Method and control device for controlling components of a vehicle's powertrain

Abstract

The present invention relates to a method and a control device for controlling components of a powertrain of a vehicle. The components include a first switching device, a converter, and a clutch. The control device provides a first operating mode and / or a second operating mode. According to the present invention, the components further include a second switching device, and the control device further provides a third operating mode and / or a fourth operating mode. In the third operating mode, the clutch decouples the electric motor from the internal combustion engine, the first switching device connects the battery to the DC electrical system, the converter causes current to flow from the system to at least one winding, and the second switching device connects the corresponding winding to a heating resistor; in the fourth operating mode, the internal combustion engine is running, the clutch couples the internal combustion engine with the electric motor, the converter causes current to flow from each winding via the second switching device to the heating resistor, and the second switching device connects the corresponding winding to the heating resistor. A control method and a powertrain are also proposed.

Description

Technical Field

[0001] The present invention relates to a control device and a control method for controlling components of a vehicle's powertrain. Further, the present invention relates to a powertrain for a vehicle. Background Art

[0002] In the prior art, such a control device and such a control method are provided for a vehicle having a hybrid powertrain that includes an internal combustion engine and a polyphase (e.g., three-phase) AC motor. In such a vehicle, it is foreseeable that each of the internal combustion engine and the AC motor can contribute to the drive torque for driving the vehicle during operation.

[0003] In particular, known control devices are provided for controlling at least the following components of a vehicle's powertrain:

[0004] - A first switching device for connecting the vehicle's battery to the vehicle's DC electrical system and for disconnecting the battery from the DC electrical system, respectively,

[0005] - A bi-directional converter for enabling current to flow in an alternating manner, e.g., in a PWM manner, from the DC electrical system to each of the multiple windings of the vehicle's polyphase AC motor to drive the AC motor, and for enabling current to flow in an alternating manner from each of the multiple windings to the DC electrical system to recover electrical energy from the AC motor, and

[0006] - A clutch for coupling the AC motor to the vehicle's internal combustion engine and for decoupling the AC motor from the internal combustion engine, respectively.

[0007] Further, the control device is designed to provide

[0008] - A first operating mode of the components, in which the first switching device connects the battery to the DC electrical system, the converter enables current to flow in an alternating manner from the DC electrical system to each of the multiple windings, and the clutch couples the AC motor to the internal combustion engine for starting the internal combustion engine or for providing additional torque in the powertrain, and / or

[0009] - A second operating mode of the components, in which the internal combustion engine is running, the clutch couples the internal combustion engine to the AC motor, the converter enables current to flow in an alternating manner from each of the multiple windings to the DC electrical system, and the first switching device connects the DC electrical system to the battery for charging the battery.

[0010] In this prior art, internal combustion engines are typically equipped with a catalyst in the exhaust passage to reduce emissions by assisting in the oxidation of unburned components of the exhaust gas. The catalyst operates at high temperatures, typically above 250 °C. To reach such high temperatures, the catalyst includes a resistive heater (heating resistor) to heat the catalyst to the required temperature more quickly ("EHC": electrically heated catalyst). This is particularly useful for hybrid and mild hybrid vehicles in which the internal combustion engine operates intermittently.

[0011] The electric power required to heat the catalyst when starting the internal combustion engine is typically in the range of several kilowatts. Typically, within a few minutes after the engine is started, the electric power can be reduced and then further reduced to zero, unless the vehicle is operating in a region with cold climate, where electric power may need to be supplied to heat the catalyst until the engine is shut down.

[0012] In the prior art of vehicles having a hybrid powertrain as described above and having an electrically heatable catalyst in the exhaust passage of the internal combustion engine, there are several methods for achieving the necessary power supply for the heatable catalyst.

[0013] One method is to supply current to the heating resistor of the catalyst in a controlled manner from the 12V or 24V DC electrical system typically used in the vehicle. However, this requires a relatively high current (about 100A or higher) to be supplied to the heating resistor, which in turn requires wiring to the heating resistor that requires a relatively large installation space volume and is expensive. In addition, the devices required to control the voltage and / or current supplied to the heatable catalyst increase the cost.

[0014] Another method is to provide a DC / DC converter for upconverting the voltage of the corresponding DC electrical system (e.g., 12V or 24V) to supply the heating resistor of the catalyst. However, since an additional DC / DC converter is provided, this results in additional cost, weight, and required installation space volume.

[0015] An object of the present invention is to avoid the above problems and provide a power supply for the heating resistor of an electrically heatable catalyst in a vehicle having a powertrain as described above. Summary of the Invention

[0016] According to the present invention, this object is solved by a control device, a control method, and a powertrain system.

[0017] Starting from the control device, the control device according to the present invention is characterized in that

[0018] - The component further includes a second switching device, which is respectively used to connect at least one of the windings of the AC motor to the heating resistor of the electrically heatable catalytic device in the exhaust passage of the internal combustion engine, and to disconnect at least one of the windings from the heating resistor,

[0019] - And the control device is further designed to provide

[0020] - A third operating mode of the component, in which the clutch decouples the AC motor from the internal combustion engine, the first switching device connects the battery to the DC electrical system, and the converter causes current to flow from the DC electrical system to the at least one winding or to each of the multiple windings in an alternating manner, wherein the second switching device connects the corresponding winding to the heating resistor of the catalytic device in order to electrically heat the catalytic device, and / or

[0021] - A fourth operating mode of the component, in which the internal combustion engine is running, the clutch couples the internal combustion engine to the AC motor, and the converter causes current to flow from each of the multiple windings in an alternating manner via the second switching device to the heating resistor of the catalytic device, wherein the second switching device connects the corresponding winding to the heating resistor in order to electrically heat the catalytic device.

[0022] Advantageously, according to the present invention, the power supply for the heating resistor of the electrically heatable catalytic device can be achieved without significantly increasing the cost, weight and installation space. The present invention uses still available components in order to achieve the power supply to the heating resistor from the battery (“third operating mode”) and / or from the AC motor coupled to the running internal combustion engine (“fourth operating mode”). Advantageously, in particular, the existing windings inside the motor are used to implement the function of the DC / DC converter to supply electrical energy to the heating resistor of the catalytic device.

[0023] According to one embodiment, the converter includes a plurality of half-bridges, each half-bridge being powered by the DC electrical system and formed by a series connection of two controllable semiconductor switches, wherein the control device is designed to implement PWM control of the half-bridge in the first operating mode and the third operating mode, so that a corresponding output voltage for driving the corresponding current is provided at the circuit node between the two semiconductor switches, and wherein the PWM control for each half-bridge is achieved by the complementary turning on and off of the two corresponding semiconductor switches.

[0024] According to one embodiment, the motor is a three-phase AC motor including three corresponding windings (such as stator windings), and the converter correspondingly includes three half-bridges arranged in parallel with each other, wherein each half-bridge is powered by the DC voltage provided by the DC electrical system, and each half-bridge has a circuit node (between the two semiconductor switches), which is electrically connected to a corresponding one of the three windings.

[0025] According to one embodiment, the DC voltage provided by the DC electrical system is at least 12V and / or at most 48V (e.g., 12V, 24V, or 48V).

[0026] According to one embodiment, in each half-bridge, the controllable semiconductor switch is formed by a transistor, in particular an FET.

[0027] According to one embodiment, the windings of the AC motor are stator windings, in particular three stator windings, in particular connected in a star configuration.

[0028] Connecting the windings in a star configuration means that each winding has a first terminal electrically connected to a common point (star point).

[0029] According to one embodiment, the windings of the AC motor are connected in a star configuration, wherein the star point (neutral point) is electrically connected to the first terminal of the switch of the second switching device, and the second terminal of the switch is electrically connected to the first terminal of the heating resistor.

[0030] In this embodiment, the second terminals of the windings can each be supplied by a respective one of the multiple output voltages of the converter. For this purpose, when using a converter including a plurality (e.g., three) of half-bridges arranged in parallel as described above, the second terminals of the windings can each be electrically connected to the circuit nodes of the respective half-bridges.

[0031] Hereinafter, the two potentials generating the DC voltage provided by the DC electrical system (and corresponding to the battery voltage) are referred to as "ground potential" and "supply potential".

[0032] Regarding the first switching device, in one embodiment of the present invention, one pole of the battery is permanently connected to the corresponding pole of the DC electrical system (e.g., "ground potential"), while the other pole of the battery can be connected to / disconnected from the corresponding other pole of the DC electrical system (e.g., "supply potential") by means of the first switching device. In this case, it is sufficient when the first switching device has only one switch for connecting the "supply potential" (e.g., the positive pole of the battery) to the corresponding pole of the DC electrical system or disconnecting it therefrom.

[0033] According to one embodiment, the powertrain of the vehicle is a hybrid powertrain including an internal combustion engine and an AC motor, which means that the vehicle is a hybrid vehicle, and the two mentioned components can contribute to the energy supply for driving the vehicle, such as the torque supply in the powertrain.

[0034] According to one embodiment, the vehicle is a hybrid vehicle, in particular such a hybrid vehicle: wherein the maximum power that the internal combustion engine can provide is at least 5 times, particularly at least 10 times, the maximum power that the polyphase AC motor can provide.

[0035] According to one embodiment, a capacitor is arranged in a circuit path between the second switching device and the heating resistor of the catalytic device so as to buffer the voltage applied to the heating resistor in the third and fourth operating modes.

[0036] In one embodiment, the circuit path connects the second terminal of the switch of the second switching device to the first terminal of the heating resistor. In this case, the converter, the windings of the polyphase AC motor, the second switching device, and the capacitor can advantageously implement the function of a "step-down converter" for performing DC / DC conversion of the DC voltage of the DC electrical system into a heating supply voltage for supplying the heating resistor, which is used in the third operating mode, i.e., for electrically heating the catalytic device from the battery.

[0037] The control device can be implemented as a software control device (such as a microcontroller), designed to implement the control used in the present invention, or can be implemented as a functional part of such a software control device (such as a vehicle ECU that also implements other functions).

[0038] According to another aspect of the present invention, the above object is solved by a method for controlling components of a vehicle's powertrain. Starting from the control method, the control method according to the present invention is characterized in that

[0039] - The component further includes a second switching device, which is respectively used to connect at least one of the windings of the AC motor to the heating resistor of an electro-heatable catalytic device in the exhaust passage of the internal combustion engine, and to disconnect at least one of the windings from the heating resistor,

[0040] - And the control method is also designed to provide

[0041] - A third operating mode of the component, in which the clutch decouples the AC motor from the internal combustion engine, the first switching device connects the battery to the DC electrical system, the converter causes current to flow from the DC electrical system to the at least one winding or to each of the multiple windings in an alternating manner, and wherein the second switching device connects the corresponding winding to the heating resistor of the catalytic device so as to electrically heat the catalytic device, and / or

[0042] - A fourth operating mode of the component, in which the internal combustion engine is running, the clutch couples the internal combustion engine to the AC motor, the converter causes current to flow from each of the multiple windings through the second switching device to the heating resistor of the catalytic device in an alternating manner, and wherein the second switching device connects the corresponding winding to the heating resistor so as to electrically heat the catalytic device.

[0043] The embodiments and specific details described herein for the control device according to the present invention can be provided, in a similar manner, individually or in any combination, as embodiments or specific details of the control method according to the present invention, and vice versa.

[0044] In one embodiment, when a first operating mode of a component for starting an internal combustion engine or providing additional torque is provided and thus a first switching device connects a battery to a DC electrical system and a clutch couples an AC motor to the internal combustion engine, a converter causes current to flow alternately from the DC electrical system to each of a plurality of windings in a PWM manner.

[0045] In one embodiment, when a second operating mode of the component (for charging the battery by using the AC motor for recovery) is provided and thus the internal combustion engine is running and the clutch couples the internal combustion engine to the AC motor and the first switching device connects the DC electrical system to the battery, the converter causes current to flow alternately from each of the plurality of windings to the DC electrical system in synchronization with the rotation of the AC motor.

[0046] According to one embodiment, in a third operating mode for electrically heating a catalytic device from a battery, the converter causes current to flow from the DC electrical system to at least one winding or to each of a plurality of windings in a PWM manner, respectively.

[0047] In an embodiment of the third operating mode, the converter causes current to flow alternately from the DC electrical system to each of the plurality of windings in a PWM manner.

[0048] When the converter includes a plurality of half - bridges, each half - bridge being powered by the DC electrical system and formed by a series connection of two controllable semiconductor switches (such as transistors), hereinafter also referred to as a "high - side switch" (connected to the supply potential of the DC system) and a "low - side switch" (connected to the ground potential of the DC system) respectively, in the third operating mode, the method can provide PWM control of the half - bridge by complementary turning on and off of the corresponding high - side and low - side switches.

[0049] In such a way, the converter, the windings of the AC motor, and the second switching device (and optionally a capacitor) can advantageously operate as a converter for supplying energy from the battery to the EHC (electrically heated catalytic device).

[0050] In this case, one or more high - side switches (e.g., high - side transistors) can each be used to supply a PWM voltage to the corresponding winding and thus supply the current flowing via the second switching device to the heating resistor of the EHC, where the corresponding low - side switch (e.g., low - side transistor) can be used to recirculate the current ("simulating" the diode in a conventional step - down DC / DC converter).

[0051] Preferably, all phases (e.g., three phases) are alternately used in such a way that the operation of each phase is shifted so that, during the entire switching period, all phases operate for an equal duration. In this case, all the above-mentioned high-side switches can be (one after another) used to supply voltage (the supply voltage of the DC electrical system) to the heating resistors and thus supply the current flowing through the corresponding windings and through the second switching means. Each time one of the high-side switches is turned off, the corresponding low-side switch is turned on to enable the current to circulate again (to the ground potential of the DC electrical system).

[0052] Advantageously, in the third operating mode, the variable voltage down-conversion can be achieved, for example, by an appropriate variation of the PWM duty cycle (e.g., defined as the ratio of the PWM "on" time to the PWM period duration of the corresponding PWM signal).

[0053] According to one embodiment, in the fourth operating mode, the first switching means disconnects the battery from the DC electrical system. In this case, in the fourth operating mode, the power from the AC motor coupled to the running internal combustion engine is only supplied to the heating resistors.

[0054] Alternatively, when the first switching means connects the battery to the DC electrical system in the fourth operating mode, the power from the AC motor in the fourth operating mode can be additionally supplied to the battery.

[0055] Advantageously, in the fourth operating mode, the variable power supplied to the EHC can be achieved, for example, by an appropriate variation of the time-dependent turning on and off of the second switching means and / or a variation of the time-dependent control of the converter.

[0056] According to another aspect of the present invention, the above object is solved by a powertrain for a vehicle, the powertrain comprising

[0057] - a first switching means for connecting the vehicle's battery to the vehicle's DC electrical system and for disconnecting the battery from the DC electrical system, respectively,

[0058] - a bidirectional converter for enabling current to flow alternately, e.g., in a PWM manner, from the DC electrical system to each of the multiple windings of the vehicle's polyphase AC motor to drive the AC motor, and for enabling current to flow alternately from each of the multiple windings to the DC electrical system to recover electrical energy from the AC motor,

[0059] - a clutch for coupling the AC motor to the vehicle's internal combustion engine and for decoupling the AC motor from the internal combustion engine, respectively, and

[0060] - A control device for controlling a first switching device, a converter, and a clutch, wherein the control device is designed to provide - a first operating mode of a powertrain, wherein the first switching device connects a battery to a DC electrical system, the converter causes current to flow from the DC electrical system to each of a plurality of windings in an alternating manner, and the clutch couples an AC motor to an internal combustion engine for starting the internal combustion engine or for providing additional torque in the powertrain, and / or - a second operating mode of the powertrain, wherein the internal combustion engine is running, the clutch couples the internal combustion engine to the AC motor, the converter causes current to flow from each of the plurality of windings to the DC electrical system in an alternating manner, and the first switching device connects the DC electrical system to the battery for charging the battery,

[0061] Characterized in that the powertrain further comprises

[0062] - A second switching device for connecting at least one of the windings of the AC motor to a heating resistor of an electrically heatable catalytic device in the exhaust passage of the internal combustion engine, and for disconnecting at least one of the windings from the heating resistor, and the control device is also designed to provide

[0063] - A third operating mode of the powertrain, wherein the clutch decouples the AC motor from the internal combustion engine, the first switching device connects the battery to the DC electrical system, the converter causes current to flow from the DC electrical system to the at least one winding or to each of the plurality of windings in an alternating manner, wherein the second switching device connects the corresponding winding to the heating resistor of the catalytic device for electrically heating the catalytic device, and / or

[0064] - A fourth operating mode of the powertrain, wherein the internal combustion engine is running, the clutch couples the internal combustion engine to the AC motor, the converter causes current to flow from each of the plurality of windings to the heating resistor of the catalytic device via the second switching device in an alternating manner, wherein the second switching device connects the corresponding winding to the heating resistor for electrically heating the catalytic device.

[0065] The embodiments and specific details described herein for the control device and / or control method according to the invention can also be provided for the powertrain according to the invention individually or in any combination. Description of the Drawings

[0066] The present invention will now be described by way of exemplary embodiments with reference to the drawings, wherein

[0067] Figure 1 A powertrain of a vehicle according to an embodiment is shown,

[0068] Figure 2is a graph showing the electric power required to heat an electro - heated catalytic device (EHC) over time,

[0069] Figure 3 shows in more detail a powertrain of a vehicle according to one embodiment, and

[0070] Figure 4 is a graph showing a control signal depending on time for implementing an operating mode of the powertrain for electrically heating the catalytic device. Detailed Description

[0071] Figure 1 Shows a hybrid powertrain 1 of a vehicle, including an alternating - current electric machine 2 and an internal combustion engine 3. In the example shown, the alternating - current electric machine 2 is a three - phase alternating - current electric machine.

[0072] The powertrain 1 further includes a clutch 40 for coupling the alternating - current electric machine 2 to the internal combustion engine 3 and for decoupling the alternating - current electric machine 2 from the internal combustion engine 3, such that both the alternating - current electric machine 2 and the internal combustion engine 3 can be operated to contribute to the drive torque for driving the vehicle.

[0073] The clutch 40 is controlled by means of a respective clutch control signal “cc”, which is generated by a control device 10 and transmitted to the clutch 40 via an electrical system “E” (circuitry).

[0074] Furthermore, the powertrain 1 includes a rechargeable battery “B” coupled to the electrical system E, such that electric power can be transferred between the battery B and the alternating - current electric machine 2 (in Figure 1 via the electrical system E).

[0075] Figure 1 The system shown also includes an electro - heatable catalytic (EHC) device 5 arranged in the exhaust passage 4 of the internal combustion engine 3. The catalytic device 5 includes a heating resistor R, such that the electric power for heating the catalytic device 5 can be provided by the current flowing through the resistor R. The catalytic device 5 is coupled to the electrical system E, such that electric power can be transferred from the electrical system E to the resistor R to heat the catalytic device 5.

[0076] Figure 2 Shows an example of the electric power P for heating the EHC (such as Figure 1 the catalytic device 5 in) depending on time t. In this example, the electric power P rises to a maximum value of approximately 3 kW after starting the internal combustion engine 3. After approximately 2 minutes, the electric power P decreases to an intermediate value, and after approximately 30 minutes, it decreases to a minimum value, approximately 0.5 kW.

[0077] From having as Figure 1Starting from the arrangement in a vehicle with a simplified hybrid powertrain shown, the present invention relates to a specific design of an electrical system E in combination with a control device 10 for providing a power supply to a heating resistor R of a catalytic device, wherein the problems of prior art solutions are avoided.

[0078] Figure 3 Shown in more detail is a Figure 1 powertrain 1 designed according to an embodiment of the present invention.

[0079] In Figure 3 the example of the powertrain 1 shown, the three-phase AC motor 2 has three stator windings W1, W2, W3, which correspond to the three phases of the AC drive of the motor 2 and are arranged in a star configuration, i.e., each of the windings W1, W2, W3 has a first terminal electrically connected to a common point ("star point"), while the second terminals of the windings W1, W2, W3 are not connected to each other but are respectively connected to the output nodes N1, N2, N3 of a converter 30 arranged in the electrical system E. For simplicity, the rotor of the AC motor 2 is omitted in Figure 3 it.

[0080] The converter 30 includes three half-bridges 30-1, 30-2, 30-3, each of which is powered by the supply voltage of a DC electrical system 6 ("on-board electrical network") between a ground potential "GND" and a supply potential "VS". Each of the half-bridges 30-1, 30-2, 30-3 is formed as a Figure 3 series connection of two transistors (generally: controllable semiconductor switches) as shown, which are hereinafter also referred to as the "high-side switch" connected to the supply potential VS and the "low-side switch" connected to the ground potential GND, respectively.

[0081] The control device 10 is designed such that complementary switching control of the half-bridges 30-1, 30-2, 30-3 can be enabled and is actually achieved in the case of a specific operating mode of the powertrain 1, which means that the control device 10 generates converter control signals c1, c2, c3, which are transmitted (via the electrical system E) to the respective half-bridges 30-1, 30-2, 30-3 such that in each half-bridge 30-1, 30-2, 30-3, the low-side switch is turned on and the corresponding high-side switch is turned off, or vice versa.

[0082] Therefore, each output potential provided at the circuit nodes N1, N2, N3 of the half-bridges 30-1, 30-2, 30-3 can be switched between the ground potential GND and the supply potential VS respectively according to the corresponding converter control signals c1, c2 and c3. Thus, with the aid of the control device 10, the corresponding output voltages (related to the ground potential GND) provided at the circuit nodes N1, N2, N3 can be switched between zero (ground potential GND) and the supply voltage (VS).

[0083] The rechargeable battery B can be formed, for example, by a lithium-ion accumulator and, in the example shown, provides a battery voltage of 48 V between the ground potential GND (negative potential of the battery B) and the supply potential VS (positive potential of the battery).

[0084] The electrical system E of the powertrain 1 further includes a first switching device 20 through which the battery B can be connected to the vehicle's DC electrical system 6 and through which the battery B can be disconnected from the DC electrical system 6.

[0085] The DC electrical system 6 forms an on-vehicle electrical network for supplying electrical power to the electrical consumers of the vehicle. In the example shown, the DC electrical system 6 is such an on-vehicle electrical network for supplying 48 V electrical consumers.

[0086] Optionally, as Figure 3 shown by the dashed line in

[0087] the DC electrical system 6 can be equipped with a filter circuit F for reducing electrical interference in the overall electrical system.

[0088] The first switching device 20 is formed by a controllable switch for connecting / disconnecting the terminal (pole) providing the supply potential VS (positive potential) of the battery B to / from the wire providing the supply potential VS of the DC electrical system 6, while the ground potential GND (negative potential) of the battery B is permanently connected to the wire providing the ground potential GND of the DC electrical system 6.

[0089] The powertrain 1 further includes the converter 30 already mentioned above, which is supplied by the supply voltage of the DC electrical system 6 (e.g., 48 V) and enables current to flow in an alternating manner, e.g., in PWM mode, from the DC electrical system 6 to each of the multiple windings W1, W2, W3 of the three-phase AC motor 2 for operating / driving the AC motor 2. The converter 30 also enables current to flow in an alternating manner from each of the windings W1, W2, W3 to the DC electrical system 6 for recovering electrical energy from the AC motor 2.

[0090] The control device 10 can be implemented as, for example, a software control device (such as a microcontroller, etc.) or as a functional part of a software control device for implementing additional functions in a vehicle (such as the central ECU of the vehicle). In the present invention, the control device 10 is particularly used to control the first switching device 20 (by means of the signal csw1), the converter 30 (by means of the signals c1, c2, c3), and the clutch 40 (by means of the signal cc), wherein the control device 10 is designed to implement the operation of the powertrain 1 according to a plurality of different "operating modes" according to the corresponding current requirements.

[0091] The first operating mode of the powertrain 1 can be initiated by the control device 10. This operating mode is used to start the internal combustion engine 3 (in the case where the internal combustion engine 3 was previously turned off) or to provide additional torque in the powertrain (by means of the electric motor 2) (in the case where the internal combustion engine 3 is already running), wherein electrical energy from the battery B is used.

[0092] In the first operating mode, the first switching device 20 connects the battery B to the DC electrical system 6, the converter 30 causes the current to flow from the DC electrical system 6 to each of the plurality of windings W1, W2, W3 in an alternating manner (e.g., PWM control), and the clutch 40 couples the AC motor 2 to the internal combustion engine 3.

[0093] In the first operating mode, the control device 10 implements PWM control of the half-bridges 30-1, 30-2, 30-3 such that corresponding output voltages for driving the current are provided at the circuit nodes N1, N2, N3, wherein the PWM control of each of the half-bridges 30-1, 30-2, 30-3 is achieved by complementary turning on and off of two corresponding high-side and low-side switches.

[0094] The second operating mode of the powertrain 1 can be initiated by the control device 10. This operating mode is used to charge the battery B, wherein electrical energy generated by the electric motor 2 in the "recovery mode" is used.

[0095] In the second operating mode, the internal combustion engine 3 is running, the clutch 40 couples the internal combustion engine 3 to the AC motor 2, the converter 30 causes the current to flow from each of the plurality of windings W1, W2, W3 to the DC electrical system 6 in an alternating manner, and the first switching device 20 connects the DC electrical system 6 to the battery B.

[0096] Regarding the specific implementation manners and details of the first and second operating modes, those skilled in the art can advantageously rely on the corresponding prior art of known hybrid powertrains. For example, in these operating modes, the control device 10 or the device implementing the control device 10 (such as the ECU of the vehicle) can take into account the rotational position and / or rotational speed of the rotor of the AC motor 2 and / or the measured instantaneous values of the current flowing through the windings W1, W2, W3.

[0097] However, according to Figure 3 the unique feature of the powertrain 1 according to the example is the second switching device 50, which is respectively used to (at least intermittently) connect the starting points of the windings W1, W2, W3 of the AC motor 2 to the first terminal of the heating resistor R of the catalytic device 5, and to disconnect the starting points from the heating resistor R. For this purpose, in the example shown, the second switching device 50 is formed by a switch having a first terminal connected to the starting point and a second terminal connected to the first terminal of the heating resistor R. As Figure 3 shown, the second terminal of the heating resistor R is permanently connected to the ground potential GND.

[0098] The second switching device 50 is controlled by means of a corresponding second switching control signal "csw2", which is generated by the control device 10 and transmitted (via the electrical system E) to the second switching device 50.

[0099] Another unique feature of the powertrain 1 is that the control device 10 is also designed to implement the operation of the powertrain 1 according to at least one of the third and fourth operating modes described below according to the corresponding current requirements. In this regard, in the present invention, the control device 10 is also particularly used to control the second switching device 50 by means of the above signal csw2.

[0100] The third operating mode of the powertrain 1 can be initiated by the control device 10. This operating mode is used to electrically heat the catalytic device 5, wherein electrical energy from the battery B is used.

[0101] In the third operating mode, the clutch 50 decouples the AC motor 2 from the internal combustion engine 3, the first switching device 20 connects the battery B to the DC electrical system 6, and the converter 30 causes current to flow in an alternating manner from the DC electrical system 6 to each of the plurality of windings W1, W2, W3, wherein the second switching device 50 is used to (at least intermittently) connect the corresponding windings W1, W2, W3 (in the example shown via the starting point of the winding arrangement) to the first terminal of the heating resistor R of the catalytic device 5 (while the second terminal of the heating resistor R is permanently connected to the ground potential GND).

[0102] In the electrical system E of the powertrain 1, a capacitor C is arranged at the wire between the second terminal of the switch of the second switching device 50 and the first terminal of the heating resistor R of the catalytic device 5 in order to buffer the voltage applied to the heating resistor R in the third operating mode (and in the fourth operating mode explained below).

[0103] In the third operating mode, the circuit including the converter 30, the electric machine 2, the second switching device 50, and the capacitor C can operate like a (conventional) multiphase buck converter to supply energy to the catalytic device 5. The high-side switch can be used to supply a PWM voltage (VS) to one of the windings W1, W2, W3 for a certain time (the "on" time in the PWM voltage), while the low-side switch can be used to recirculate the corresponding current (simulating the diode in a conventional buck converter). In the example shown, the switches of the second switching device 50 are closed (turned on) throughout the duration of the third operating mode.

[0104] In the example shown, in the third operating mode, all of the plurality of phases (of the electric machine 2) are used alternately, and thus all of the plurality of windings (W1, W2, W3) are used alternately. This is shown in Figure 4 FIG.

[0105] Figure 4 FIG. shows the converter control signals c1, c2, c3 that depend on time t when the third operating mode is activated. In Figure 4 FIG., it is assumed that the high ("1") level of the signal c1 means that the corresponding high-side switch (of the half-bridge 30-1) is turned on and the corresponding low-side switch (of the half-bridge 30-1) is turned off, while the low ("0") level of the signal c1 means that the corresponding high-side switch is turned off and the corresponding low-side switch is turned on. Similarly, this also applies to the signals c2 (for the half-bridge 30-2) and c3 (for the half-bridge 30-III) in the example shown.

[0106] As can be seen from Figure 4 FIG., in the example shown, advantageously, all of the plurality of (three) windings (W1, W2, W3) are cycled through within a time period T, which can be selected to correspond to a PWM frequency (1 / T) in the range of a few kilohertz, for example. In the example shown, the "on" times of the signals c1, c2, c3 are each selected to be equal.

[0107] For example, when signal c1 has a high (“1”) level (the “on” time of the PWM), current flows from the positive terminal (pole) of the battery B via the switch of the first switching device 20, the high-side switch of the bridge 30-1, the winding W1, the switch of the second switching device 50, and the heating resistor R to the negative terminal (pole) of the battery B. Due to the inductance provided by the winding W1, this current increases during the duration of the “on” time. Then, when signal c1 becomes low (“0”) level (the “off” (“OFF”) time of the PWM of c1), the current recirculates, i.e., from the first terminal of the winding W1 via the switch of the second switching device 50, the heating resistor R, the low-side switch of the bridge 30-1, and the node N1 to the second terminal of the winding W1. Due to the energy dissipation in the resistor R, the current decreases during the duration of this “off” time. Similarly, this also applies to the “on” and “off” times of signal c2 (current flowing through winding W2) and c3 (current flowing through winding W2). Advantageously, the variable voltage down-conversion can be achieved, for example, by a corresponding change in the PWM duty cycle (e.g., defined as the ratio of the PWM “on” time of signals c1, c2, c3 to the PWM period).

[0108] The fourth operating mode of the powertrain 1 can be initiated by the control device 10. This operating mode is used for electrically heating the catalytic device 5, where the electrical energy generated by the electric machine 2 in the “recovery mode” is used.

[0109] In the fourth operating mode, the internal combustion engine 3 is running, the clutch 40 couples the internal combustion engine 3 to the AC electric machine 2, and the converter 30 causes current to flow in an alternating manner from each of the plurality of windings W1, W2, W3 via the second switching device 50 to the heating resistor R of the catalytic device 5, where the second switching device 50 (at least intermittently) connects the corresponding winding (via the starting point of the winding arrangement) to the first terminal of the heating resistor R of the catalytic device 5 (while the second terminal of the heating resistor R is permanently connected to the ground potential GND).

[0110] Furthermore, in the above-described first and second operating modes, the second switching device 50 is permanently off, i.e., the switch disconnects the windings W1, W2, W3 (here: the starting point) from the wire leading to the first terminal of the heating resistor R.

[0111] In the fourth operating mode, similar to the third operating mode, the circuit including the converter 30, the electric machine 2, the second switching device 50, and the capacitor C can also operate like a multi-phase buck converter to supply energy to the catalytic device 5. However, in the fourth operating mode, the electrical energy is not transferred from the battery B, but from the windings of the AC electric machine 2, which is coupled to the internal combustion engine 3 and driven by the internal combustion engine 3 (recovery mode).

[0112] To this end, in the illustrated embodiment, the switch of the second switching device 50 is closed (turned on) throughout the duration of the fourth operating mode, but the low-side switch of the converter 30 is alternately operated and synchronized with the rotation of the electric machine 2, such that the voltage generated in each of the windings W1, W2, W3 is applied to the heating resistor R of the catalytic device 5.

[0113] Advantageously, also in the fourth operating mode, all of the plurality (three) of windings (W1, W2, W3) are cycled for a period of time which, in the fourth operating mode, depends on the instantaneous rotational speed of the electric machine 2 in order to achieve the above synchronization. To this end, the control device 10 can take into account, for example, the measured instantaneous value of the rotational position of the rotor of the AC electric machine 2.

[0114] Advantageously, in the fourth operating mode, regardless of the determination of the available power provided by the AC electric machine 2, the change in the power actually supplied to the EHC can be achieved within the framework of the present invention by appropriate variation of the time-dependent control of the converter. Alternatively or additionally, for this purpose, a time-dependent closing and opening (and for example its variation) of the second switching device can also be foreseen.

[0115] In summary, an embodiment of the present invention relates to a control device (10) for controlling components (20, 30, 40, 50) of a powertrain (1) of a vehicle, the components (20, 30, 40, 50) including: a first switching device (20) for connecting / disconnecting a battery (B) to / from a DC electrical system (6); a converter (30) for enabling current to flow from the system (6) to each of the windings (W1, W2, W3) of a polyphase AC motor (2) to drive the motor (2), and for enabling current to flow from each of the windings (W1, W2, W3) to the system (6) to recover electrical energy from the motor (2); a clutch (40) for coupling / decoupling the motor (2) to / from an internal combustion engine (3). The control device (10) provides a first operating mode and / or a second operating mode. In the first operating mode, the first switching device (20) connects the battery (B) to the system (6), the converter (30) enables current to flow from the system (6) to each of the windings (W1, W2, W3), and the clutch (40) couples the motor (2) to the engine (3), for example to start the engine (3). In the second operating mode, the engine (3) is running, the clutch (40) couples the engine (3) to the motor (2), the converter (30) enables current to flow from each of the windings (W1, W2, W3) to the system (6), and the first switching device (20) connects the system (6) to the battery (B) to charge the battery (B). According to the present invention, the components (20, 30, 40, 50) further include a second switching device (50) for connecting / disconnecting at least one of the windings (W1, W2, W3) of the motor (2) to / from a heating resistor (R) of an electro-heatable catalytic device (5) of the engine (3), wherein the control device (10) further provides a third operating mode and / or a fourth operating mode. In the third operating mode, the clutch (40) decouples the motor (2) from the engine (3), the first switching device (20) connects the battery (B) to the system (6), the converter (30) enables current to flow from the system (6) to at least one of the windings (W1, W2, W3), and the second switching device (50) connects the corresponding winding (W1, W2, W3) to the heating resistor (R) to electro-heat the catalytic device (5). In the fourth operating mode, the engine (3) is running, the clutch (40) couples the engine (3) to the motor (2), the converter (30) enables current to flow from each of the windings (W1, W2, W3) through the second switching device (50) to the heating resistor (R), and the second switching device (50) connects the corresponding winding (W1, W2, W3) to the heating resistor (R) to electro-heat the catalytic device (5). In addition, the present invention proposes a corresponding control method and a corresponding powertrain (1).

[0116] List of reference numerals

[0117] 1 Power transmission system

[0118] 2 Alternating current motor

[0119] W1, W2, W3 Stator windings

[0120] 3 Internal combustion engine

[0121] B Battery

[0122] 4 Exhaust passage

[0123] 5 Electrically heatable catalytic device

[0124] R Heating resistor

[0125] P Electric power

[0126] t Time

[0127] E Electrical system (circuit arrangement)

[0128] 6 Direct current electrical system (vehicle electrical network)

[0129] F Filter circuit

[0130] VS Supply potential

[0131] GND Ground potential

[0132] 10 Control device

[0133] 20 First switching device

[0134] csw1 First switching control signal

[0135] 30 Converter

[0136] 30-1, 30-2, 30-3 Half-bridge

[0137] c1, c2, c3 Converter control signals

[0138] 40 Clutch

[0139] Cc Clutch control signal

[0140] 50 Second switching device

[0141] csw2 Second switching control signal

[0142] T Time period (in the third operating mode)

[0143] C Capacitor.

Claims

1. A control device for controlling components of a vehicle's powertrain, the components including - a first switching device for connecting a vehicle battery to the vehicle's DC electrical system and for disconnecting the battery from the DC electrical system, - a bi-directional converter for enabling current to flow in an alternating manner from the DC electrical system to each of a plurality of windings of a polyphase AC motor of the vehicle to drive the AC motor, and for enabling current to flow in an alternating manner from each of the plurality of windings to the DC electrical system to recover electrical energy from the AC motor, - A clutch, respectively used to couple an AC motor with an internal combustion engine of a vehicle and to decouple the AC motor from the internal combustion engine, wherein, The control device is designed to provide - a first operating mode of the components, in which the first switching device connects the battery to the DC electrical system, the converter enables current to flow in an alternating manner from the DC electrical system to each of the plurality of windings, and a clutch couples the AC motor to an internal combustion engine to start the internal combustion engine or to supply additional torque in the powertrain, and / or - a second operating mode of the components, in which the internal combustion engine is running, the clutch couples the internal combustion engine to the AC motor, the converter enables current to flow in an alternating manner from each of the plurality of windings to the DC electrical system, and the first switching device connects the DC electrical system to the battery to charge the battery, Characterized in that the components further include - a second switching device for connecting at least one of the windings of the AC motor to a heating resistor of an electrically heatable catalytic device in the exhaust passage of the internal combustion engine and for disconnecting at least one of the windings from the heating resistor, And the control device is also designed to provide - a third operating mode of the components, in which the clutch decouples the AC motor from the internal combustion engine, the first switching device connects the battery to the DC electrical system, the converter enables current to flow from the DC electrical system to at least one winding or in an alternating manner to each of the plurality of windings, wherein the second switching device connects the corresponding winding to the heating resistor of the catalytic device to electrically heat the catalytic device, and / or - a fourth operating mode of the components, in which the internal combustion engine is running, the clutch couples the internal combustion engine to the AC motor, the converter enables current to flow in an alternating manner from each of the plurality of windings via the second switching device to the heating resistor of the catalytic device, wherein the second switching device connects the corresponding winding to the heating resistor to electrically heat the catalytic device.

2. The control device according to claim 1, wherein, The converter includes a plurality of half-bridges, each half-bridge being powered by the DC electrical system and formed by a series connection of two controllable semiconductor switches, wherein the control device is designed to implement PWM control of the half-bridges in the first operating mode and the third operating mode such that a corresponding output voltage for driving a corresponding current is provided at a circuit node between the two semiconductor switches, wherein the PWM control for each of the half-bridges is achieved by complementary turning on and off of two corresponding semiconductor switches.

3. The control device according to claim 1 or 2, wherein, The windings of the AC motor are stator windings.

4. The control device according to claim 1 or 2, wherein The vehicle's powertrain is a hybrid powertrain including an internal combustion engine and an AC motor.

5. The control device according to claim 1 or 2, wherein, A capacitor is arranged in the circuit path between the second switching device and the heating resistor of the catalytic device so as to buffer the voltage applied to the heating resistor in the third and fourth operating modes.

6. A method for controlling components of a vehicle's powertrain, the components including - a first switching device for connecting the vehicle's battery to the vehicle's DC electrical system respectively and for disconnecting the battery from the DC electrical system, - a bi-directional converter for enabling current to flow alternately from the DC electrical system to each of a plurality of windings of a poly-phase AC motor of the vehicle to drive the AC motor and for enabling current to flow alternately from each of the plurality of windings to the DC electrical system to recover electrical energy from the AC motor, - A clutch, respectively used to couple an AC motor with an internal combustion engine of a vehicle and to decouple the AC motor from the internal combustion engine, wherein, The method is designed to provide - a first operating mode of the components, in which the first switching device connects the battery to the DC electrical system, the converter enables current to flow alternately from the DC electrical system to each of the plurality of windings, and the clutch couples the AC motor to the internal combustion engine to start the internal combustion engine or to supply additional torque in the powertrain, and / or - a second operating mode of the components, in which the internal combustion engine is running, the clutch couples the internal combustion engine to the AC motor, the converter enables current to flow alternately from each of the plurality of windings to the DC electrical system, and the first switching device connects the DC electrical system to the battery to charge the battery, It is characterized in that the components further include - a second switching device for connecting at least one of the windings of the AC motor to a heating resistor of an electrically heatable catalytic device in the exhaust passage of the internal combustion engine respectively and for disconnecting at least one of the windings from the heating resistor, And the method is further designed to provide - a third operating mode of the components, in which the clutch decouples the AC motor from the internal combustion engine, the first switching device connects the battery to the DC electrical system, the converter enables current to flow from the DC electrical system to at least one winding or to each of the plurality of windings alternately, and the second switching device connects the corresponding winding to the heating resistor of the catalytic device to electrically heat the catalytic device, and / or - a fourth operating mode of the components, in which the internal combustion engine is running, the clutch couples the internal combustion engine to the AC motor, the converter enables current to flow alternately from each of the plurality of windings through the second switching device to the heating resistor of the catalytic device, and the second switching device connects the corresponding winding to the heating resistor to electrically heat the catalytic device.

7. The method according to claim 6, wherein, In the third operating mode, the converter enables current to flow from the DC electrical system to at least one winding in a PWM manner or to each of the plurality of windings in a PWM manner respectively.

8. The method according to claim 6 or 7, wherein, In the fourth operating mode, the first switching device disconnects the battery from the DC electrical system.

9. A powertrain for a vehicle, including - a first switching device for connecting the vehicle's battery to the vehicle's DC electrical system respectively and for disconnecting the battery from the DC electrical system, - A bi-directional converter, respectively used to enable current to flow from the DC electrical system to each of the multiple windings of the vehicle's polyphase AC motor in an alternating manner to drive the AC motor, and used to enable current to flow from each of the multiple windings to the DC electrical system in an alternating manner to recover electrical energy from the AC motor, - A clutch, respectively used to couple the AC motor to the vehicle's internal combustion engine, and used to decouple the AC motor from the internal combustion engine, and - A control device for controlling a first switching device, a converter, and a clutch, wherein, The control device is designed to provide - A first operating mode of the powertrain, in which the first switching device connects the battery to the DC electrical system, the converter enables current to flow from the DC electrical system to each of the multiple windings in an alternating manner, and the clutch couples the AC motor to the internal combustion engine to start the internal combustion engine or to supply additional torque in the powertrain, and / or - A second operating mode of the powertrain, in which the internal combustion engine is running, the clutch couples the internal combustion engine to the AC motor, the converter enables current to flow from each of the multiple windings to the DC electrical system in an alternating manner, and the first switching device connects the DC electrical system to the battery to charge the battery, It is characterized in that the powertrain further includes - A second switching device, respectively used to connect at least one of the windings of the AC motor to the heating resistor of the electro-heatable catalytic device in the exhaust passage of the internal combustion engine, and used to disconnect at least one of the windings from the heating resistor, And the control device is also designed to provide - A third operating mode of the powertrain, in which the clutch decouples the AC motor from the internal combustion engine, the first switching device connects the battery to the DC electrical system, the converter enables current to flow from the DC electrical system to at least one winding or to each of the multiple windings in an alternating manner, wherein the second switching device connects the corresponding winding to the heating resistor of the catalytic device to electro-heat the catalytic device, and / or - A fourth operating mode of the powertrain, in which the internal combustion engine is running, the clutch couples the internal combustion engine to the AC motor, the converter enables current to flow from each of the multiple windings to the heating resistor of the catalytic device via the second switching device in an alternating manner, wherein the second switching device connects the corresponding winding to the heating resistor to electro-heat the catalytic device.

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