Drive device and method for operating a drive device

Abstract

The present invention relates to a drive device and a method for operating the drive device, the drive device comprising: a rotatably supported planet carrier; a planetary gear; a ring gear, the ring gear having an internal tooth portion and an external tooth portion; a rotatably supported sun gear; a first gear, the first gear meshing with the external tooth portion of the ring gear; the first gear being connected to the rotor shaft of a first motor in a non-rotatable manner, the drive device comprising a second gear, the second gear meshing with a toothed component, in particular a third gear, the second gear being connected to the rotor shaft of a second motor in a non-rotatable manner, and the toothed component being connected to the sun gear in a non-rotatable manner.

Description

Technical Field

[0001] The invention relates to a drive device and a method for operating a drive device. Background Art

[0002] As is well known, transmissions have transmission ratios. For example, planetary gear transmissions have high transmission ratios.

[0003] A hybrid transmission high-voltage connection is known from DE 10 2019 114 810 A1.

[0004] A drive train with a variable input speed and a constant output speed is known from DE 103 18 696 A1.

[0005] A hybrid vehicle is known from DE 695 16 129 T2.

[0006] A control strategy for an electromechanical power-split hybrid drive is known from DE 103 33 931 A1.

[0007] A power transmission system for a hybrid vehicle is known from DE 698 35 174 T2. Summary of the invention

[0008] It is therefore an object of the present invention to improve a drive device in which the transmission ratio can be controlled.

[0009] According to the invention, this object is achieved with a drive device according to the features of claim 1 or 2 and with a method according to the features of claim 13 or 15 .

[0010] An essential feature of the invention in the drive device according to claim 1 is that the drive device is designed to transmit power from an input shaft, in particular a planet carrier, to an output shaft.

[0011] wherein part of the power to be transmitted is supplied from the input shaft to a first electric machine operated as a generator and converted into electrical power, which is at least partially supplied to a second electric machine operated as a motor, and the mechanical power of the second electric machine is supplied to the output shaft,

[0012] The first motor is powered by the interface on the AC voltage side of the first converter / inverter, the interface on the DC voltage side of the first converter is powered by the interface on the DC voltage side of the second converter, and the interface on the AC voltage side of the second converter is powered by the second motor.

[0013] In particular, the first electric machine has an electromagnetically actuatable holding brake, the activation of which causes the portion of the power to be transmitted to become infinitesimally small, while the deactivation of the holding brake allows the portion of the power to be transmitted to be controlled by the converter,

[0014] In this case, the remainder of the power to be transmitted is transmitted from the input shaft via a mechanical transmission, in particular a planetary gear, to the output shaft.

[0015] Advantageously, no power is conducted via the electrical path when the holding brake is engaged. However, when the holding brake is disengaged, the power conducted via the electrical path can be regulated by suitable control of the converter. In particular, the overall transmission ratio of the drive can be controlled, in particular between zero and a value greater than the transmission ratio that can be achieved by a purely mechanical path, i.e., in particular via a reduction gear / transmission.

[0016] In the drive device according to claim 1, an important feature of the present invention is that the drive device has:

[0017] a rotatably mounted planet carrier, which is in particular connected to the drive shaft in a rotationally fixed manner,

[0018] - planetary wheels, which are rotatably mounted on pins connected to the planet carrier,

[0019] a ring gear having an inner toothing and an outer toothing,

[0020] - a rotatably mounted sun gear, and

[0021] - a first gear, which meshes with the outer toothing of the ring gear,

[0022] The first gear is connected to a rotor shaft of a first electric machine in a rotationally fixed manner, wherein the first electric machine is in particular a synchronous machine, in particular a synchronous machine in the form of a three-phase AC machine.

[0023] The drive device has a second gear, which meshes with a toothed component, which is in particular a third gear.

[0024] The second gear is connected to a rotor shaft of a second electric machine in a rotationally fixed manner, wherein the second electric machine is in particular a synchronous machine, in particular a synchronous machine in the form of a three-phase AC machine.

[0025] The toothed component is connected to the sun gear in a relatively rotationally fixed manner.

[0026] It is advantageous that the mechanical power and electrical power transmission paths are implemented in parallel. Because part of the power is directed from the ring gear to the first motor in generator operation. The electrical power provided in this way is supplied to the output shaft of the drive device via the second motor. Therefore, the power path mechanically transmitted by the planetary gear transmission is parallel to the electrical power path that can be adjusted by means of the converter. In this way, the power component guided via the electrical path can also be used to control or adjust the transmission ratio, that is, the quotient of the rotational speed of the output shaft and the rotational speed of the planet carrier. When a constant transmission ratio that can only be generated by a mechanical path, that is, a planetary gear transmission, is desired, the drive device can be operated purely mechanically, especially like a planetary gear transmission with a fixed ring gear, by activating the brake of the first motor and by deactivating the second motor, especially activating the currentless state of the second motor. However, when a different transmission ratio is desired, the first motor can be operated in a generator-like manner in a regulating operating state by releasing the brake of the first motor, and the power generated by the generator can be supplied to the output shaft via the second motor that is regulated in motor operation. However, instead of prescribing a specific transmission ratio, a time-dependent profile, ie a time sequence of different transmission ratios, can also be prescribing.

[0027] In an advantageous embodiment, the first electric machine is supplied with power from an AC voltage-side interface of a first converter, the DC voltage-side interface of the first converter is electrically connected, in particular connected in parallel, to an interface of a DC voltage-side interface of a second converter, the AC voltage-side interface of the second converter supplies power to the second electric machine. It is advantageous here that the power to be received as a generator can be controlled in particular in such a way that the speed of the input shaft, in particular the planet carrier, is controlled to a target value and the corresponding torque is determined as a function of the power to be transmitted in the electrical path. The power is supplied to the output shaft in such a way that a torque is supplied that causes the speed of the output shaft to reach the desired total transmission ratio of the drive. Alternatively, this can also be implemented via a voltage regulator.

[0028] In an advantageous embodiment, the control signal for the first converter is generated by the first signal electronics. Advantageously, the first converter determines the operation of the first motor-generator control.

[0029] In an advantageous embodiment, the control signal for the second converter is generated by the second signal electronics. Advantageously, the second converter determines the generator-controlled operation of the first electric machine. If an energy store is arranged between the first converter and the second converter, the generator power and the motor power do not have to be identical but can deviate from one another. As a result, control deviations do not lead to fluctuating states in the drive. This improves the control quality.

[0030] In an advantageous embodiment, the first signal electronics has a speed regulator, in particular a first linear regulator, in particular a P regulator or a PI regulator, whose regulating variable is the generator torque, in particular the generator torque, of the first electric machine. Advantageously, a simple implementation can be implemented.

[0031] In an advantageous embodiment, the second signal electronics has a second linear regulator, the regulating variable of which is in particular the motor torque of the second electric machine. Advantageously, a simple implementation can be implemented.

[0032] In an advantageous embodiment, a first sensor for detecting the rotational speed of the first gear wheel is connected to the first signal electronics, in particular a sensor for detecting the voltage present at the DC voltage-side connection of the first converter is also connected to the first signal electronics.

[0033] And / or, a second sensor for detecting the rotational speed of the second gear wheel is connected to the second signal electronics, and a sensor for detecting the voltage present at the DC voltage-side interface of the second converter is also connected to the second signal electronics. Advantageously, the electric machines can be designed as synchronous machines each having a rotational speed sensor.

[0034] In an advantageous embodiment, a first sensor for detecting an output current at an AC voltage-side interface of the first converter is connected to the first signal electronics.

[0035] And / or a second sensor for detecting the output current at the AC voltage-side connection of the second converter is connected to the second signal electronics. It is advantageous here if the motor current is detected.

[0036] In an advantageous embodiment, a sensor for detecting the voltage present at the DC voltage-side connection of the first converter or the second converter is connected to the first signal electronics. Advantageously, a pulse width modulation operation of the controllable semiconductor switches of the converters can be implemented, wherein the pulse width can be determined as a function of the DC voltage supplied to the respective converter. Thus, in the event of fluctuations in the intermediate circuit voltage, a well-defined AC voltage can be generated at the AC voltage-side connection of the second converter.

[0037] In an advantageous embodiment, the energy storage device is electrically connected in parallel to the DC voltage-side connection of the first converter and the second converter. This advantageously allows power fluctuations caused by control deviations to be buffered. In the case of a larger capacity of the energy storage device, even different control strategies can be used for the two converters. For example, after starting, a smaller power flow is initially supplied to the output shaft by the motor than from the first electric machine to the energy storage device. As a result, the speed can initially accelerate more slowly than if it were to accelerate with full power transmission.

[0038] In an advantageous embodiment, the energy storage device comprises a battery and / or a double-layer capacitor, in particular a supercapacitor. Advantageously, a large buffer energy can be provided.

[0039] In an advantageous embodiment, the first electric machine is designed as a synchronous machine. Advantageously, a high torque can be generated and / or an efficient generator operation can be performed.

[0040] In an advantageous embodiment, the second electric machine is designed as a synchronous machine. Advantageously, a high torque can be generated and / or an efficient motor operation can be performed.

[0041] An important feature of the method for operating a drive device is that the torque of the first electric machine, in particular the motor current of the first electric machine and in particular the motor voltage of the first electric machine, is regulated in such a way that the rotational speed n1_ist of the rotor shaft of the first electric machine is detected and adjusted to a target value n1_soll, in particular by means of a first converter,

[0042] The torque of the second electric machine, in particular the motor current of the second electric machine and in particular the motor voltage of the second electric machine is regulated in such a way that a detected voltage U_z_ist present at the DC voltage-side connection of the second converter is adjusted to a target value U_z_Soll, in particular by means of the second converter.

[0043] It is advantageous here that the electric machine regulated as a generator attempts to increase the voltage, while the electric machine regulated as a motor attempts to reduce the voltage, wherein a limitation of the voltage can additionally be implemented in a simple manner.

[0044] In an advantageous embodiment, the target value n1_target is determined by the rotational speed n2_ist detected at the rotor shaft of the second electrical machine, taking into account a predetermined transmission ratio and a predetermined distribution ratio.

[0045] In particular, the transmission ratio is equal to a desired value of the quotient of the rotational speed of the sun gear shaft and the rotational speed of the planet carrier or a desired value of the quotient of the rotational speed of the rotor shaft of the second electric machine and the rotational speed of the first electric machine. Advantageously, the rotational speed target value of the first electric machine is determined by the actual value of the rotational speed of the output shaft and thus takes into account the transmission ratio desired for the electrical path.

[0046] An important feature of the method for operating a drive device according to claim 13 is that the torque of the first electric machine, in particular the motor current of the first electric machine and in particular the motor voltage of the first electric machine, is regulated in such a way that the speed n1_ist of the rotor shaft of the first electric machine is detected and adjusted to a target value n1_soll, in particular by means of a first converter.

[0047] The torque of the second electric machine, in particular the motor current of the second electric machine and in particular the motor voltage of the second electric machine, is regulated in such a way that the rotational speed n2_ist of the rotor shaft of the second electric machine is detected and adjusted to a target value n2_soll, in particular by means of a second converter,

[0048] In this case, the target value n2_target is determined from the detected rotational speed n1_ist of the rotor shaft of the first electrical machine, taking into account a predetermined transmission ratio and a predetermined transmission ratio distribution for the electrical and mechanical distribution of the drive.

[0049] It is advantageous here if the rotational speed target value of the first electric machine corresponds to the actual rotational speed of the output shaft and if both electric machines can be operated in a speed-controlled manner, ie with the same type of regulator structure.

[0050] In an advantageous embodiment, the transmission ratio of the drive is predetermined as a monotonically increasing function of time, and when a target value is reached the holding brake of the first electrical machine is activated, ie in particular the holding brake is engaged.

[0051] In this case, the transmission ratio of the drive device is equal to a target value in the case of a fixed ring gear. It is advantageous here that the brake is released to start the drive device and the ring gear is thus allowed to rotate. Furthermore, during the start-up, not only the rotational speed of the output shaft increases, but also the transmission ratio of the drive device increases from a small value (e.g. zero) to a target value, which is equal to the transmission ratio of a purely mechanical path, in particular a reducer.

[0052] Further advantages result from the dependent claims. The invention is not limited to the combination of features of the claims. For a person skilled in the art, further meaningful combinations of the claims and / or individual claim features and / or features of the description and / or drawings will appear to the person skilled in the art, in particular from the stated objectives and / or objectives arising from a comparison with the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] The present invention will now be explained in more detail with reference to the schematic diagram:

[0054] Figure 1 The drive device according to the invention is shown schematically. DETAILED DESCRIPTION

[0055] like Figure 1 As shown in FIG. 1 , a torque source 1 , in particular an electric machine, drives a rotatably mounted planet carrier 2 of a drive device.

[0056] The planet carrier 2 is connected to pins which are oriented parallel to the axis of rotation of the planet carrier 2 and on which the planet gears 4 are rotatably mounted, in particular via needle bearings or other rolling bearings.

[0057] The planetary gears 4 , which are preferably spaced uniformly apart from one another in the circumferential direction, mesh on the one hand with a centrally arranged sun gear 5 and on the other hand with a rotatably mounted ring gear 3 which radially surrounds the planetary gears 4 .

[0058] The ring gear 3 has both internal teeth meshing with external teeth of the planetary gears 4 , wherein the external teeth of the planetary gears 4 mesh with external teeth of the sun gear 5 , and external teeth meshing with external teeth of the first gear wheel 6 .

[0059] The first gear wheel 6 is rotatably mounted and connected in a rotationally fixed manner to the rotor shaft of a first electric machine, in particular a synchronous machine, which can be supplied with power by a converter 7. In generator operation, the torque from the ring gear 3 is thus transmitted to the first gear wheel 6 and, as a function of the rotational speed of the first gear wheel 6, the electrical power from the first electric machine is thus conducted to the converter.

[0060] The AC voltage-side interface of the converter 7 is connected to an interface of the electric machine, ie in particular to the stator of the first electric machine.

[0061] The DC voltage side interface of the converter 7 is connected to the DC voltage side interface of the second converter 9, and the AC voltage side interface of the second converter is connected to the interface of the second electric machine, in particular a synchronous machine. The second electric machine in particular directly drives a second gear 10 meshing with a toothed part 11, in particular a third gear, which is connected in a rotationally fixed manner to a corresponding shaft 12, which in turn is connected in a rotationally fixed manner to the sun gear 5, i.e., in particular to the output shaft of the planetary gear. The sun gear 5 is therefore connected in a rotationally fixed manner to the toothed part 11.

[0062] The connection of the DC voltage-side interfaces of the two converters 7 , 9 can be referred to as an intermediate circuit 8 , wherein an upper potential of the DC voltage and a lower potential of the DC voltage, ie, the intermediate circuit voltage, are provided.

[0063] Optionally, an energy storage device can be added to the intermediate circuit 8 , so that energy generated in the manner of a generator can be stored in the energy storage device and can be used in particular as buffer energy.

[0064] The first converter 7 has means for detecting the motor current, ie the output current supplied to the first motor, the rotor shaft of which is connected to the first gear 6 in a rotationally fixed manner.

[0065] A transmission ratio is predetermined for operating the drive. To achieve this, the first converter is operated in a speed-controlled manner. The detected speed n1_ist of the first gear 6 is adjusted to the target value n1_soll, i.e., the set torque M1, in the following manner. Here, the torque is generator-like, i.e. has a negative value.

[0066] The actual value U_z_ist of the intermediate circuit voltage is detected and regulated by the second converter 9 to the target value U_z_target by applying a torque M2 as a control variable to the second gear wheel 10 via the second electric machine.

[0067] The target value U_z_Target is predetermined to be as low as possible, for example to be 100 volts.

[0068] The power supplied in a generator-like manner attempts to increase the intermediate circuit voltage, which is however limited to a maximum value U_z_max, for example 650 Volts or a value between 650 Volts and 800 Volts.

[0069] Therefore, the first converter 7 tends to increase the intermediate circuit voltage, while the second converter 9 tends to reduce the intermediate circuit voltage. Ideally, the intermediate circuit voltage is first kept at an intermediate value, wherein the intermediate circuit voltage reaches a negligible minimum value, in particular zero, after the brake of the first electrical machine is activated (ie applied).

[0070] By providing a capacitor in intermediate circuit 8 , in particular by providing an energy store in intermediate circuit 8 , control fluctuations in first converter 7 have a smaller influence on the control behavior of the second converter and the fluctuation tendency of the entire system is reduced.

[0071] The speed regulator of the first converter 7 is preferably designed as a linear regulator, for example a P regulator or a PI regulator. The regulator of the second converter 9 is also preferably designed as a linear regulator, for example a P regulator or a PI regulator.

[0072] Therefore, only the rotational speed of the first electric machine and the intermediate circuit voltage and the output current of the two converters 7, 9 at their respective AC voltage-side interfaces need to be detected. In addition, the rotational speed detection of the second electric machine helps to generate a rotating field that is as well matched as possible.

[0073] The first electric machine is preferably designed as a three-phase AC machine and the second electric machine is also designed as a three-phase AC machine.

[0074] The respective converter 7, 9 has a parallel circuit consisting of three series circuits supplied with an intermediate circuit voltage, wherein each series circuit has two controllable semiconductor switches, in particular IGBTs or MOSFETs, connected in series. In this way, a three-phase voltage can be provided at the AC voltage-side interface of the respective converter.

[0075] The control voltage for the semiconductor switch is generated by signal electronics, which preferably consists of a first part, which is arranged in the housing together with the first converter 7, and a second part, which is arranged in the housing together with the second converter 9. The two parts are connected by means of a data exchange connection. The first part contains the speed regulator and the second part contains the voltage regulator, wherein both regulators each have the torque as the control variable.

[0076] The sun gear 5 is arranged radially inside the planet gears 4 , which in turn are arranged radially inside the ring gear 3 .

[0077] In another embodiment according to the invention, a different regulator structure is used. Here, the two converters 7 and 9 are respectively operated with speed regulation and the desired transmission ratio is predetermined for the electrical branch. The speed n1_ist detected on the first motor is adjusted to the predetermined target speed variation curve n1_Soll(t) in the following manner, that is, the torque M1 is adjusted and thus directed to the first gear 6 via the first motor. The second converter obtains a value related to the detected speed n1_ist as the target speed n2, and adjusts the detected speed n2_ist of the toothed component 11 to the target speed n2 in the following manner, that is, the second converter sets the corresponding torque M2. Here, the target speed is preferably determined as the sum of the speed of the planetary carrier 2 detected by the speed sensor and multiplied by the mechanical transmission ratio and the speed additionally generated via the electrical path.

[0078] In a further embodiment according to the invention, a constant value is not predefined for the transmission ratio, in particular the gear ratio, but instead a time profile of the transmission ratio is predefined. In particular, when the drive is started, during the acceleration from zero speed until the target speed is reached, the gear ratio is increased from zero to a value that corresponds to the purely mechanical gear ratio of the planetary gear, that is to say - when the second electric machine is deactivated - the gear ratio that is achieved with the brake of the first electric machine activated, that is to say with the ring gear 3 fixed. Therefore, the brake is activated and the ring gear 3 is thus fixed only when the gear ratio reaches a value that can be achieved purely mechanically by the planetary gear.

[0079] List of reference numerals:

[0080] 1 Torque source, especially the motor

[0081] 2 Planet carrier

[0082] 3 Ring gear

[0083] 4 Planetary gears

[0084] 5 Sun gear

[0085] 6 First gear

[0086] 7 Converters, especially those operating as generators

[0087] 8 Intermediate circuit

[0088] 9 Converters, especially those operated as motors

[0089] 10 Second gear

[0090] 11 Toothed parts, especially the third gear

[0091] 12 Axis, especially output shaft

Claims

1. A drive device for transmitting power from an input shaft to an output shaft, A portion of the power to be transmitted is supplied from the input shaft to a first electric machine operated as a generator and converted into electrical power, which is supplied at least partially to a second electric machine operated as a motor, the mechanical power of which is supplied to the output shaft, The first motor is powered by the interface on the AC voltage side of the first converter, the interface on the DC voltage side of the first converter is powered by the interface on the DC voltage side of the second converter, and the interface on the AC voltage side of the second converter is powered by the second motor. the first electric machine has an electromagnetically actuatable holding brake, the activation of which makes the portion of the power to be transmitted infinitesimal, while the deactivation of which makes the portion of the power to be transmitted controllable by the converter, The remainder of the power to be transmitted is transferred from the input shaft via a mechanical transmission to the output shaft, The control signal for the first converter is generated by a first signal electronics device, and, The control signal for the second converter is generated by the second signal electronics, The first signal electronics system has a speed regulator, the regulating variable of which is the torque of the first electric machine.

2. The driving device according to claim 1, characterized in that: have: a rotatably mounted planet carrier which is connected to the drive shaft in a rotationally fixed manner, - planetary wheels which are rotatably mounted on pins connected to the planet carrier, a toothed ring having an inner toothing and an outer toothing, - a rotatably mounted sun gear, and - a first gear which meshes with the outer toothing of the ring gear, The first gear is connected to the rotor shaft of the first motor in a non-rotatable manner. The drive device has a second gear which meshes with the toothed member, The second gear is connected to the rotor shaft of the second motor in a non-rotatable manner. The toothed member is connected to the sun gear in a rotationally fixed manner.

3. The driving device according to claim 1, It is characterized in that The first motor is powered by an interface on the AC voltage side of the first converter, an interface on the DC voltage side of the first converter is electrically connected to an interface on the DC voltage side of the second converter, and an interface on the AC voltage side of the second converter powers the second motor.

4. A drive device according to any one of the preceding claims 1 to 3, It is characterized in that The speed regulator is a P regulator or a PI regulator, and the regulating variable is the generator torque of the first electric machine.

5. A drive device according to any one of the preceding claims 1 to 3, It is characterized in that The second signal electronics has a second linear regulator, the regulation variable of which is the torque of the second electric machine.

6. The driving device according to claim 5, It is characterized in that The regulating parameter of the second linear regulator is the motor torque of the second electric machine.

7. A drive device according to any one of claims 1 to 3, It is characterized in that A first sensor for detecting the rotational speed of the first gear is connected to the first signal electronics, a sensor for detecting the voltage present at the interface on the DC voltage side of the first converter is connected to the first signal electronics, And / or a second sensor for detecting the rotational speed of the second gear wheel is connected to the second signal electronics, and a sensor for detecting the voltage present at the DC voltage-side interface of the second converter is connected to the second signal electronics.

8. A drive device according to any one of the preceding claims 1 to 3, It is characterized in that A first sensor for detecting the output current at the interface on the AC voltage side of the first converter is connected to the first signal electronics, And / or a second sensor for detecting an output current of the second converter at a connection on the AC voltage side is connected to the second signal electronics.

9. A drive device according to any one of the preceding claims 1 to 3, It is characterized in that A sensor for detecting the voltage present at the DC voltage-side interface of the first converter or the second converter is connected to the first signal electronics.

10. A drive device according to any one of the preceding claims 1 to 3, It is characterized in that The energy store is electrically connected in parallel to the DC voltage-side connections of the first converter and the second converter.

11. The driving device according to claim 10, It is characterized in that The energy storage device comprises a battery and / or a supercapacitor.

12. A drive device according to any one of the preceding claims 1 to 3, It is characterized in that The first electric machine is designed as a synchronous machine, and / or, The second electric machine is designed as a synchronous machine.

13. Method for operating a drive device according to any one of the preceding claims 1 to 12, It is characterized in that The motor current of the first electric machine and the motor voltage of the first electric machine are regulated in such a way that the rotational speed n1_ist of the rotor shaft of the first electric machine is detected and adjusted to a target value n1_target by means of a first converter, The motor current of the second electric machine and the motor voltage of the second electric machine are regulated in such a way that the detected voltage U_z_ist present at the DC voltage-side connection of the second converter is adjusted to a target value U_z_target, which is done by means of the second converter.

14. The method according to claim 13, It is characterized in that The target value n1_target is determined by the rotational speed n2_ist detected at the rotor shaft of the second electric machine, taking into account a predetermined gear ratio and a predetermined distribution ratio. The speed ratio is equal to an expected value of the quotient of the rotational speed of the sun gear shaft and the rotational speed of the planet carrier or an expected value of the quotient of the rotational speed of the rotor shaft of the second electric machine and the rotational speed of the first electric machine.

15. Method for operating a drive device according to any one of claims 1 to 12, It is characterized in that The motor current of the first electric machine and the motor voltage of the first electric machine are regulated in such a way that the rotational speed n1_ist of the rotor shaft of the first electric machine is detected and adjusted to a target value n1_target by means of a first converter, The motor current of the second electric machine and the motor voltage of the second electric machine are regulated in such a way that the rotational speed n2_ist of the rotor shaft of the second electric machine is detected and adjusted to a target value n2_target by means of a second converter, The target value n2_target is determined from the detected rotational speed n1_ist of the rotor shaft of the first electrical machine, taking into account a predetermined transmission ratio and a predetermined transmission ratio distribution for the electrical and mechanical divisions of the drive.

16. The method according to claim 15, It is characterized in that The transmission ratio of the drive is predetermined as a monotonically increasing function of time, and when the target value is reached, the holding brake of the first electric machine is activated. Therein, the transmission ratio of the drive device is equal to the target value when the ring gear is fixed.

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