Method for operating a drive system, drive system and motor vehicle

Abstract

Method for operating a propulsion system (1) of a motor vehicle (2), wherein the propulsion system (1) comprises an internal combustion engine (3) for propelling the motor vehicle (2) and a first three-way catalyst (4) for cleaning exhaust gases of the internal combustion engine (3), wherein the method comprises: - Providing a first sulfur loading model (BM1) of the first three-way catalyst (4) by means of a control device (5) of the drive system (1), - Determining operating parameters (BP) of the internal combustion engine (3) by the control device (5), - Applying the operating parameters (BP) of the internal combustion engine (3) to the first sulfur loading model (BM1) to determine a first sulfur loading (SB1) of the first three-way catalyst (4) by the control device (5), - Determining a current first catalyst temperature (KT1) of the first three-way catalyst (4) by the control device (5), and - Performing a first predefined desulfurization measure (EM1) depending on the determined first sulfur loading (SB1) and the determined current first catalyst temperature (KT1) by the control device (5), characterized by that the control device (5) as a first predefined desulfurization measure (EM1) performs a targeted heating (GA) of the first three-way catalyst (4) to a passive regeneration temperature if the determined first sulfur loading (SB1) is greater than a first predefined loading limit (BG1) and less than a second predefined loading limit (BG2) and the current first catalyst temperature (KT1) is less than the passive regeneration temperature, wherein the passive regeneration temperature is a catalyst temperature (KT1, KT2) that can be achieved by normal operation of the internal combustion engine (3) to propel the motor vehicle (2), wherein the control device (5) has an artificial intelligence that is configured to adjust the first sulfur loading model (BM1) of the first three-way catalyst (4) depending on the first predefined to verify the plausibility of the desulfurization measure (EM1), the determined operating parameter (BP) of the combustion engine (3) and the exhaust gas values ​​determined by means of at least one exhaust gas sensor (7).

Description

[0001] The present invention relates to a method for operating a drive system of a motor vehicle with an internal combustion engine. Furthermore, the invention relates to a drive system with an internal combustion engine for a motor vehicle, as well as to a motor vehicle with a drive system comprising an internal combustion engine and configured to carry out a method according to the invention.

[0002] Motor vehicles with internal combustion engine drive systems are known to have one or more exhaust gas purification devices. Examples of known exhaust gas purification devices include particulate filters and three-way catalytic converters.

[0003] Conventional fuels can contain sulfur. Sulfur in the fuel can cause the three-way catalytic converter to enter the system, leading to a progressive decrease in its efficiency. Depending on the vehicle's driving profile, passive regeneration of the three-way catalytic converter may not occur, resulting in the catalyst becoming "poisoned" over time and thus insufficiently cleaning the combustion exhaust gases. As a measurable result of this sulfur ingress, the vehicle's emissions increase.

[0004] Document DE 10 2021 111 331 A1 discloses a method for operating a drive system with an internal combustion engine and a three-way catalytic converter. A computational model determines the sulfur loading of the three-way catalytic converter, and if a limit value is exceeded, active regeneration of the three-way catalytic converter is carried out by operating a first combustion chamber of the internal combustion engine with a substoichiometric air-fuel ratio and a second combustion chamber of the internal combustion engine with a superstoichiometric air-fuel ratio. Document EP 1 007 826 B1 discloses a method for regenerating a three-way catalytic converter of a motor vehicle during a cold start and a warm start. After starting the internal combustion engine, the three-way catalytic converter is brought to an active regeneration temperature, regardless of the actual sulfur loading.Document DE 10 2013 203 602 A1 discloses a system for determining the sulfur storage capacity of an exhaust gas purification device. A sulfur adsorption module allows the determination of the sulfur adsorption rate of the exhaust gas purification device. A total sulfur storage module allows the determination of the total amount of sulfur stored in the exhaust gas purification device based on the sulfur adsorption rate. Documents DE 198 47 875 A1, US 2008 / 0 104 946 A1 and DE 10 2018 001 923 A1 disclose various methods for operating internal combustion engines.

[0005] Known methods for operating drive systems with an internal combustion engine and a three-way catalytic converter have the disadvantage that desulfurization of the three-way catalytic converter is performed more frequently than necessary. In some methods, the three-way catalytic converter regenerates every time the engine is started, meaning that regeneration occurs even when there is virtually no sulfur load. Other methods automatically perform active regeneration at a specific temperature whenever a sulfur load limit is exceeded. In both cases, fuel consumption is particularly high.

[0006] It is therefore an object of the present invention to eliminate, or at least partially eliminate, the disadvantages described above in a method for operating a drive system of a motor vehicle. In particular, it is an object of the present invention to provide a method for operating a drive system of a motor vehicle, a drive system for a motor vehicle, and a motor vehicle that avoid unnecessary regenerations of the three-way catalytic converter and / or have reduced fuel consumption in a simple and cost-effective manner.

[0007] The aforementioned problem is solved by the claims. Accordingly, the problem is solved by a method for operating a drive system of a motor vehicle with the features of independent claim 1, by a drive system for a motor vehicle with the features of dependent claim 8, and by a motor vehicle with the features of dependent claim 9. Further features and details of the invention will become apparent from the dependent claims, the description, and the drawings. Features and details described in connection with the method according to the invention naturally also apply in connection with the drive system and the motor vehicle according to the invention, and vice versa, so that the disclosure of the individual aspects of the invention always makes, or can make, reciprocal references.

[0008] According to a first aspect of the invention, the problem is solved by a method for operating a drive system of a motor vehicle. The method comprises: - Providing an initial sulfur loading model of the first three-way catalyst by means of a drive system control device, - Determining operating parameters of the internal combustion engine by the control device, - Applying the operating parameters of the internal combustion engine to the first sulfur loading model to determine an initial sulfur loading of the first three-way catalyst by the control device, - Determining a current first catalyst temperature of the first three-way catalyst by the control device, and - Performing a first predefined desulfurization measure depending on the determined first sulfur loading and the determined current first catalyst temperature by the control device.

[0009] According to the invention, the control device, as a first predefined desulfurization measure, performs a targeted heating of the first three-way catalyst to a passive regeneration temperature if the determined first sulfur load is greater than a first predefined loading limit and less than a second predefined loading limit, and the current first catalyst temperature is lower than the passive regeneration temperature. The passive regeneration temperature is a catalyst temperature that can be achieved through normal operation of the internal combustion engine to power the vehicle.Furthermore, the control device has an artificial intelligence that is trained to validate the first sulfur loading model of the first three-way catalyst depending on the first predefined desulfurization measure carried out, the operating parameters of the combustion engine determined, and the exhaust gas values ​​determined by means of at least one exhaust gas sensor.

[0010] The combustion engine of the drive system is preferably designed as a gasoline engine.

[0011] The first sulfur loading model of the first three-way catalytic converter is provided by the drive system's control unit, for example, by reading data from a data storage device. This first sulfur loading model uses operating parameters of the combustion engine, such as air mass flow, fuel mass flow, lambda value, engine speed, torque, coolant temperature, and the like, to determine the initial sulfur loading in the first three-way catalytic converter over a given period. Therefore, measurements to determine the initial sulfur loading are not required.

[0012] The operating parameters of the internal combustion engine are determined by the control device. These parameters can be determined, for example, by using sensors such as temperature sensors, pressure sensors, force sensors, acceleration sensors, or the like, and / or by directly controlling components of the drive system, such as injectors, injection pumps, or the like, and / or by using an operating model of the internal combustion engine. The operating parameters are preferably determined continuously in such a way that all operating parameters relevant to the sulfur load are ascertained. This ensures that the determined sulfur load corresponds to the actual sulfur load or at least falls within specified tolerances.

[0013] The control device applies the determined operating parameters of the combustion engine to the first sulfur loading model and thus determines the initial sulfur loading of the first three-way catalyst. The application of the combustion engine's operating parameters to the first sulfur loading model and the determination of the initial sulfur loading preferably occur continuously or repeatedly in such a way as to ensure targeted monitoring of the current initial sulfur loading.

[0014] Furthermore, the control device determines the current first catalyst temperature of the first three-way catalyst. This can be done continuously or intermittently, such that the determined current first catalyst temperature deviates from the actual first catalyst temperature only within predefined tolerances, for example, by less than 10°C. The current first catalyst temperature can be determined, for example, by directly measuring the temperature of a wall of the first three-way catalyst, by measuring the exhaust gas temperature before and after the first three-way catalyst in conjunction with an energy balance calculation at the first three-way catalyst, for example, taking into account an exhaust gas mass flow, or via a computer model of the drive system or similar methods.

[0015] Furthermore, the control device performs the first predefined desulfurization measure depending on the determined initial sulfur load and the determined current initial catalyst temperature. The control device determines which first predefined desulfurization measure to be performed based on several criteria. The first predefined desulfurization measure involves a targeted heating of the first three-way catalyst to the passive regeneration temperature if the determined initial sulfur load is greater than the first predefined loading limit. As a further condition, the determined initial sulfur load must be less than the second predefined loading limit. Additionally, the current initial catalyst temperature must be lower than the passive regeneration temperature.

[0016] Within the scope of the invention, the passive regeneration temperature is understood to be the catalyst temperature of the three-way catalytic converter that can be achieved by operating the internal combustion engine solely for the propulsion of the vehicle. In such operation, no operating parameters of the internal combustion engine are adjusted to specifically increase the catalyst temperature. The passive regeneration temperature is preferably between 600°C and 650°C.

[0017] A key difference between the inventive method and methods known from the prior art is the targeted implementation of a relatively mild regeneration using simple means when a moderate sulfur load is present. This allows sulfur levels to be reduced at an early stage. In known methods, desulfurization occurs either consistently at every engine start or when a threshold value is exceeded, resulting in a particularly high regeneration effort.

[0018] A method according to the invention for operating a drive system of a motor vehicle has the advantage over conventional methods that desulfurization tailored to specific needs is provided using simple means and in a cost-effective manner, and excessive fuel consumption is avoided by avoiding unnecessary regeneration processes with an active regeneration temperature.

[0019] According to a preferred embodiment of the invention, a method may be provided in which the control device selects the first predefined desulfurization measure from a set of several predefined first desulfurization measures, each defined for different first sulfur loadings, depending on the determined first sulfur loading. It is therefore preferred that several predefined first desulfurization measures are available to the control device, wherein the first predefined desulfurization measures have intensities that increase with the sulfur loading. Thus, for example, if the sulfur loading is below the first predefined loading limit, it may be specified that the corresponding first predefined desulfurization measure defines normal continued operation of the combustion engine without additional measures for regenerating the three-way catalyst.According to the invention, in the case of a sulfur loading above the first predefined loading limit as well as below the second predefined loading limit, the corresponding first predefined desulfurization measure is defined as a targeted heating of the three-way catalyst to the passive regeneration temperature. This has the advantage that resource-saving and reliable desulfurization of the three-way catalyst is improved using simple means and in a cost-effective manner.

[0020] According to the invention, it is preferred that the control device, as a first predefined desulfurization measure, performs targeted regeneration of the first three-way catalyst at an active regeneration temperature by means of an additional heating measure beyond the normal operation of the combustion engine, if the determined first sulfur load is greater than the second predefined load limit. The determined first sulfur load can, for example, be greater than the second predefined load limit if regeneration at the passive regeneration temperature is not efficient enough to remove sufficient sulfur from the three-way catalyst. In this case, according to the invention, the combustion engine is operated such that the catalyst temperature is increased to the active catalyst temperature. Within this framework, the combustion engine is operated in a manner geared towards the regeneration of the three-way catalyst.Parallel driving operation can also be provided, whereby regeneration at the active regeneration temperature can also be carried out when the vehicle is stationary or rolling. The active regeneration temperature is preferably greater than or equal to the passive regeneration temperature. To reach the active regeneration temperature, an additional heating measure is implemented, which goes beyond the normal operation of the combustion engine to power the vehicle. Such an additional heating measure can, for example, include the additional introduction of fuel and / or oxygen into the exhaust system, for example, by direct injection into the exhaust system or via the cylinders of the combustion engine. This has the advantage that particularly reliable desulfurization of the three-way catalytic converter is provided using simple and cost-effective means.

[0021] More preferably, the control device provides a second sulfur loading model of a second three-way catalyst of the drive system, wherein the control device applies the operating parameters of the combustion engine to the second sulfur loading model to determine a second sulfur loading of the second three-way catalyst, wherein the control device determines a current second catalyst temperature of the second three-way catalyst, and wherein the control device performs a predefined second desulfurization measure depending on the determined second sulfur loading and the determined current second catalyst temperature, wherein the control device performs a targeted heating of the second three-way catalyst to the passive regeneration temperature as a second predefined desulfurization measure.if the determined second sulfur loading is greater than the first predefined loading limit and less than the second predefined loading limit, and the current second catalyst temperature is less than the passive regeneration temperature. Preferably, the first three-way catalyst is configured as the main catalyst and the second three-way catalyst as the subfloor catalyst.

[0022] The second sulfur loading model of the second three-way catalytic converter is provided by the drive system's control unit, for example, by reading data from a data storage device. This second sulfur loading model uses operating parameters of the combustion engine, such as air mass flow, fuel mass flow, lambda value, engine speed, torque, coolant temperature, and the like, to determine the second sulfur loading in the second three-way catalytic converter over a given period. Therefore, measurements to determine the second sulfur loading are not required.

[0023] The control device applies the determined operating parameters of the combustion engine to the second sulfur loading model and thus determines the second sulfur loading of the second three-way catalyst. The application of the combustion engine's operating parameters to the second sulfur loading model and the determination of the second sulfur loading preferably occur continuously or repeatedly in such a way as to ensure targeted monitoring of the current second sulfur loading.

[0024] Furthermore, the control device determines the current temperature of the second three-way catalyst. This can be done continuously or intermittently, such that the determined current second catalyst temperature deviates from the actual second catalyst temperature only within predefined tolerances, for example, by less than 10°C. The current second catalyst temperature can be determined, for example, by directly measuring the temperature of a wall of the second three-way catalyst, by measuring the exhaust gas temperature before and after the second three-way catalyst in conjunction with an energy balance calculation at the second three-way catalyst, for example, taking into account an exhaust gas mass flow, or via a computer model of the drive system or similar methods.

[0025] Furthermore, the control device executes the second predefined desulfurization measure depending on the determined second sulfur load and the determined current second catalyst temperature. The control device determines which second predefined desulfurization measure to be performed based on several criteria. The second predefined desulfurization measure involves targeted heating of the second three-way catalyst to the passive regeneration temperature if the determined second sulfur load is greater than the first predefined loading limit. As a further condition, the determined second sulfur load must be less than the second predefined loading limit. Additionally, the current second catalyst temperature must be lower than the passive regeneration temperature.

[0026] This has the advantage that reliable desulfurization of several three-way catalysts simultaneously and in a resource-saving manner is ensured using simple means and in a cost-effective way.

[0027] In a particularly preferred embodiment of the invention, a method may be provided that the control device applies the first predefined desulfurization measure to the first sulfur loading model and thus determines an updated first sulfur loading. Alternatively or additionally, the invention may provide that the control device applies the second desulfurization measure to the second sulfur loading model and thus determines an updated second sulfur loading. The updated sulfur loading of the respective three-way catalyst can be reliably determined by the duration and intensity of the respective desulfurization measure using the respective sulfur loading model.Preferably, this is achieved by terminating or replacing a predefined desulfurization step, such as the first or second predefined desulfurization step, with a less intensive desulfurization step when, for example, the second or first loading limit is undershot. This is preferably done taking into account hysteresis or a dead-time function, so that, for example, excessively frequent or high-frequency switching between two desulfurization steps is avoided. This has the advantage of improving resource-efficient and reliable desulfurization of the three-way catalyst in a simple and cost-effective manner.

[0028] Preferably, the control device executes the first and second predefined desulfurization measures simultaneously as soon as the execution of one of the two predefined desulfurization measures has been determined. This means, for example, that the second predefined desulfurization measure is already carried out when the control device has determined the execution of the first desulfurization measure, even if the second sulfur load has not yet reached the first or second load threshold. In this way, a supporting effect of the first desulfurization measure can be utilized when the second desulfurization measure is carried out prematurely, thus reducing, for example, the resource expenditure for carrying out the second desulfurization measure.This has the advantage that resource-saving and reliable desulfurization of the three-way catalyst can be improved using simple means and in a cost-effective manner.

[0029] According to a preferred embodiment of the invention, the internal combustion engine is operated with a stoichiometric air-fuel ratio during driving. Alternatively, the internal combustion engine can be operated with a lean air mixture. With such air mixtures, the passive regeneration temperature is not reached during driving, so the first and second sulfur loads increase until intervention by the control device occurs. This has the advantage that resource-saving and reliable desulfurization of the three-way catalyst is improved in a simple and cost-effective manner.

[0030] The control device includes an artificial intelligence configured to validate the first sulfur loading model of the first three-way catalyst based on the first predefined desulfurization step, the determined operating parameters of the combustion engine, and exhaust gas values ​​determined by at least one exhaust gas sensor. Preferably, the artificial intelligence is configured to validate the second sulfur loading model of the second three-way catalyst based on the second predefined desulfurization step, the determined operating parameters of the combustion engine, and exhaust gas values ​​determined by at least one exhaust gas sensor. Preferably, several exhaust gas sensors are used for this purpose, with one exhaust gas sensor preferably arranged upstream of the respective three-way catalyst and one exhaust gas sensor arranged downstream of the respective three-way catalyst.The cleaning performance of each three-way catalyst can be determined from the difference in the measured exhaust gas values, with any impairment of cleaning performance being directly proportional to the respective sulfur loading. Plausibility checks reveal whether the respective sulfur loading model is determining excessively high or low sulfur loading values. Preferably, the control device is further designed to update the respective sulfur loading model based on the plausibility check such that the sulfur loading determined by the sulfur loading model approximates the sulfur loading determined from the exhaust gas values. This has the advantage of further improving the reliability of the inventive method in a simple and cost-effective manner.

[0031] According to a second aspect of the invention, the problem is solved by a drive system for a motor vehicle. The drive system comprises an internal combustion engine for propelling the motor vehicle, a first three-way catalytic converter for cleaning exhaust gases from the internal combustion engine, and a control device for controlling the internal combustion engine. According to the invention, the drive system is configured to carry out a method according to the invention.

[0032] The drive system according to the invention offers all the advantages already described in relation to a method for operating a motor vehicle drive system according to the first aspect of the invention. Accordingly, the drive system according to the invention has the advantage over conventional drive systems that it provides particularly demand-oriented desulfurization using simple means and in a cost-effective manner, and avoids excessive fuel consumption by preventing unnecessary regeneration processes with an active regeneration temperature.

[0033] According to a third aspect of the invention, the problem is solved by a motor vehicle. The motor vehicle has a drive system comprising an internal combustion engine for propelling the motor vehicle, a first three-way catalytic converter for cleaning exhaust gases from the internal combustion engine, and a control device for controlling the internal combustion engine.

[0034] The motor vehicle according to the invention offers all the advantages already described for a method for operating a drive system of a motor vehicle according to the first aspect of the invention and for a drive system according to the second aspect of the invention. Accordingly, the motor vehicle according to the invention has the advantage over conventional motor vehicles that desulfurization is provided in a particularly demand-oriented manner using simple means and in a cost-effective way, and excessive fuel consumption is avoided by preventing unnecessary regeneration processes with an active regeneration temperature.

[0035] A method according to the invention for operating a drive system of a motor vehicle, a drive system according to the invention for a motor vehicle, and a motor vehicle according to the invention are explained in more detail below with reference to the drawings. The drawings schematically show: Fig. 1 in a flowchart a preferred embodiment of the method according to the invention, Fig. 2 processes that can be coordinated by a control device in a process diagram during the execution of the method according to the invention, Fig. 3 in a time-sulfur loading diagram a time course of a first sulfur loading of a first three-way catalyst during the execution of the process according to the invention, and Fig. 4 in a side view a preferred embodiment of a motor vehicle according to the invention.

[0036] Elements with the same function and mode of operation are in the Fig. Numbers 1 to 4 are each labelled with the same reference numerals.

[0037] In Fig. Figure 1 shows a preferred embodiment of the method according to the invention schematically in a flowchart. In a first process step 100, a control device 5 of a drive system 1 of a motor vehicle 2 with an internal combustion engine 3 and a first three-way catalyst 4 provides a first sulfur loading model BM1 of the first three-way catalyst 4. In a second process step 200, the control device 5 determines operating parameters BP of the internal combustion engine 3. In a third process step 300, the control device 5 applies the operating parameters BP of the internal combustion engine 3 to the first sulfur loading model BM1. From this, the control device 5 generates a first sulfur loading SB1 of the first three-way catalyst 4.

[0038] In a fourth process step 400, the control device 5 determines a current first catalyst temperature KT1 of the first three-way catalyst 4, for example by means of one or more temperature sensors. In a fifth process step 500, the control device 5 carries out a first predefined desulfurization measure EM1 depending on the determined first sulfur loading SB1 and the determined current first catalyst temperature KT1.

[0039] Fig. Figure 2 schematically shows, in a process diagram, the processes that can be coordinated by the control device 5 during the execution of the method according to the invention. The operating parameters BP determined by the control device 5 are used as input variables for a first sulfur loading model BM1 shown in the upper branch of the process diagram. From this, the control device 5 determines the first sulfur loading SB1 of the first three-way catalyst 4. Taking into account the first catalyst temperature KT1 of the first three-way catalyst 4, the control device 5 selects one of several first predefined desulfurization measures EM1 depending on the determined first sulfur loading SB1. Normal operation NB is provided as the first predefined desulfurization measure EM1 if the first sulfur loading SB1 is less than the first predefined loading limit BG1.If the first sulfur loading SB1 is greater than the first predefined loading limit BG1 and less than the second predefined loading limit BG2, and the first catalyst temperature KT1 is lower than the passive regeneration temperature, a targeted heating GA of the first three-way catalyst 4 to the passive regeneration temperature is carried out as the first predefined desulfurization measure EM1. If the first sulfur loading SB1 is greater than the second predefined loading limit BG2, a targeted regeneration GR of the first three-way catalyst 4 to the active regeneration temperature, which is higher than the passive regeneration temperature, is carried out as the first predefined desulfurization measure EM1.

[0040] Furthermore, the operating parameters BP determined by the control device 5 are used as input variables for a second sulfur loading model BM2, which is shown in the lower branch of the process diagram. From this, the control device 5 determines the second sulfur loading SB2 of the second three-way catalyst 6. Taking into account the second catalyst temperature KT2 of the second three-way catalyst 6, the control device 5 selects one of several second predefined desulfurization measures EM2, depending on the determined second sulfur loading SB2. Normal operation NB is provided as the second predefined desulfurization measure EM2 if the second sulfur loading SB2 is less than the first predefined loading limit BG1.If the second sulfur loading SB2 is greater than the first predefined loading limit BG1 and less than the second predefined loading limit BG2, and the second catalyst temperature KT2 is lower than the passive regeneration temperature, a targeted heating GA of the second three-way catalyst 6 to the passive regeneration temperature is carried out as the second predefined desulfurization measure EM2. If the second sulfur loading SB2 is greater than the second predefined loading limit BG2, a targeted regeneration GR of the second three-way catalyst 6 to the active regeneration temperature, which is higher than the passive regeneration temperature, is carried out as the second predefined desulfurization measure EM2.

[0041] In Fig. Figure 3 schematically depicts the time course of the initial sulfur loading SB1 of the first three-way catalyst 4 during the execution of the process according to the invention in a time-sulfur loading diagram. At a starting time t0, the first three-way catalyst 4 has no initial sulfur loading SB1. Between the starting time t0 and a first time t1, the internal combustion engine 3 is operated in normal operation NB, during which no desulfurization measures are carried out on the first three-way catalyst 4. Thus, the initial sulfur loading SB1 increases continuously.

[0042] At the first time point t1, the initial sulfur load SB1 reaches the first predefined loading limit BG1. From this point onward, the control device 5 initiates a targeted heating GA of the first three-way catalyst 4 to the passive regeneration temperature. This results in the removal of sulfur from the first three-way catalyst 4. As can be seen from the curve, the operation of the combustion engine 3 continues to deposit more sulfur in the three-way catalyst 4 than is removed. Consequently, the initial sulfur load SB1 increases at a lower rate between the first time point t1 and the second time point t2 than it did before the first time point t1.

[0043] At the second time point t2, the first sulfur load SB1 reaches the second predefined loading limit BG2. From the second time point t2 onwards, the control device 5 performs a targeted regeneration GR of the first three-way catalyst 4 to the active regeneration temperature, which in this example is higher than the passive regeneration temperature. Thus, the sulfur is reduced significantly more by the first three-way catalyst 4 than before the second time point t2. The profile of the first sulfur load SB1 shown in this example is reached, for instance, when the driving profile in which the vehicle is operated is insufficient to achieve complete or adequate sulfur regeneration. According to the invention, there can also be sulfur load profiles that occur only in the ranges of normal operation NB or normal operation NB and targeted heating GA, without requiring targeted regeneration GR.

[0044] Fig.Figure 4 schematically shows a preferred embodiment of a motor vehicle 2 according to the invention in a side view. The motor vehicle 2 has a drive system 1 with an internal combustion engine 3, a first three-way catalytic converter 4, a second three-way catalytic converter 6, several exhaust gas sensors 7, and a control device 5. The motor vehicle 2 is configured to carry out a method according to the invention. Reference symbol list 1 Drive system 2 motor vehicles 3 Internal combustion engine 4 first three-way catalytic converter 5 Control device 6 second three-way catalytic converter 7 Exhaust gas sensor 100 first procedural action 200 second procedural action 300 third procedural action 400 fourth procedural action 500 fifth procedural action BG1 first predefined load limit BG2 second predefined load limit BM1 first sulfur loading model BM2 second sulfur loading model BP operating parameters EM1 first predefined desulfurization measure EM2 second predefined desulfurization measure GA targeted heating GR targeted regeneration KT1 first catalyst temperature KT2 second catalyst temperature NB Normal operation SB1 first sulfur loading SB2 second sulfur loading t0 Start time t1 first time point t2 second time point

Claims

[1] Method for operating a propulsion system (1) of a motor vehicle (2), wherein the propulsion system (1) comprises an internal combustion engine (3) for propelling the motor vehicle (2) and a first three-way catalyst (4) for cleaning exhaust gases of the internal combustion engine (3), wherein the method comprises: - Providing a first sulfur loading model (BM1) of the first three-way catalyst (4) by means of a control device (5) of the drive system (1), - Determining operating parameters (BP) of the internal combustion engine (3) by the control device (5), - Applying the operating parameters (BP) of the internal combustion engine (3) to the first sulfur loading model (BM1) to determine a first sulfur loading (SB1) of the first three-way catalyst (4) by the control device (5), - Determining a current first catalyst temperature (KT1) of the first three-way catalyst (4) by the control device (5), and - Performing a first predefined desulfurization measure (EM1) depending on the determined first sulfur loading (SB1) and the determined current first catalyst temperature (KT1) by the control device (5), characterized by , that the control device (5) as a first predefined desulfurization measure (EM1) performs a targeted heating (GA) of the first three-way catalyst (4) to a passive regeneration temperature if the determined first sulfur loading (SB1) is greater than a first predefined loading limit (BG1) and less than a second predefined loading limit (BG2) and the current first catalyst temperature (KT1) is less than the passive regeneration temperature, wherein the passive regeneration temperature is a catalyst temperature (KT1, KT2) that can be achieved by normal operation of the internal combustion engine (3) to propel the motor vehicle (2), wherein the control device (5) has an artificial intelligence that is configured to adjust the first sulfur loading model (BM1) of the first three-way catalyst (4) depending on the first predefined to verify the plausibility of the desulfurization measure (EM1), the determined operating parameter (BP) of the combustion engine (3) and the exhaust gas values ​​determined by means of at least one exhaust gas sensor (7). [2] Method according to claim 1, characterized by , that the control device (5) selects the first predefined desulfurization measure (EM1) from a specification of several first predefined desulfurization measures (EM1) defined for different first sulfur loadings (SB1) depending on the determined first sulfur loading (SB1). [3] Method according to claim 1 or 2, characterized by, that the control device (5) as the first predefined desulfurization measure (EM1) performs a targeted regeneration (GR) of the first three-way catalyst (4) with an active regeneration temperature by means of an additional heating measure to the normal operation of the combustion engine (3) if the determined first sulfur loading (SB1) is greater than the second predefined loading limit (BG2). [4] Method according to at least one of the preceding claims, characterized by, that the control device (5) provides a second sulfur loading model (BM2) of a second three-way catalyst (6) of the drive system (1), wherein the control device (5) applies the operating parameters (BP) of the internal combustion engine (3) to the second sulfur loading model (BM2) to determine a second sulfur loading (SB2) of the second three-way catalyst (6), wherein the control device (5) determines a current second catalyst temperature (KT2) of the second three-way catalyst (6), and wherein the control device (5) performs a predefined second desulfurization measure (EM2) depending on the determined second sulfur loading (SB2) and the determined current second catalyst temperature (KT2), ​​wherein the control device (5) as the second predefined desulfurization measure (EM2) is a targeted heating (GA) of the second three-way catalyst (6) performs passive regeneration at theif the determined second sulfur loading (SB2) is greater than the first predefined loading limit (BG1) and less than the second predefined loading limit (BG2), and the current second catalyst temperature (KT2) is less than the passive regeneration temperature. [5] Method according to claim 4, characterized by , that the control device (5) applies the first predefined desulfurization measure (EM1) performed to the first sulfur loading model (BM1) and thus determines an updated first sulfur loading (SB1) and / or applies the second desulfurization measure (EM2) performed to the second sulfur loading model (BM2) and thus determines an updated second sulfur loading (SB2). [6] Method according to claim 4 or 5, characterized by, that the control device (5) performs the first predefined desulfurization measure (EM1) and the second predefined desulfurization measure (EM2) simultaneously as soon as the execution for one of the two predefined desulfurization measures (EM1, EM2) has been determined. [7] Method according to at least one of the preceding claims, characterized by , that the internal combustion engine (3) is operated in a driving mode with a stoichiometric combustion air ratio. [8] Propulsion system (1) for a motor vehicle (2), comprising an internal combustion engine (3) for propelling the motor vehicle (2), a first three-way catalyst (4) for cleaning exhaust gases of the internal combustion engine (3) and a control device (5) for controlling the internal combustion engine (3), characterized by , that the drive system (1) is designed to carry out a method according to at least one of the preceding claims. [9] Motor vehicle (2) comprising a drive system (1) with an internal combustion engine (3) for driving the motor vehicle (2), a first three-way catalytic converter (4) for cleaning exhaust gases of the internal combustion engine (3) and a control device (5) for controlling the internal combustion engine (3), characterized by , that the motor vehicle (2) is designed to carry out a method according to at least one of claims 1 to 7.

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