DE102018133079A1 - Method for operating a vehicle electrical system of an internal combustion engine and a control device - Google Patents

Abstract

The invention relates to a method for operating a vehicle electrical system of an internal combustion engine, in particular an internal combustion engine of a vehicle and a Steuergeräts.Es a method for operating a vehicle electrical system of an internal combustion engine, in particular an internal combustion engine of a vehicle and a control device is provided. Such a method comprises the following steps: supplying the on-board network with energy in the form of electric current by means of at least one generator and / or at least one battery; Supplying the control unit and at least two consumers by means of energy in the form of electrical current of the electrical system; Determining a current limit of the at least one generator to which a supply of the electrical system is performed exclusively by means of at least one generator with energy in the form of electric current; wherein the control unit at least one of the consumers turns off at least temporarily when reaching and / or exceeding the current limit of the at least one generator and / or abregelt its performance. In addition, a control unit (200) is provided for operating an electrical system of an internal combustion engine, in particular an internal combustion engine of a vehicle.

Description

The invention relates to a method for operating a vehicle electrical system of an internal combustion engine, in particular an internal combustion engine of a vehicle, and a control device.

An internal combustion engine, for example for a motor vehicle, produces during operation exhaust gases or emissions which are chemically treated by means of catalysts in their composition before they are emitted into the atmosphere. This change occurs via reactions in the catalyst. These reactions have a broad temperature field above a light-off temperature in order to achieve the desired conversion rates accordingly. In this case, an ideal temperature can not be reached, in particular directly after the start, so that measures are taken to achieve the light-off temperature as quickly as possible. A known measure is the heating of the catalyst by a load increase of the internal combustion engine or a change in the efficiency of the internal combustion engine by a subsequent ignition (Zündwinkelspätverstellung). Also, a heating of the catalyst and / or the exhaust gas itself can be provided by means of a heating element.

This is from the publication DE 10 2014 223 491 A1 an exhaust treatment device and a method for exhaust aftertreatment known. In this case, the exhaust gas treatment device for an internal combustion engine, in particular a diesel engine, is provided and comprises a arranged in an exhaust line, heated by a heater passive NO _x storage catalytic converter and the passive NO _x storage catalytic downstream SCR catalyst with a device for supplying an NH ₃ releasing substance. Furthermore, a control unit is provided, which can control the heating device in such a way that the passive NO _x storage catalytic converter is heated independently of an exhaust gas temperature predetermined by the internal combustion engine. In this context, a gas supply device is provided, which can generate a gas flow independent of the internal combustion engine through the exhaust gas line, so that after switching off the internal combustion engine for a predetermined period of time, a gas flow through the exhaust gas line can be generated. At the same time, the NO _x storage catalyst is heated to a temperature above its desorption temperature and the SCR catalyst is maintained at its operating temperature, discharging the NO _x storage catalyst.

From the publication WO 2017/063832 A1 is a vehicle electrical system, in particular a hybrid electric vehicle, known. The vehicle electrical system or hybrid electric vehicle in this case comprises at least one AC unit, at least one DC unit and at least one bridge circuit for providing AC currents for the at least one AC unit. In addition, the vehicle electrical system or hybrid electric vehicle comprises at least one half-bridge with at least one positive-voltage-side semiconductor switch and at least one negative-voltage-side semiconductor switch. In this context, at least one current path is provided, which connects a power connection of the at least one DC unit to a power connection between the at least one positive voltage side semiconductor switch and the at least one negative voltage side semiconductor switch of the at least one half-bridge.

The invention has for its object to provide a method for improved operation of a vehicle electrical system of an internal combustion engine, so that a reliable operation of the electrical system is ensured in all operating conditions of the internal combustion engine.

According to the invention, a method for operating a vehicle electrical system of an internal combustion engine, in particular an internal combustion engine of a vehicle, and a control device is provided. Such a method comprises the following steps: supplying energy to the electrical system in the form of electric current by means of at least one generator and / or at least one battery. Subsequently or at the same time, the control unit and at least two consumers are supplied by means of energy in the form of electrical current of the vehicle electrical system. In addition, a current limit of the at least one generator is determined, up to which a supply of the electrical system is performed exclusively by means of at least one generator with energy in the form of electric current, wherein the controller at least when reaching and / or exceeding the current limit of the at least one generator one of the consumers at least temporarily turns off and / or abregelt its performance. In this way, an improved operation of the electrical system of the internal combustion engine can be provided so that a reliable operation of the electrical system is ensured in all operating conditions of the internal combustion engine, since a conditional shutdown of at least one consumer always a prioritized power supply, for example, for a charging of the battery or another component ensures. Also, it can not come in this way during the supply of the electrical system by means of the generator to an unwanted discharge of the battery, so that, for example, a necessary for a startup amount of energy from the battery is not unnecessary must be used. The generator may be, for example, an alternator of the internal combustion engine of the vehicle, wherein the vehicle may be, for example, a motor vehicle for road traffic.

According to a further aspect of the invention, a control device for operating a vehicle electrical system of an internal combustion engine, in particular an internal combustion engine of a vehicle, is provided. The electrical system and the control unit are supplied by at least one generator and / or at least one battery with electric power. Such a control device comprises at least one electrical line, which is connectable to at least two consumers, at least one arithmetic unit and at least one memory, wherein in the memory a program is stored, which is set up (in particular in at least partial execution in the arithmetic unit), the execute inventive method.

The above-mentioned advantages apply to the extent applicable to the intended use of the control device, whose use in the method according to the invention relates to a further aspect of the invention.

Further preferred embodiments of the invention will become apparent from the remaining, mentioned in the dependent claims characteristics.

Thus, in a further preferred embodiment of the invention, it is provided that a switch-off process and / or a power reduction process of the at least one consumer is additionally performed as a function of at least one state of the internal combustion engine and / or a classification of the at least one consumer. Thus, the power utilization of the electrical system can be regulated at the same time at least partial operation of the consumer in an advantageous manner.

It is also provided in a further preferred embodiment of the invention that the at least one state of the internal combustion engine is selected from: engine operating point, dynamics of operating point change, ambient pressure, ambient temperature, coolant temperature, exhaust gas temperature before and / or behind a turbocharger of the internal combustion engine, temperature of at least one exhaust gas purification component, Modeled particulate matter emissions at a current operating point, modeled raw nitrogen oxide emissions at a current operating point, level in a particulate filter of the internal combustion engine, level of a nitrogen oxide storage catalytic converter of the internal combustion engine and / or an engaged gear of an associated vehicle from the internal combustion engine. Thus, the operating map of the internal combustion engine can be brought into connection with the operation of the electrical system in an advantageous manner. It implicitly means that the individual states mentioned above are each measured individually and in a modeled form, so that a correspondingly technical application is possible.

Furthermore, in a further preferred embodiment of the invention, it is provided that a classification of the at least one consumer into permanent consumers and short-term consumers is performed so that the switch-off process and / or the power regulation process of the at least one consumer is carried out in accordance with a decision structure based on this classification by means of the control device. Thus, a prioritization and division of the different consumers for the decision structure can be made in an advantageous manner.

In addition, it is provided in a further preferred embodiment of the invention that the classification of the at least one consumer comprises a subdivision into comfort consumers and system consumers, so that the shutdown and / or the Leistungsabregelungsvorgang the at least one consumer according to a decision structure based on this subdivided classification performed by the controller becomes. Such a classification can therefore be made according to two classes. On the one hand, a classification of permanent consumers can take place. All consumers who require permanent or extended operation can be included in this class. An extended operation may be defined as a duration of more than 2, more than 3, more than 5, more than 8, or more than 10 seconds. A prioritization and classification of different consumers for the decision-making structure can thus be made even better.

Furthermore, it is provided in another preferred embodiment of the invention that the at least one consumer is selected from: heating element of an electrically heated catalyst upstream or in a substrate of the catalyst, seat heating, rear window heating, windscreen heating, air conditioning, at least one control unit, consumer electronics, dipped beam, Fog light, at least one sensor, emission-relevant consumer, consumer relevant to the law. A prioritization and classification of different consumers for the decision-making structure can thus be made even better. Said catalyst may be, for example, a diesel oxidation catalyst, a selective reduction catalyst or a nitrogen oxide storage catalyst. In addition, each of these catalysts can also be arranged heated or not heated on the exhaust side of the internal combustion engine. Here are all Combinations and sequences conceivable that are technically meaningful. It is also possible to arrange a plurality of catalysts of one type on the exhaust side of the internal combustion engine. The heating element can be operated electrically. In this case, preferably a power of 2 to 5 kW, preferably a power of 2.8 to 3.7 kW, more preferably a power of 3.0 to 3.5 kW installed. The heating element of the catalyst can be operated accordingly. The services mentioned are particularly advantageous for quickly reaching the light-off temperature. The heating element of the catalyst may bring the catalyst to a temperature corresponding to an activation temperature for the functionality of the catalyst. This temperature may preferably be at least 110 ° C, at least 140 ° C, at least 180 ° C, at least 200 ° C or at least 230 ° C. As a result, an exhaust gas aftertreatment can advantageously be carried out by the functionality of the catalyst, which otherwise could only start much later. The functionality of the catalyst means to activate the catalytically active substances, for example barium oxides in nitrogen oxide storage catalysts or platinum and other metals. The activation temperature or light-off temperature is the temperature at which 50% of the corresponding exhaust gas components are converted. In other words, by means of the presented method, therefore, a prioritization and classification of the different consumers for the decision structure can be provided which ensures, for example, an advantageous supply of the vehicle electrical system and the heating element of the catalytic converter with energy, so that, for example, an exhaust gas temperature can be raised further, which for example resulting in a load increase of the internal combustion engine. Thus, therefore, an improved operation of the exhaust system and the internal combustion engine can be ensured. It can thus be optimized during operation of the internal combustion engine and the optionally drivable compressor, the performance and at the same time the emission of noxious gases can be reduced.

It is also provided in a further preferred embodiment of the invention that the method is operated for a maximum of 150 seconds, in particular for a maximum of 120 seconds, preferably for a maximum of 100 seconds after a start of the internal combustion engine. During this period, the effect of the procedure is most effective.

Furthermore, it is provided in a further preferred embodiment of the invention that the method is operated at least during a cold start of the internal combustion engine. In this case, the cold start is characterized in particular by an ambient temperature of at most 0 ° C., preferably at most -5 ° C., particularly preferably at most -10 ° C., and / or an internal combustion engine temperature which corresponds to an ambient temperature. Thus, it can be advantageously ensured that the method is operated in a state which profits particularly from this. For example, it can thus be implicitly deduced from the above-mentioned values that a coolant or engine oil temperature at a cold start from the engine then deviates less than 5 ° C. from the current ambient temperature.

It is also provided in a further preferred embodiment of the invention that a shutdown and / or Leistungsabregelungsvorgang a non-emission-relevant consumer and / or a non-law-relevant consumer is performed before a shutdown and a power reduction operation of an emission-relevant consumer and / or a consumer. In other words, the deactivation and / or curtailment of non-emission and / or law-relevant consumers is prioritized over emission and / or law-relevant consumers. Thus, advantageously, a safe and legally compliant mode can be ensured.

In general, an emission-relevant consumer is defined by the fact that the electrical operation of this consumer has a direct or indirect effect on the emission behavior of the vehicle. As an emission-relevant consumer, for example, an engine control unit or an electrically operated compressor can be considered. In general, a consumer relevant to the law is defined by the fact that the electrical operation of this consumer is directly or indirectly associated with a legal standard to be fulfilled in the country in which the vehicle is moved or permitted, for example by law. As a consumer relevant to the law, for example, a rear fog lamp can be considered.

In addition, it is provided in a further preferred embodiment of the invention that before a shutdown and / or a Leistungsabregelungsvorgang a heating element of an electrically heated catalyst upstream or in a substrate of the catalyst, a shutdown and / or Leistungsabregelungsvorgang a non-emission-relevant consumer and / or a non-law-relevant consumer is done. Thus, support of an emission-relevant consumer and / or a consumer relevant to the law by means of the heating element can be initially supported in order to ensure a safe and legally compliant operating mode, before initially supplying less relevant consumers with electricity.

It is also provided in a further preferred embodiment of the invention that a shutdown and / or Leistungsabregelungsvorgang a heating element of an electrically heated catalyst upstream or in a substrate of the catalyst is performed before a shutdown and a power control operation of an emission-relevant consumer and / or a law-relevant consumer , In this way it can be ensured even better that a safe and legally compliant operating mode is guaranteed.

In addition, it is provided in a further preferred embodiment of the invention that the shutdown and / or Leistungsabregelungsvorgang a heating element of an electrically heated catalyst upstream or in a substrate of the catalyst is at least partially completed. Thus, the shutdown can be advantageously divided into intervals. This briefly disconnected or regulated consumer may in particular be a heating element of a catalytic converter. This can be switched on, in particular for the short-term switched-off total duration, as soon as the limit of the current remains below when switching on.

Furthermore, it is provided in a further preferred embodiment of the invention that a shutdown and / or a Leistungsabregelungsvorgang a non-emission-relevant consumer and / or a non-law-relevant consumer for a period of less than 3 seconds, especially shorter than 1.5 seconds, preferably for about 2 seconds is performed when a short-term consumer needs the power. The aforementioned advantages are thus even better accessible. In general, a short-term consumer is defined by the fact that the electrical operation of this consumer occurs only extremely short and not in a longer time period with respect to the operating time of the vehicle without interruption. As a short-term consumer, for example, a turn signal or an electric window can be viewed.

The various embodiments of the invention mentioned in this application are, unless otherwise stated in the individual case, advantageously combinable with each other.

• 1 ein erstes Diagramm einer Strombilanz eines Bordnetzes ohne Anwendung eines Verfahrens zum Betreiben eines Bordnetzes einer Brennkraftmaschine;
• 2 ein zweites Diagramm einer Strombilanz eines Bordnetzes mit Anwendung eines Verfahrens zum Betreiben eines Bordnetzes einer Brennkraftmaschine;
• 3 einen Prozessablauf eines Verfahrens zum Betreiben eines Bordnetzes einer Brennkraftmaschine;
• 4 ein Steuergerät zum Betreiben eines Bordnetzes einer Brennkraftmaschine.

In the following, the invention will be explained in more detail with reference to exemplary embodiments. To show:

• 1 a first diagram of a power balance of a vehicle electrical system without application of a method for operating a vehicle electrical system of an internal combustion engine;
• 2 a second diagram of a power balance of a vehicle electrical system with application of a method for operating a vehicle electrical system of an internal combustion engine;
• 3 a process flow of a method for operating a vehicle electrical system of an internal combustion engine;
• 4 a control unit for operating a vehicle electrical system of an internal combustion engine.

1 shows a first diagram 10 a power balance of a vehicle electrical system without application of a method for operating a vehicle electrical system of an internal combustion engine, in particular an internal combustion engine of a vehicle. It will be on the Y -Axis 12 the power consumption of the electrical system is indicated in amperes [A]. On the X -Axis 14 the time is displayed in seconds [s]. A first area 16 indicates a basic power requirement, which is used for example for control units. A second area 18 indicates the power requirements for an electrically heatable catalyst, which ultimately meant hereby, for example, the power requirements for a heating element. A third area 20 Indicates the power consumption of continuous consumers. Such a permanent consumer may for example be a seat heater of a vehicle. In addition, a fourth area 22 shown, which is segmented into individual power demand peaks of short-term consumers. A drawn boundary line 24 represents a current limit of a generator. Up to this limit line 24 the power requirement of the vehicle electrical system can be covered by the generator. In addition, must be accessed in accordance with a reserved battery. In this respect, it can be seen in the first period, to what extent this boundary line 24 is exceeded and thus takes place an unwanted discharge of the battery.

2 shows a second diagram 26 a power balance of a vehicle electrical system with application of a method for operating a vehicle electrical system of an internal combustion engine, in particular an internal combustion engine of a vehicle. The second diagram 26 is similar to the first diagram 10 , so that at least partially the same reference numerals are used.

Also this second diagram 26 shows on the Y -Axis 12 the power consumption of the electrical system in amperes [A]. In addition, on the X -Axis 14 the time in seconds [s] is displayed. Again shows a first surface 16 a basic power demand, which is used for example for control units. A second area 18 indicates the power requirements for an electrically heatable catalyst, which ultimately meant hereby, for example, the power requirements for a heating element. Also shows a third area 20 the power requirements of permanent consumers, such as a seat heating of a vehicle. In addition, here is a fourth area 22 shown, which is segmented into individual power demand peaks of short-term consumers. In addition, also a drawn boundary line 24 drawn, which represents a current limit of a generator. as well as in 1 can be up to this boundary line 24 the power requirements of the electrical system are covered by the generator. In contrast to the representation in 1 show the 2 However, a temporary shutdown of one or more short consumers in a first period of time to about 110 seconds, so that in this area does not exceed the boundary line 24 takes place and according to the power requirements can be covered only by the generator and an unwanted discharge of the battery is thus completely avoided.

3 shows a process flow 100 a method for operating a vehicle electrical system of an internal combustion engine, in particular an internal combustion engine for a vehicle. In a first step 110 A supply of the on-board network with energy in the form of electrical current by means of at least one generator and / or at least one battery. In a second step 120 becomes a controller 200 and supplies at least two consumers by means of energy in the form of electrical power of the electrical system. In a third step 130 a current limit of the at least one generator is set to which a supply of the electrical system is performed exclusively by means of at least one generator with energy in the form of electrical current. When reaching and / or exceeding the current limit of the at least one generator at least one consumer is at least temporarily by means of the control unit 200 switched off and / or its performance is regulated.

4 shows a control unit 200 for operating a vehicle electrical system of an internal combustion engine, in particular an internal combustion engine for a vehicle. The control unit 200 is shown only schematically and can be arranged or installed, for example, in a vehicle. In the control unit 200 are also schematically a memory 210 and a computing unit 220 shown. A double arrow 230 represents the functional relationship between the memory 210 and the arithmetic unit 220 represents.

In addition, a block arrow symbolizes 240 an interface, for example in the form of an electrical line, to possible other consumers.

LIST OF REFERENCE NUMBERS

10

first diagram

12

Y -Axis

14

X -Axis

16

first surface

18

second surface

20

third area

22

fourth area

24

boundary line

26

second diagram

100

process flow

110

first step

120

second step

130

Third step

200

control unit

210

Storage

220

computer unit

230

double arrow

240

block arrow

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102014223491 A1 [0003]
• WO 2017/063832 A1 [0004]

Claims (15)

Method for operating a vehicle electrical system of an internal combustion engine and a control unit, comprising the following steps: supplying the vehicle electrical system with energy in the form of electric current by means of at least one generator and / or at least one battery; Supplying the control unit and at least two consumers by means of energy in the form of electrical current of the electrical system; Determining a current limit of the at least one generator to which a supply of the electrical system is performed exclusively by means of at least one generator with energy in the form of electric power, characterized in that the control unit when reaching and / or exceeding the current limit of the at least one generator at least one of the consumers at least temporarily turns off and / or abregelt its performance. Method according to Claim 1 wherein a switch-off and / or a Leistungsabregelungsvorgang the at least one consumer is additionally performed in dependence on at least one state of the internal combustion engine and / or a classification of the at least one consumer. Method according to Claim 2 wherein the at least one state of the internal combustion engine is selected from: engine operating point, dynamics of an operating point change, ambient pressure, ambient temperature, coolant temperature, exhaust gas temperature upstream and / or downstream of a turbocharger of the internal combustion engine, temperature of at least one exhaust gas purification component, modeled particulate matter emissions at a current operating point, modeled nitrogen oxide Raw emissions at a current operating point, level in a particulate filter of the internal combustion engine, level of a nitrogen oxide storage catalytic converter of the internal combustion engine and / or an engaged gear of a vehicle driven by the internal combustion engine. Method according to one of Claims 2 to 3 in which a classification of the at least one consumer into permanent consumers and short-term consumers is carried out, so that the switch-off process and / or the power regulation process of the at least one consumer is performed according to a decision structure based on this classification by means of the control device. Method according to Claim 4 in which the classification of the continuous consumer comprises a subdivision into comfort consumers and system consumers, so that the switching off operation and / or the power regulation process of the at least one consumer is carried out in accordance with a decision structure based on this subdivision by means of the control device. Method according to one of the preceding claims, wherein the at least one consumer is selected from: heating element of an electrically heated catalyst upstream or in a substrate of the catalyst, seat heating, rear window heating, windscreen heating, air conditioning, control unit, consumer electronics, dipped beam, fog light, sensor, emission-relevant consumer, Legislative consumer. Method according to one of the preceding claims, wherein the method is operated for a maximum of 150 seconds after a start of the internal combustion engine. Method according to one of the preceding claims, wherein the method is operated at least during a cold start of the internal combustion engine, wherein the cold start in particular by an ambient temperature of at most 0 ° C, preferably at most -5 ° C, more preferably at most -10 ° C, and / or an internal combustion engine temperature which corresponds to the ambient temperature is characterized. Method according to one of the preceding claims, wherein a shutdown and / or Leistungsabregelungsvorgang a non-emission-relevant consumer and / or a non-law-relevant consumer is performed before a shutdown and / or a power reduction process of an emission-relevant consumer and / or a law-relevant consumer. Method according to one of the preceding claims, wherein prior to a shutdown and / or a power control of a heating element of an electrically heated catalyst upstream or in a substrate of the catalyst, a shutdown and / or Leistungsabregelungsvorgang a non-emission-relevant consumer and / or a non-law-relevant consumer is completed. Method according to one of the preceding claims, wherein before a shutdown and / or a power reduction process of an emission-relevant consumer and / or a consumer relevant to the law, a shutdown and / or Leistungsabregelungsvorgang a heating element of an electrically heated catalyst upstream or in a substrate of the catalyst is completed. Method according to one of Claims 9 to 11 wherein the shutdown and / or Leistungsabregelungsvorgang a heating element of an electrically heated catalyst upstream or in a substrate of the catalyst is at least partially completed. Method according to one of the preceding claims, wherein a switch-off and / or a Leistungsabregelungsvorgang a non-emission-relevant consumer and / or a non-law-relevant consumer for a period of less than 3 seconds, especially shorter than 1.5 seconds, preferably for 2 seconds is performed when a short-term consumer needs the electricity. Control unit (200) for operating a vehicle electrical system of an internal combustion engine, in particular an internal combustion engine of a vehicle, wherein the electrical system and the control unit (200) of at least one generator and / or at least one battery can be supplied with electric power comprising at least one electrical line, which with at least two consumers can be connected, at least one arithmetic unit and at least one memory (210), characterized in that in the memory (210) a program is stored, which is set up, the method according to Claims 1 to 13 perform. Using the control unit (200) according to Claim 14 in a method according to Claims 1 to 13 ,

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