executed cyclically during the operation of the electric drive unit for the vehicle R. 416719

[0090] - 13 - completed.

[0091] In the example described above, only the rotor 12, the stator 14, and the oil 16 were temperature-controlled. However, the method can also include other components to be temperature-controlled, such as a rolling bearing or several rolling bearings, and can additionally apply the same process steps to these components as described above for rotor 12 and stator 14.

Claims

R. 416719 - 14 - Claims 1. Method for determining a drive parameter (Q) for a drive of an oil pump (35) of an electric drive unit (10) for a vehicle, wherein the drive parameter (Q) is the delivery rate (n pU mp) of the oil pump (35), wherein the electric drive unit (10) comprises components to be tempered, namely at least a rotor (12) of an electric machine, a stator (14) of the electric machine and oil (16) which is driven by the oil pump (35) in an oil circuit (25) of the electric drive unit (10) to temper the rotor (12) and the stator (14), wherein the method comprises steps which provide for receiving data relating to the temperatures of the components of the drive unit (10) to be tempered, at least: - Receiving data representing the temperature of the oil (Toii.act), - Receiving data representing the temperature of the stator (TsTM.act), - Receiving data representing a rotor temperature (TRTM.act); wherein the method includes steps that provide for the determination of temperature error signals as the difference between the temperatures of the components to be tempered and the temperature setpoints individually assigned to the components to be tempered, at least: - Determining an oil temperature fault signal (e O ii) as the difference between the temperature of the oil (Toii.act) and a target value for the oil temperature (Toil.ref), - Determining a stator temperature error signal (OSTM) as the difference between the stator temperature (TsTM.act) and a setpoint for the stator temperature (TsTM.ref), - Determining a rotor temperature error signal (6RTM) as the difference between the rotor temperature (TRTM.act) and a setpoint rotor temperature (TRTM.ret); wherein the method includes steps that determine R. 416719 - 15 - Provide control variables for the temperatures of the components to be tempered as a result of calculating the temperature error signals with predefined gain functions, at least: - Determining a control variable for the oil temperature (K) O ii) as a result of the processing of the oil temperature fault signal (e O ii) with a predefined oil control amplification function (f oi i) - Determining a control variable (KSTM) for the stator temperature as a result of calculating the stator temperature error signal (OSTM) with a predefined stator control gain function (fs™), - Determining a control variable (KRTM) for the rotor temperature as a result of calculating the rotor temperature error signal (6R M) with a predefined rotor control gain function (fR™); wherein the method involves selecting a maximum value (K ma x) from the control variables, where the control variables include at least the control variable for oil temperature (K O ii) comprising the control variable for the stator temperature (KSTM) and the control variable for the rotor temperature (KRTM); wherein the method provides for a calculation of the drive parameter from the maximum value according to a predefined calculation function and wherein the selection of the maximum value (K ma x) from the control variables according to the criterion that the delivery quantity (n pU mp) of the oil pump (35) is maximized by the selection.

2. The method of claim 1, wherein the electric drive unit (10) comprises a rolling bearing which is a component to be tempered, or comprises several rolling bearings which are components to be tempered, such that the method comprises the steps: - Receiving data representing the temperature of the rolling bearing, or receiving data representing the temperatures of the rolling bearings, - Determining a rolling bearing temperature error signal as the difference between the temperature of the rolling bearing and a target value of the rolling bearing temperature, or determining rolling bearing temperature error signals as differences between the temperatures of the rolling bearings and their target values. - Determining a control variable for the rolling bearing temperature as a result R. 416719 - 16 - the calculation of the rolling bearing temperature error signal with a predefined rolling bearing control amplification function or determining control variables for the rolling bearing temperatures as a result of the calculation of the rolling bearing temperature error signals with predefined rolling bearing control amplification functions, wherein the control variables include the control variable for the rolling bearing temperature or the control variables for the rolling bearing temperatures.

3. Method according to claim 1 or 2, wherein the oil circuit (25) comprises a heat exchanger (18) in which the oil (16) can exchange heat with a fluid temperature control medium (20) for its temperature control.

4. Method according to claim 3, wherein data are received representing a temperature of the fluid temperature control medium, wherein the temperature setpoints are dynamically determined as a function of the temperature of the temperature control medium.

5. The method of claim 4, wherein the setpoint of the oil temperature (Toii.ref) is selected to be identical to the temperature of the temperature control medium, or the setpoint of the oil temperature (Toii.ref) is selected as the sum of the temperature of the temperature control medium and a fixed positive offset; and / or the setpoint of the stator temperature (TsTM.ref) is selected as the sum of the temperature of the temperature control medium and the fixed positive offset or another fixed positive offset; and / or the setpoint of the rotor temperature (TRTM.ref) is selected as the sum of the temperature of the temperature control medium and the fixed positive offset or another fixed positive offset or yet another fixed positive offset.

6. Method according to one of claims 1, 2 or 3, wherein the setpoint of the oil temperature (Toii.ref) is fixed, the setpoint of the stator temperature (TsTM.ref) is fixed, and the setpoint of the rotor temperature (TRTM.ref) is fixed. R. 416719 - 17 - 7. Method according to any one of claims 1 to 6, wherein at least two operating modes are provided, namely a first operating mode and a second operating mode, wherein the setpoint values ​​of the oil temperature (T) Oii,ref), the stator temperature (TsTM.ref) and the rotor temperature (TRTM.ref) in the first operating mode differ from the setpoints of the oil temperature (Toü.ref), the stator temperature (TsTM.ref) and the rotor temperature (TRTM.ref) in the second operating mode; or wherein the setpoints of the oil temperature (Toü.ref), the stator temperature (TsTM.ref) and the rotor temperature (TRTM.ref) in the first operating mode are determined by first calculation rules and wherein the setpoints of the oil temperature, the stator temperature and the rotor temperature in the second operating mode are determined by second calculation rules and wherein the first calculation rules differ from the second calculation rules, or wherein the setpoints of the oil temperature (Toü.ref), the stator temperature (TsTM.ref) and the rotor temperature (TRTM.(ref) are fixed in the first operating mode and are determined by calculation rules in the second operating mode and are in particular a function of the temperature of the temperature control medium.

8. Method according to any one of claims 1 to 7, wherein the oil control enhancement function (foil) has only proportional and integral components.

9. Method according to claim 8, wherein the oil control amplification function (f o n) has an anti-windup feature.

10. Method according to any one of claims 1 to 9, wherein the stator control amplification function (fsTM) and the rotor control amplification function (fsTM) have only proportional components.

11. Method according to claim 10, wherein the stator control gain function (fsTM) and the rotor control gain function (f RT M) exhibit an initial saturation.

12. Method according to one of the preceding claims, wherein the temperature of the stator (TsTM.act) is determined using a model that includes at least operating parameters of the electric machine and the temperature of the oil. R. 416719 - 18 - (Tone, act) continuously receive, and that the temperature of the rotor (TRTM.act) is determined with a model that continuously receives at least operating parameters of the electric machine and the temperature of the oil (Tone, act).

13. Control unit (50) configured to execute the method according to any one of claims 1 to 12.

14. Electric drive unit (10) for a vehicle, comprising an oil pump (35) and components to be temperature-controlled, namely at least a rotor (12) of an electric machine, a stator (14) of the electric machine and oil (16) which is driven by the oil pump (35) in an oil circuit (25) of the electric drive unit (10) to temperature-control the rotor (12) and the stator (14); and comprising a control unit (50) according to claim 13.

15. Electric drive unit (10) according to claim 14, additionally with an oil thermometer (61) for measuring the temperature of the oil (T0n,act), wherein the control unit (50) is further configured to receive data indicating the temperature of the oil (T o n,act) represent, to be received from the oil thermometer (61).

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