Method and control unit for operating an electric machine, converter unit, electric axle drive and vehicle

Abstract

A vehicle (100) has an electric machine (105), an energy supply device (110) for providing a supply voltage (135), a converter (115) for converting the supply voltage (135) into a three-phase drive voltage (140) for the electric machine (105), a charging device (120) for converting a three-phase charging voltage into a DC voltage (150) and for converting the DC voltage (150) into the supply voltage (135) for charging the energy supply device (110). In order to operate the electric machine (105) at a first operating point, the supply voltage (135) is converted into the three-phase drive voltage (140) having a high voltage level using the converter (115). In contrast, in order to operate the electric machine (105) at a second operating point, the supply voltage (135) is converted into the three-phase drive voltage (140) having a low voltage level using the charging device (120).

Description

[0001] ZF Friedrichshafen AG File 302402 Friedrichshafen 2024-08-14

[0002] Method and control device for operating an electric machine, converter device, electric axle drive and vehicle

[0003] The present invention relates to a method and a control device for operating an electric machine, a converter device, an electric axle drive and a vehicle.

[0004] A vehicle, for example an electric vehicle, can have a drive system with an inverter and an electric motor, as well as a charging device, whereby the drive system and the charging device can be two completely separate systems. The charging device can, for example, be active only during a charging process.

[0005] Against this background, the present invention provides an improved method and an improved control device for operating an electric machine, an improved converter device, an improved electric axle drive, and an improved vehicle according to the main claims. Advantageous embodiments will become apparent from the dependent claims and the following description.

[0006] The advantages achievable with the approach presented here consist in particular of creating a method that can enable reliable and efficient operation of an electrical machine optionally at a first operating point and at a second operating point.

[0007] A method is provided for operating an electric machine for a vehicle. The vehicle comprises the electric machine, a power supply unit for providing a supply voltage, a first inverter for converting the supply voltage into a three-phase drive voltage for the electric machine, a charging unit with a second inverter for converting a three-phase charging voltage into a DC voltage, and a DC-DC converter for converting the DC voltage into the supply voltage for charging the power supply unit. ZF Friedrichshafen AG File 302402 Friedrichshafen 2024-08-14

[0008] The process comprises a conversion step and a reconversion step. In the conversion step, the supply voltage is converted into the high-voltage three-phase drive voltage using the first inverter to operate the electric machine at a first operating point. Alternatively, in the reconversion step, the supply voltage is converted into the low-voltage three-phase drive voltage using at least one component of the charging device to operate the electric machine at a second operating point.

[0009] The vehicle can be electrically powered. The electric motor and the first inverter can represent the electric drive for the vehicle. In the approach presented here, the electric drive and the charging device can represent an interconnectable system within the vehicle. At the first operating point, the electric motor can be operated at a high voltage, and at the second operating point, it can be operated at a low voltage. Depending on the desired operating point, the drive voltage for the electric motor can be generated either exclusively using the first inverter or at least partially using the charging device. The charging device, which can also be referred to as an on-board charger, can thus be used during the vehicle's active operation.The approach presented here can also be understood as a topology and control method for using an on-board charger for electric machine operation.

[0010] Depending on the design, more or fewer components of the charging device and optionally the first inverter can be used, particularly for operating the electric machine in the second operating point.

[0011] According to a first embodiment, in the conversion step, the supply voltage can be converted into the three-phase drive voltage, which has a low voltage level, using the DC-DC converter and the second converter of the charging device. By using the second converter (ZF Friedrichshafen AG File 302402, Friedrichshafen, 2024-08-14), a variable or ideally reduced intermediate circuit voltage can be applied to the winding of the electric machine.

[0012] The conversion step can involve opening a battery switch to disconnect the power supply from the first inverter and closing a disconnect switch to connect the second inverter to the electric machine. The supply voltage can then be converted to DC using the DC-DC converter, and the DC voltage can be converted to three-phase drive voltage using the second inverter.

[0013] According to a first embodiment, in the conversion step the supply voltage can be converted into the three-phase drive voltage having a low voltage level using the second inverter, bypassing the DC voltage converter of the charging device.

[0014] The conversion step can include opening a battery switch to disconnect the power supply from the first inverter, closing a bypass switch to directly connect the power supply to the second inverter, and closing a disconnect switch to connect the second inverter to the electric machine. The supply voltage can then be converted into the three-phase drive voltage using the second inverter.

[0015] According to a third embodiment, in the conversion step the supply voltage can be converted into the three-phase drive voltage having a low voltage level using the DC-DC converter and the first converter, bypassing the second converter.

[0016] The conversion step can include setting a battery switch to a position that disconnects the power supply from the first inverter and connecting the DC-DC converter to the first inverter. The supply voltage can then be converted to DC using the DC-DC converter, and the DC voltage can then be converted to the three-phase drive voltage using the first inverter.

[0017] The conversion step can involve closing a battery switch or further switching positions of the battery switch to connect the power supply unit to the first inverter, and opening a disconnect switch to disconnect the second inverter from the electric machine. The supply voltage can then be converted into the three-phase drive voltage using the first inverter.

[0018] A control device is provided for operating an electric machine for a vehicle. The vehicle includes the electric machine, a power supply unit for providing a supply voltage, a first inverter for converting the supply voltage into a three-phase drive voltage for the electric machine, a charging unit with a second inverter for converting a three-phase charging voltage into a DC voltage, and a DC-DC converter for converting the DC voltage into the supply voltage for charging the power supply unit. The control device can operate the electric machine reliably.

[0019] The control device is configured to provide a first control signal to the first inverter to convert the supply voltage into a high-voltage, three-phase drive voltage using the first inverter, in order to operate the electric machine at a first operating point. Alternatively or additionally, the control device is configured to provide a second control signal to at least one component of the charging device to convert the supply voltage into a low-voltage, three-phase drive voltage using at least one component of the charging device, in order to operate the electric machine at a second operating point. This allows the most suitable inverter topology to be advantageously selected during operation.

[0020] A converter device for use in a vehicle that is at least partially electrified comprises a first inverter for converting the supply voltage into a three-phase drive voltage for the electric machine, a charging device with a second inverter for converting a three-phase charging voltage into a DC voltage, and a DC-DC converter for converting the DC voltage into the supply voltage for charging the power supply unit. The converter device includes an embodiment of a control device described herein.

[0021] An electric axle drive for a vehicle that is at least partially electrified comprises at least one electric machine, a transmission device and an embodiment of a converter device mentioned herein.

[0022] A vehicle, in particular a vehicle that is at least partially electrified, has an embodiment of an electric axle drive mentioned herein and / or an embodiment of a converter device mentioned herein and / or an embodiment of a control device mentioned herein.

[0023] The invention is explained in more detail with reference to the accompanying drawings. These show:

[0024] Fig. 1 shows a schematic representation of an exemplary embodiment of a vehicle;

[0025] Fig. 2 shows a schematic representation of an embodiment of a control device for operating an electric machine;

[0026] Fig. 3 a schematic representation of an embodiment of a vehicle; Fig. 4 a schematic representation of an embodiment of a vehicle; Fig. 5 a schematic representation of an embodiment of a vehicle; Fig. 6 a schematic representation of an embodiment of a vehicle; Fig. 7 a flowchart of an embodiment of a method for operating an electric machine for a vehicle; and ZF Friedrichshafen AG File 302402 Friedrichshafen 2024-08-14

[0027] Fig. 8 shows a block diagram of an exemplary embodiment of a control device for operating an electric machine.

[0028] 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.

[0029] Fig. 1 shows a schematic representation of an embodiment of a vehicle 100. The vehicle 100 is, for example, a vehicle that is at least partially electrified by an electric drive 102.

[0030] The vehicle 100 comprises an electric machine 105, a power supply unit 110, a first inverter 115, a charging unit 120 with a second inverter 125, and a DC / DC converter 130. The electric machine 105 and the first inverter 115, for example, form the drive 102. Optionally, the vehicle 100 includes a transmission unit 133. Using the transmission unit 133, torque provided by the electric machine 105 can be converted into drive torque for driving at least one wheel of the vehicle 100. The transmission unit 133 can include a gearbox for reducing the speed of the electric machine 105 and, optionally, a differential. Alternatively, the wheel can be driven directly by the electric machine 105.

[0031] The power supply unit 110 is configured to provide a supply voltage 135. The first converter 115 is configured to convert the supply voltage 135 into a three-phase drive voltage 140 for the electric machine 105.

[0032] The second inverter 125 is designed to convert a three-phase charging voltage 145 into a DC voltage 150. The DC-DC converter 130 is designed to convert the DC voltage 150 into the supply voltage 135 for charging the power supply unit 110. For this purpose, known components can be used.

[0033] The electric machine 105 can be operated at a first operating point and a second operating point. The first operating point represents operation of the electric machine 105 at a high voltage. The electric machine 105 is therefore operated or controlled with a high-voltage three-phase drive voltage 140. The second operating point represents operation of the electric machine 105 at a low voltage. The electric machine 105 is therefore operated or controlled with a low-voltage three-phase drive voltage 141.

[0034] When the electric machine 105 is operated at the first operating point, the supply voltage 135 is converted into the three-phase drive voltage 140 using the first converter 115. According to one embodiment, no components of the charging device 120 are used.

[0035] When the electric machine 105 is operated at the second operating point, the supply voltage 135 is converted into the three-phase drive voltage 141 using at least one component of the charging device 120, i.e., using the second inverter 125 and / or the DC-DC converter 130. Optionally, the first inverter 115 is also used in combination with at least one component of the charging device 120.

[0036] Fig. 2 shows a schematic representation of an embodiment of a control device 200 for operating an electric machine 105. The electric machine 105 is similar to or corresponds to the electric machine from Fig. 1.

[0037] The vehicle 100, which resembles or corresponds to the vehicle in Fig. 1, for example, has the control device 200. Additionally, the vehicle 100 has the electric machine 105, the power supply unit 110, the first converter 115, the second converter 125, and the DC-DC converter 130. ZF Friedrichshafen AG File 302402 Friedrichshafen 2024-08-14

[0038] The control device 200, together with the first converter 115 and the charging device 120, is also referred to as a converter device. The converter device is suitable for converting the supply voltage 135 provided by the power supply device 110 into the three-phase drive voltage 140 for driving the electric machine 105.

[0039] According to one embodiment, a first terminal 205 of the power supply unit 110 is connected via an optional battery switch 210 to a first terminal 215 of the first inverter 115. A second terminal 220 of the first inverter 115 is, for example, connected to a terminal 225 of the electric machine 105.

[0040] According to one embodiment, a second terminal 230 of the power supply unit 110, which may correspond to the first terminal 205 of the power supply unit 110 or may be short-circuited with the first terminal 205, is connected to a first terminal 235 of the DC-DC converter 130 and, via a bypass switch 240, to a first terminal 245 of the second converter 125, bypassing the DC-DC converter 130.

[0041] For example, a second terminal 250 of the second converter 125 is connected to the terminal 225 of the electric machine 105 via a disconnect switch 255.

[0042] A second terminal 260 of the DC voltage converter 130 is connected to the first terminal 245 of the second converter 125 or, according to one embodiment, via the battery switch 210 to the first terminal 215 of the first converter 115.

[0043] The control device 200 is designed to control at least one of the switches 210, 240, 255 for operating the electric machine 105, i.e., to open or close it by means of control signals 265, 270, 275, 280 in order to operate the electric machine 105 at a desired operating point. ZF Friedrichshafen AG File 302402 Friedrichshafen 2024-08-14

[0044] The electric machine 105 can thus be controlled, for example, successively at a first operating point and a second operating point. The first operating point represents operation of the electric machine 105 at a high voltage. The electric machine 105 is therefore operated or controlled with a high-voltage three-phase drive voltage 140. The second operating point represents operation of the electric machine 105 at a low voltage. The electric machine 105 is therefore operated or controlled with a low-voltage three-phase drive voltage.

[0045] The control device 200 is configured to provide a first control signal 265 for operating the electric machine 105 at the first operating point according to a first embodiment. This signal closes the battery switch 210 to connect the power supply unit 110 to the first inverter 115. In this way, the supply voltage 135 is converted by the first inverter 115 into the drive voltage 140 at the high voltage level.

[0046] According to one embodiment, the first control signal 265 additionally causes the disconnect switch 255 to open, thus disconnecting the second inverter 125 from the electric machine 105. In this way, the supply voltage 135 is converted into the three-phase drive voltage exclusively using the first inverter 115.

[0047] According to a first embodiment, the control device 200 is configured to provide a second control signal 270 for operating the electric machine 105 at the second operating point. This signal opens the battery switch 210 to disconnect the power supply unit 110 from the first inverter 115, connect the second inverter 125 to the electric machine 105, and control the DC-DC converter 130. In this way, the supply voltage 135 is converted by the DC-DC converter 130 into the DC voltage 150, and the DC voltage 150 is converted into the three-phase drive voltage using the second inverter 125. The three-phase drive voltage has a low voltage level. ZF Friedrichshafen AG File 302402 Friedrichshafen 2024-08-14

[0048] According to a second embodiment, the control device 200 is configured to provide a third control signal 275 for operating the electric machine 105 at the second operating point. This signal opens the battery switch 210 to disconnect the power supply unit 110 from the first inverter 115 and closes the bypass switch 240. In this way, the power supply unit 110 is directly connected to the second inverter 125, bypassing the DC-DC converter 130. Using the third control signal 275, the disconnect switch 255 is also closed to connect the second inverter 125 to the electric machine 105. In this way, the supply voltage 135 is converted into the three-phase drive voltage using the second inverter 125. Depending on the design of the second inverter 125, the three-phase drive voltage has a low voltage level.

[0049] According to a third embodiment, the control device 200 is configured to provide a fourth control signal 280 for operating the electric machine 105 at the second operating point. This signal moves the battery switch 210 to a position that disconnects the power supply unit 110 from the first inverter 115 and connects the DC-DC converter 130 to the first inverter 115. In this way, the supply voltage 135 is converted to the DC voltage 150 using the DC-DC converter 130, and the DC voltage 150 is converted to the three-phase drive voltage using the first inverter 115. The three-phase drive voltage has a low voltage level.

[0050] The approach presented here shows an electrical connection and control device 200 for controlling the electric machine 105 and the charging device 120, which can also be referred to as an on-board charger, using a circuit and control unit that employs a switch and control algorithm or control scheme to combine the first inverter 115, which can also be referred to as an e-machine inverter, and the second inverter 125, which can also be referred to as a charging inverter or on-board charger. The switching and control scheme is characterized, for example, by the fact that it connects the involved inverters 115 and 125 in different topologies depending on the e-drive system optimum and switches between the topologies during operation depending on the operating point.According to one embodiment, the battery switch 210 and / or the bypass switch 240 and / or the disconnect switch 255 are, for example, switched without power.

[0051] In the approach presented here, the charging device 120 and the drive, which includes the electric machine 105 and the first converter 115, are combined as a complete system, whereby partial components of the charging device 120 and the drive 102 create synergies in combination and are, for example, reusable, i.e., dual use for the charging device 120 and the drive.

[0052] Thus, the second inverter 125 can be used for the drive 102 or the electric machine, as well as parts of it.

[0053] The approach presented here allows for the multiple use of converters 115 and 125, enabling the advantages of each converter topology to be leveraged for the benefit of the overall system, for example, efficiency, depending on the operating point. It is possible to connect the converter systems in different topologies.

[0054] The control device 200 for controlling motor phase currents utilizes the various inverters 115 and 125 in different ways to provide the output signal. Switching between the modulation methods of the inverters 115 and 125 occurs during operation. The control scheme is characterized by its dynamic use of the most suitable inverter topology during operation.

[0055] In other words, the drive 102, which includes the first inverter 115 and the electric machine 105, and the charging device 120 form a cohesive system within the electric vehicle 100. Thus, the charging device 120, already present in the vehicle 100 and active during a charging process (ZF Friedrichshafen AG File 302402 Friedrichshafen 2024-08-14), is now also used during active ferry operation when the first inverter 115 is active. Therefore, the charging device 120, or rather the second inverter 125, is reused during active ferry operation. By using the second inverter 125, a variable, or ideally reduced, intermediate circuit voltage is pulsed onto a winding of the electric machine 105 using the integrated DC / DC converter 130.This results in lower losses in the electric machine 105, which significantly increases the efficiency of the drive 102 in the range of low output levels, low speeds, and low to medium torque. The focus of the approach presented here is therefore, for example, a control method for electric drives.

[0056] The already installed second inverter 125 is advantageously integrated during electric motor operation. This is particularly beneficial at operating points with low modulation levels, i.e., low speed with low to medium torque, since the typically high DC link voltage of the vehicle's power supply unit 110 (which can also be referred to as the battery) leads to unnecessarily high losses in the electric motor 105. In conventional electric drives, the DC link voltage is determined solely by the state-of-charge (SoC) of the power supply unit. This then results in the DC link voltage that the first inverter 115 applies to the winding of the electric motor 105.

[0057] By using the second converter 125 with the integrated DC voltage converter 130, a variable or ideally reduced intermediate circuit voltage is pulsed onto the winding of the electric machine 105.

[0058] The approach presented here also includes a control method that allows switching between the two topologies during operation, depending on the output level. At low output levels and presumably low power levels, for example, less than 22 kilowatts, the second converter 125 is used to control the electric machine 105, which can also be referred to as an electric motor. At high output levels or high power levels, for example, more than 22 kilowatts, the first converter 115 is used. ZF Friedrichshafen AG File 302402 Friedrichshafen 2024-08-14

[0059] In summary, the approach presented here combines the charging unit 120 and the drive 102 into a system that can be described as an E-Drive Charger. This advantageously reduces weight and installation space. Additionally, system complexity is reduced. Costs for the overall system, i.e., charger and electric drive, can also be drastically reduced through the reuse of existing components (dual use). Reusing existing components also enables increased efficiency. The efficiency of the electric drive in the low-speed range is increased by approximately 3 to 4 percent by reducing the DC voltage when it is not required.

[0060] The inverters 115, 125 can be connected via the disconnect switch 255 and a control concept in order to use both inverters 115, 125 alone or combined depending on the E-Drive operating point.

[0061] Fig. 3 shows a schematic representation of an embodiment of a vehicle 100. The vehicle 100 resembles or corresponds to the vehicle from one of the figures described above.

[0062] The vehicle 100 comprises the electric machine 105, the power supply unit 110, the DC-DC converter 130, and the second inverter 125. Optionally, the vehicle 100 includes a filter unit 300. According to the embodiment shown here, the electric machine 105 is operated at the second operating point, i.e., at a low voltage level, according to a first embodiment.

[0063] The supply voltage is provided by the power supply unit 110 to the DC-DC converter 130. The filter unit 300 is connected, for example, between the power supply unit 110 and the DC-DC converter 130. The DC-DC converter 130 converts the supply voltage into DC voltage. The DC voltage is then converted into the three-phase drive voltage using the second inverter 125. The three-phase drive voltage has a low voltage level. By closing the disconnect switch 255, the second inverter 125 and the electric machine 105 are connected. Thus, the three-phase drive voltage is supplied to the electric machine 105.

[0064] In other words, Fig. 3 shows an approach to operating the electric machine 105 at a low modulation index, i.e., a low speed.

[0065] If a high voltage is not practical and high power is not required, the DC / DC converter 130, which can also be called a DC / DC converter, is used to lower the intermediate circuit voltage.

[0066] Fig. 4 shows a schematic representation of an embodiment of a vehicle 100. The vehicle 100 resembles or corresponds to the vehicle from one of the figures described above.

[0067] The following components of the vehicle 100 are shown by way of example only: the electric machine 105, the first converter 115 and the power supply unit 110. According to the embodiment shown here, the electric machine 105 is operated at the first operating point, i.e. at a high voltage level.

[0068] The supply voltage is provided by the power supply unit 110 to the first inverter 115. For this purpose, the battery switch 210 is closed, for example, to connect the power supply unit 110 to the first inverter 115. The first inverter 115 is designed to convert the supply voltage into the three-phase drive voltage, which has a high voltage level.

[0069] In other words, Fig. 4 shows an approach to operating the electric machine 105 at a high modulation index, i.e., a high speed, for example, standard operation. If a high voltage is useful or high power is required, the DC-DC converter is not used.

[0070] Fig. 5 shows a schematic representation of an embodiment of a vehicle 100. The vehicle 100 resembles or corresponds to the vehicle from one of the figures described above.

[0071] Shown are the power supply unit 110, the DC voltage converter 130, the second converter 125, the electric machine 105 and optionally the filter unit 300.

[0072] According to the second embodiment shown here, the electric machine 105 is operated at the second operating point, i.e., at a low voltage level.

[0073] For this purpose, the supply voltage is converted into the three-phase drive voltage, which has a low voltage level, using the second inverter 125 and bypassing the DC-DC converter 130. To do this, the bypass switch 240 is closed to connect the power supply unit 110 directly to the second inverter 125. Additionally, the disconnect switch 255 is closed to connect the second inverter 125 to the electric machine 105.

[0074] In other words, Fig. 5 shows an approach to operating the electrical machine 105 at a low modulation index, i.e., at a low speed.

[0075] Fig. 6 shows a schematic representation of an embodiment of vehicle 100. Vehicle 100 resembles or corresponds to the vehicle shown in one of the figures described above. ZF Friedrichshafen AG File 302402 Friedrichshafen 2024-08-14

[0076] Shown are the power supply unit 110, the DC voltage converter 130, the first converter 115, the electric machine 105 and optionally the filter unit 300.

[0077] According to the third embodiment shown here, the electric machine 105 is operated at the second operating point, i.e., at the low voltage level.

[0078] For this purpose, the supply voltage is converted into the three-phase drive voltage, which has a low voltage level, using the DC voltage converter 130 and the first converter 115, bypassing the second converter.

[0079] More precisely, the battery switch 210 is set to a switch position that disconnects the power supply unit 110 from the first inverter 115 and connects the DC voltage converter 130 to the first inverter 115.

[0080] In other words, Fig. 6 shows an approach to operating the electric machine 105 at a low modulation index, i.e., at a low speed.

[0081] Fig. 7 shows a flowchart of an embodiment of method 700 for operating an electric machine for a vehicle. The electric machine is similar to or corresponds to the electric machine from one of the figures described above.

[0082] Procedure 700 comprises a conversion step 705 and a conversion step 710. Optionally, procedure 700 includes a reading step 715. In reading step 715, a voltage signal is read that represents a voltage required for the first or second operating point. ZF Friedrichshafen AG File 302402 Friedrichshafen 2024-08-14

[0083] If the voltage signal represents a high voltage for operating the electric machine, conversion step 705 is executed. In conversion step 705, the supply voltage is converted into the high-voltage three-phase drive voltage using the first converter to operate the electric machine at the first operating point.

[0084] If the voltage signal represents a low voltage for operating the electric machine, step 710 of the conversion process is executed. In step 710, the supply voltage is converted into the three-phase drive voltage, which has a low voltage level, using at least one component of the charging device, in order to operate the electric machine at a second operating point.

[0085] According to one embodiment, in step 705 of the conversion process, a battery switch is closed to connect the power supply unit to the first inverter, and a disconnect switch is opened to disconnect the second inverter from the electric machine. The supply voltage is then converted into the three-phase drive voltage using the first inverter.

[0086] According to a further embodiment, in step 710 of the conversion process, the supply voltage is converted into the three-phase drive voltage, which has a low voltage level, using the DC-DC converter and the second inverter of the charging device. This involves opening a battery switch to disconnect the power supply from the first inverter and closing a disconnect switch to connect the second inverter to the electric machine. The supply voltage is thus converted into DC using the DC-DC converter, and the DC voltage is converted into the three-phase drive voltage using the second inverter. ZF Friedrichshafen AG File 302402 Friedrichshafen 2024-08-14

[0087] According to a further embodiment, in step 710 of the conversion process, the supply voltage is converted into the three-phase drive voltage, which has a low voltage level, using the second inverter, bypassing the DC-DC converter of the charging device. This involves opening a battery switch to disconnect the power supply from the first inverter, closing a bypass switch to directly connect the power supply to the second inverter, and closing a disconnect switch to connect the second inverter to the electric machine. The supply voltage is thus converted into the three-phase drive voltage using the second inverter.

[0088] According to a further embodiment, in step 710 of the conversion process, the supply voltage is converted into the three-phase drive voltage, which has a low voltage level, using the DC-DC converter and the first inverter, bypassing the second inverter. This is achieved by setting a battery switch to a position that disconnects the power supply from the first inverter and connects the DC-DC converter to the first inverter. The supply voltage is thus converted into DC using the DC-DC converter, and the DC voltage is then converted into the three-phase drive voltage using the first inverter.

[0089] Fig. 8 shows a block diagram of an embodiment of a control device 200 for operating an electric machine. The control device 200 is similar to or corresponds to the control device from Fig. 2 and / or is configured to control and / or execute the method from Fig. 7.

[0090] The control device 200 comprises a conversion unit 805 and a conversion unit 810. The conversion unit 805 is configured to provide a first control signal 815 to the first converter 115. Responding to the first control signal 815 (ZF Friedrichshafen AG File 302402 Friedrichshafen 2024-08-14), the supply voltage is converted into the high-voltage, three-phase drive voltage using the first converter 115.

[0091] The conversion unit 810 is configured to provide a second control signal 820 to at least one component of the charging device 120. Responding to the second control signal 820, the supply voltage is converted into the three-phase drive voltage, which has a low voltage level, using at least one component of the charging device 120.

[0092] ZF Friedrichshafen AG File 302402 Friedrichshafen 2024-08-14

[0093] Reference mark

[0094] 100 vehicles

[0095] 102 Drive

[0096] 105 electric machine

[0097] 110 Energy supply facility

[0098] 115 first converter

[0099] 120 charging equipment

[0100] 125 second converter

[0101] 130 DC / DC converters

[0102] 133 Gearbox unit

[0103] 135 Supply voltage

[0104] 140 three-phase drive voltage according to a first operating point

[0105] 141 three-phase drive voltage according to a second operating point

[0106] 145 three-phase charging voltage

[0107] 150 DC voltage

[0108] 200 control device

[0109] 205 first connection of the energy supply facility

[0110] 210 battery switch

[0111] 215 first connection of the first converter

[0112] 220 second connection of the first converter

[0113] 225 Connection of the electric machine

[0114] 230 second connection of the energy supply facility

[0115] 235 first connection of the DC-DC converter

[0116] 240 bypass switches

[0117] 245 first connection of the second converter

[0118] 250 second connection of the second inverter

[0119] 255 Disconnect switches

[0120] 260 second connection of the DC-DC converter

[0121] 265 first control signal

[0122] 270 second control signal

[0123] 275 third control signal ZF Friedrichshafen AG File 302402

[0124] Friedrichshafen 2024-08-14

[0125] 280 fourth control signal

[0126] 300 filter unit

[0127] 700 methods for operating an electric machine

[0128] 705 Step of Transformation

[0129] Step 710 of the conversion process

[0130] Step 715 of the reading process

[0131] 805 Unit for conversion

[0132] 810 units to convert

[0133] 815 first control signal

[0134] 820 second control signal

Claims

ZF Friedrichshafen AG File 302402 Friedrichshafen 2024-08-14 Patent claims 1. Method (700) for operating an electric machine (105) for a vehicle (100), wherein the vehicle (100) comprises the electric machine (105), a power supply device (110) for providing a supply voltage (135), a first converter (115) for converting the supply voltage (135) into a three-phase drive voltage (140) for the electric machine (105), a charging device (120) with a second converter (125) for converting a three-phase charging voltage (145) into a DC voltage (150), and a DC-DC converter (130) for converting the DC voltage (150) into the supply voltage (135) for charging the power supply device (110), wherein the method (700) comprises the following steps: Converting (705) the supply voltage (135) into the high-voltage three-phase drive voltage (140) using the first converter (115) to operate the electric machine (105) at a first operating point; and / or Converting (710) the supply voltage (135) into the three-phase drive voltage (141) having a low voltage level using at least one component of the charging device (120) to operate the electric machine (105) at a second operating point.

2. Method (700) according to claim 1, wherein in step (710) of conversion the supply voltage (135) is converted into the three-phase drive voltage (141) having a low voltage level using the DC voltage converter (130) and the second converter (125) of the charging device (120).

3. Method (700) according to claim 2, wherein the conversion step (710) comprises opening a battery switch (210) to disconnect the power supply device (110) from the first converter (115) and closing a disconnect switch (255) to connect the second converter (125) to the electric machine (105), wherein the supply voltage (135) is adjusted using the ZF Friedrichshafen AG File 302402 Friedrichshafen 2024-08-14 DC voltage converter (130) is converted into DC voltage (150) and the DC voltage (150) is converted into the three-phase drive voltage (141) using the second converter (125).

4. Method (700) according to one of the preceding claims, wherein in step (710) of conversion the supply voltage (135) is converted into the three-phase drive voltage (141) having a low voltage level using the second converter (125), bypassing the DC voltage converter (130), the charging device (120).

5. Method (700) according to claim 4, wherein the conversion step (710) comprises opening a battery switch (210) to disconnect the power supply device (110) from the first converter (115) and closing a bypass switch (240) to directly connect the power supply device (110) to the second converter (125) and closing a disconnect switch (255) to connect the second converter (125) to the electric machine (105), wherein the supply voltage (135) is converted into the three-phase drive voltage (141) using the second converter (125).

6. Method (700) according to one of the preceding claims, wherein in step (710) of conversion the supply voltage (135) is converted into the three-phase drive voltage (141) having a low voltage level using the DC voltage converter (130) and the first converter (115), bypassing the second converter (125).

7. Method (700) according to claim 6, wherein the conversion step (710) comprises setting a battery switch (210) to a switch position for disconnecting the power supply device (110) from the first converter (115) and for connecting the DC voltage converter (130) to the first converter (115), wherein the supply voltage (135) is converted into the DC voltage (150) using the DC voltage converter (130) and the DC voltage (150) is converted into the three-phase drive voltage (140) using the first converter (115). ZF Friedrichshafen AG File 302402 Friedrichshafen 2024-08-14 8. Method (700) according to one of the preceding claims, wherein the conversion step (705) comprises closing a battery switch (210) to connect the power supply device (110) to the first converter (115) and opening a disconnect switch (255) to disconnect the second converter (125) from the electric machine (105), wherein the supply voltage (135) is converted into the three-phase drive voltage (140) using the first converter (115).

9. Control device (200) for operating an electric machine (105) for a vehicle (100), wherein the vehicle (100) comprises the electric machine (105), a power supply device (110) for providing a supply voltage (135), a first inverter (115) for converting the supply voltage (135) into a three-phase drive voltage (140) for the electric machine (105), a charging device (120) with a second inverter (125) for converting a three-phase charging voltage (145) into a DC voltage (150), and a DC-DC converter (130) for converting the DC voltage (150) into the supply voltage (135) for charging the power supply device (110), wherein the control device (200) is configured to provide a first control signal (815) to the first inverter (115) to convert the supply voltage (135) into the high-voltage three-phase to convert the drive voltage (140) using the first converter (115),to operate the electric machine (105) at a first operating point, and / or wherein the control device (200) is configured to provide a second control signal (820) to at least one component of the charging device (120) to convert the supply voltage (135) into the three-phase drive voltage (141) having a low voltage level using at least one component of the charging device (120) to operate the electric machine (105) at a second operating point.

10. Converter device for use in an at least partially electrified vehicle (100), comprising the control device (200) according to claim 9 and the first converter (115) for converting the supply voltage (135) into a ZF Friedrichshafen AG File 302402 Friedrichshafen 2024-08-14 three-phase drive voltage (140) for the electric machine (105), the charging device (120) with the second converter (125) for converting the three-phase charging voltage (145) into the DC voltage (150) and the DC voltage converter (130) for converting the DC voltage (150) into the supply voltage (135) for charging the power supply device (110).

11. Electric axle drive for an at least partially electrified vehicle (100) comprising at least one electric machine (105), a transmission device (133) and a converter device, characterized in that the converter device is designed according to claim 10.

12. Vehicle (100), in particular at least partially electrified vehicle (100), comprising an electric axle drive according to claim 11 and / or a converter device according to claim 10 and / or a control device (200) according to claim 9.

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