Electric powertrains of battery-electric vehicles

Abstract

The invention relates to electric powertrains (100, 100') of battery-electric vehicles. According to one aspect, the invention relates to an electric powertrain (100) of a battery-electric vehicle, comprising at least one electric machine (101), a rechargeable traction battery (102) for electrochemical energy storage, an intermediate circuit (103) with an inverter (105), and a DC-DC converter (104) arranged between them. A circuit arrangement (1) for performing electrical switching operations under load is provided in parallel with the DC-DC converter (104). This arrangement comprises an electromagnetic switching element, a bypass circuit path (3) with a power electronic switching element, and a control device that controls both switching elements.Under normal operating conditions, the electromagnetic switching element is closed and the power electronic switching element is open, so that current flows only through the electromagnetic switching element. During a shutdown process, the control device first activates the power electronic switching element to direct the current to the bypass circuit path, then opens the electromagnetic switching element, and finally switches the power electronic switching element off again. The power electronic switching element is implemented as a MOSFET or an IGBT.

Description

[0001] The present invention relates to electric drive trains of battery-electric motor vehicles.

[0002] Powertrains for battery-electric vehicles are known in various embodiments from the prior art.

[0003] Circuit arrangements for performing electrical switching operations under load are also known from the prior art, comprising an electromagnetic switching element, a bypass circuit path connected in parallel to the electromagnetic switching element and comprising a power electronic switching element, and a control device connected to the electromagnetic switching element and to the power electronic switching element, wherein the circuit arrangement is configured such that in normal operation, in which a load connected to the circuit arrangement is electrically supplied, the electromagnetic switching element is closed and the power electronic switching element is open, so that an electric current flows only through the electromagnetic switching element, wherein the control device is configured toDuring a shutdown process, a first switching signal closes the power electronic switching element to commutate the electrical current flow to the bypass circuit path, a second switching signal opens the electromagnetic switching element when the bypass circuit path at least partially takes over the current flow, and a third switching signal puts the power electronic switching element into an electrically non-conductive state after the electromagnetic switching element has opened.

[0004] An electromagnetic switching element, such as that used in the circuit arrangements described above, has the disadvantage that it cannot be switched under load. If the electrical contact of the electromagnetic switching element is opened during current flow, an arc may form, which could potentially damage the electromagnetic switching element. Therefore, in circuit arrangements known from the prior art, a bypass circuit path, which can be activated as needed, is connected in parallel to the electromagnetic switching element. In the activated state, the current flow is commutated to the bypass circuit path before the electromagnetic switching element is opened. Corresponding circuit arrangements of the type mentioned above are known, for example, from DE 698 08 033 T2 and EP 1 677 323 A1.In these previously known circuit arrangements, the power electronic switching element in the bypass circuit path is formed by two thyristors connected in antiparallel to each other. Thyristors are electrically non-conductive in their initial state and can be switched to an electrically conductive state by a current pulse at the gate. Once a thyristor is in an electrically conductive state, it remains in this state until the current drops below a defined holding current. Thyristors have the disadvantage that their switching processes are relatively slow.

[0005] DE 10 2011 016 056 A1 and DE 103 15 982 A1 disclose a circuit arrangement for carrying out electrical switching operations under load, comprising - an electromagnetic switching element, - a bypass circuit path connected in parallel to the electromagnetic switching element and comprising a power electronic switching element, and - a control device connected to the electromagnetic switching element and the power electronic switching element, wherein the circuit arrangement is designed such that in normal operation, in which a load connected to the circuit arrangement is electrically supplied, the electromagnetic switching element is closed and the power electronic switching element is open, so that an electric current flows only through the electromagnetic switching element, wherein the control device is configured to, during a shutdown process, by means of a first switching signal, transfer the power electronic switching element into an electrically conductive state in order to commutate the electrical current flow to the bypass circuit path, by means of a second switching signal, open the electromagnetic switching element when the bypass circuit path at least partially takes over the current flow, and by means of a third switching signal, transfer the power electronic switching element into an electrically non-conductive state after the electromagnetic switching element has been opened.

[0006] In both of the circuit arrangements mentioned above, the power electronic switching element is designed as a metal-oxide-semiconductor field-effect transistor (MOSFET) or as an insulated-gate bipolar transistor (IGBT). Unlike a thyristor, a MOSFET or IGBT is controlled by an electrical voltage applied to the gate. When a sufficiently high voltage is applied to the gate, the MOSFET or IGBT becomes electrically conductive. When the voltage is removed, the MOSFET or IGBT switches off and thus becomes electrically non-conductive.Compared to a bypass circuit using a thyristor, as known from the prior art, the use of a metal-oxide-semiconductor field-effect transistor (MEFT) or a bipolar transistor with an insulated gate electrode offers the advantage of easy switching. When the electromagnetic switching element is in the open state, the third switching signal can be generated by the control device, interrupting the control voltage for the MEFT or the bipolar transistor with an insulated gate electrode. The removal of this voltage causes the MEFT or the bipolar transistor with an insulated gate electrode to cease conducting electrically, thus preventing current from flowing through the bypass circuit and deactivating the bypass circuit.This circuit arrangement allows the typically low on-resistance of an electromagnetic switching element to be utilized in the conducting state, while still avoiding the disadvantage of switching under load.

[0007] From DE 10 2017 219 985 A1, a power converter component for a motor vehicle with an electric drive motor is known, which has a series resonant circuit and a multi-purpose power electronic component that optionally contributes either to the functionality of a drive converter or to the functionality of a battery charging unit. Metal-oxide-semiconductor field-effect transistors based on silicon carbide (SiC) are used.

[0008] The object of the invention is to provide electric drive trains for battery-electric motor vehicles with improved properties.

[0009] This problem is solved by an electric drive train of a battery-electric motor vehicle with the features of claim 1 and by an electric drive train of a battery-electric motor vehicle with the features of claim 2. The dependent claims relate to advantageous further developments of the invention.

[0010] According to a first aspect of the present invention, an electric powertrain of a battery-electric motor vehicle is provided, comprising - at least one electric machine, - a rechargeable traction battery, within which energy for the operation of the electric machine can be stored electrochemically, - an intermediate circuit which is connected on the input side to the traction battery and on the output side to the electric machine, wherein the intermediate circuit comprises an inverter and a DC / DC converter which is positioned between the traction battery and the inverter, - a circuit arrangement for performing electrical switching operations under load, which is connected in parallel to the DC voltage converter, wherein the circuit arrangement - an electromagnetic switching element, - a bypass circuit path connected in parallel to the electromagnetic switching element and comprising a power electronic switching element, and - a control device connected to the electromagnetic switching element and the power electronic switching element, wherein the circuit arrangement is designed such that in normal operation, in which a load connected to the circuit arrangement is electrically supplied, the electromagnetic switching element is closed and the power electronic switching element is open, so that an electric current flows only through the electromagnetic switching element, wherein the control device is configured, during a shutdown operation, to transfer the power electronic switching element to an electrically conductive state by means of a first switching signal in order to commutate the electrical current flow to the bypass circuit path, to open the electromagnetic switching element by means of a second switching signal when the bypass circuit path at least partially takes over the current flow, and to transfer the power electronic switching element to an electrically non-conductive state by means of a third switching signal after the electromagnetic switching element has opened, comprising, and wherein the power electronic switching element is implemented as a metal-oxide-semiconductor field-effect transistor or as a bipolar transistor with an insulated gate electrode. This advantageously allows the DC-DC converter to be bypassed in certain operating modes of the drive train.

[0011] According to another aspect of the present invention, an electric powertrain of a battery-electric motor vehicle is provided, comprising - at least one electric machine with three winding strands, - a rechargeable traction battery, within which energy for the operation of the electric machine can be stored electrochemically, - an intermediate circuit which is connected on the input side to the traction battery and on the output side to the electric machine and which has an inverter which is designed to generate a three-phase alternating voltage from a DC voltage for the operation of the electric machine, which is applied on three conductors on the output side, with one of the winding strands of the electric machine being connected to each of the three conductors, - a first switching path from an output of a first winding strand to an input of a second winding strand, a second switching path from an output of the second winding strand to an input of a third winding strand, and a third switching path from an output of the third winding strand to an input of the first winding strand, such that a triangular linking of the winding strands is formed by the first switching path, the second switching path, and the third switching path, - a fourth switching path downstream of an output of the first winding strand, a fifth switching path downstream of an output of the second winding strand, and a sixth switching path downstream of an output of the third winding strand, which are connected together to form a star connection to a common star point, wherein each of the switching paths has a circuit arrangement for performing electrical switching operations under load, wherein the circuit arrangement - an electromagnetic switching element, - a bypass circuit path connected in parallel to the electromagnetic switching element and comprising a power electronic switching element, and - a control device connected to the electromagnetic switching element and the power electronic switching element, wherein the circuit arrangement is designed such that in normal operation, in which a load connected to the circuit arrangement is electrically supplied, the electromagnetic switching element is closed and the power electronic switching element is open, so that an electric current flows only through the electromagnetic switching element, wherein the control device is configured, during a shutdown operation, to transfer the power electronic switching element to an electrically conductive state by means of a first switching signal in order to commutate the electrical current flow to the bypass circuit path, to open the electromagnetic switching element by means of a second switching signal when the bypass circuit path at least partially takes over the current flow, and to transfer the power electronic switching element to an electrically non-conductive state by means of a third switching signal after the electromagnetic switching element has opened, comprising, and wherein the power electronic switching element is designed as a metal oxide semiconductor field-effect transistor or as a bipolar transistor with an insulated gate electrode.

[0012] By appropriately controlling the opening and closing of the circuit arrangements in the switching paths, it is advantageously possible to switch from a delta connection of the winding strands to a star connection of the winding strands (and vice versa) during the ongoing operation of the electrical machine.

[0013] In one embodiment, it is proposed that the intermediate circuit includes a DC-DC converter positioned between the traction battery and the inverter. The DC-DC converter can be configured, in particular, to regulate the input voltage of the inverter as well as the voltage with which the inverter supplies the traction battery during recuperation of the battery-electric vehicle.

[0014] In certain operating modes of the drive train, it may be necessary to bypass the DC-DC converter. Therefore, in an advantageous embodiment, it is proposed that the electric drive train have a circuit arrangement for performing electrical switching operations under load, which is connected in parallel to the DC-DC converter, wherein the circuit arrangement - an electromagnetic switching element, - a bypass circuit path connected in parallel to the electromagnetic switching element and comprising a power electronic switching element, and - a control device connected to the electromagnetic switching element and the power electronic switching element, wherein the circuit arrangement is designed such that in normal operation, in which a load connected to the circuit arrangement is electrically supplied, the electromagnetic switching element is closed and the power electronic switching element is open, so that an electric current flows only through the electromagnetic switching element, wherein the control device is configured to, during a shutdown process, by means of a first switching signal, transfer the power electronic switching element into an electrically conductive state in order to commutate the electrical current flow to the bypass circuit path, and by means of a second switching signal the to open the electromagnetic switching element when the bypass circuit path at least partially takes over the current flow, and to transfer the power electronic switching element to an electrically non-conductive state by means of a third switching signal after the electromagnetic switching element has opened, comprising, and wherein the power electronic switching element is designed as a metal oxide semiconductor field-effect transistor or as a bipolar transistor with an insulated gate electrode.

[0015] Preferably, the control device is configured to, during a switch-on process, first switch the metal-oxide-semiconductor field-effect transistor or the bipolar transistor with an insulated gate electrode into an electrically conductive state to direct the current flow through the bypass circuit path, then close the electromagnetic switching element with a second switch signal to commutate the current flow to the electromagnetic switching element, and finally switch the metal-oxide-semiconductor field-effect transistor or the bipolar transistor with an insulated gate electrode into a non-conductive state with a third switch signal. Analogous to the switch-off process, during the switch-on process the bypass circuit path is also activated first and the current flow is directed through it before a switching operation of the electromagnetic switching element is initiated.This effectively prevents arcing at the electromagnetic switching element during closing.

[0016] In an advantageous embodiment, it is proposed that the electromagnetic switching element be designed as a contactor. A contactor is an electromagnetic switching element that can open and close an electrical circuit. When an electrical voltage is applied to the auxiliary contacts of the contactor by the control device, an electric current flow generates a magnetic field in a coil, which attracts a movable armature of the contactor's core. This closes the electrical connection of the main conductors. When the electrical voltage is removed, the armature returns to its original position due to the restoring action of a return spring. A contactor is designed for high electrical power and, in the closed state, advantageously ensures low losses due to its very low on-resistance. The disadvantage of a contactor is that it cannot be switched under load.If the electrical contact opens during current flow, an arc can be generated, which can damage the contactor during operation. However, this disadvantage can be prevented by activating the bypass path by closing the metal-oxide-semiconductor field-effect transistor or the bipolar transistor with an insulated gate electrode before the contactor is opened or closed.

[0017] In an advantageous embodiment, it is proposed that the metal-oxide-semiconductor field-effect transistor be designed as a SiC MOSFET. A SiC MOSFET is characterized in particular by its high reverse voltage, preferably about 1200 V, and its high short-term current carrying capacity.

[0018] Further features and advantages of the present invention will become clear from the following description of preferred embodiments with reference to the accompanying figures. Fig. 1 A representation of a circuit arrangement for carrying out electrical switching operations under load, which is used in an electric powertrain of a battery-electric motor vehicle, Fig. 2 a schematic representation of a first example of use of the circuit arrangement according to Fig. 1 in an electric powertrain of a battery-electric vehicle, Fig. 3 a schematic representation of a second example of use of the circuit arrangement according to Fig. 1 in an electric powertrain of a battery-electric vehicle.

[0019] With reference to Fig. The basic structure of a circuit arrangement 1 for performing electrical switching operations under load will be explained in more detail below. The circuit arrangement 1 comprises an electromagnetic switching element, which in this case is designed as a contactor 2. A contactor 2 is designed for high power and, in the closed state, ensures particularly low electrical losses due to its very low on-resistance. The fundamental disadvantage of a contactor 2 is that it cannot be switched under load. If the electrical contact opens during current flow, an arc can be generated, which can cause damage during the operation of the contactor 2.

[0020] To overcome this problem, the circuit arrangement 1 includes a bypass circuit path 3 connected in parallel to the contactor 2 and comprising a metal-oxide-semiconductor field-effect transistor (MOSFET) 4, which functionally constitutes a power electronic switching element. In an alternative embodiment, the power electronic switching element can also be implemented as a bipolar transistor with an insulated gate electrode.

[0021] The circuit arrangement 1 further comprises a control device, not explicitly shown in the drawing here, which is connected to the contactor 2 and to the metal-oxide-semiconductor field-effect transistor 4, and is configured to control the contactor 2 and the metal-oxide-semiconductor field-effect transistor 4 in such a way that they can selectively assume electrically conductive (i.e. closed) or electrically non-conductive (i.e. open) states.

[0022] The circuit arrangement 1 is designed such that in normal operation, in which a consumer connected to the circuit arrangement 1 is electrically supplied, the contactor 2 is closed and the metal oxide semiconductor field-effect transistor 4 is open, so that an electric current flows only through the contactor 2.

[0023] When the system is to be switched off under load and contactor 2 is to be opened, the control unit generates a first switching signal in the form of an electrical voltage. This voltage causes the metal-oxide-semiconductor field-effect transistor 4 to become electrically conductive, thereby commutating the electrical current flow to the bypass circuit path 3. If the bypass circuit path 3 subsequently takes over at least part of the current flow, the control unit generates a second switching signal for contactor 2 to open it. After contactor 2 has opened, the control unit generates a third switching signal and interrupts the voltage applied to the gate of the metal-oxide-semiconductor field-effect transistor 4. This causes the metal-oxide-semiconductor field-effect transistor 4 to cease conducting electrically, thus interrupting the current flow through the circuit arrangement 1.

[0024] The circuit arrangement 1 presented here allows the low on-resistance of the contactor 2 to be utilized in the electrically conducting state, while still avoiding the disadvantage of switching under load. This is achieved by the circuit arrangement 1 incorporating the activatable bypass circuit path 3 with the metal-oxide-semiconductor field-effect transistor 4. Compared to a bypass circuit path 3 with a thyristor, as known from the prior art, the use of the metal-oxide-semiconductor field-effect transistor 4 offers the advantage of being easily switched off. When selecting the metal-oxide-semiconductor field-effect transistor 4, it is important that it exhibits a high reverse voltage (e.g., 1200 V) and a high short-term current-carrying capacity. For example, the metal-oxide-semiconductor field-effect transistor 4 can be implemented as a SiC MOSFET.

[0025] The switch-on process is analogous. First, the semiconductor field-effect transistor 4 is activated by a first switching signal from the control unit. This signal applies an electrical voltage to the gate of the semiconductor field-effect transistor 4, causing it to become electrically conductive and allowing current to flow through the bypass circuit path 3. To subsequently commutate the current flow to contactor 2, the control unit generates a second switching signal. This signal closes contactor 2, allowing current to flow through it. After contactor 2 closes, the control unit generates a third switching signal, interrupting the voltage applied to the gate of the metal-oxide-semiconductor field-effect transistor 4.This causes the metal-oxide-semiconductor field-effect transistor 4 to cease conducting electrically, thus interrupting the current flow through the bypass circuit path 3. Under normal operating conditions, the electrical current therefore flows only through contactor 2.

[0026] The circuit arrangement 1 presented here is particularly suitable for use in an electric drive train 100, 100' of a battery-electric motor vehicle for carrying out electrical switching operations under load.

[0027] With reference to Fig. 2. A first embodiment of such a use will be explained in more detail below.

[0028] The electric powertrain 100 comprises at least one electric machine 101, by means of which the battery-electric vehicle can be driven, and a rechargeable traction battery 102, within which energy for the operation of the electric machine 101 can be stored electrochemically. The traction battery 102 operates on a high-voltage basis.

[0029] Between the traction battery 102 and the electric machine 101 is an intermediate circuit 103 with power electronic components, which is connected to the traction battery 102 on the input side and to the electric machine 101 on the output side. In this embodiment, the intermediate circuit 103 comprises a DC / DC converter 104, which is configured to convert an input voltage U1 (direct current, DC) into an output voltage U2 (direct current, DC). Furthermore, the intermediate circuit 103 comprises an inverter 105, which is configured to convert the output voltage U2 of the DC / DC converter 104, which it receives as an input voltage, into a three-phase AC voltage U3 for operating the electric machine 101.

[0030] In this embodiment, the DC-DC converter 104 is thus arranged upstream of the inverter 105. Its purpose here is to regulate the input voltage of the inverter 105 as well as the voltage with which the inverter 105 supplies the traction battery 102 during recuperation of the battery-electric vehicle.

[0031] In certain operating modes of the drive train 100, it may be necessary to bypass the DC-DC converter 104. For this purpose, the electric drive train 100 has a circuit arrangement 1, which is described according to Fig. 1 is formed and is connected in parallel to the DC voltage converter 104 and enables the execution of switching operations under load in the manner explained above.

[0032] With reference to Fig. Section 3 below describes a second embodiment of a use of the circuit arrangement 1 according to Fig. 1 in an electric powertrain 100' of a battery-electric vehicle. This embodiment involves a winding switching operation of an electric machine 101', which is connected to an inverter 105' of an intermediate circuit 103' of the electric powertrain 100'.

[0033] The 105' inverter provides a three-phase alternating voltage on the output side. Fig. Figure 3 shows the corresponding conductors L1, L2, L3. The electric machine 101' has three winding strands U, V, W, which are connected to the conductors L1, L2, L3. The winding strands U, V, W can be connected to each other in either a delta or a star connection.

[0034] To obtain a delta connection (triangle circuit) of the three winding strands U, V, W, the electric machine 101' has a first switching path 106 from an output of a first winding strand U to an input of a second winding strand V, a second switching path 107 from an output of the second winding strand V to an input of a third winding strand W, and a third switching path 108 from an output of the third winding strand W to an input of the first winding strand U. A circuit arrangement 1.1, 1.2, 1.3 is provided in each of these three switching paths 106, 107, 108. These circuit arrangements 1.1, 1.2, 1.3 are like those in Fig. 1. Circuit arrangement shown in 1 is executed.

[0035] To obtain a star connection (star circuit) of the three winding strands U, V, W, the electric machine 101' has a fourth switching path 109 downstream of an output of the first winding strand U, a fifth switching path 110 downstream of an output of the second winding strand V, and a sixth switching path 111 downstream of an output of the third winding strand W, which are connected to a common star point 112. Each of these three switching paths 109, 110, 111 contains a circuit arrangement 1.4, 1.5, 1.6. These three circuit arrangements 1.4, 1.5, 1.6 are like those in Fig. 1. Circuit arrangement shown in 1 is executed.

[0036] The in Fig.The circuit shown in Figure 3 advantageously allows the three winding strands U, V, W to be switched from the delta connection, in which the circuit arrangements 1.1, 1.2, 1.3 within the first switching path 106, the second switching path 107 and the third switching path 108 are closed and the circuit arrangements 1.4, 1.5, 1.6 within the fourth switching path 107, the fifth switching path 108 and the sixth switching path 108 are open, to the star connection, in which the circuit arrangements 1.1, 1.2, 1.3 within the first switching path 106, the second switching path 107 and the third switching path 108 are open and circuit arrangements 1.4, 1.5, 1.6 within the fourth switching path 107, the fifth switching path 108 and the sixth switching path 108 are open. 108 are closed, and vice versa from the star connection to the delta connection during the ongoing operation of the electric machine 101'.

[0037] Finally, it should be noted that the uses of the circuit arrangements 1, 1.1-1.6 shown in Fig. 2 and 3 in an electric powertrain 100, 101' of a battery electric motor vehicle can also be combined with each other.

Claims

[1] Electric powertrain (100) of a battery-electric motor vehicle, comprising - at least one electric machine (101), - a rechargeable traction battery (102) within which energy for the operation of the electric machine (101) can be stored electrochemically, - an intermediate circuit (103) which is connected on the input side to the traction battery (102) and on the output side to the electric machine (101), wherein the intermediate circuit (103) comprises an inverter (105) and a DC / DC converter (104) which is positioned between the traction battery (102) and the inverter (105), and - a circuit arrangement (1) for performing electrical switching operations under load, which is connected in parallel to the DC voltage converter (104), wherein the circuit arrangement (1, 1.1-1.6) - an electromagnetic switching element, - a bypass circuit path (3) connected in parallel to the electromagnetic switching element and comprising a power electronic switching element, and - a control device connected to the electromagnetic switching element and the power electronic switching element, wherein the circuit arrangement (1, 1.1-1.6) is designed such that in normal operation, in which a load connected to the circuit arrangement (1, 1.1-1.6) is electrically supplied, the electromagnetic switching element is closed and the power electronic switching element is open, so that an electric current flows only through the electromagnetic switching element, wherein the control device is configured to, during a shutdown process, by means of a first switching signal, transfer the power electronic switching element into an electrically conductive state in order to commutate the electrical current flow to the bypass circuit path (3), by means of a second switching signal, open the electromagnetic switching element when the bypass circuit path (3) at least partially takes over the current flow, and by means of a third switching signal, transfer the power electronic switching element into an electrically non-conductive state after the electromagnetic switching element has opened, comprising, and wherein the power electronic switching element is designed as a metal oxide semiconductor field-effect transistor (4) or as a bipolar transistor with an insulated gate electrode. [2] Electric powertrain (100') of a battery-electric motor vehicle, comprising - at least one electric machine (10') with three winding strands (U, V, W), - a rechargeable traction battery, within which energy for the operation of the electric machine (101') can be stored electrochemically, - an intermediate circuit (103') which is connected on the input side to the traction battery (102') and on the output side to the electric machine (101') and has an inverter (105') which is designed to generate a three-phase alternating voltage from a DC voltage for the operation of the electric machine (101'), which is applied on the output side to three conductors (L1, L2, L3), wherein one of the winding strands (U, V, W) of the electric machine (101') is connected to each of the three conductors (L1, L2, L3), - a first switching path (106) from an output of a first winding strand (U) to an input of a second winding strand (V), a second switching path (107) from an output of the second winding strand (V) to an input of a third winding strand (W) and a third switching path (108) from an output of the third winding strand (W) to an input of the first winding strand (U), such that a triangular link of the winding strands (U, V, W) is formed by the first switching path (106), the second switching path (107) and the third switching path (108), - a fourth switching path (109) behind the output of the first winding strand (U), a fifth switching path (110) behind the output of the second winding strand (V) and a sixth switching path (111) behind the output of the third winding strand (W), which are connected together to form a star connection to a common star point (112), wherein each of the switching paths (106-111) has a circuit arrangement (1.1-1.6) for performing electrical switching operations under load, wherein the circuit arrangement (1.1-1.6) - an electromagnetic switching element, - a bypass circuit path (3) connected in parallel to the electromagnetic switching element and comprising a power electronic switching element, and - a control device connected to the electromagnetic switching element and the power electronic switching element, wherein the circuit arrangement (1, 1.1-1.6) is designed such that in normal operation, in which a load connected to the circuit arrangement (1, 1.1-1.6) is electrically supplied, the electromagnetic switching element is closed and the power electronic switching element is open, so that an electric current flows only through the electromagnetic switching element, wherein the control device is configured to, during a shutdown process, by means of a first switching signal, transfer the power electronic switching element into an electrically conductive state in order to commutate the electrical current flow to the bypass circuit path (3), by means of a second switching signal, open the electromagnetic switching element when the bypass circuit path (3) at least partially takes over the current flow, and by means of a third switching signal, transfer the power electronic switching element into an electrically non-conductive state after the electromagnetic switching element has opened, comprising, and wherein the power electronic switching element is designed as a metal oxide semiconductor field-effect transistor (4) or as a bipolar transistor with an insulated gate electrode. [3] Electric drive train according to claim 2, characterized by, that the intermediate circuit (103') has a DC voltage converter (104) positioned between the traction battery and the inverter (105'). [4] Electric drive train according to claim 3, characterized by , that the electric drive train (100') has a circuit arrangement (1) which is connected in parallel to the DC voltage converter (104), wherein the circuit arrangement (1) - an electromagnetic switching element, - a bypass circuit path (3) connected in parallel to the electromagnetic switching element and comprising a power electronic switching element, and - a control device connected to the electromagnetic switching element and the power electronic switching element, wherein the circuit arrangement (1) is designed such that in normal operation, in which a load connected to the circuit arrangement (1) is electrically supplied, the electromagnetic switching element is closed and the power electronic switching element is open, so that an electric current flows only through the electromagnetic switching element, wherein the control device is configured to, during a shutdown process, by means of a first switching signal, transfer the power electronic switching element into an electrically conductive state in order to commutate the electrical current flow to the bypass circuit path (3), by means of a second switching signal, open the electromagnetic switching element when the bypass circuit path (3) at least partially takes over the current flow, and by means of a third switching signal, transfer the power electronic switching element into an electrically non-conductive state after the electromagnetic switching element has opened, comprising, and wherein the power electronic switching element is designed as a metal oxide semiconductor field-effect transistor (4) or as a bipolar transistor with an insulated gate electrode. [5] Electric powertrain according to any one of claims 1 to 4, characterized by, that the control device is configured to, during a switch-on operation, by means of a first switching signal, to bring the metal-oxide-semiconductor field-effect transistor (4) or the bipolar transistor with insulated gate electrode into an electrically conductive state in order to direct the electric current flow through the bypass circuit path (3), and by means of a second switching signal to close the electromagnetic switching element in order to commutate the electric current flow to the electromagnetic switching element, and by means of a third switching signal to bring the metal-oxide-semiconductor field-effect transistor (4) or the bipolar transistor with insulated gate electrode into an electrically non-conductive state. [6] Electric powertrain according to any one of claims 1 to 5, characterized by , that the electromagnetic switching element is designed as a contactor (2). [7] Electric powertrain according to any one of claims 1 to 6, characterized by, that the metal oxide semiconductor field effect transistor (4) is designed as a SiC MOSFET.

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