DE102021128749A1 - Invention for operating a motor vehicle and control device for implementing such a method - Google Patents

Abstract

The invention relates to a method for operating a motor vehicle, in particular a commercial vehicle, which comprises at least one drive system, a first energy storage device for electrical energy and at least one second energy storage device, in particular a storage container for a further energy source, with the drive system being set up to to be operated by the energy carrier stored in the first energy store and by means of the energy carrier stored in the second energy store, and having at least one control device for controlling the drive system, comprising the steps of:- specifying a destination to be traveled to with the vehicle on the control device;- determining at the destination or at energy sources available at an intermediate destination on the journey to the destination to fill up the first and/or second energy store;- comparing prices for the energy sources available at the destination or intermediate destination, and- controlling the energy supply to the drive system by means of the control device in such a way that on the journey to the intermediate destination and /or destination, the first or second energy store is emptied with priority, preferably emptied to the maximum, which stores the energy carrier that is cheaper in terms of price at the intermediate destination and/or destination.

Description

The invention relates to a method for operating a motor vehicle, in particular a commercial vehicle, which comprises at least one drive system, a first energy storage device for electrical energy and at least one second energy storage device, in particular a storage container for another energy carrier, the drive system being set up for this purpose , to be operated by means of the energy sources stored in the two energy stores, and having at least one control device for controlling the drive system. The invention also relates to a control device for a motor vehicle for implementing such a method.

It is generally known that motor vehicles, both passenger cars and commercial vehicles, are equipped with a drive system that combines two different drives with one another. Such drive systems, also referred to as hybrid drives, include an electric drive as the first drive and at least one additional (second) drive, such as an internal combustion engine or a fuel cell. The drive system can be designed as a serial hybrid, with the second drive generating electricity that is used to supply energy to the first, electric drive. In the serial hybrid, the vehicle moves exclusively via the electric drive. The drive system can also be designed as a power-split hybrid, in which case the vehicle can be moved both via the first, electric drive and via the second drive.

Further refinements of such drive systems provide for the possibility of charging the energy storage device present on the vehicle for the first electric drive via the power grid. For this purpose, these drive systems, also referred to as plug-in hybrids, have at least one plug-in contact for connection to the power grid.

In the past, any price differences for the energy sources used to operate the vehicle played no role, since the range in purely electric operation was limited. With the improved range in electric operation and efficient control of the drive system, there can be a significant cost difference when recharging/replenishing the energy sources used for a route. As a result, there is an increasing need for effective control and an associated targeted energy supply for the drive system on such vehicles. Furthermore, it is difficult for a user to compare the different price information for the various energy carriers, taking into account their efficiencies, and to determine the resulting price difference.

The present invention was therefore based on the object of specifying a method for operating a motor vehicle, by means of which the costs for operating a motor vehicle can be reduced.

The invention solves the problem on which it is based in a method for operating a motor vehicle of the type described above with the features of the subject matter of claim 1. In particular, the method according to the invention solves the above problem with the steps: Specifying a destination to be traveled to with the vehicle on the control device; Determining available energy carriers at the destination or at an intermediate destination on the journey to the destination for filling up the first and/or second energy store; Comparing the prices of the energy carriers available at the destination or intermediate destination, and controlling the energy supply to the drive system by means of the control device in such a way that on the journey to the intermediate destination or destination, the energy store is emptied with priority, preferably emptied to the maximum, of the energy carrier that is cheaper in terms of price at the intermediate destination stockpiled.

The method according to the invention pursues the approach that on a motor vehicle, such as a passenger car or a commercial vehicle, which has two energy stores for different energy carriers, the drive system primarily or specifically on the journey to the destination or on the journey to the destination lying intermediate destination is operated by the energy source that has the lower price. What is thus achieved is that upon arrival at the destination or the intermediate destination and an associated break, the vehicle is primarily recharged with the energy carrier that has the lower price at the destination or intermediate destination. The energy carriers are preferably refilled individually from the outside via a corresponding access, such as a connecting piece or a connecting plug, on the vehicle.

The term "price" of the energy carrier, especially in the case of liquid or gaseous energy carriers such as diesel or hydrogen, does not mean the price per unit of mass or volume. When comparing the prices of the energy sources, the costs of the respective energy source per kilometer driven or per kilowatt hour generated are taken into account. Furthermore, in the present case, under the concept of energy memory to understand both an energy store for electrical energy, such as an accumulator, and a storage container for liquid or gaseous energy sources, which has a specific container volume.

The control device for the drive system is set up to reduce the energy supply from the more expensive energy source in good time before reaching the destination or the intermediate destination and to switch exclusively to the energy supply from the cheaper energy source. The energy store for the cheaper energy carrier is then preferably largely, in particular completely, emptied upon arrival at the destination/intermediate destination. Assuming that the price for electricity at the stopover or destination is cheaper than the price for, for example, hydrogen as a possible second energy source for supplying the drive system, the drive system is supplied with energy on the journey to the destination/stopover, at least for a section of the route, purely electrically, preferably until the energy store for the electrical energy is completely emptied. Any remaining distance is then covered by supplying the drive system with the second energy carrier, e.g. hydrogen, petrol, biofuel or diesel fuel, LPG, CNG, synthetic fuel. The preferably complete emptying of the energy store for the cheaper energy source always results in the maximum possible cost savings when operating the vehicle.

If, on the other hand, the price for electricity at the destination or intermediate destination is higher than the price of the second energy source, only the second energy source, such as e.g. B. hydrogen, used to power the drive system and the energy storage for electrical energy remains full.

According to a preferred embodiment of the method according to the invention, it is provided that after the intermediate destination/destination has been specified on the control device, preferably by the control device itself, the distance to the intermediate destination or destination and the predicted energy requirement for the journey to the intermediate destination or destination are determined, preferably on Basis of at least the current vehicle mass and the route. By determining the distance to be covered and preferably the course of the route to the destination, such as the altitude to be overcome, the method according to the invention can preferably be used to determine the point in time from which the energy supply can be reduced by the more expensive energy source in the direction of the drive system. This preferably makes it possible to determine from when the energy supply can be completely stopped by the more expensive energy source for the remaining distance to the intermediate destination or destination, so that from then on only the energy source is supplied to supply the drive system that is available at the intermediate destination or destination has cheaper price. As a result, the energy store, which stocks the cheaper energy source, is actually emptied to the maximum when the intermediate destination/destination is reached, so that it can then be completely filled again. By considering the distance when implementing the method according to the invention, a renewed supply of the drive system with the more expensive energy carrier shortly before reaching the intermediate destination/destination and the associated unnecessary switching on of a fuel cell, for example, is to be avoided. Preferably, a continuous or intermittent position query of the vehicle is carried out while driving and the resulting remaining distance to the stopover or destination, so that the control device can optionally intervene in the energy supply of the drive system.

In one embodiment of the invention, the predicted energy requirement is determined on the basis of the current vehicle mass and the course of the route, such as the altitude difference to be overcome, which has a decisive influence on the energy consumption per kilometer to be determined, particularly in the case of commercial vehicles. For example, when driving empty, i.e. without charging, the energy supply can be shut down much earlier by the more expensive energy source, for example the energy supply via a fuel cell, compared to a fully loaded commercial vehicle.

A development of the method according to the invention provides that the comparison of the prices of the available energy carriers at the intermediate destination or destination is carried out taking into account the vehicle efficiency, with the vehicle efficiency preferably being determined dynamically. Taking the vehicle efficiency into account, which in the present case means the efficiency of the various individual drives of the drive system, enables a targeted influence on switching between the different energy carriers. The correct point in time for switching can thus be selected more precisely, depending on the operating parameters that are actually currently present, such as the actual energy consumption of the vehicle while driving. In city traffic, the efficiency of the purely electric drive is better than that of a combustion engine compared to a long-distance journey, since electrical energy is recovered during recuperation during braking effected. If a dynamic determination of the vehicle efficiency is not possible, a parameterized efficiency assumption is made, which is then preferably used as a basis when comparing the prices for the available energy sources.

According to an inventive step of the method, the drive system is supplied solely by the cheaper energy source as soon as the amount of energy required to cover the remaining route is equal to or greater than the energy quantity of the cheaper energy source stored in the energy store. If the cheaper energy carrier is the electrical energy stored in a battery, the vehicle is operated purely electrically on the remaining distance to the intermediate destination or destination and this energy is used up completely according to the invention. This results in a maximum of cost savings with the implementation of the method according to the invention when operating the motor vehicle. In one embodiment, as described above, the drive system is supplied purely electrically when a predetermined remaining distance to the intermediate destination or destination is reached.

An alternative embodiment provides that the drive system is supplied in parallel by the more expensive energy carrier and by the cheaper energy carrier. When the vehicle is in operation, load peaks can preferably be intercepted using the cheaper energy source from the first energy store. The more expensive energy carrier stored in the second energy store is then used to ensure a base load when supplying the drive system. A fuel cell operated by hydrogen is preferably operated at partial load when hydrogen is the more expensive energy source, so that more electricity is drawn from the first energy store than can be recharged. When the intermediate destination or destination is reached, the first energy store for the electrical energy is then preferably empty.

A development of the method according to the invention provides that the supply of the drive system with the cheaper energy source is controlled depending on the waiting time/length of stay to be expected at the intermediate destination or destination in order to fill up the energy store(s). This ensures that only as much energy is taken from preferably the energy store for electrical energy while driving as can also be recharged during the subsequent idle time of the vehicle. As a result, unnecessary waiting times at an intermediate destination and/or the destination of the trip can be avoided. Conventional energy carriers, such as fuels or hydrogen, can be converted to the corresponding energy storage devices relatively quickly. Only the charging process of the energy store for electrical energy always requires a corresponding charging time. This depends on the charging power of a charging station for charging the electrical energy store and of course also on the charging capacity of the energy store. In exceptional cases, more energy can be drawn from the energy store than can be recharged at the next stopover, in particular if the remaining distance to be covered is shorter than the amount of energy contained in the energy store for the electrical energy, and if the stay at the next stopover or the destination is then longer is sufficient to fully recharge the energy store.

According to a further step according to the invention, the control device determines the optimum point in time for shutting down/switching off the supply of the drive system with the more expensive energy source, such as hydrogen or conventional fuels, and carries out the shutting down/switching off in a controlled manner such that upon arrival at the intermediate destination or destination, the remaining amount of energy in the first energy store is below 10%. In particular in the case of an energy store for electrical energy, a large part of the available amount of energy is thus consumed upon arrival at the intermediate destination or final destination. The energy store is preferably not discharged below a predetermined value of, for example, 5%. The considerations made above are based on the assumption that the cheaper energy source at the intermediate destination or destination is the electrical energy available from the power grid and that the other energy source, such as hydrogen or diesel, has a higher price. The second energy store is set up to store such a large quantity of the energy carrier that the motor vehicle can cover several hundred kilometers before the second energy store has to be refilled.

According to a preferred embodiment, the step is provided of displaying the charging process(es) to be carried out by the driver at the intermediate destination or destination in order to fill the energy store(s) with the energy source(s) consumed during the journey. By displaying the information about the charging/filling processes to be carried out by the driver on the energy stores, assistance is provided for the driver, which supports him in operating the vehicle. In addition, incorrect operation is counteracted by displaying the energy sources to be refilled.

A development of the method according to the invention provides for the step of displaying the cheaper energy source available at the intermediate destination or destination. Based on the price calculations, the driver can be informed before starting or during the journey and thus independently of the determined level of the energy sources in the first and second energy store whether and if so, which energy store needs to be recharged or topped up. If the price for the electric power is below the price for the other energy sources stored in the vehicle in the second energy store, such as hydrogen, the driver knows in advance that the vehicle control will change the energy supply while driving to the intermediate destination or destination . Consequently, a corresponding recharging process of the first energy store for the electrical energy then has to take place, which the driver can then start immediately after arrival without losing valuable time for the recharging process.

The method according to the invention for operating a motor vehicle also includes the step of filling, preferably completely filling, the first and/or second energy store with the energy carrier(s) available at the intermediate destination or destination. By filling, preferably completely filling, the first and/or second energy store at the intermediate destination or destination, the driver of the motor vehicle or a charging/refilling system at the intermediate destination or destination then restores the vehicle's full operational readiness. When the energy stores are full, the optimum and, above all, individual energy supply for the vehicle's drive system is then made possible when the journey starts again. The energy stores are filled up via supply lines which are electrically or fluidly coupled to the respective energy store(s) at the intermediate destination or destination. The supply lines are connected to the corresponding connections on the vehicle.

According to a development of the method according to the invention, the step is provided of specifying a defined limit value in the control device for the minimum cost savings to be achieved when using the method, by means of which it is defined whether the method for operating the motor vehicle for the upcoming trip is based on the current trip Price comparison between the energy sources available at the intermediate destination or destination is applied or the supply is made by means of the energy sources stored in the second energy store, albeit more expensive. The discharging and recharging of the first energy store for the electrical energy is also subject to a certain amount of wear and tear and therefore only a correspondingly limited number of charging cycles of the energy store for the electrical energy can be carried out. Thus, switching over to the energy supply by means of electrical energy preferably only takes place if the cost savings between the energy carriers make a difference of, for example, more than 10 euros per charging/refilling process.

This threshold value for the cost savings to be achieved can be preset, for example, by an external fleet management system coupled to the vehicle's control device. Adjustments to the limit value are preferably possible.

In a further aspect, the invention relates to a control device for a motor vehicle, which is set up to execute a method for operating a motor vehicle, in particular a commercial vehicle, according to one of the preferred embodiments described above. By means of such a control device according to the invention, the energy supply of the motor vehicle can be influenced directly in order to keep the costs of operating the vehicle as low as possible. The energy supply between the energy storage devices present on the motor vehicle and the drive system of the vehicle is preferably controlled or regulated by means of the control device. The energy supply is controlled in particular on the basis of data previously read into the controller, such as the destination or any intermediate destinations to be headed for on the journey to the destination. Furthermore, the control device is set up to determine the optimal route to the destination or the energy sources available at the destination or at the intermediate destination. The control device is preferably also set up to compare the prices of the available energy carriers at the destination or intermediate destination in order to determine which of the energy carriers available at the destination/intermediate destination is the cheaper one. After the expected difference in costs has been determined by the control device, it controls the energy supply in the direction of the drive system, with priority being given to the energy store being emptied, which stores the cheaper energy carrier at the destination/intermediate destination.

With regard to the preferred developments, reference is made to the preferred refinements or embodiments of the method according to the invention described above.

• 1 eine schematische Darstellung des erfindungsgemäßen Verfahrens in einem Blockschaltbild;
• 2 eine tabellarische Übersicht der mittels des erfindungsgemäßen Verfahrens zu berücksichtigenden Parameter;
• 3A ein Diagramm, welches zeigt, wie ein Kraftfahrzeug im Stand der Technik betrieben wird;
• 3B ein Diagramm, welches zeigt, wie ein Kraftfahrzeug mittels eines erfindungsgemäßen Verfahrens betrieben wird, und
• 4 eine schematische Darstellung eines Kraftfahrzeuges gemäß einer bevorzugten Ausführungsform.

The invention is described in more detail below using a preferred exemplary embodiment with reference to the attached figures. Here show:

• 1 a schematic representation of the method according to the invention in a block diagram;
• 2 a tabular overview of the parameters to be taken into account by means of the method according to the invention;
• 3A a diagram showing how a motor vehicle is operated in the prior art;
• 3B a diagram showing how a motor vehicle is operated using a method according to the invention, and
• 4 a schematic representation of a motor vehicle according to a preferred embodiment.

1 shows a block diagram of a preferred embodiment of a method 10 according to the invention for operating a motor vehicle 100, in particular a commercial vehicle. The motor vehicle 100 operated by means of the method, in particular a fuel cell plug-in hybrid, includes a drive system 102 which is basically operated using electrical energy. On the one hand, the electrical energy is provided from a first energy store 106 for electrical energy and, on the other hand, it is generated by means of a fuel cell 110 . In order to operate the fuel cell, motor vehicle 100 has at least one second energy store 108 for hydrogen. In addition, motor vehicle 100 includes at least one control device 116 for controlling drive system 102 using the energy sources stored in various energy stores 106, 108.

In a first method step 12 of the method, a destination Z and any intermediate destinations on a route are specified, in particular read into control device 116 . The distance to the destination and preferably also the expected energy consumption up to the destination are determined by means of the control device 116 . The energy consumption is determined on the basis of the determined distance and, in one embodiment of the method, on the basis of the course of the route to the destination and the current vehicle mass.

In the next step 14, it is determined whether the destination Z has a charging station for electrical energy and a hydrogen filling station. If there is no charging station for electrical energy on site, the operating strategy will not be adjusted. This means that the power supply of the drive system is carried out as originally parameterized, and thus there is no change in the power supply. In the present case, only the hydrogen stored in the second energy accumulator 108 is then used to supply the drive system 102 with energy up to the intermediate destination or destination Z.

If both energy carriers are available at the destination Z, in step 16 the prices of hydrogen and electricity at the destination are compared. The comparison of prices is made taking into account the efficiency of the vehicle, which can vary when using the different energy sources (electricity or hydrogen) depending on the characteristics of the route to be covered.

If the result in step 18 is that operating the drive system 102 using the electrical current stored in the first energy store 106, an accumulator, would be more expensive than supplying energy to the drive system from the fuel cell 110 due to the higher charging costs, there is again no adjustment in the operational strategy. The drive system is supplied with energy exclusively using the hydrogen stored in the second energy store. The energy storage 108 for the hydrogen is a storage container with a predetermined capacity.

However, if the result in step 18 is that operating the drive system using the electrical current stored in the first energy store, the accumulator, would be cheaper than supplying energy to the drive system from the fuel cell, then in the next step 20 it is checked whether the expected service life for a Plug-in charging is sufficient or is determined by the control device, which amount of energy can be recharged from electric current during the expected service life via the electric charging station at the destination.

On the basis of the ascertained potentially rechargeable amount of energy, in step 22 the starting time is then ascertained from which the shutting down of the fuel cell 100 can begin. In one embodiment of the method, as described above, the start time for shutting down the fuel cell is selected in such a way that the idle time at the destination is sufficient to fully recharge the first energy store 106 for the electrical energy. In a second embodiment of the method according to the invention, it is provided that the start time for shutting down the fuel cell is set independently of the idle time at the destination in such a way that the amount of energy of the electrical current in the first energy storage device is below 10% when the destination is reached. At the destination, however, only as much energy is loaded into the first energy store as during the actual journey can be reloaded after a certain downtime in order to avoid unnecessary additional downtime. The onward journey with the vehicle would then be continued with the first energy store not being fully charged. If the idle time (step 20) is not sufficient for efficient recharging of the energy store, the operating strategy is not adjusted.

In the next step 24 of the method according to the invention, as soon as the start time for shutting down the fuel cell has been reached, the energy supply is controlled in the direction of the fuel cell. In particular, the fuel cell is shut down so that the energy supply via the fuel cell is only partial and thus a part of the energy supply is purely electrical. The more the fuel cell is shut down, which can be done over a distance of more than 100 kilometers, for example, the lower the energy supply from the fuel cell, with the proportion of the energy supply of the drive system via the stored, purely electrical energy increasing.

In one embodiment of the invention, fuel cell 110 is completely switched off after a certain route before reaching the destination, so that the remaining route is then covered solely using the cheaper electrical current to supply energy to the drive system. The drive system is then preferably operated purely electrically for the last few kilometers of the route.

Upon arrival at the destination (step 26) and using the method according to the invention, the amount of energy present in the first energy storage device is preferably below 10% of the maximum possible energy level, which results in efficient use of the electrical current when the vehicle is operating. Preferably, before or when the vehicle reaches the destination, the driver is informed in step 28 about charging processes to be carried out on the vehicle for filling the first energy carrier 106, i.e. charging the accumulator, and possibly also the second energy carrier 108, i.e. filling the storage container for the hydrogen. pointed out.

After vehicle 100 has been parked at the destination, in step 30 the first energy storage device is coupled to a charging station in order to achieve the greatest possible charging and the charging process is started, preferably before any discharging or charging of the vehicle at the destination or intermediate destination is started.

2 FIG. 12 shows a table that provides data used to calculate the energy savings in operating the vehicle 100. FIG. On the one hand, it contains the hydrogen price per kilogram and the electricity price per kilowatt hour at the destination, which are compared with data from a preferably freely accessible database or provided by a fleet management system 122 . The gross energy content of hydrogen, which is around 33.3 kWh/kg, and the gross energy content of electricity, which is 1 per kWh, are taken into account for the calculation of the possible savings potential. The overall efficiency of the system is also included in the calculation, which is around 50% when the energy is supplied by hydrogen and around 85% when the energy is supplied by electricity. This results in a net energy content of 16.65 kWh/kg hydrogen and a net energy content of the electricity of 0.85 kWh. If the price for hydrogen is 9.50 euros/kg hydrogen, the price is 0.57 euros per net kilowatt hour of hydrogen. If the price for electricity is 0.35 euros per net kilowatt hour, there is a difference of 0.22 euros/kWh. With an available battery capacity of 110 kWh, using the method according to the invention then results in a saving of around 24 euros per charge. The savings per battery charge depend primarily on the net price per kilowatt hour for hydrogen and electricity. If the difference in the net price, based on the efficiency-adjusted price per kWh, i.e. the net kilowatt hour, between the energy sources decreases, the savings per electricity charge used also decrease when the process is used. Below a predetermined limit value for the maximum possible savings, such as 10 euros, the method is no longer used since the accumulator is subject to a certain amount of wear during use and its use is therefore associated with corresponding costs for a possible replacement/maintenance.

In 3A a diagram is shown which shows a method known from the prior art for operating a motor vehicle which is designed as a fuel cell plug-in hybrid. As can be seen from the diagram, the fuel cell 102 is driven over the entire route of more than 1000 kilometers, plotted on the horizontal axis H1a, at a constant power of around 95 kW (characteristic curve B), shown on the left vertical axis V1 a. At the same time, the energy store for electrical energy built into the vehicle as a result has a constant energy level of 100 kWh (characteristic curve A), plotted on the right vertical axis V1b of the diagram, since it is hardly ever used. In the conventional operation of such a vehicle 100 there is no efficient use of energy.

3B FIG. 12 shows a diagram depicting the operation of a vehicle 100 using the method according to the invention. As can be seen from the diagram, a destination Z to be reached, plotted on the horizontal axis H2a, is at a driving distance of 700 kilometers. When the method is used, the fuel cell 110 is then shut down, the power of which, shown on the left vertical axis V2a as characteristic curve B, is preferably linearly shut down when the distance traveled is approximately 500 kilometers. As a result, the energy level of the first energy store 106 for the electrical energy, plotted on the right-hand vertical axis V2b as characteristic curve A, also begins to decrease. With a driving distance of 650 kilometers, the fuel cell 110 is then completely shut down, so that the remaining driving distance of 50 kilometers then takes place with a purely electric drive of the drive system 102 . When the destination Z is reached, the first energy store 106 for the electrical energy is preferably completely empty. At the destination, the energy store 106 (characteristic curve A) is then fully charged again, see the right-hand vertical axis V2b of the diagram. When the journey begins, the fuel cell 110 (characteristic curve B) is also slowly ramped up again, so that after a further 50 kilometers the fuel cell 110 returns to its original output of around 95 kW (axis V2a) and from this distance the energy supply is purely hydrogen-based.

In 4 a motor vehicle 100 is shown schematically. The illustration is limited to the components essential to the invention, it being understood here that motor vehicle 100, in addition to the components shown, has other components required for the operation of the motor vehicle, such as B. has a drive train or an air conditioning device. Such components have not been shown in favor of a concise description of the invention.

The motor vehicle 100 has a drive system 102 which, in the present embodiment, has one or more electric motors 104 . Drive system 102 is set up to move vehicle 100 .

Motor vehicle 100 also includes a first energy store 106 for electrical energy and at least one second energy store 108 for a further energy source. In the embodiment shown, the first energy store 106 is an accumulator and the second energy store 108 is a hydrogen tank for storing hydrogen.

The drive system 102 is set up to be operated both by means of the energy carrier stored in the first energy store 106 and by means of the energy carrier stored in the second energy store 108 .

The second energy store 108 is connected to a fuel cell 110, which is set up to also generate electricity from the hydrogen stored in the second energy store 108, which is used to supply energy to the drive system 102, in particular the electric motor or motors 104.

The at least one electric motor 104 of the drive system 102 is in each case connected in an energy-transmitting manner (arrow 112) to the first energy store 106 and in an energy-transmitting manner (arrow 114) to the fuel cell 110. The electric motor 104 is mechanically coupled to a drive train of the motor vehicle 100 (not shown in detail). The mechanical work converted from the electrical energy is transferred to the drive train, where it is converted into propulsion of motor vehicle 100 .

Motor vehicle 100 also has a control device 116 which, in the embodiment shown, includes at least one data memory 118 and one processor 120 . The control device 116 is connected to the drive system 102 and the first energy store 106, the second energy store 108 and the fuel cell 110 in a signal-conducting manner. The control device 116 is set up to control the components connected to it.

The control device 116 can be a dedicated control unit or can be assigned to another component of the motor vehicle 100 in terms of hardware or software.

The control device 116 is set up to control the drive system 102, the first energy store 106, the second energy store 108 and the fuel cell 110 in such a way that the method according to the preferred embodiments described above can be carried out. In one embodiment of the invention, the control device 116 can be controlled by an external fleet management system 122 . The control device 116 can, for example, receive journey information and/or information on the prices of the energy sources available on the journey from the fleet management system 122 .

Instructions or processes are stored in the data memory 118 of the control device 116, which execute the method according to the invention with its various steps as described above. For the processor 120 is responsible for executing the instructions and processes.

Reference List

10

Proceedings

12

"Read destination" step

14

"Determination of energy sources" step

16

"Price comparison" step

18

"Result price comparison" step

20

"Determine service life" step

22

"Specify start time" step

24

"Fuel cell shutdown" step

26

"Arrival notification" step

28

"Display loading information" step

30

"Perform loading process" step

100

motor vehicle

102

drive system

104

electric motor

106

First energy storage

108

Second energy storage

110

fuel cell

112

Arrow

114

Arrow

116

control device

118

data storage

120

processor

122

fleet management system

V1a, V2a

"Fuel cell power" axis

V1b, V2b

"Battery power" axis

H1a, H2a

"Distance in kilometers" axis

A

Characteristic accumulator

B

Fuel cell characteristic

Z

destination

Claims (11)

Method (10) for operating a motor vehicle (100), in particular a commercial motor vehicle, which has at least one drive system (102), a first energy storage device (104) for electrical energy and at least one second energy storage device (106), in particular a storage container for a further energy source comprises, wherein the drive system (102) is set up to be operated by means of the energy carrier stored in the first energy store (104) and by means of the energy carrier stored in the second energy store (106), and at least one control device (116) for controlling the drive system (102 ) comprising the steps: - Specification (12) of a destination (Z) to be approached with the vehicle (100) on the control device (116); - Determination (14) of energy sources available at the destination (Z) or at an intermediate destination on the journey to the destination for filling up the first and/or second energy store (106, 108); - Compare (16) prices of energy sources available at the destination (Z) or intermediate destination, and - Control (24) of the energy supply to the drive system (102) by means of the control device (116) in such a way that the first energy store (106) or second energy store (108) is preferably emptied on the journey to the intermediate destination and/or destination (Z). emptied to the maximum, which stores the energy source that is cheaper in terms of price at the intermediate destination and/or destination (Z). procedure after claim 1 , wherein after specifying (12) the intermediate destination and/or destination (Z), the distance to the intermediate destination and/or destination and the predicted energy requirement for the journey to the intermediate destination and/or destination is determined, preferably on the basis of at least the current vehicle mass and of the route. procedure after claim 1 or 2 , wherein the comparison of the prices of the available energy sources at the intermediate destination or destination (Z) is carried out taking into account the vehicle efficiency, the vehicle efficiency preferably being determined dynamically. Method according to one of the preceding claims, in which the drive system (102) is supplied solely by the cheaper energy source as soon as the amount of energy required to cover the remaining route is equal to or less than that in the first energy store (106) or second energy store (108 ) amount of stored energy of the cheaper energy source. A method according to any of the foregoing Claims 1 until 3 , the drive system (102) being supplied in parallel by the more expensive energy carrier and by the cheaper energy carrier. Method according to one of the preceding claims, wherein the supply of the drive system (102) with the cheaper energy carrier, depending on the waiting time/length of stay expected at the intermediate destination or destination (Z), for filling up the first energy store (106) and/or the second energy store (108) is controlled. Method according to one of the preceding claims, wherein the control device (116) determines the optimal point in time for shutting down/switching off the supply of the drive system (102) by the more expensive energy carrier and carries out the shutting down/switching off in a controlled manner such that upon arrival at the intermediate destination or destination ( Z) the remaining amount of energy of the cheaper energy source in the first energy store (106) is below 10%. A method according to any one of the preceding claims, further comprising the step of Displaying the charging processes to be carried out by the driver at the intermediate destination or destination (Z) in order to fill the first energy store (106) and/or second energy store (108) with the energy carrier(s) consumed during the journey, and or, Display of the cheaper energy sources available at the intermediate destination and/or destination (Z). Method according to one of the preceding claims, further comprising the step of filling up, preferably completely filling up, the first energy store (106) and/or second energy store (108) with the energy carrier(s) available at the intermediate destination and/or destination (Z) . Method according to one of the preceding claims, further comprising the step of establishing a defined limit value in the control device (116) for the minimum cost savings to be achieved when using the method (10), by means of which it is defined whether the method for operating the motor vehicle (100 ) is used for the upcoming trip based on the current price comparison between the energy sources available at the intermediate destination and/or destination (Z) or the drive system (102) is supplied by means of the energy source stored in the second energy store (108). Control device (116) for a motor vehicle (100), which is set up to implement a method (10) for operating a motor vehicle (100), in particular a commercial vehicle, according to one of Claims 1 until 10 to execute.

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