Power converter assembly, drive unit and method for operating the drive unit

Abstract

The invention relates to a power converter assembly (100) comprising a DC voltage terminal (110), a positive busbar (121), a negative busbar (122), a first AC voltage terminal (130) having at least three first load contacts (131, 132, 133), a second AC voltage terminal (140) having at least three second load contacts (141, 142, 143), and a first power converter circuit (150) and a second power converter circuit (160) each having at least three half-bridges (151, 152, 153, 161, 162, 163). Each of the half-bridges (151, 152, 153, 161, 162, 163) has a series circuit consisting of a high-side switch (151a, 152a, 153a, 161a, 162a, 163a) and a low-side switch (151b, 152b, 153b, 161b, 162b, 163b), wherein a centre tap (151c, 152c, 153c, 161c, 162c, 163c) is formed between the high-side switch (151a, 152a, 153a, 161a, 162a, 163a) and the low-side switch (151b, 152b, 153b, 161b, 162b, 163b). One of the three first load contacts (131, 132, 133) and one of the three second load contacts (141, 142, 143) are each connected to a respective centre tap (151c, 152c, 153c, 161c, 162c, 163c). An isolating switch (170) for interrupting either the positive busbar (121) or the negative busbar (122) is arranged at a point between the first power converter circuit (150) and the second power converter circuit (160).

Description

[0001] R.417109

[0002] - 1 -

[0003] Description

[0004] title

[0005] Power converter arrangement, drive unit and method for operating the drive unit

[0006] The present invention relates to a power converter arrangement, a drive unit comprising the power converter arrangement and an electric machine, a method for operating the drive unit, and a computer program for carrying out the method.

[0007] Background of the invention

[0008] Drive units, for example for powering a fully or partially electric vehicle, comprise an electric machine, a power converter arrangement for supplying the phase windings of the electric machine with an alternating voltage (so-called inverter), typically an electromagnetic compatibility (EMC) filter, computing electronics or a control unit (controller) for control purposes, and a high-voltage connection through which the drive unit can be supplied with a high-voltage direct current (DC) voltage, i.e., a DC voltage above a permissible touch voltage of 60 V, for example, several hundred volts. The electric machine has a number of phase windings (usually three: II, V, W), which can be connected in different configurations, for example, in a delta or star connection or in an H-bridge connection.

[0009] Disclosure of the invention

[0010] According to the invention, a power converter arrangement, a drive unit with the power converter arrangement and an electric machine, a method for R.417109

[0011] - 2 -

[0012] The operation of the drive unit and a computer program for carrying out the method with the features of the independent claims are proposed. Advantageous embodiments are the subject of the dependent claims and the following description.

[0013] Specifically, the power converter arrangement comprises a DC voltage connection with a positive and a negative DC voltage contact, a positive busbar connected to the positive DC voltage contact, and a negative busbar connected to the negative DC voltage contact. Furthermore, the power converter arrangement comprises a first AC voltage connection with at least three first load contacts and a second AC voltage connection with at least three second load contacts.

[0014] Furthermore, the converter arrangement comprises a first converter circuit with at least three first half-bridges and a second converter circuit with at least three second half-bridges, wherein each of the first half-bridges has a series connection of a first high-side switch and a first low-side switch, wherein a first center tap is formed between the first high-side switch and the first low-side switch, and wherein the series connection of the first high-side switch and the first low-side switch is connected between the positive and the negative busbar.Each of the second half-bridges has a series connection of a second high-side switch and a second low-side switch, with a second center tap formed between the second high-side switch and the second low-side switch, and the series connection of the second high-side switch and the second low-side switch being connected between the positive and negative busbars. In other words, the first converter circuit and the second converter circuit are configured as B6 bridge circuits (or, for more than three phases, correspondingly higher).

[0015] Each of the three first load contacts is connected to a first center tap, and each of the three second load contacts is connected to a second center tap. R.417109

[0016] - 3 -

[0017] The first and second load contacts are used to connect a multi-phase load, in particular several phase windings of a stator of an electrical machine, wherein each of the phase windings is connected at one end, or on the one hand, to a first load contact and at the other end, or on the other hand, to a second load contact.

[0018] The arrangement of the first and second converter circuits thus allows the electric machine to be operated in an H-bridge configuration. This advantageously enables the electric machine to be operated with bipolar PWM control, unipolar PWM control, and unfolding PWM control.

[0019] Furthermore, the power converter arrangement has a disconnect switch for interrupting either the positive busbar or the negative busbar at a point between the first power converter circuit and the second power converter circuit.

[0020] The disconnect switch has two normally open contacts. Normally open contacts are those contacts that are connected or disconnected by switching the disconnect switch. The first of the two normally open contacts is connected to the positive or negative busbar on the side of the first converter circuit, and the second of the two normally open contacts is connected to the same busbar on the side of the second converter circuit.

[0021] The invention enables a multiphase electric machine with three or more phase windings to be operated in different circuit configurations, in particular a star connection and an H-bridge connection, requiring only a few additional switching elements. In particular, a converter arrangement with two converter circuits designed for operation as an H-bridge connection can also be adapted for operation in a star connection by means of a single additional disconnect switch. R.417109

[0022] - 4 -

[0023] When this revelation refers to "connect", "connected", "connection", etc., it always refers to an electrical connection unless otherwise stated.

[0024] According to one embodiment, the second working contact of the disconnect switch is connected to a positive charging contact, and the negative DC contact is connected to a negative charging contact. The positive charging contact and the negative charging contact form part of a charging terminal through which the power converter assembly can be connected to a DC voltage source. The power converter assembly can then be operated as a DC-DC converter, in particular to charge a battery connected to the DC voltage terminal.

[0025] According to one embodiment, the power converter arrangement further comprises a boost circuit consisting of a boost capacitor and a boost switch connected in series, with the boost circuit being connected between the positive and negative charging contacts. This allows the power converter arrangement to advantageously also be operated as a boost converter to charge a battery connected to the DC voltage terminal with a higher charging voltage than is available at the charging terminal.

[0026] According to one embodiment, the power converter arrangement further comprises an intermediate circuit capacitor connected between the positive and negative busbars. This allows the DC voltage between the positive and negative busbars to be smoothed and buffered.

[0027] A drive unit according to the invention comprises the converter arrangement according to the invention and an electric machine with at least three phase windings, each phase winding being connected at one end, or on the one hand, to a first load contact and at the other end, or on the other hand, to a second load contact. This allows the advantages described in connection with the converter arrangement to be realized in a drive unit as well. R.417109

[0028] - 5 -

[0029] According to one embodiment, the drive unit further comprises a DC voltage source connected to the DC voltage terminal. If the DC voltage source is advantageously a battery, a mobile drive unit, particularly for use in electric vehicles, can be advantageously provided.

[0030] In the inventive method for operating the inventive drive unit, in a first operating mode the electric machine is operated in a star connection and in a second operating mode the electric machine is operated in an H-bridge connection.

[0031] According to one embodiment, the second operating mode includes bipolar PWM control and / or unipolar PWM control and / or expanding PWM control. This extends the application range of the method to numerous different use cases. For details on bipolar and unipolar PWM control, please refer to technical literature, e.g., EHE Aboadla, S. Khan, MH Habaebi, T. Gunawan, BA Hamidah and MB Yaacob, "Effect of modulation index of pulse width modulation inverter on Total Harmonic Distortion for Sinusoidal", 2016 International Conference on Intelligent Systems Engineering (ICISE), Islamabad, Pakistan, 2016, pp. 192-196, doi: 10.1109 / INTELSE.2016.7475119.

[0032] For details on the unfolding PWM control, see S. Nayak and A. Das, "A DAB based Folder-Unfolder circuit in Cascaded H-Bridge Converter for MV Grid Application", 2022 IEEE International Conference on Power Electronics, Drives and Energy Systems (PEDES), Jaipur, India, 2022, pp. 1-6, doi:

[0033] 10.1109 / PEDES56012.2022.10080647. referred.

[0034] According to one embodiment, the first operating mode comprises switching the disconnect switch to a non-conductive state, switching those of the second low-side switches and second high-side switches that are electrically connected to the second working contact to a conductive state, and switching those of the second low-side switches and second high-side switches that are not electrically connected to the second working contact, inR.417109

[0035] - 6 -

[0036] a non-conductive state. The first converter circuit then serves to supply the electric machine with the desired alternating currents in a known manner. If the converter arrangement has a boost switch, this is non-conductive or open in the first operating mode.

[0037] If, for example, the converter arrangement has the disconnect switch on the negative bus, the first operating mode involves switching the second low-side switch to a conducting state and switching the second high-side switch to a non-conducting state. In this case, the neutral point is formed by the second low-side switch.

[0038] If, however, the power converter arrangement has, for example, the disconnect switch on the positive busbar, the first operating mode involves switching the second low-side switch to a non-conducting state and switching the second high-side switch to a conducting state. In this case, the neutral point is formed by the second high-side switch.

[0039] According to one embodiment, the second operating mode comprises switching the disconnect switch to a conductive state, activating the first converter circuit to convert the DC voltage applied to the DC input into the AC voltage applied to the first AC input, and activating the second converter circuit to convert the DC voltage applied to the DC input into the AC voltage applied to the second AC input. If the converter arrangement includes a boost switch, this switch is non-conductive or open in the first operating mode.

[0040] In this operating mode, the desired control schemes can be easily generated by appropriately controlling the first and second converter circuits. With unipolar control, for example, the control signal to the second converter circuit can be phase-shifted by 180° relative to the first. With expanded control, for example, the control signal to the first converter circuit can be PWM, and the control signal to the second can be... (R.417109)

[0041] - 7 -

[0042] The converter arrangement should be a block clocking (fundamental frequency control) in which the switches are turned on and off in 120° blocks.

[0043] According to one embodiment, a third operating mode includes operating the drive unit as a DC-DC converter. As explained above, this allows for a simple charging function.

[0044] According to one embodiment, the third operating mode, when the disconnect switch is configured to interrupt the positive busbar, includes switching the disconnect switch to a non-conductive state, and when the disconnect switch is configured to interrupt the negative busbar, it includes switching the disconnect switch to a conductive state. Furthermore, the third operating mode includes switching those of the second low-side switches and second high-side switches that are electrically connected to the second working contact of the disconnect switch to a conductive state, and switching those of the second low-side switches and second high-side switches that are not electrically connected to the second working contact to a non-conductive state.

[0045] In the third operating mode, a star point of the electric machine is formed by those of the second low-side switches and second high-side switches that are electrically connected to the second working contact of the disconnect switch, i.e., those that are also connected to the positive charging contact.

[0046] Furthermore, the boost switch is switched to a conducting state, i.e., the boost capacitor is connected in parallel to the charging terminal. The first converter circuit is then used to convert the DC voltage applied to the charging terminal into a DC voltage applied to the DC input, particularly with a higher amplitude. This makes it very easy to charge a battery connected to the DC input. Alternatively, the first converter circuit can be used to convert the DC voltage applied to the DC input into a DC voltage applied to the charging terminal. R.417109

[0047] - 8 -

[0048] The device is controlled by the applied DC voltage. This allows an energy sink connected to the charging port to be powered.

[0049] A computing unit according to the invention, e.g. a control unit of the drive unit, is, in particular in terms of programming, equipped to carry out a method according to the invention.

[0050] Implementing a method according to the invention in the form of a computer program or computer program product with program code for carrying out all method steps is also advantageous, as this incurs particularly low costs, especially if an executing control unit is already available for other tasks. Finally, a machine-readable storage medium is provided with a computer program stored on it as described above. Suitable storage media or data carriers for providing the computer program are, in particular, magnetic, optical, and electrical storage media, such as hard drives, flash memory, EEPROMs, DVDs, etc. Downloading a program via computer networks (Internet, intranet, etc.) is also possible. Such a download can be wired or wireless (e.g., via a WLAN network, a 3G, 4G, 5G, or 6G connection, etc.).

[0051] Further advantages and embodiments of the invention will become apparent from the description and the accompanying drawing.

[0052] The invention is schematically illustrated in the drawing using exemplary embodiments and is described below with reference to the drawing.

[0053] Brief description of the drawings

[0054] Figure 1 shows an embodiment of a drive unit with a power converter arrangement. R.417109

[0055] - 9 -

[0056] Figure 2 shows another embodiment of a drive unit with a power converter arrangement.

[0057] Detailed description

[0058] Figures 1 and 2 show two different drive units 10 according to embodiments of the invention and are described together below. Identical or equivalently acting elements are designated with the same reference numerals.

[0059] The drive unit 10 comprises a power converter arrangement 100 according to embodiments of the invention and an electric machine 20. The electric machine 20 has a rotor and a stator with three phase windings, which are symbolized as inductance.

[0060] Furthermore, the drive unit 10 has a DC voltage source 30 which is connected to a DC voltage terminal 110 of the converter arrangement 100. The DC voltage terminal 110 has a positive DC voltage contact 111 and a negative DC voltage contact 112.

[0061] The power converter arrangement 100 has a positive busbar 121 which is connected to the positive DC contact 111, and a negative busbar 122 which is connected to the negative DC contact 112.

[0062] The converter arrangement 100 has a first AC voltage connection 130 with at least three first load contacts 131, 132, 133 and a second AC voltage connection 140 with at least three second load contacts 141, 142, 143. Each of the three phase windings of the electrical machine 20 is connected at one end to a first load connection 131, 132, 133 and at the other end to a second load connection 141, 142, 143.

[0063] - 10 -

[0064] The converter arrangement 100 comprises a first converter circuit 150 with at least three first half-bridges 151, 152, 153 and a second converter circuit 160 with at least three second half-bridges 161, 162, 163.

[0065] Each of the first half-bridges 151, 152, 153 has a series connection consisting of a first high-side switch 151a, 152a, 153a and a first low-side switch 151b, 152b, 153b, with a first center tap 151c, 152c, 153c formed between the first high-side switch 151a, 152a, 153a and the first low-side switch 151b, 152b, 153b. The series connection of the first high-side switch 151a, 152a, 153a and the first low-side switch 151b, 152b, 153b is connected between the positive bus 121 and the negative bus 122.

[0066] Each of the second half-bridges 161, 162, 163 has a series connection consisting of a second high-side switch 161a, 162a, 163a and a second low-side switch 161b, 162b, 163b, with a second center tap 161c, 162c, 163c formed between the second high-side switch 161a, 162a, 163a and the second low-side switch 161b, 162b, 163b. The series connection of the second high-side switch 161a, 162a, 163a and the second low-side switch 161b, 162b, 163b is connected between the positive bus 121 and the negative bus 122.

[0067] Each of the three first load contacts 131, 132, 133 is connected to a first center tap 151c, 152c, 153c. Specifically, the first load contact 131 is connected to the first center tap 151c, the first load contact 132 is connected to the first center tap 152c, and the first load contact 133 is connected to the first center tap 153c.

[0068] Each of the three second load contacts 141, 142, 143 is connected to a second center tap 161c, 162c, 163c. Specifically, the second load contact 141 is connected to the second center tap 161c, the second load contact 142 is connected to the second center tap 162c, and the second load contact 143 is connected to the second center tap 163c. R.417109

[0069] - 11 -

[0070] The converter arrangement 100 according to Fig. 1 has a disconnect switch 170 for interrupting the negative busbar 122 at a point between the first converter circuit 150 and the second converter circuit 160.

[0071] The converter arrangement 100 according to Fig. 2 has a disconnect switch 170 for interrupting the positive busbar 121 at a point between the first converter circuit 150 and the second converter circuit 160.

[0072] The disconnect switch 170 has two working contacts 171, 172, wherein a first working contact 171 of the two working contacts is connected to the first power converter circuit 150 and the second working contact 172 of the two working contacts is connected to the second power converter circuit 160.

[0073] The second working contact 172 of the disconnect switch 170 is connected to a positive charging contact 181 of a charging terminal 180, and the negative DC voltage contact 111 is connected to a negative charging contact 182 of the charging terminal 180. In particular, in the power converter arrangement 100 according to Fig. 2, the positive charging contact 181 is connected to the positive busbar 121 and the negative charging contact 182 is connected to the negative busbar 122.

[0074] A boost circuit 190 comprising a series circuit of a boost capacity 191 and a boost switch 192 is connected between the positive charging contact 181 and the negative charging contact 182.

[0075] A DC link capacitor of 200 is connected between the positive busbar 121 and the negative busbar 122.

[0076] Such a drive unit 10 as described can advantageously be operated in different operating modes, wherein in a first operating mode the electric machine 20 is operated in a star connection, in a second operating mode the electric machine 20 is operated in an H-bridge connection, and in a third operating mode the drive unit 10 is operated as a DC voltage converter, in particular to charge the battery 30 from a R.417109

[0077] - 12 -

[0078] to charge an energy source connected to charging port 180, or conversely to discharge the battery 30 into an energy sink connected to charging port 180.

[0079] In the first operating mode, the disconnect switch 170 is opened, i.e., switched to a non-conductive state. This prevents a connection or short circuit between the neutral point to be established and the positive or negative busbar.

[0080] Furthermore, those of the second low-side switches 161b, 162b, 163b and second high-side switches 161a, 162a, 163a that are electrically connected to the second working contact 172 are switched to a conductive state or closed. Specifically, in the embodiment shown in Fig. 1, these are the second low-side switches 161b, 162b, 163b, and in the embodiment shown in Fig. 2, the second high-side switches 161a, 162a, 163a. ​​This establishes the neutral point of the electrical machine, i.e., connects the free phase windings.

[0081] Furthermore, those of the second low-side switches 161b, 162b, 163b and second high-side switches 161a, 162a, 163a that are not electrically connected to the second working contact 172 are switched to a non-conductive state or opened. Specifically, in the embodiment shown in Fig. 1, these are the second high-side switches 161a, 162a, 163a, and in the embodiment shown in Fig. 2, the second low-side switches 161b, 162b, 163b. This prevents a short circuit.

[0082] Then the first power converter circuit 150 is used to convert the DC voltage applied to the DC voltage terminal 110 into the AC voltage applied to the first AC voltage terminal 130 in order to supply the electric machine 20 with the necessary AC voltage.

[0083] In the second operating mode, the disconnect switch 170 is switched to a conductive state, i.e., closed. Then the first R.417109

[0084] - 13 -

[0085] The converter circuit 150 is used to convert the DC voltage applied to the DC voltage terminal 110 into the AC voltage applied to the first AC voltage terminal 130, and the second converter circuit 160 is used to convert the DC voltage applied to the DC voltage terminal 110 into the AC voltage applied to the second AC voltage terminal 130.

[0086] According to an embodiment of the invention, the second operating mode comprises bipolar PWM control and / or unipolar PWM control and / or unfolding PWM control. In bipolar control, the corresponding first and second switches, i.e., 151a and 161b, 152a and 162b, 153a and 163b, 151b and 161a, 152b and 162a, 153b and 163a, are opened and closed simultaneously.

[0087] In unipolar control, for example, the control of the second converter arrangement 160 can be phase-shifted by 180° relative to the first converter arrangement 150.

[0088] In the fully developed control system, for example, the control of the first converter arrangement 150 can be a PWM control and the control of the second converter arrangement 160 can be a block clocking (fundamental frequency control), in which the switches 161a, ... , 163b are switched on and off in a suitable sequence in 120° blocks.

[0089] In the third operating mode, a distinction must be made between the embodiments shown in Figures 1 and 2. If, as shown in Figure 1, the disconnect switch 170 is configured to interrupt the negative busbar 122, the disconnect switch 170 is switched to a conductive state, i.e., closed. If, as shown in Figure 2, the disconnect switch 170 is configured to interrupt the positive busbar 121, the disconnect switch 170 is switched to a non-conductive state, i.e., open.

[0090] Furthermore, as in the first operating mode, those of the second low-side switches 161b, 162b, 163b and second high-side switches 161a,R.417109

[0091] - 14 -

[0092] 162a, 163a, which are electrically connected to the second working contact 172, are switched to a conductive state or closed. Specifically, in the embodiment shown in Fig. 1, these are the second low-side switches 161b, 162b, 163b, and in the embodiment shown in Fig. 2, the second high-side switches 161a, 162a, 163a. ​​This establishes the neutral point of the electric machine, i.e., connects the free phase windings, and connects them to the positive charging contact 181.

[0093] As in the first operating mode, those of the second low-side switches 161b, 162b, 163b and second high-side switches 161a, 162a, 163a that are not electrically connected to the second working contact 172 are switched to a non-conductive state or opened. Specifically, in the embodiment shown in Fig. 1, these are the second high-side switches 161a, 162a, 163a, and in the embodiment shown in Fig. 2, the second low-side switches 161b, 162b, 163b. This prevents a short circuit.

[0094] The boost switch 192 is switched to a conductive state or closed to activate the boost capacity 191.

[0095] Then the first power converter circuit 150 is activated to convert a DC voltage applied to the charging terminal 180 into a DC voltage applied to the DC terminal 110, or vice versa to convert a DC voltage applied to the DC terminal 110 into a DC voltage applied to the charging terminal 180.

[0096] The power converter arrangement can also be advantageously operated as a boost converter to charge a battery connected to the DC voltage terminal with a higher charging voltage than is available at the charging terminal.

[0097] A computing unit 1 of the drive unit 10 is specifically designed to carry out all the described process steps and to open and close the described switches in the correct manner.

Claims

R.417109 - 15 - Claims 1. Power converter arrangement (100), comprising the power converter arrangement (100) - a DC voltage connection (110) with a positive DC voltage contact (111) and a negative DC voltage contact (112), - a positive busbar (121) which is connected to the positive DC voltage contact (111), - a negative busbar (122) which is connected to the negative DC voltage contact (112), - a first AC voltage connection (130) with at least three first load contacts (131, 132, 133), - a second AC voltage connection (140) with at least three second load contacts (141, 142, 143), - a first converter circuit (150) with at least three first half-bridges (151, 152, 153), - a second converter circuit (160) with at least three second half-bridges (161, 162, 163), wherein each of the first half-bridges (151, 152, 153) has a series connection of a first high-side switch (151a, 152a, 153a) and a first low-side switch (151b, 152b, 153b), wherein a first center tap (151c, 152c, 153c) is formed between the first high-side switch (151a, 152a, 153a) and the first low-side switch (151b, 152b, 153b), wherein the series connection of the first high-side switch (151a, 152a, 153a) and the first low-side switch (151b, 152b, 153b) is connected between the positive bus (121) and the negative bus (122), wherein each of the second half-bridges (161, 162, 163) has a series connection of a second high-side switch (161a, 162a, 163a) and a second low-side switch (161b, 162b, 163b), wherein a second center tap (161c, 162c, 163c) is located between the second high-side switch (161a, R.417109 - 16 - 162a, 163a) and the second low-side switch (161b, 162b, 163b), wherein the series connection of the second high-side switch (161a, 162a, 163a) and the second low-side switch (161b, 162b, 163b) is connected between the positive power rail (121) and the negative power rail (122), wherein each of the three first load contacts (131, 132, 133) is connected to a first center tap (151c, 152c, 153c), wherein each of the three second load contacts (141, 142, 143) is connected to a second center tap (161c, 162c, 163c), - a disconnect switch (170) for interrupting either the positive busbar (121) or the negative busbar (122) at a point between the first converter circuit (150) and the second converter circuit (160), wherein the disconnect switch (170) has two working contacts (171, 172), wherein a first working contact (171) of the two working contacts is connected to the first converter circuit (150) and the second working contact (172) of the two working contacts is connected to the second converter circuit (160).

2. Power converter arrangement (100) according to claim 1, wherein the second working contact (172) of the disconnect switch (170) is connected to a positive charging contact (181) of a charging terminal (180), and wherein the negative DC voltage contact (112) is connected to a negative charging contact (182) of the charging terminal (180).

3. Power converter arrangement (100) according to claim 2, further comprising a boost circuit (190) comprising a series circuit of a boost capacitor (191) and a boost switch (192), wherein the boost circuit (190) is connected between the positive charging contact (181) and the negative charging contact (182).

4. Power converter arrangement (100) according to one of the preceding claims, further comprising an intermediate circuit capacitor (200) connected between the positive busbar (121) and the negative busbar (122)R.417109 - 17 - is connected.

5. Drive unit (10) comprising the converter arrangement (100) according to one of the preceding claims and an electric machine (20), the electric machine (20) comprising a rotor and a stator with at least three phase windings, wherein each of the at least three phase windings is connected at one end to a first load connection (131, 132, 133) and at the other end to a second load connection (141, 142, 143).

6. Drive unit (10) according to claim 5, further comprising a DC voltage source (30) which is connected to the DC voltage terminal (110).

7. Method for operating a drive unit (10) according to claim 5 or 6, the method comprising: in a first operating mode, the electric machine (20) is operated in a star connection, and in a second operating mode the electric machine (20) is operated in an H-bridge circuit.

8. The method of claim 7, comprising in the first operating mode: switching the disconnect switch (170) to a non-conductive state, switching those of the second low-side switches (161b, 162b, 163b) and second high-side switches (161a, 162a, 163a) that are electrically connected to the second working contact (172) to a conductive state, switching those of the second low-side switches (161b, 162b, 163b) and second high-side switches (161a, 162a, 163a) that are not electrically connected to the second working contact (172) to a non-conductive state, and Controlling the first power converter circuit (150) to convert the DC voltage applied to the DC voltage terminal (110) into the AC voltage applied to the first AC voltage terminal (130). R.417109 - 18 - 9. Method according to claim 7 or 8, comprising in the second operating mode: Switching the disconnect switch (170) to a conducting state, controlling the first converter circuit (150) to convert the DC voltage applied to the DC voltage terminal (110) into the AC voltage applied to the first AC voltage terminal (130), and Controlling the second power converter circuit (160) to convert the DC voltage applied to the DC voltage terminal (110) into the AC voltage applied to the second AC voltage terminal (130).

10. Method according to any one of claims 7 to 9, with reference at least to claim 3, comprehensively in a third operating mode, the drive unit (10) is operated as a DC voltage converter.

11. Method according to claim 10, comprising in the third operating mode: when the disconnect switch (170) is configured to interrupt the positive busbar (121), switching the disconnect switch (170) to a non-conductive state, if the disconnect switch (170) is configured to interrupt the negative busbar (122), switching the disconnect switch (170) to a conductive state, Switching those of the second low-side switches (161b, 162b, 163b) and second high-side switches (161a, 162a, 163a) that are electrically connected to the second working contact (172) of the disconnect switch (170) into a conductive state, and Switching those of the second low-side switches (161b, 162b, 163b) and second high-side switches (161a, 162a, 163a) that are not electrically connected to the second working contact (172) into a non-conductive state, Switching the boost switch (192) to a conducting state, controlling the first power converter circuit (150) to convert from an R.417109 - 19 - DC voltage applied to the charging port (180) into a DC voltage applied to the DC voltage port (110), or to convert a DC voltage applied to the DC voltage port (110) into a DC voltage applied to the charging port (180).

12. Drive unit (10) according to claim 5 or 6, further comprising a computing unit configured to perform all process steps of a method according to any one of claims 7 to 11.

13. Computer program that causes the computing unit of the drive unit (10) according to claim 12 to perform all process steps of a method according to any one of claims 7 to 11 when executed on the computing unit.

14. Machine-readable storage medium with a computer program stored thereon according to claim 13.

Images