WO2020016074A1

WO2020016074A1 - Drive unit

Info

Publication number: WO2020016074A1
Application number: PCT/EP2019/068521
Authority: WO
Inventors: Dominik Grauvogl; Josef Laumer; Thomas Knorr
Original assignee: Vitesco Technologies GmbH
Priority date: 2018-07-18
Filing date: 2019-07-10
Publication date: 2020-01-23
Also published as: DE102018211993A1

Abstract

The invention relates to a drive unit (1). The drive unit (1) has at least two permanently excited synchronous motors (11, 12), at least two asynchronous motors (13, 14) and a transmission unit (20). The two permanently excited synchronous motors (11, 12) are coupled to one another by means of a first coupling (25). The two asynchronous motors (13, 14) are coupled to one another by means of a second coupling (26). The transmission unit (20) comprises the first coupling (25) and the second coupling (26), and the transmission unit (20) is designed to transfer the rotation of the two permanently excited synchronous motors (11, 12) and the rotation of the two asynchronous motors (13, 14) to a common output shaft (21). The two permanently excited synchronous motors (11, 12) and the two asynchronous motors (13, 14) have a common stator.

Description

description

drive unit

The invention relates to a drive unit, in particular for a vehicle, a vehicle with such a drive unit, a method for operating a drive unit and a computer program element.

With three-phase electric motors, there are essentially two different motor types. On the one hand the synchronous motors and on the other hand the asynchronous motors (induction motors). The synchronous motors are characterized in that the rotating field in the stator is synchronous with the speed of the rotor. For control purposes, the synchronous motors require a position encoder in order to record the current rotor position. In asynchronous motors, the rotating field of the stator is asynchronous to the speed of the rotor, the rotating field of the stator is faster or slower. This difference in speed is called slip. The resulting slip induces a voltage in the rotor of the asynchronous motor, which generates a current flow when the rotor rods are short-circuited, which in turn leads to an output torque. In particular with regard to the efficiency or the efficiency, the installation space, the use of materials and the costs, the two engine types sometimes have different properties. Synchronous motors typically have the best efficiency at low speeds (30% of the maximum speed) and higher torques (60% of the maximum torque). Asynchronous motors have the best efficiency at higher speeds (50% of the maximum speed) and lower torques (20% of the maximum torque). The combination of the two motor types can improve the efficiency of the drive system, since the optimal combination of asynchronous motor and Synchronous motor can be selected. This can be particularly advantageous in the case of highly dynamic and constantly changing load requirements, such as when driving a vehicle.

Vehicles are operated over a large speed range (starting up to driving on the motorway) and load range (rolling away and full load acceleration). Furthermore, high demands are placed on efficiency in vehicles, since this can increase the range of the vehicle without having to install additional heavy batteries.

It is an object of the invention to provide an efficient and resource-saving drive.

This object is achieved by the subject of the independent claims. Embodiments and developments can be found in the dependent claims, the description and the figures.

A first aspect of the invention relates to a drive unit. The drive unit has at least two permanently excited synchronous motors, at least two asynchronous motors and a gear unit. The two permanently excited synchronous motors are coupled to one another via a first coupling. The two asynchronous motors are coupled to one another via a second coupling. The gear unit has the first coupling and the second coupling and the gear unit is set up to transmit the rotation of the two permanently excited synchronous motors and the rotation of the two asynchronous motors to a common output shaft. The two permanently excited synchronous motors and the two asynchronous motors have a common stator.

By combining at least two permanently excited synchronous motors and at least two asynchronous motors, the four motors have a common stator, the advantages of the two motor types can be combined in one drive unit. Material and installation space can be reduced and at the same time the efficiency or efficiency of the drive unit can be increased. Furthermore, the drive unit can be controlled by only one converter unit. The torque generated by the two permanently excited synchronous motors and the two asynchronous motors can be transmitted to a common output shaft by means of a gear unit. The gear unit can have a first coupling and a second coupling, which are rigid or fixed or connected to one another via a coupling. The first coupling can couple the two permanently excited synchronous motors to one another and the second coupling can couple the two asynchronous motors to one another. The first and the second coupling can, for example, have a gear pair or a friction gear pair. It should be noted that the first coupling, the second coupling and the output shaft rotate in the same direction.

A synchronous rotation is understood to mean a rotation with the same speed and the same direction of rotation. An opposite rotation is a rotation at the same speed but in the opposite direction.

Alternatively or additionally, three, four or more permanently excited synchronous motors and three, four or more asynchronous motors can also be arranged in a common stator.

According to one embodiment, the common stator has six stator windings. Due to the advantageous arrangement of the four motors with a common stator, the number can be increased

Stator windings can be reduced from 12 (three per motor) to six. This saves space, material and costs. Furthermore, by using a common stator magnetically active material can be saved, especially in the corners of the stator.

According to one embodiment, the drive unit also has a converter unit. The converter unit is set up to supply the two permanently excited synchronous motors and the two asynchronous motors with current and to control the drive unit according to the current operating point.

The control of the drive unit can thus be selected depending on the operating point, e.g. Control like a synchronous motor (synchronous motor control) or like an asynchronous motor (asyn chronomotor control). Furthermore, depending on the operating point, it can also be decided which motor type is suitable, permanently excited synchronous motor or asynchronous motor. It should be noted that only one converter unit is required for the drive unit. This can have three phases, wherein two coils can be assigned to one phase. Furthermore, it should be noted that the converter unit can have a processor and a memory in order to determine the controlled variables / signals as a function of the desired operating point.

According to a further embodiment, the rotors of the two permanently excited synchronous motors and the rotors of the two asynchronous motors are arranged in a diamond shape in the common stator. Furthermore, the rotors of the two permanently excited synchronous motors and the rotors of the two asynchronous motors are each arranged opposite in the common stator.

The two permanently excited synchronous motors and the two asynchronous motors can be arranged in a diamond shape in the common stator. Especially when the two are permanently excited Synchronous motors and the two asynchronous motors have different maximum powers, there are other necessary rotor diameters, which may require the diamond-shaped arrangement. Furthermore, the diamond-shaped arrangement of the motors allows the first coupling and the second coupling to be better integrated into the drive unit. Furthermore, the two permanently excited synchronous motors are arranged opposite one another and the two asynchronous motors are arranged opposite one another. The magnetic flux through the common stator means that the motors arranged opposite each other rotate in the same direction, but neighboring motors rotate in opposite directions. In this case, the two permanently excited synchronous motors rotate in the same direction and the two asynchronous motors rotate in the same direction, but the two permanently excited synchronous motors rotate in opposite directions with respect to the two asynchronous motors.

According to one embodiment, the first coupling and the second coupling are a gear pair. However, too

Friction wheels are used. It should also be noted that the first coupling can be an external gear and the second coupling can be an internal gear. As a result, the first coupling and the second coupling can rotate in the same direction, although the two permanently excited synchronous motors rotate in opposite directions to the two asynchronous motors.

According to a further embodiment, the first coupling and the second coupling rotate in the same direction.

It should be noted that the translation between the two permanent magnet synchronous motors and the first coupling can be the same as the translation between the two asynchronous motors and the second coupling so that the first coupling and the second coupling rotate in unison. According to one embodiment, the two permanently excited synchronous motors and the two asynchronous motors rotate in the same direction. The permanently excited synchronous motors rotate in opposite directions with respect to the asynchronous motors. This is caused by the magnetic flux through the common stator. It is therefore expedient for the same motor types to be arranged opposite one another, so that the same motor types each rotate in the same direction. This can be particularly useful when designing the two permanent magnet synchronous motors and the two asynchronous motors with different maximum powers.

According to one embodiment, the converter unit is set up to regulate the drive unit like a permanently excited synchronous motor while the drive unit is starting up. The converter unit is also set up to control the drive unit like an asynchronous motor from a first predefined speed or a predefined first operating point.

The common stator and a converter unit enable the drive unit to be controlled like a permanent-magnet synchronous motor when starting up, starting up or starting up. In other words, a field synchronous with the position of the rotor of the motors can be generated in the stator. It should be noted that the current rotor position of the two permanently excited synchronous motors can be detected by a position encoder. Due to the common stator and the mechanical coupling via the gear unit, the two asynchronous motors are also subjected to a synchronous rotating field at their speed. This means that they rotate synchronously, but without outputting any significant torque. In other words, the torque is output at this operating point at the common drive shaft in particular through the two permanently excited synchronous motors. As soon as a first predefined speed or a predefined operating point (speed, torque and dynamics) is reached, the converter unit can begin to transfer the control to the control of an asynchronous motor. In particular, an asynchronous rotating field is then generated in relation to the rotor speed of the motors. First, the output torque and the speed on the common output shaft are kept constant, but the torque is generated more and more by the two asynchronous motors, for example by increasing slip. The converter unit can then completely change the control to an asynchronous motor control. In particular, the control can be switched to asynchronous motor control from a second predefined speed or a second predefined operating point. It should be noted that the control can also be switched back to the synchronous motor control if the predefined speed or the predefined operating point is undershot.

According to one embodiment, the gear ratio between the permanently excited synchronous motors and the first coupling is equal to the gear ratio between the asynchronous motors and the second coupling. When using friction wheels, the ratio between the output radius of the two permanently excited synchronous motors and the radius of the first coupling can be equal to the ratio between the output radius of the two asynchronous motors and the radius of the second coupling.

According to a further embodiment, the gear unit has a fixed or rigid connection between the first coupling and the second coupling in order to transmit the rotation of the two synchronous motors excited by man and the two asynchronous motors to the common output shaft. According to one embodiment, the transmission unit also has a clutch, the clutch being set up to decouple the first coupling from the output shaft so that the permanently excited synchronous machines can be decoupled.

Thus, the influence of the two permanently excited synchronous motors on the output torque on the common drive shaft can be prevented if the drive unit is controlled by the converter unit like an asynchronous motor.

According to one embodiment, the asynchronous motors have a higher maximum power than the permanently excited synchronous motors. The drive unit can thus be better adapted to the respective application. For example, the two permanently excited synchronous motors can be designed smaller than the two asynchronous motors. The two permanently excited synchronous motors can be used in particular for starting a vehicle and the two asynchronous motors can be used in higher speed ranges.

According to a further embodiment, the power ratio between the two asynchronous motors and the two permanently excited synchronous motors is 5: 1. It should be noted that other power ratios such as 2: 1, 3: 1 or 1: 2 can also be selected. This depends in particular on the intended application.

According to one embodiment, the converter unit, the two permanently excited synchronous motors, the two asynchronous motors and the gear unit are arranged in a common housing. The drive unit can thus be made compact and space-saving.

Another aspect of the invention relates to a vehicle with a drive device described above and below.

The vehicle is, for example, a

Motor vehicle, such as a car, bus or truck, or else around a rail vehicle, a ship, an aircraft, such as a helicopter or plane, or for example a bicycle.

A further aspect of the invention relates to a method for operating a drive unit which has at least two permanently excited synchronous motors and at least two asynchronous motors, the two permanently excited synchronous motors and the two asynchronous motors having a common stator, comprising the following steps:

- Regulation of the drive unit such as a permanent magnet synchronous motor during the start of the drive unit;

- Pass the control as in a permanently excited synchronous motor (synchronous motor control) to the control as an asynchronous motor (asynchronous motor control) as soon as a first predefined speed or a first predefined operating point is reached; and

- Control the drive unit like an asynchronous motor when a second predefined speed or a second predefined operating point is reached.

During the transfer, the torque and speed on the common output shaft are kept constant, but they are now generated by the asynchronous motors. This transient operation or transfer is quickly possible.

Another aspect of the invention relates to a program element which, when executed on a converter unit for operating a drive unit, instructs the drive unit to carry out the method described above and below. Another aspect of the invention relates to a computer-readable medium on which a program element is stored which, when it is executed on a converter unit for operating a drive unit, guides the drive unit to carry out the method described above and below.

Further features, advantages and possible uses of the invention result from the following description of the exemplary embodiments and the figures.

The figures are schematic and not to scale. If the same reference numerals are given in the following description of the figures, they denote the same or similar elements.

1 shows a schematic view of a drive unit according to an embodiment.

2 shows an equivalent circuit diagram of a drive unit according to an embodiment.

3 shows a sectional view of a drive unit according to an embodiment.

4 shows a common stator with four rotors according to one embodiment.

Fig. 5 shows a block diagram for a control of a drive unit according to an embodiment.

6 shows a vehicle with a drive unit according to an embodiment.

7 shows a flowchart for a method for operating a Drive unit according to one embodiment.

1 shows a schematic view of the drive unit 1, in particular for a vehicle. The drive unit 1 has at least two permanently excited synchronous motors 11, 12, at least two asynchronous motors 13, 14, a gear unit 20 and a converter unit 30. The converter unit 30, the motors 11, 12, 13, 14 and the gear unit 20 can be arranged in a common housing 10, whereby the drive unit 1 can be made compact. The engines 11,

12, 13, 14 each have a rotor. The motors 11, 12,

13, 14 also have a common stator. This saves active material in the stator. Furthermore, by combining permanent-magnet synchronous motors 11, 12 and asynchronous motors 13, 14, the efficiency or efficiency of the drive unit 1 can be increased, since, depending on the current operating point, the permanent-magnet synchronous motors 11, 12 or the asynchronous motors 13, 14 can be regulated , which allows the advantages of both engine types to be combined. The two permanently excited synchronous motors 11, 12 are connected to one another via a first coupling. Furthermore, the two permanently excited synchronous motors 11, 12 rotate in the same direction. The asynchronous motors 13, 14 are connected to one another via a second coupling, and the asynchronous motors 13, 14 also rotate in the same direction. The first coupling and the second coupling can have a pair of gearwheels or a pair of friction wheels. The transmission unit 20 has the first coupling and the second coupling and transmits the rotation of the permanently excited synchronous motors 11, 12 and the rotation of the asynchronous motors 13, 14 to a common output shaft 21. Here, the transmission unit 20 can rigidly or respectively the first coupling with the second coupling . firmly connect so that the first coupling and the second coupling rotate in the same direction. Alternatively or additionally, the gear unit 20 can have a clutch between the Provide drive shaft 21 and the first coupling so that the two permanently excited synchronous motors 11, 12 can be decoupled from the output shaft 21. The converter unit 30 is set up to supply the two permanently excited synchronous motors 11, 12 and the two asynchronous motors 13, 14 with current and to regulate them in accordance with the current operating point of the drive unit 1. Here, the converter unit 30 can control the drive unit 1 during startup like a permanently excited synchronous motor, the asynchronous motors running synchronously and without torque. The converter unit 30 is also set up to regulate the drive unit 1 like an asynchronous motor from a predefined speed or a predefined operating point. The predefined speed or the predefined operating point can, in particular, depend on the dimensions of the two permanently excited synchronous motors 11, 12 and the two asynchronous motors 13, 14, for example the two asynchronous motors 13, 14 can be dimensioned larger than the two permanently excited synchronous motors 11, 12. Thus the drive unit 1 can be further adapted to the later intended use. For example, a maximum power between the two permanently excited synchronous motors 11, 12 and the two asynchronous motors 13, 14 is seen in a ratio of 1: 5.

Fig. 2 shows an electrical equivalent circuit of the drive unit 1. The dark boxes each symbolize a coil of the drive unit 1. Due to the advantageous arrangement of the four rotors (two permanently excited synchronous motors and two asynchronous motors), the number of coils can be reduced from 12 to six. Furthermore, these six coils can be controlled by the converter unit via three phase-shifted electrical lines. In other words, the four rotors of the motors can be controlled over three phases. To do this, two coils are connected to one phase. Fig. 3 shows a cross section through the gear unit 20 or through the output shafts of the motors 11, 12, 13, 14. In the middle you can see the first coupling 25, which couples the two permanent magnet synchronous motors 11, 12 together. The first coupling 25 can be a gear wheel or a friction wheel. In Fig. 3, the respective direction of rotation of the components is symbolized by the curved arrows. The first coupling rotates clockwise, so the two permanently excited synchronous motors 11, 12 rotate counterclockwise. Furthermore, four black points can be seen on the first coupling 25, which represent mounting points 27 for a flange of the output shaft. Furthermore, the two permanently excited synchronous motors 11, 12 are arranged opposite one another.

An outer ring 26 can also be seen in FIG. 3. This represents the second coupling 26, which may have internal teeth, for example. The second coupling 26 couples the two asynchronous motors 13, 14 to one another. Also on the second coupling four mounting points 27 are provided for the flange of the drive shaft. The first coupling 25 and the second coupling 26 can be connected to one another via this flange, so that these drive the output shaft together. Thus, the second coupling 26 rotates in the same way as the first coupling 25 (clockwise). The two asynchronous motors 13, 14 rotate in Fig. 3 clockwise and thus in opposite directions to the permanent magnet synchronous motors 11, 12. By connecting the first coupling 25 to the second coupling 26, the transmission ratio between the two permanently excited synchronous motors 11, 12 and the first coupling 25 be equal to the gear ratio between the two asynchronous motors 13, 14 and the second coupling 26. The straight arrows 11a, 13a, 25a, 26a in FIG. 3 represent the radii of the respective component. Thus, the following must apply if the couplings 25, 26 are friction wheels, that the ratio between the radius of the permanently excited synchronous motor 11a and the radius of the first coupling 25a is equal to the ratio between the radius of the asynchronous motor 13a and the radius of the second coupling 26a.

Fig. 4 shows the common stator 15 and the four motors 11, 12, 13, 14. The permanent magnet synchronous motors 11, 12 and the asynchronous motors 13, 14 are arranged opposite each other. Overall, the four motors 11, 12, 13, 14 are arranged roughly ten-shaped. Via the common stator 15, the individual motors 11, 12, 13, 14 are magnetically connected to one another. The magnetic flux is represented in FIG. 4 by the arrows within the common stator 15. Furthermore, the six coils 16 can be seen, which are controlled by the converter unit in such a way that a rotating field is created and the motors 11, 12, 13, 14 rotate accordingly. The coils 16 are each connected to form coil pairs, so that only three phases have to be regulated by the converter unit. Furthermore, it can be seen that, due to the geometric arrangement, the respective opposite motors 11, 12, 13, 14, that is to say the permanently excited synchronous motors 11, 12 and the asynchronous chronomotors 13, 14, rotate in the same direction.

5 shows a control circuit or a block diagram for the control of the drive unit. This control loop can be carried out by the converter unit 30. The current controller 31 receives, as input variables, the phase currents which are output to the stator, the setpoint specification 36 and the magnetization current for the two asynchronous motors 13, 14 of the magnetization current controller 37. As an output, the current controller 31 outputs voltage specifications. These are converted by the pulse generation 32 into pulses for pulse width modulation. These pulses drive the converter 33, which applies the corresponding voltage to the phases at a predetermined frequency Control of the motors 11, 12, 13, 14 outputs. The current rotor position of the permanently excited synchronous motors 11, 12 is detected by the position sensor 38 and the speed n and the electrical stator resistance g are calculated therefrom in a calculation module 34. The calculation module 34 together with the module 35 forms the machine model for the asynchronous motor control. The speed n then goes into the setpoint specification 36 and the magnetizing current controller 37. When the drive unit starts up or starts up, it is controlled like a permanently excited synchronous motor. The setpoint of the dq currents is thus based on the current speed and the torque setpoint. Thus, the stator frequency and the stator angle are equal to the rotor position angle of the two permanently excited synchronous motors 11, 12. At this operating point, the two asynchronous motors 13, 14 rotate synchronously and without torque. From a first predefined speed or a first pre-defined operating point, the control is transferred to an asynchronous motor control. Initially, the speed and the required torque remain the same, but the torque is generated by the two asynchronous motors 13, 14. Different dq currents result and, with the change in the machine model, a different stator frequency. For the two asynchronous motors 13, 14, a slip to the mechanical speed is necessary at this point, but the feed frequency can be changed very quickly.

Fig. 6 shows a vehicle 2 with a drive unit 1 described above and below. The drive unit 1 can be arranged on the front axle and / or the rear axle of the vehicle 2 in order to drive the vehicle 2. Furthermore, when the vehicle 2 is started up, the permanently excited synchronous motors can be used primarily for propulsion, ie the drive unit is regulated like a permanently excited synchronous motor (synchronous rotating field). In other words, at low Speeds and comparatively high moments. As soon as the vehicle 2 has reached a certain speed and / or the loads decrease, the asynchronous motors can be transferred, ie the drive unit is regulated like an asynchronous motor (asynchronous rotating field). Furthermore, the permanently excited synchronous motors and the asynchronous motors can have different maximum powers, so that the two permanently excited synchronous motors can be designed smaller than the two asynchronous motors. By combining the two motor types (permanent-magnet synchronous motor and asynchronous motor), the advantages of both motor types can be combined, so that the efficiency of the drive unit can be increased. Furthermore, material can be saved on the stator by the combination of the motors and by a common stator. The number of coils of the stator can also be reduced compared to individual motors. In other words, space, material and energy can be saved. The range of the vehicle can thus be increased.

7 shows a flowchart for a method for operating a drive unit which has at least two permanently excited synchronous motors and at least two asynchronous motors, the two permanently excited synchronous motors and the two asynchronous motors having a common stator. In a step S1, the drive unit is regulated by a converter unit such as a permanently excited synchronous motor, ie a rotating field that is synchronous with the speed is generated in the stator. In step S1, the drive unit is located in particular when starting up, ie at low speeds, for example when starting a vehicle. In step S2, the control is transferred from a synchronous motor control to an asynchronous motor control. This transfer takes place as soon as a first predefined speed or a first predefined operating point of the drive unit is reached. In step S3, the drive unit becomes like Asynchronous motor controlled, especially at higher speeds and low torques. The asynchronous motor control takes place in particular when a second predefined speed or a second predefined operating point is reached.

Claims

claims

1. Drive unit (1), comprising:

- at least two permanently excited synchronous motors (11,

12);

- at least two asynchronous motors (13, 14); and

- a gear unit (20);

the two permanently excited synchronous motors (11, 12) being coupled to one another via a first coupling (25),

the two asynchronous motors (13, 14) being coupled to one another via a second coupling (26),

wherein the gear unit (20) has the first coupling (25) and the second coupling (26) and is set up to rotate the two permanently excited synchronous motors (11, 12) and the rotation of the two asynchronous motors (13, 14) to transmit common output shaft (21),

the two permanently excited synchronous motors (11, 12) and the two asynchronous motors (13, 14) having a common stator.

2. Drive unit (1) according to claim 1, further comprising a converter unit (30),

wherein the converter unit (30) is set up to control the two permanently excited synchronous motors (11, 12) and the two

To supply asynchronous motors (13, 14) with power and to control the drive unit (1) according to the current operating point.

3. Drive unit (1) according to claim 1 or 2,

wherein the rotors of the two permanently excited synchronous motors (11, 12) and the rotors of the two asynchronous motors (13, 14) are arranged in a diamond shape in the common stator, and wherein the rotors of the two permanently excited synchronous motors (11, 12) 12) and the rotors of the two asynchronous motors (13, 14) are arranged opposite each other in the common stator.

4. Drive unit (1) according to one of the preceding claims,

wherein the first coupling (25) and the second coupling (26) are a gear pair.

5. Drive unit (1) according to one of the preceding claims,

wherein the first coupling (25) and the second coupling (26) rotate in the same direction.

6. Drive unit (1) according to one of the preceding claims,

the two permanently excited synchronous motors (11, 12) rotating in unison and the two asynchronous motors (13, 14) rotating in unison,

the permanent magnet synchronous motors (11, 12) rotating in opposite directions with respect to the asynchronous motors (13, 14).

7. Drive unit (1) according to one of claims 2 to 6, wherein the converter unit (30) is set up to regulate the drive unit (1) during the start-up of the drive unit like a permanently excited synchronous motor, wherein the converter unit (30) is also set up to do so is to regulate the drive unit (1) like an asynchronous motor from a first predefined speed or a predefined first operating point.

8. Drive unit (1) according to one of the preceding claims,

wherein the transmission ratio between the permanent magnet synchronous motors (11, 12) and the first coupling (25) is equal to the gear ratio between the Asyn chronmotoren (13, 14) and the second coupling (26).

9. Drive unit (1) according to one of the preceding claims,

wherein the gear unit (20) has a fixed or rigid connection between the first coupling (25) and the second coupling (26) in order to rotate the two permanently excited synchronous motors (11, 12) and the two asynchronous motors (13, 14) to be transmitted to the common output shaft (21).

10. Drive unit (1) according to one of claims 1 to 8, wherein the transmission unit (20) further comprises a clutch, the clutch being set up to decouple the first coupling (25) from the output shaft (21), so that the permanently excited synchronous machines (11, 12) can be uncoupled.

11. Drive unit (1) according to one of the preceding claims,

the asynchronous motors (13, 14) having a higher maximum power than the permanently excited synchronous motors (11, 12).

12. Drive unit (1) according to one of claims 2 to 11, wherein the converter unit (30), the two permanently excited

Synchronous motors (11, 12), the two asynchronous motors (13, 14) and the gear unit (20) are arranged in a common housing (10).

13. Vehicle (2) with a drive unit (1) according to one of the preceding claims.

14. Method for operating a drive unit, which we at least two permanent magnet synchronous motors and at least has two asynchronous motors, the two permanently excited synchronous motors and the two asynchronous motors having a common stator, comprising the following steps:

- Rules (Sl) of the drive unit such as a permanently excited synchronous motor during startup of the drive unit;

Transfer (S2) the control as in a permanently excited synchronous motor to the control as an asynchronous motor as soon as a first predefined speed or a first predefined operating point is reached; and

- Controlling (S3) the drive unit like an asynchronous motor when a second predefined speed or a second predefined operating point is reached.

15. Computer program element which, when executed on a converter unit for operating a drive unit, guides the drive unit to carry out the method according to claim 14.