Procedures for operating a hybrid vehicle and hybrid vehicle

Abstract

The disclosure generally relates to a method (38) for operating a hybrid vehicle (10) and a hybrid vehicle (10) comprising at least one fuel cell (16) and an energy storage device (14). The state of charge of the energy storage device (14) of the hybrid vehicle (10) is monitored when the hybrid vehicle (10) is stationary. The fuel cell (16) is operated to charge the energy storage device (14) when the hybrid vehicle (10) is stationary, at least as long as the state of charge of the energy storage device (14) falls below a first state of charge threshold. Operating the fuel cell (16) generates waste heat. A vehicle interior (24) of the hybrid vehicle (10) and / or a cargo space of the hybrid vehicle (10) is heated with the generated waste heat and / or with an electric heating element (28), for which a first supply current from the energy storage device (14) is ensured.

Description

[0001] The disclosure generally relates to a method for operating a hybrid vehicle and a hybrid vehicle.

[0002] If outside temperatures are too low, the vehicle interiors or, under certain circumstances, also the cargo areas of vehicles must be heated, even during breaks in driving when the vehicle is stationary.

[0003] In conventional vehicles, a parking heater is typically used for this purpose, which has its own combustion chamber to heat the coolant. In electrically powered vehicles, an electrically operated heating element can be used, but this reduces the charge level of the energy storage device, thus limiting the driving range.

[0004] US 2015 / 298523 A1 discloses a vehicle with an auxiliary heater that includes a parking mode for heating the vehicle's passenger compartment. The auxiliary heater may include a fuel-based heater and / or an electric heating element. The auxiliary heater is deactivated when the fuel level and / or battery charge level falls below certain thresholds. If the battery charge level is lower than the threshold, it cannot be raised again. Therefore, at persistently low temperatures, further battery discharge can occur, preventing the maintenance of a minimum battery charge. Since the battery is required to start the vehicle, even in the case of an internal combustion engine, the vehicle's functionality cannot be guaranteed.

[0005] JP 2011031704 A discloses an air conditioning system for hybrid vehicles. The hybrid vehicle comprises an internal combustion engine and a battery that supplies electrical energy to an electric motor. The air conditioning system has a vapor compression refrigerant circuit and a hot water heater. The hot water heater warms the blown air by using the coolant from the internal combustion engine as a heat source. The internal combustion engine is used when the remaining battery voltage falls below a predicted threshold. The electric motor can be stopped when the battery charge is insufficient. In this way, the coolant temperature can be raised at a certain point. Heating can then continue without interruption, even as the battery's remaining capacity decreases. However, this method does not allow for an increase in the battery's state of charge.In addition, the printed document does not address the task of ensuring an appropriate temperature while the vehicle is stationary.

[0006] EP 3 055 154 A1 discloses a hybrid vehicle comprising an internal combustion engine, a generator, an electrical storage device, an electric motor, an electronic control device, and a heating device for heating the vehicle cabin. The electronic control device regulates the vehicle's operation by selectively applying a CD mode, in which the charge level of the electrical storage device is reduced, and a CS mode, in which the charge level is maintained. The electric heater heats the vehicle cabin using the electrical energy stored in the electrical storage device. The electronic control device regulates the electric heater so that the heating output is reduced in CS mode compared to CD mode. This means that the heating power is reduced in CS mode, which may prevent a constant temperature in the vehicle cabin.

[0007] There is therefore a need to eliminate or at least reduce the disadvantages of known methods for operating hybrid vehicles. In particular, there is a need to create a method for operating a hybrid vehicle that ensures a consistently desired temperature in the vehicle interior and / or cargo area, and that permanently guarantees that the state of charge of an energy storage device does not fall below a desired minimum level.

[0008] The problem is solved by the subject matter of the independent claims. Advantageous embodiments are specified in the dependent claims and the subsequent description, each of which, individually or in (sub-)combination, can represent aspects of the disclosure. Some features are explained with regard to methods, others with regard to apparatus. However, the corresponding aspects are interchangeable.

[0009] According to one aspect, some embodiments of the disclosure relate to a method for operating a hybrid vehicle comprising at least one fuel cell and an energy storage device. The method comprises at least the following steps: The charge level of the hybrid vehicle's energy storage system is monitored when the hybrid vehicle is stationary.

[0010] The fuel cell is operated to charge the energy storage system when the hybrid vehicle is stationary, at least as long as the energy storage system's state of charge falls below a certain initial threshold. Operating the fuel cell generates waste heat.

[0011] The interior of the hybrid vehicle and / or its cargo area is heated using the waste heat generated and / or an electric heating element. An initial power supply for the electric heating element is provided by the energy storage system.

[0012] This creates a process by which the energy storage system's state of charge is increased again after the initial charge threshold has been reached. This ensures that the energy storage system maintains a minimum state of charge at all times, even in the case of persistently low ambient temperatures. Such ambient temperatures could otherwise lead to further discharge of the energy storage system. This also ensures that the energy storage system has a sufficiently high state of charge to be used to start the vehicle after it has been stationary. It should be noted that energy from the energy storage system is required to start a drive motor, for example, to preheat various components.Additionally, increasing the state of charge of the energy storage also increases the range of the hybrid vehicle, insofar as it is powered based on the electrical charge of the energy storage.

[0013] The waste heat generated during the operation of the fuel cell is usually lost as waste heat. Here, however, it is used advantageously to heat the vehicle interior and / or the cargo area. This reduces the load on the energy storage system. Additionally, it creates redundancy regarding the possible heating mechanisms.

[0014] In some embodiments, the fuel cell's operation is terminated if the energy storage device's state of charge exceeds a second charge threshold. The vehicle interior and / or cargo space is then heated exclusively by the electric heating element, powered by the energy storage device. Once the energy storage device's state of charge has been sufficiently increased by operating the fuel cell, the fuel cell can be deactivated. However, the temperature of the vehicle interior and / or cargo space can still be maintained at a constant level, as it is then supplied by the electric heating element using the energy storage device. This advantageously saves fuel, such as hydrogen, intended for the fuel cell, for later use.

[0015] Preferably, the second state-of-charge threshold is higher than the first state-of-charge threshold. This ensures that the temperature control of the vehicle interior and / or the cargo space is based solely on the energy storage system only when its state of charge has increased relative to the time the fuel cell is activated.

[0016] Optionally, the fuel cell can be reactivated if the energy storage system's state of charge falls below a third threshold. This third threshold is lower than the second. Because the vehicle interior and / or cargo space are heated exclusively using the energy storage system, its state of charge decreases. Therefore, once the third threshold is reached, the fuel cell can be reactivated to restore the energy storage system's state of charge.

[0017] It is particularly desirable for the third state-of-charge threshold and the first state-of-charge threshold to coincide.

[0018] Alternatively, the third state-of-charge threshold and the first state-of-charge threshold can also be different. For example, the third state-of-charge threshold can be higher or lower than the first state-of-charge threshold.

[0019] By appropriately selecting the state-of-charge thresholds, an interval regarding the state of charge of the energy storage system can be defined within which the state of charge is permanently maintained, for example by activating the fuel cell as needed.

[0020] In some embodiments, the fuel cell is operated intermittently. This means that the fuel cell is activated and deactivated multiple times within a reference time interval. The reference time interval can be, for example, one hour, preferably 30 minutes, and more preferably 10 minutes. During operation of the fuel cell, a coolant is used to maintain the fuel cell temperature within a standard range. The coolant heats up during operation of the fuel cell, generating waste heat. By operating the fuel cell intermittently, the coolant temperature can be maintained within a predetermined temperature range. As a result, a constant amount of waste heat can be generated, which can be used to heat the vehicle interior and / or the cargo area.This allows for a more even heating process of the vehicle interior and / or cargo space during fuel cell operation. In particular, the coolant temperature range can be adjusted by modifying the fuel cell's operating intervals to optimize the efficiency of heat transfer for heating the vehicle interior and / or cargo space.

[0021] Optionally, the hybrid vehicle features an air conditioning system that is powered, at least temporarily, by waste heat and, at least temporarily, by the primary power supply. In other words, the air conditioning system is designed to release heat to the vehicle interior and / or the cargo area, based either on the waste heat generated during the operation of the fuel cell and / or heat generated by the operation of at least one electric heating element.

[0022] Preferably, the climate control system includes at least one heat exchanger that is at least indirectly coupled to the electric heating element. The heat exchanger can be configured to operate, at least indirectly, with the coolant used to cool the fuel cell during its operation. This also means that the coolant can have an optimized temperature at which the efficiency of the heat exchanger is optimized. This demonstrates that the intermittent operation of the fuel cell is advantageous for adjusting the coolant temperature and thus optimizing the efficiency of heating the vehicle interior and / or cargo space.

[0023] In some embodiments, the hybrid vehicle has a cooling device that is operated, at least temporarily, by a secondary power supply generated by the fuel cell or provided by the energy storage system. In particular, the cargo space of the hybrid vehicle may sometimes require a temperature lower than the ambient temperature. For operation, a cooling device is used whose power supply can be provided by both the fuel cell and the energy storage system. Specifically, the secondary power supply can be provided by the energy storage system if its state of charge does not fall below the first and / or third state of charge thresholds. If the fuel cell is operated to increase the state of charge of the energy storage system, a portion of the output current generated by the fuel cell can be used to operate the cooling device.This increases the electrical load on the fuel cell, which advantageously leads to improved fuel cell efficiency. Fuel cells generally exhibit higher efficiency at higher electrical loads.

[0024] Alternatively, it is also conceivable that the second supply current is provided proportionally by the fuel cell and the energy storage system.

[0025] Optionally, a control device is provided that regulates the operation of the fuel cell and the energy storage system. This control device is coupled with a trajectory planner. Knowing that the hybrid vehicle will be stationary, the control device prevents the fuel cell from operating before the vehicle comes to a complete stop, thus ensuring that the hybrid vehicle can continue moving solely on the energy storage system.

[0026] Optionally, the decision as to whether the hybrid vehicle is powered solely by the energy storage system can depend on a time interval until the vehicle's planned standstill. For example, the control device can be configured to ensure the hybrid vehicle is powered solely by the energy storage system if the time interval until the planned standstill falls below 30 minutes, preferably 40 minutes, and more preferably 60 minutes. The time interval can also be adjusted by user input.

[0027] Additionally, the decision of whether the hybrid vehicle is powered solely by the energy storage system can depend on the energy storage system's state of charge. It may be necessary for the state of charge to be higher than a minimum level for the vehicle to be powered exclusively by the energy storage system, and for the control device to regulate the hybrid vehicle accordingly. This minimum state of charge could, for example, correspond to the first state-of-charge threshold.

[0028] The hybrid vehicle has an electric motor. A supply current is used to operate the electric motor. This supply current can be provided by the fuel cell and / or the energy storage system. Since the control device is coupled with the trajectory planner, it knows when the vehicle is expected to stop. This might be because it knows that a planned route is about to end or that the driver wants or needs to take a break. For example, truck drivers are required to observe mandatory rest periods (breaks) during which the vehicle is parked. Knowing the expected stoppage, the control device can therefore regulate the hybrid vehicle's electrical system so that the supply current for the electric motor is provided exclusively by the energy storage system.This allows fuel for the fuel cell, such as hydrogen, to be saved. If the energy storage system's state of charge subsequently falls below the first charge threshold while the vehicle is stationary, the fuel cell can be activated to increase the charge level again. Nevertheless, this approach can advantageously save fuel for the fuel cell, at least initially.

[0029] Preferably, the control device only prevents the operation of the fuel cell to the extent necessary to ensure a minimum state of charge of the energy storage system. In other words, the propulsion of the hybrid vehicle is ensured solely by the energy storage system only for the final leg of the journey before the expected standstill. This prevents the energy storage system's state of charge from falling below a minimum level. This minimum state of charge could, for example, correspond to the first state-of-charge threshold.

[0030] According to another aspect, some embodiments of the disclosure also relate to a hybrid vehicle. The hybrid vehicle comprises at least a fuel cell, an energy storage device, a state-of-charge sensor, a vehicle interior and / or a cargo space, an air conditioning device comprising at least one electric heating element, and a control device. Based on the control device, the hybrid vehicle is configured to execute the method as described above.

[0031] The advantages achieved by the method described herein are also realized in a corresponding manner by the hybrid vehicle presented here.

[0032] Preferably, the fuel cell and energy storage system are configured to provide a power supply for the hybrid vehicle's drive motor. This means that the hybrid vehicle can be propelled using either the fuel cell or the energy storage system.

[0033] Optionally, a charge level sensor is installed to detect the charge level of the energy storage device. The sensor is preferably coupled to the control device.

[0034] Alternatively, the control device can be configured to determine the state of charge of the energy storage device based on at least one measured value recorded by the at least one state of charge sensor.

[0035] Optionally, the climate control system is at least coupled to the vehicle interior and / or the cargo space of the hybrid vehicle and is designed to heat at least one of the spaces.

[0036] Preferably, the climate control system includes at least one heat exchanger. The heat exchanger is designed to interact, at least indirectly, with a coolant used to cool the fuel cell during operation. In this way, heat generated during the operation of the fuel cell can be transferred to the heat exchanger via the coolant and used to heat a space within the hybrid vehicle, such as the passenger compartment.

[0037] In some embodiments, the climate control device also includes at least one electric heating element. The electric heating element is designed to generate heat based on a supplied current. The electric heating element can, for example, be a resistance heater.

[0038] Optionally, the electric heating element can be at least indirectly coupled to or integrated into the heat exchanger. In this case, only one thermally conductive connection to the vehicle interior and / or the cargo area of ​​the hybrid vehicle is advantageously required. This thermally conductive connection can be used for heat transfer based on the coolant or based on heat generated by the electric heating element to regulate the temperature of the vehicle interior and / or the cargo area.

[0039] Preferably, the control device can be coupled with a human-machine interface. Based on the human-machine interface, the control device can receive user input, for example, to define state-of-charge thresholds. Based on the human-machine interface, the control device can also output states of the procedure outlined herein. In particular, the control device can be configured to indicate, based on the human-machine interface, whether a heating process of the vehicle interior and / or the cargo space of the hybrid vehicle is taking place based on the operation of the fuel cell or the use of the energy storage system.

[0040] Optionally, the control device can also be configured to receive information about a planned standstill of the hybrid vehicle via the human-machine interface. In this case, the control device can regulate the hybrid vehicle's drive system for the final section before the planned standstill, ensuring that it operates solely on the basis of the energy storage system.

[0041] Preferably, the hybrid vehicle may also include additional sensors, such as temperature sensors designed to detect the outside temperature.

[0042] Optionally, the control device can also receive specifications (user inputs) regarding a desired target temperature of a vehicle interior and / or a cargo space of the hybrid vehicle via the human-machine interface.

[0043] In some embodiments, the control device can also be coupled with a sensor that is configured to detect the state of charge of the fuel cell.

[0044] Additionally, the control device can be coupled with a trajectory planner, through which it can, for example, obtain information about a planned standstill of the vehicle.

[0045] Optionally, the hybrid vehicle can also have a cooling system designed to cool the vehicle interior and / or cargo area. The control system can then be configured to operate the cooling system based on a power supply provided by the fuel cell.

[0046] Preferably, the cooling device, the air conditioning device, the electric heating element, and / or the heat exchanger can be components of an air conditioning circuit of the hybrid vehicle. This means that these components can be at least indirectly coupled to each other and the heat flows can be adjusted accordingly as needed.

[0047] For the purposes of this disclosure, hybrid vehicles may include, in particular, land vehicles, namely, among others, off-road and on-road vehicles such as passenger cars, buses, trucks, and other commercial vehicles. Vehicles may be manned or unmanned.

[0048] All features explained with regard to the various aspects can be combined individually or in (sub-)combination with other aspects.

[0049] The disclosure, as well as further advantageous embodiments and developments thereof, are described and explained in more detail below with reference to the examples shown in the drawings. These show: - Fig. 1 a simplified schematic representation of a hybrid vehicle according to an embodiment of the present disclosure, - Fig. 2 a simplified schematic representation of a method for operating the hybrid vehicle according to an embodiment of the present disclosure, - Fig. 3 a simplified schematic representation of operating states of the hybrid vehicle in connection with the method according to an embodiment of the present disclosure, - Fig. 4 a simplified schematic representation of a process diagram for operating the fuel cell and the electric heating element in connection with the method according to an embodiment of the present disclosure, and - Fig. 5 a simplified schematic representation of a process diagram for selecting an energy source for propelling the hybrid vehicle in connection with the method according to an embodiment of the present disclosure.

[0050] The detailed description below, in conjunction with the accompanying drawings, in which identical numbers refer to identical elements, is intended to describe various embodiments of the disclosed subject matter and is not meant to represent the only embodiments. Each embodiment described in this disclosure serves only as an example or illustration and should not be construed as preferable or advantageous over other embodiments. The illustrative examples contained herein do not claim to be exhaustive and do not limit the claimed subject matter to the exact forms disclosed. Various modifications of the described embodiments are readily apparent to the person skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the described embodiments.Therefore, the described embodiments are not limited to the embodiments shown, but have the broadest possible scope of application that is compatible with the principles and features disclosed here.

[0051] All features disclosed below with reference to the exemplary embodiments and / or the accompanying figures can be combined alone or in any subcombination with features of the aspects of the present disclosure, including features of preferred embodiments, provided that the resulting combination of features is meaningful to a person skilled in the art.

[0052] For the purposes of this disclosure, the phrase “at least one of A, B and C” means, for example, (A), (B), (C), (A and B), (A and C), (B and C), or (A, B and C), including all other possible combinations where more than three elements are listed. In other words, the term “at least one of A and B” generally means “A and / or B”, namely “A” alone, “B” alone, or “A and B”.

[0053] Fig. Figure 1 shows a simplified schematic representation of a hybrid vehicle 10 according to an embodiment of the present disclosure.

[0054] The hybrid vehicle 10 comprises an electric motor 12, which is configured to drive the hybrid vehicle 10. Additionally, the hybrid vehicle 10 comprises an energy storage device 14, a fuel cell 16, and a control device 18.

[0055] The control device 18 is coupled to the energy storage device 14. At least one charge state sensor 20 is also coupled to the energy storage device 14 and configured to detect the charge state of the energy storage device 14 and transmit it to the control device 18.

[0056] Furthermore, the control device 18 is coupled to the fuel cell 16. According to this embodiment, a fuel sensor 22 is provided which is configured to detect the fuel state of the fuel cell 16 and transmit it to the control device 18.

[0057] The fuel cell 16 is also coupled to the energy storage device 14. The fuel cell 16 is configured to use a fuel, for example hydrogen, based on a chemical reaction to provide an output current that can be used within the electrical system of the hybrid vehicle 10, for example to charge the energy storage device 14.

[0058] The hybrid vehicle 10 also includes a vehicle interior 24 in which people are normally seated.

[0059] In other embodiments, the hybrid vehicle 10 can also include a cargo space.

[0060] Additionally, the hybrid vehicle 10 includes an air conditioning unit 26, which is coupled to the control unit 18. In this case, the air conditioning unit 26 has at least one electric heating element 28 and a heat exchanger 30.

[0061] The electric heating element 28 is configured to generate heat based on a supply current and transfer it to the vehicle interior 24 to heat it. For this purpose, the electric heating element 28 is at least coupled to the energy storage device 14, from which the electric heating element 28 can draw the supply current.

[0062] In an alternative embodiment, the electric heating element 28 can additionally be coupled to the fuel cell 16 to obtain a supply current.

[0063] The heat exchanger 30 is coupled to the fuel cell 16. During operation of the fuel cell 16, a coolant is used to dissipate the heat generated during its operation. This allows the temperature of the fuel cell 16 to be maintained within a set range during operation. The heat exchanger 30 is designed to absorb heat from the coolant and transfer it to the vehicle interior 24 for heating purposes. The coolant can then be returned to the fuel cell 16.

[0064] According to this embodiment, the hybrid vehicle 10 also has a temperature sensor 32 which is designed to detect an outside temperature and to determine it for the control device 18.

[0065] In addition, the hybrid vehicle 10 according to this embodiment includes a cooling device 34, which is coupled to both the control device 18 and the fuel cell 16. A supply current generated by the operation of the fuel cell 16 can be used to operate the cooling device 34, thus ensuring cooling functionality for the vehicle interior 24. This allows the temperature in the vehicle interior 24 to be lowered.

[0066] Furthermore, the hybrid vehicle 10 includes a human-machine interface 36, which is coupled to the control device 18. Based on the human-machine interface 36, the control device 18 can receive user input and output sensor readings, system states, or information about the operation of the hybrid vehicle 10 to a user.

[0067] The control device 18 is generally coupled to at least the energy storage device 14, the fuel cell 16, at least the state-of-charge sensor 20, and the climate control device 26 in order to adjust various functions for the operation of the hybrid vehicle 10 accordingly. For example, the control device 18 can determine and specify whether a supply current for the electric heating element 28 of the climate control device 26 is ensured based on the energy storage device 14 and / or the fuel cell 16.

[0068] In addition, the control device 18 can be coupled with other components, for example the fuel sensor 22, the temperature sensor 32, the human-machine interface 36 and the cooling device 34. The operation of the hybrid vehicle 10 can then be adapted as required.

[0069] In further embodiments, the hybrid vehicle 10 may have additional components, for example a temperature sensor which is set up to detect a temperature of the vehicle interior 24 and transmit it to the control device 18.

[0070] The temperature adjustment functionality described below with regard to the vehicle interior 24 can also be ensured in further embodiments with regard to a cargo space of the hybrid vehicle 10.

[0071] Fig. Figure 2 shows a simplified schematic representation of a method 38 for operating the hybrid vehicle 10 according to an embodiment of the present disclosure. Optional steps are shown with dashed lines.

[0072] Method 38 comprises at least step 40, in which the state of charge of the energy storage device 14 of the hybrid vehicle 10 is monitored when the hybrid vehicle 10 is stationary. For this purpose, for example, the state of charge sensor 20 can be used, which can transmit corresponding measured values ​​to the control device 38, which can determine the state of charge of the energy storage device 14 based on the measured values.

[0073] In step 42, the fuel cell 16 is operated while the hybrid vehicle 10 is stationary to charge the energy storage device 14, at least as long as the state of charge of the energy storage device 14 falls below a first state of charge threshold S1. Operating the fuel cell 16 generates waste heat.

[0074] The method 38 additionally includes step 44, in which, in the present case, the vehicle interior 24 of the hybrid vehicle 10 (alternatively: and / or a cargo space of the hybrid vehicle 10) is heated with the waste heat generated and / or with an electric heating element 28, for which an initial supply current from the energy storage device 14 is ensured.

[0075] In this context, it shows Fig. Figure 3 shows a simplified schematic representation 60 of operating states of the hybrid vehicle 10 in connection with the method 38 according to an embodiment of the present disclosure. The state of charge (SOC) of the energy storage device 14 is plotted on the Y-axis against time t on the X-axis. Fig. Figure 4 shows a simplified schematic representation of a process diagram 62 for operating the fuel cell 16 and the electric heating element 28 in connection with the method 38 according to an embodiment of the present disclosure.

[0076] The start of the standstill of the hybrid vehicle 10 corresponds to the start of the time interval T2. At this time, the state of charge of the energy storage device 14 has the value SF.

[0077] In step 44, the decision as to whether the electric heating element 28 is used to heat the vehicle interior 24 may depend on whether the state of charge of the energy storage device 14 is greater than a state of charge threshold, for example greater than the second state of charge threshold S2 (see Fig. 4, Fig. 64).

[0078] Provided this condition ( Fig. 4, Fig. 64) is fulfilled, the vehicle interior 24 is then heated with the electric heating element 28 (HE: electric heating element), which reduces the state of charge of the energy storage device 14 from the value SF (see Fig. 3, time interval T2 and Fig. 4, Fig. 66). This means that the vehicle interior 24 is then heated exclusively by means of the electric heating element 28. The operation of the fuel cell 16 (FC) is then terminated.

[0079] Provided the condition ( Fig. 4, Fig. 64) if the required state of charge of the energy storage device 14 is not met, the operation of the fuel cell 16 is triggered, see Fig. 4, Fig. 70.

[0080] As soon as the state of charge of the energy storage device 14 falls below the first state of charge threshold S1 (see Fig. 4, Fig. 68), operation of fuel cell 16 is triggered (see Fig. 4, Fig. 70). This increases the charge level of the energy storage device 14 (ES: energy storage device) during the time interval T3.

[0081] The operation of the fuel cell 16 also generates waste heat. During time interval T3, at least this waste heat is used to heat the vehicle interior 24.

[0082] Optionally, the electric heating element 28 can also be used, for which, however, the supply current is not guaranteed from the energy storage unit 14 during the time interval T3, but rather from the fuel cell 16.

[0083] The procedure 38 can be further developed by optionally terminating the operation of the fuel cell 16 in step 46 if the state of charge of the energy storage device 14 exceeds a second state of charge threshold S2 (see Fig. 4, Fig. 64). The vehicle interior 24 is then heated exclusively by the electric heating element 28 (see Fig. 4, Fig. 66). In illustration 60, this corresponds to the time interval T4, during which the state of charge of the energy storage device 14 decreases again from the second state of charge threshold S2 by providing a supply current for the electrical heating element 28.

[0084] Preferably, the method 38 can also include the optional step 48 in which the operation of the fuel cell 16 is reactivated if the state of charge of the energy storage device 14 falls below a third state of charge threshold S3. In Figure 60, this corresponds to the time interval T5.

[0085] According to the present embodiment, the second state-of-charge threshold S2 is greater than the first state-of-charge threshold S1. Additionally, the third state-of-charge threshold S3 is less than the second state-of-charge threshold S2.

[0086] In this case, the third state-of-charge threshold S3 is greater than the first state-of-charge threshold S1. Alternatively, the first state-of-charge threshold S1 and the third state-of-charge threshold S3 could also be the same.

[0087] By appropriately selecting the state-of-charge thresholds S1 to S3, a state-of-charge interval for the energy storage device 14 can be determined, which is ensured during the hybrid vehicle 10's standstill by activating the fuel cell 16 as needed. This prevents the state of charge of the energy storage device 14 from becoming undesirably low, even at persistently low ambient temperatures. In other words, the energy storage device 14 is recharged intermittently, and during these charging intervals, the waste heat generated by the operation of the fuel cell 16 is used to heat the vehicle interior 24.

[0088] In a particular embodiment, the first state-of-charge threshold S1 is 50% of the maximum state of charge of the energy storage device 14, the second state-of-charge threshold S2 is 80% of the maximum state of charge of the energy storage device 14, and the first state-of-charge threshold S1 and the third state-of-charge threshold S3 are equal.

[0089] To define the state-of-charge thresholds, the control device 18 can, for example, receive corresponding user input via the human-machine interface 36. Alternatively, the state-of-charge thresholds can also be predefined. In addition, the state-of-charge thresholds can also depend on vehicle parameters or external measured values, such as the outside temperature recorded by the temperature sensor 32.

[0090] Before the hybrid vehicle 10 comes to a standstill, the control device 18 can initiate specific operating modes of the hybrid vehicle 10 to save fuel. In this context, the procedure 38 can be further developed by the optional step 50, in which the control device 18 receives information about a planned standstill of the hybrid vehicle 10. For example, the control device 18 can be coupled with a trajectory planner of the hybrid vehicle 10 or receive corresponding user input via the human-machine interface 36.

[0091] In this context, it shows Fig. 5 a simplified schematic representation of a process diagram 72 for selecting an energy source for propelling the hybrid vehicle 10 in connection with the method 38 according to an embodiment of the present disclosure.

[0092] In the present case, the decision as to whether the hybrid vehicle 10 is powered exclusively on the basis of the energy storage device 14 depends on whether a time interval of less than 40 minutes has elapsed until the planned standstill of the hybrid vehicle 10, see Fig. 5, Fig. 74.

[0093] The time interval can also be adjusted, for example by user input via the human-machine interface 36.

[0094] Will this condition ( Fig. 5, Fig. 74) If not fulfilled, no action will be taken, see Fig. 5, Fig. 76. This means that both the fuel cell 16 and, cumulatively or alternatively, the energy storage device 14 can be used to provide a supply current for the electric motor 12 to drive the hybrid vehicle 10.

[0095] Will the condition ( Fig. 5, Fig. 74) is fulfilled, the charge level of the energy storage device 14 is checked, see Fig. 5, Fig. 78. The charge level sensor 20 can be used for this purpose.

[0096] Depending on the state of charge of the energy storage device 14, the control device 18 can adjust the control of the energy source to provide a supply current for the electric motor 12 according to the optional step 52 of the procedure 38.

[0097] To this end, it is determined whether the state of charge of the energy storage device 14 is greater than a defined state of charge threshold, for example greater than the first state of charge threshold S1, see Fig. 5, Fig. 78.

[0098] Is the condition ( Fig. 5, Fig. 78) is not fulfilled, the energy storage device 14 will consequently not be used or will no longer be used to provide a supply current for the electric motor 12, see Fig. 5, Fig. 80.

[0099] In particular, the control device 18 regulates the fuel cell 16 and the energy storage device 14 in such a way that, knowing that the hybrid vehicle 10 is stationary, the operation of the electric motor 12 is ensured exclusively on the basis of the energy storage device 14 before the hybrid vehicle 10 is stationary ( Fig. 5, Fig. 82), provided the condition ( Fig. 5, Fig. 78) is fulfilled.

[0100] This means that the operation of the fuel cell 16 is terminated and it is therefore not used to provide a power supply for the electric motor 12. In other words, the propulsion of the hybrid vehicle 10 is ensured exclusively based on the energy storage device 14, see Fig. 5, Fig. 82. This allows fuel to be saved in view of the imminent shutdown of the hybrid vehicle 10.

[0101] The state of charge of the energy storage device 14 is then continuously monitored, for example by means of the state of charge sensor 20. The condition is thus repeatedly checked according to... Fig. 5, Fig. 78 were evaluated and based on this a decision was triggered regarding the energy source to supply the electric motor 12.

[0102] Optionally, step 52 can be further developed by step 54, in which the control device 18 ensures that the operation of the fuel cell 16 is only prevented to the extent that a minimum state of charge of the energy storage device 14 is guaranteed in any case. For example, the minimum state of charge of the energy storage device 14 can correspond to the first state of charge threshold S1.

[0103] In a particular embodiment, the minimum charge level of the energy storage device 14 is 50% of the maximum charge level of the energy storage device 14.

[0104] Additionally, the process 38 can be further developed by operating the fuel cell 16 intermittently according to step 56. Since the operation of the fuel cell 16 produces waste heat, which is dissipated by a suitable coolant to maintain the fuel cell 16 within a target temperature range, intermittent operation can be used to ensure a uniform coolant temperature. Thus, the fuel cell 16 can be activated and deactivated multiple times within a unit of time, for example, one minute. In particular, intermittent operation of the fuel cell 16 can be configured to optimize the efficiency of the heat exchanger 30, which receives the coolant to heat the vehicle interior 24 using the heat from the coolant.

[0105] Additionally, the method 38 can be further developed by the optional step 58, in which a cooling device 34 of the hybrid vehicle 10 is operated exclusively based on a supply current provided by the operation of the fuel cell 16. Cooling devices 34 generally have a higher current requirement compared to heating elements 28. This means that operating the cooling device 34 based on a supply current provided by the energy storage device 14 would lead to a rapid decrease in the state of charge of the energy storage device 14. Therefore, it is advantageous to operate the cooling device 34 by a supply current provided by the operation of the fuel cell 16. The control device 18 is configured to control the cooling device 34 and at least the fuel cell 16 accordingly.

[0106] Specific embodiments disclosed herein, in particular the control device 18, use circuits (e.g., one or more circuits) to implement standards, protocols, methods, or technologies disclosed herein, to functionally couple two or more components, to generate information, to process information, to analyze information, to generate signals, to encode / decode signals, to convert signals, to transmit and / or receive signals, to control other devices, etc. Circuits of any type may be used.

[0107] In one embodiment, a circuit such as the control device comprises, among other things, one or more data processing devices such as a processor (e.g., a microprocessor), a central processing unit (CPU), a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a system-on-a-chip (SoC), or similar, or any combination thereof, and may include discrete digital or analog circuit elements or electronics, or combinations thereof. In one embodiment, the circuit comprises hardware circuit implementations (e.g., implementations in analog circuits, implementations in digital circuits, and the like, as well as combinations thereof).

[0108] In one embodiment, circuits comprise combinations of circuits and computer program products with software or firmware instructions stored on one or more computer-readable memories that interact to cause a device to execute one or more of the protocols, methods, or technologies described herein. In one embodiment, the circuit technology comprises circuits, such as microprocessors or parts of microprocessors, that require software, firmware, and the like for operation. In another embodiment, the circuits comprise one or more processors or parts thereof and the associated software, firmware, hardware, and the like.

[0109] This application may refer to quantities and numbers. Unless expressly stated otherwise, such quantities and numbers are not to be considered limiting, but rather as examples of the possible quantities or numbers in connection with this application. In this context, the term "plural" may also be used in this application to refer to a quantity or number. In this context, "plural" means any number greater than one, e.g., two, three, four, five, etc. The terms "about," "approximately," "close," etc., mean plus or minus 5% of the stated value.

[0110] Although the disclosure has been presented and described in relation to one or more embodiments, the person skilled in the art will be able to make equivalent changes and modifications after reading and understanding this description and the accompanying drawings. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 2015 / 298523 A1

[0004] JP 2011031704 A

[0005] EP 3 055 154 A1

[0006]

Claims

[1] Method (38) for operating a hybrid vehicle (10) having at least one fuel cell (16) and one energy storage device (14), the method (38) comprising at least the following steps: - monitoring a charge state of the energy storage device (14) of the hybrid vehicle (10) when the hybrid vehicle (10) is at a standstill, - operating the fuel cell (16) when the hybrid vehicle (10) is at a standstill to charge the energy storage device (14), at least if the state of charge of the energy storage device (14) falls below a first state of charge threshold value, wherein waste heat is generated by operating the fuel cell (16), and - heating a vehicle interior (24) of the hybrid vehicle (10) and / or a loading space of the hybrid vehicle (10) with the waste heat generated and / or with an electrical heating element (28) for which a first supply current is ensured from the energy store (14). [2] Method (38) according to claim 1, characterized by that the operation of the fuel cell (16) is terminated if the charge state of the energy store (14) exceeds a second charge state threshold value, wherein the vehicle interior (24) and / or the loading space is then heated exclusively with the electrical heating element (28). [3] Method (38) according to claim 2, characterized by that the second state of charge threshold is greater than the first state of charge threshold. [4] Method (38) according to claim 2 or 3, characterized by that the operation of the fuel cell (16) is reactivated if the state of charge of the energy store (14) falls below a third state of charge threshold value, wherein the third state of charge threshold value is smaller than the second state of charge threshold value. [5] Method (38) according to one of the preceding claims, characterized by that the fuel cell (16) is operated intermittently. [6] Method (38) according to one of the preceding claims, characterized by that the hybrid vehicle (10) has an air conditioning device (26) which is operated at least temporarily with the waste heat and at least temporarily with the first supply current. [7] Method (38) according to one of the preceding claims, characterized by that the hybrid vehicle (10) has a cooling device (34) which is operated at least temporarily with a second supply current generated by the fuel cell (16) or ensured by the energy store (14). [8] Method (38) according to one of the preceding claims, characterized bythat a control device (18) is provided which controls the operation of the fuel cell (16) and the energy store (14), wherein the control device (18) is coupled to a trajectory planner, and wherein the control device (18), knowing that the hybrid vehicle (10) is at a standstill, prevents operation of the fuel cell (16) before the hybrid vehicle (10) comes to a standstill, so that movement of the hybrid vehicle (10) is ensured exclusively based on the energy store (14). [9] Method (38) according to claim 8, wherein the control device prevents the operation of the fuel cell (16) only to the extent that a minimum charge state of the energy storage device (14) is ensured. [10] Hybrid vehicle (10) with at least one fuel cell (16), an energy storage device (14), a charge state sensor (20), a vehicle interior (24) and / or a cargo space, an air conditioning device (26) which has at least one electrical heating element (28), and a control device (18), wherein the hybrid vehicle (10) is configured, based on the control device (18), to carry out the method (38) according to one of the preceding claims.

Images