Drive device and method for operating a drive device for a vehicle

Abstract

Drive device (102) for a vehicle (100), wherein the drive device (102) comprises the following features: a storage interface (112) having a first connection (230) and a second connection (232) to an energy storage device (104) for storing electrical energy; an electric machine (106) with a plurality of inductors (234, 236, 238); an inverter (110) with a plurality of switching devices (240, 241, 242, 243, 244, 245) each with a switch (248) and a diode (249) connected in parallel, wherein the inverter (110) is connected between the storage interface (112) and the electrical machine (106); a charging interface (114) having a first connection (256) and a second connection (258) for applying an inlet voltage; and a control device (116) for controlling the operation of the inverter (110), wherein the control device (116) is configured to control the switches (248) of the inverter (110) in a drive mode of the drive device (102) to provide an alternating voltage for operating the electric machine (106) using a battery voltage applied to the storage interface (112), and in a charging mode of the drive device (102) to control the switches (248) of the inverter (110) to provide a charging voltage for charging the energy storage device (104) at the storage interface (112) using the supply voltage applied to the charging interface (114), wherein the charging voltage is greater than the supply voltage; characterized by the fact that the control device (116) is configured in the charging mode to control the switches (248) of the inverter (110) to cause a current flow through at least one of the inductors (234, 236, 238) of the electric machine (106), wherein the current flow during the charging mode generates a torque of the electric machine (106) having a constant direction of rotation, and the control device (116) is configured in the charging mode to provide a brake signal (118) to activate a brake device (120) coupled to the electric machine (106) in the form of a mechanically blocking element to support the torque.

Description

[0001] The present invention relates to a drive device and a method for operating a drive device for a vehicle.

[0002] For electric vehicles designed as 800V battery electric vehicles (BEVs), the problem today is that the majority of the charging infrastructure of public DC charging stations can only charge up to 400V.

[0003] DE 10 2018 207 188 A1 discloses an inverter for converting electrical energy from a DC voltage source into an AC voltage and for boosting the charging voltage of a charging device. According to one embodiment, a first charging terminal is connected to a neutral terminal of an electric machine via a first charging contactor. DE 10 2017 123 348 A1 discloses an inverter configured to charge a traction battery when a neutral terminal of the three-phase motor is connected to a charging station. DE 10 2016 110 870 A1 discloses a charging system with an electric machine and a pulse inverter. The neutral terminal of the electric machine is connected to a pole of a DC charging station terminal. DE 10 2009 014 704 A1 discloses a charging circuit in which a stator winding is connected to an energy storage device via an inverter.DE 10 2015 208 747 A1 discloses a charging mode in which a power converter is supplied via a series-connected winding of an electrical machine from an external energy source and generates a charging signal for an electrical energy storage device.

[0004] Against this background, the present invention provides an improved drive device and an improved method for operating a drive device for a vehicle according to the main claims. Advantageous embodiments are described in the dependent claims and the following description.

[0005] The described approach makes it possible to charge a vehicle's electrical energy storage system with a charging voltage higher than that provided by a charging infrastructure. Advantageously, this does not require the integration of an additional DC-DC booster. Instead, a cost-effective dual use can be achieved using an existing inverter and the inductors of an electric motor within the drive system. The inverter and inductors can be used as a charging booster while the vehicle is stationary during charging.

[0006] A suitable drive device for a vehicle has the following characteristics: a storage interface having a first connection and a second connection to an energy storage device for storing electrical energy; an electric machine with a plurality of inductors; an inverter with a plurality of switching devices, each with a switch and a diode connected in parallel, wherein the inverter is connected between the storage interface and the electrical machine; a charging interface having a first connection and a second connection for applying an input voltage; and A control device for controlling the operation of the inverter, wherein the control device is configured to control the inverter switches in a drive mode of the drive device to provide an alternating voltage for operating the electric machine using a battery voltage applied to the storage interface, and in a charging mode of the drive device to control the inverter switches to provide a charging voltage for charging the energy storage device at the storage interface using a feed-in voltage applied to the charging interface, wherein the charging voltage is greater than the feed-in voltage, and wherein the control device in the charging mode is configured to control the inverter switches to cause a current flow through at least one of the inductors of the electric machine.the current flow during charging mode generates a torque of the electric machine with a constant direction of rotation.

[0007] The vehicle can be an electric vehicle that can be powered, at least partially, by electrical energy drawn from the energy storage device. For example, the energy storage device can be a rechargeable battery. The electric machine can be an electric motor, as used in known electric vehicles. The multiple inductors can be coils of the electric machine, used to generate a magnetic field to drive a rotor. The inverter can also be called a power inverter. The inverter's switches can be transistors, for example, semiconductor power switches with insulated gate electrodes. The control device can be similar to known control devices for regulating the operation of the inverter.In drive mode, the drive unit's inverter, similar to those used in electric vehicles, can be used to convert the battery voltage supplied by the energy storage system, which typically corresponds to an intermediate circuit voltage, into an alternating voltage for driving the electric motor via pulse width modulation. In drive mode, the electric motor can be energized using the inverter to provide torque for propelling the vehicle. In charging mode, the inverter can be controlled to perform inverter charging. In this process, the supply voltage at the charging interface is converted into the charging voltage for charging the energy storage system using the electric motor and the inverter.A current flowing through at least one of the inductors can be adjusted so that the electric machine maintains a constant torque during charging, for example, throughout the entire charging process. The constant direction of rotation of the torque can mean that its magnitude is consistently non-zero and it always has the same direction. This advantageously prevents noise generation within the drive device. The torque can be appropriately supported, for example, by a parking brake activated during the charging process.

[0008] The control unit can be configured in charging mode to connect the inverter's switches and diodes, as well as the electric machine's inductors, to a first boost converter and a second boost converter to convert the input voltage into the charging voltage. A boost converter is also known as a DC-DC converter, where the output voltage is always higher than the input voltage.

[0009] For example, the control unit can be configured in charging mode to control the inverter's switches so that the first and second boost converters operate with a 180° phase difference. This configuration is also known as an interleaved boost converter. The two boost converters can be connected in parallel with a 180° phase delay and operated at the same frequency. The switches associated with the boost converters can be opened and closed alternately. If more than two boost converters are used, they can be operated with a suitable alternative phase difference, for example, 120° for three boost converters. Using more than one boost converter allows for high signal quality of the generated charging voltage.

[0010] According to one embodiment, the control unit can be configured in charging mode to provide a brake signal to activate a braking device coupled to the electric motor to counteract the torque. This prevents the vehicle from moving during the charging process.

[0011] For example, the first terminal of the charging interface can be connected to a star point of the inductors of the electric machine via a star point switch. The control unit can be configured in charging mode to close the star point switch. This allows current flowing through the charging interface to be fed into the electric machine.

[0012] The second port of the charging interface can be connected to the second port of the storage interface via a charging switch. The control unit can be configured in charging mode to close the charging switch. In this way, the charging interface can be connected or disconnected depending on the operating mode of the drive device.

[0013] The switching devices can be connected between the first terminal of the storage interface and the first terminals of the inductors, as well as between the second terminal of the storage interface and the first terminals of the inductors. This allows the individual inductors to be alternately connected to the different voltage potentials of the storage interface via the switching devices, similar to conventional inverters.

[0014] According to one embodiment, the first terminal of the charging interface can be connected to the first terminal of the storage interface via a bypass switch. The control unit can be configured in a further charging mode to close the bypass switch, thus providing the supply voltage at the charging interface as the charging voltage to the storage interface. This is advantageous if the supply voltage already corresponds to the required charging voltage.

[0015] The drive unit can include an energy storage device connected to the storage interface. The energy storage device can be in the form of a battery that can store the electrical energy required to power the vehicle.

[0016] The control unit can have an interface to a sensor device for acquiring at least one operating parameter of the electric machine. The control unit can be configured to actuate the inverter switches in charging mode using at least one sensor signal representing the operating parameter. The sensor device can include sensors conventionally used to control the operation of an electric machine. For example, the operating parameter can represent a current flowing through the inductors of the electric machine, a value of the torque generated by the electric machine, and / or the position of a rotor of the electric machine. Using appropriate measured values, it can be ensured during charging mode that the current flowing through the electric machine generates torque with a constant direction of rotation.The measured values ​​from the sensor device, which represent at least one sensor signal, can be used to control the switches in the operating mode of the drive device. This allows a control loop to be implemented to control the inverter's switches so that the electric machine can provide the requested torque.

[0017] A method for operating said drive device comprises the following steps: Controlling the inverter switches in a drive mode of the drive device to provide an alternating voltage for operating the electric machine using a battery voltage applied to the storage interface; and Controlling the switches of the inverter in a charging mode of the drive device to provide a charging voltage for charging the energy storage device at the storage interface using a feed-in voltage applied at the charging interface, wherein the charging voltage is greater than the feed-in voltage, and wherein controlling the switches in the charging mode causes a current flow through at least one of the inductors of the electric machine, which generates a constant-direction torque of the electric machine during the charging mode.

[0018] A computer program product with program code that can be stored on a machine-readable medium such as semiconductor memory, hard disk memory or optical memory and is used to carry out the method according to one of the embodiments described above is also advantageous when the program is executed on a computer or control device.

[0019] A control device can be an electrical device that processes electrical signals, such as sensor signals, and outputs control signals accordingly. The control device can have one or more suitable interfaces, which can be implemented in hardware and / or software. In the case of a hardware implementation, the interfaces can, for example, be part of an integrated circuit in which the functions of the control device are implemented. The interfaces can also be separate integrated circuits or consist at least partially of discrete components. In the case of a software implementation, the interfaces can be software modules that are present, for example, on a microcontroller alongside other software modules.

[0020] The invention is explained in more detail by way of example with reference to the accompanying drawings. These show: Fig. 1 a schematic representation of a vehicle with a drive device according to an exemplary embodiment; Fig. 2 a circuit diagram of a drive device according to an exemplary embodiment; and Fig. 3 A flowchart for operating a drive device according to an exemplary embodiment.

[0021] In the following description of preferred embodiments of the present invention, the same or similar reference numerals are used for the elements shown in the various figures and having a similar effect, without repeating these elements.

[0022] Fig. Figure 1 shows a schematic representation of a vehicle 100 with a drive device 102 according to an exemplary embodiment. For example, the vehicle 100 is an electric vehicle 100 with an energy storage device 104 for storing electrical energy and at least one electric machine 106 for driving at least one wheel 108 of the vehicle using energy stored in the energy storage device 104. An inverter 110 is used to convert a direct current voltage provided by the energy storage device 104 into an alternating current voltage suitable for operating the electric machine 106. For this purpose, the inverter 110 is connected, on the one hand, directly or via at least one other device via a storage interface 112, to the energy storage device 104 and, on the other hand, to the electric machine. The energy storage device 104 is optionally part of the drive device 102.

[0023] To charge the energy storage device, the vehicle 100 has a charging interface 114, via which the vehicle 100 can be connected to, for example, a public power grid. At least one inductor of the electric machine can be used together with elements of the inverter to convert a supply voltage applied to the charging interface into a charging voltage for charging the energy storage device 104. Advantageously, the current flow through the at least one inductor is controlled such that the electric machine continuously generates a torque with a constant direction of rotation during the conversion of the supply voltage into the charging voltage. In this way, noise generation within the drive device 102 can be avoided.

[0024] The drive device 102 has a drive mode in which the electric machine 106 is used to move the vehicle 100. Furthermore, the drive device 102 has a charging mode in which at least one inductor of the electric machine is used to charge the energy storage device using the supply voltage provided at the charging interface.

[0025] The drive device 102 includes a control unit 116 for controlling the operation of the inverter 110 during drive mode and charging mode. The control unit 116 is configured to control the inverter 110 during drive mode such that the battery voltage supplied by the energy storage device 104 at the storage interface 112 is converted into the alternating voltage for operating the electric machine 106. Furthermore, the control unit 116 is configured to control the inverter 110 during charging mode such that the supply voltage present at the charging interface 114 is boosted to the charging voltage for charging the energy storage device 104.Advantageously, the control device 116 is designed to control the inverter 110 during the charging mode in such a way that a current flow through at least one of the inductors of the electric machine 106 causes a torque of the electric machine 106 having a constant direction of rotation.

[0026] According to one embodiment, the charging of the energy storage device 104 via the charging interface 114 is carried out while the vehicle 110 is stationary. The torque generated by the electric machine 106 during the charging process can be supported in a suitable manner to prevent the vehicle 100 from rolling away. According to one embodiment, the control device 116 is configured to provide a brake signal 118 in charging mode to activate a brake device 120 mechanically coupled to the electric machine 106 to support the torque. For example, the brake device 120 is coupled to a drive shaft or rotor of the electric machine 106 or to one of the wheels 108 of the vehicle 100.

[0027] According to one embodiment, the control unit 116 has an interface to a sensor unit 122 for detecting at least one operating parameter of the electric machine 106. Optionally, the sensor unit 122 is part of the drive unit 102. The sensor unit 122 comprises one or more sensors. For example, the sensor unit 122 comprises a position sensor for detecting the rotor position of the electric machine 106 and additionally or alternatively one or more current sensors for detecting phase currents flowing through the inductors of the electric machine 106 and additionally or alternatively a torque sensor for detecting the torque generated by the electric machine 106. For example, the sensor unit 122 is configured to provide detected operating parameters to the control unit 116 via at least one sensor signal 124.The control device 116 is configured according to one embodiment to provide at least one control signal 126 for controlling the inverter 110 using at least one sensor signal 124 and, for example, a preset signal for specifying a desired torque to be provided by the electric machine 106. The control signal 126 is suitable for appropriately controlling switches of the inverter 110 both during drive mode and during charging mode. For example, the control device 116 is configured to determine the control signal 126 using a control loop.

[0028] The described approach enables a noiseless control strategy for so-called inverter charging. According to one embodiment, a defined control of the desired output torque in the electric machine 106 is performed during the charging process to suppress noise generation. The aim is to achieve the smallest possible, but purely fluctuating, torque. This torque is supported, for example, by the braking device 120 in the form of a mechanical element, such as a parking lock or a handbrake. The described approach can be used in conjunction with traction inverters and complete systems with traction inverters in e-mobility applications.

[0029] The described approach prevents unwanted torques from arising during inverter charging in practice. These torques, caused by the energizing of the inductors (windings) of the electric machine 106, could lead to disruptive noise or damage through "clicking" due to play in the drivetrain, which includes, for example, a gearbox and a differential, up to and including the mechanically locking element (parking lock or parking brake). According to one embodiment, a control method is implemented that avoids this clicking.

[0030] Such a control method shifts the average desired output torque at the electric machine 106 by targeted current modulation from an average of zero output torque, which in practice always fluctuates slightly, towards a defined, one-sided output torque. This torque is supported via the drive train, for example, at the braking device 120 in the form of a mechanically blocking element. Thus, during the charging process, the drive train no longer exhibits a slightly fluctuating torque, but rather a purely pulsating one, which no longer causes noise or damage from "clicking," e.g., on gear teeth.

[0031] Fig. Figure 2 shows a circuit diagram of a drive device 102 according to an exemplary embodiment. This is, for example, an exemplary embodiment based on Fig. 1 described drive device for a vehicle.

[0032] The energy storage device 104 is exemplified as a high-voltage battery, for example an 800V battery, and is connected via the storage interface 112. The storage interface 112 has a first connection 230 and a second connection 232.

[0033] According to this embodiment, the inverter 110 is designed to convert the battery voltage applied to the storage interface 112 into a three-phase alternating voltage for operating the electric machine 106. According to this embodiment, the electric machine has three inductors 234, 236, 238. As with known inverters, the inverter 110 has a plurality, here six, of switching devices 240, 241, 242, 243, 244, 245, each with a switch 248 and a diode 249 connected in parallel.

[0034] The first switching device 240 is arranged between the first terminal 230 of the memory interface 112 and a first terminal of the first inductor 234. The second switching device 241 is arranged between the second terminal 232 of the memory interface 112 and the first terminal of the first inductor 234. The third switching device 242 is arranged between the first terminal 230 of the memory interface 112 and a first terminal of the second inductor 236. The fourth switching device 243 is arranged between the second terminal 232 of the memory interface 112 and the first terminal of the second inductor 236. The fifth switching device 244 is arranged between the first terminal 230 of the memory interface 112 and a first terminal of the third inductor 238.The sixth switching device 245 is arranged between the second terminal 232 of the memory interface 112 and the first terminal of the third inductor 238.

[0035] The switches 248 of the switching devices 240, 241, 242, 243, 244, 245 are, for example, controlled by the Fig. The control device described in section 1 is controlled, i.e., opened or closed.

[0036] According to one embodiment, a DC link capacitor 250 is connected between the first terminals 230, 232 of the storage interface 112. Optionally, a filter 252 is arranged between the inverter 110 and the storage interface 112.

[0037] To charge the energy storage device 104, the charging interface 114 of the drive unit 102 can be connected to a charging station 254. For example, the charging station 254 enables DC charging with up to 200 kW or DC charging with up to 400 kW. The charging interface 114 has a first terminal 265 and a second terminal 258 to which a feed-in voltage provided by the charging station 254 can be applied. For example, the charging interface 114 is designed for a feed-in current of up to 500 A. Optionally, a filter 260 is arranged at the charging interface 114. According to one embodiment, a capacitor 262 is connected between terminals 256 and 258 of the charging interface 114.

[0038] According to one embodiment, the second terminal 258 of the charging interface 114 is connected to the second terminal 232 of the storage interface 112 via a charging switch 264. According to another embodiment, the first terminal 256 of the charging interface 114 is connected to a star point 268 of the inductors 234, 236, 238 of the electric machine 106 via a star point switch 266. According to yet another embodiment, the second terminals of the inductors 234, 236, 238 are connected to each other via the star point 268.

[0039] According to one embodiment, the first terminal 256 of the charging interface 114 is connected to the first terminal 230 of the storage interface 112 via a bypass switch 270.

[0040] According to one embodiment, switches 264, 266, 270 are operated using the method described above. Fig. The control device described in section 1 is controlled, i.e., closed or open.

[0041] During the drive mode of the drive device 102, the switching devices 240, 241, 242, 243, 244, 245 of the inverter 110 and the switches 264, 266, 270 are switched according to one embodiment such that the electric machine 106 provides torque using the battery voltage supplied by the energy storage device 104, which can be used to move the vehicle. According to one embodiment, the switches 264, 266, 270 are open in the drive mode so that the storage interface 112 and the charging interface 114 are not electrically connected.

[0042] During the charging mode of the drive device 102, the switching devices 240, 241, 242, 243, 244, 245 of the inverter and the switches 264, 266, 270 are switched according to one embodiment such that the supply voltage applied to the charging interface 114 is boosted to the charging voltage for charging the energy storage device 104 at the storage interface 112. For example, a 400V supply voltage is converted into an 800V charging voltage. According to one embodiment, the bypass switch 270 is opened and the charging switch 264 and the neutral switch 266 are closed for this purpose. The switching devices 240, 241, 242, 243, 244, 245 of the inverter 110 are switched in such a way that a current flow via the star point 268 and through at least one of the inductors 234, 236, 238 is enabled.The switching devices 240, 241, 242, 243, 244, 245 are switched such that a current flow through at least one of the inductors 234, 236, 238 generates a torque of the electric machine 106 with a constant direction of rotation. According to one embodiment, the torque has either a positive or a negative sign during the entire charging mode or for a defined duration, for example, at least a few seconds, during the charging mode. This avoids a permanent change in the direction of the torque, which can result in noise.

[0043] According to one embodiment, the inductors 234, 236, 238 and the switching devices 240, 241, 242, 243, 244, 245 are connected to form at least one boost converter in the charging mode. For example, such a boost converter comprises the first inductor 234, the diode of the first switching device 240, and the switch 248 of the second switching device 241. During the charging mode, the switch 248 of the first switching device 240 is, for example, continuously open, and the switch 248 of the second switching device 241 is opened and closed alternately.

[0044] Optionally, a second boost converter is operated in parallel. The second boost converter comprises, for example, the second inductor 236, the diode of the third switching device 242, and the switch 248 of the fourth switching device 243. During charging mode, the switch 248 of the third switching device 242 is continuously open, while the switch 248 of the fourth switching device 243 opens and closes alternately. For example, the switches 248 of the second switching device 241 and the fourth switching device 243 are opened and closed in opposite directions to operate the first and second boost converters with a phase difference of 180°.

[0045] Optionally, a third boost converter is operated in a corresponding manner.

[0046] This makes it possible to realize a 3-phase boost converter, where the electrical machine 106 is used as a boost inductor.

[0047] The star point switch 266 enables a connection to the star point 268 of the electrical machine 106, for example an electric motor. This requires wiring from the star point 268 out of the electrical machine 106.

[0048] According to one embodiment, the drive device 102 enables an additional charging mode. In this additional charging mode, the terminals 256 and 258 of the charging interface 144 are directly connected to the terminals 230 and 232 of the storage interface 112. For this purpose, the charging switch 264 and the bypass switch 270 are closed, and the star point switch 266 is opened. This allows the supply voltage present at the charging interface 114, for example, 800 V DC, to be directly provided as the charging voltage at the storage interface 112.

[0049] According to one embodiment, during a 400V charging process, the inverter 110 is controlled as an inverter based on the principle of an interleaved boost converter. However, in contrast to a typical DC-DC converter application, the torque generation in the electric machine 106 is also always considered here. In the case of a control strategy with a target value of torque = 0, noise can occur, for example, in components coupled to the electric machine 106, such as the transmission and axle of a vehicle, because the torque actually oscillates around zero, resulting in a constant change of sign. To avoid this, the machine 106 is excited during the charging process in such a way that this oscillation does not occur around zero, but rather around a small torque with a constant sign. This significantly reduces or eliminates noise, for example, in the transmission and axle.In other words, according to one embodiment, there is always a fluctuating torque that is constant with respect to its sign.

[0050] Fig. Figure 3 shows a flowchart for operating a drive device according to an exemplary embodiment. For example, this could be a drive device as described with reference to the preceding figures.

[0051] In order to utilize the drive power provided by the electric machine, in a drive mode of the drive device, in step 301 the switches of the inverter are controlled so that, using the battery voltage present at the storage interface, the alternating voltage is provided to operate the electric machine.

[0052] In order to recharge the energy storage device, in a charging mode of the drive device, in step 303 the switches of the inverter are controlled in such a way that, using the supply voltage applied to the charging interface, the charging voltage for charging the energy storage device is provided at the storage interface and, in addition, a provision of torque with constant direction of rotation is stimulated by the electric machine.

[0053] Steps 301 and 303 can be repeated and performed in the required order. Reference sign 100 vehicles 102 Drive device 104 Energy storage 106 electric machine 108 wheel 110 inverters 112 Memory interface 114 Charging interface 116 Control unit 118 Brake signal 120 Brake system 122 Sensor device 124 Sensor signal 126 Control signal 230 first connection of the memory interface 232 second connection of the memory interface 234 first inductance 236 first inductance 238 first inductance 240 first switching device 241 second switching device 242 third switching device 243 fourth switching device 244 fifth switching device 245 sixth switching device 248 switches 249 Diode 250 Intermediate circuit capacitor 252 filters 254 charging stations 256 First connection of the charging interface 258 second connection of the charging interface 260 filters 262 Capacitor 264 charging switches 266 star point switches 268 Star point 270 bypass switches 301st step of the control process during a drive mode 303 Step of the control process during a charging mode

Claims

[1] Drive device (102) for a vehicle (100), wherein the drive device (102) comprises the following features: a storage interface (112) having a first connection (230) and a second connection (232) to an energy storage device (104) for storing electrical energy; an electric machine (106) with a plurality of inductors (234, 236, 238); an inverter (110) with a plurality of switching devices (240, 241, 242, 243, 244, 245) each with a switch (248) and a diode (249) connected in parallel, wherein the inverter (110) is connected between the storage interface (112) and the electrical machine (106); a charging interface (114) having a first connection (256) and a second connection (258) for applying an inlet voltage; and a control device (116) for controlling the operation of the inverter (110), wherein the control device (116) is configured to control the switches (248) of the inverter (110) in a drive mode of the drive device (102) to provide an alternating voltage for operating the electric machine (106) using a battery voltage applied to the storage interface (112), and in a charging mode of the drive device (102) to control the switches (248) of the inverter (110) to provide a charging voltage for charging the energy storage device (104) at the storage interface (112) using the supply voltage applied to the charging interface (114), wherein the charging voltage is greater than the supply voltage; characterized by , that the control device (116) is configured in the charging mode to control the switches (248) of the inverter (110) to cause a current flow through at least one of the inductors (234, 236, 238) of the electric machine (106), wherein the current flow during the charging mode generates a torque of the electric machine (106) having a constant direction of rotation, and the control device (116) is configured in the charging mode to provide a brake signal (118) to activate a brake device (120) coupled to the electric machine (106) in the form of a mechanically blocking element to support the torque. [2] Drive device (102) according to claim 1, characterized by, that the control device (116) is configured in the charging mode to connect the switches (248) and diodes (249) of the inverter (110) and the inductors (234, 236, 238) of the electric machine (106) to a first boost converter and to a second boost converter for converting the supply voltage into the charging voltage. [3] Drive device (102) according to claim 2, characterized by , that the control device (116) is configured in charging mode to control the switches (248) of the inverter (110) to operate the first boost converter and the second boost converter with a phase difference of 180°. [4] Drive device (102) according to one of the preceding claims, characterized by, that the first terminal (256) of the charging interface (114) is connected via a star point switch (266) to a star point (268) of the inductors (234, 236, 238) of the electric machine (106), and the control device (116) is configured in the charging mode to close the star point switch (266). [5] Drive device (102) according to one of the preceding claims, characterized by , that the second terminal (258) of the charging interface (114) is connected to the second terminal (232) of the storage interface (112) via a charging switch (264), and the control device (116) is configured in charging mode to close the charging switch (264). [6] Drive device (102) according to one of the preceding claims, characterized by, that the switching devices (240, 241, 242, 243, 244, 245) are connected between the first terminal (230) of the memory interface (112) and the first terminals of the inductors (234, 236, 238) and between the second terminal (232) of the memory interface (112) and the first terminals of the inductors (234, 236, 238). [7] Drive device (102) according to one of the preceding claims, characterized by , that the first terminal (256) of the charging interface (114) is connected to the first terminal (230) of the storage interface (112) via a bypass switch (270), wherein the control device (116) is configured in a further charging mode to close the bypass switch (270) in order to provide the supply voltage at the charging interface (114) as the charging voltage to the storage interface (112). [8] Drive device (102) according to one of the preceding claims, characterized by, that the drive device (102) has the energy storage device (104) which is connected to the storage interface (112). [9] Drive device (102) according to one of the preceding claims, characterized by , that the control device (116) has an interface to a sensor device (122) for detecting an operating parameter of the electric machine (106) and is configured to control the switches (248) of the inverter (110) in the charging mode using a sensor signal (124) representing the operating parameter. [10] Drive device (102) according to claim 9, characterized by , that the operating parameter represents a current flowing through the inductances (234, 236, 238) of the electric machine (106) and / or a value of the torque generated by the electric machine (106) and / or a position of a rotor of the electric machine (106). [11] Method for operating a drive device (102) for a vehicle (100), wherein the drive device (102) has a storage interface (112) having a first connection (230) and a second connection (232) to an energy storage device (104) for storing electrical energy, an electric machine (106) with a plurality of inductors (234, 236, 238), an inverter (110) with a plurality of switching devices (240, 241, 242, 243, 244, 245) each with a switch (248) and a diode (249) connected in parallel, wherein the inverter (110) is connected between the storage interface (112) and the electric machine (106), and a charging interface (114) having a first connection (256) and a second connection (258) for applying an input voltage, and wherein the method The following steps are included: Controlling (301) the switches (248) of the inverter (110) in a drive mode of the drive device (102) to provide an alternating voltage for operating the electric machine (106) using a battery voltage applied to the storage interface (112); and Controlling (301) the switches (248) of the inverter (110) in a charging mode of the drive device (102) to provide a charging voltage for charging the energy storage device (104) at the storage interface (112) using a feed-in voltage applied at the charging interface (114), wherein the charging voltage is greater than the feed-in voltage, characterized by , that The actuation (301) of the switches (248) in the charging mode causes a current flow through at least one of the inductors (234, 236, 238) of the electric machine (106), which generates a constant direction of rotational torque of the electric machine (106) during the charging mode, and in the charging mode a brake signal (118) is provided to activate a brake device (120) coupled to the electric machine (106) in the form of a mechanically blocking element to support the torque. [12] Computer program with program code for carrying out the method according to claim 11 when the program is executed on a computer.

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