Freeze protection control for fuel cell vehicles

Abstract

A computer-implemented method of controlling a powertrain of a vehicle, the powertrain including a plurality of fuel cell systems and an electrical energy storage system. The method includes estimating a duration of vehicle stop of the vehicle; determining whether anti-freezing protection is required during the vehicle staying period; and if it is determined that the freeze protection is not required, shutting down the fuel cell system without enabling the freeze protection. If it is determined that the freeze protection is needed, the method may include estimating a threshold time indicative of a time at which a cost of maintaining operation of the fuel cell system exceeds a cost at which the fuel cell system is shut down; and if the estimated duration of vehicle stop expires after the threshold time, shutting down the fuel cell system and enabling the freeze protection.

Description

Technical Field

[0001] The present disclosure generally relates to antifreeze protection of a fuel cell system in a vehicle. The present disclosure also relates to a powertrain, a control unit, a vehicle, a computer program product and a computer readable medium.

[0002] The present disclosure may be applied to heavy vehicles such as trucks, buses, and construction equipment. Background Art

[0003] A fuel cell is an electrochemical device that includes an electrolyte sandwiched between two electrodes such as an anode and a cathode. A solid polymer electrolyte fuel cell using a proton exchange type solid polymer membrane electrolyte electrochemically converts reactants-fuels (such as hydrogen) and oxidants (such as oxygen or air) to generate electricity. The anode receives hydrogen, and the cathode receives oxygen or air. The structure including the solid polymer membrane electrolyte sandwiched between the two electrodes is called a membrane electrode assembly (MEA). Multiple fuel cells are usually arranged together as a fuel cell stack to provide a higher output voltage. In addition, multiple fuel cell stacks can be assembled together to form a fuel cell system.

[0004] The main byproducts of the electrochemical reactions occurring within a fuel cell are water and heat. Therefore, proton exchange membrane fuel cell (PEMFC) vehicles (PEMFCV) have recently attracted increasing attention due to their advantages of low or zero emissions.

[0005] In certain applications, fuel cells may undergo repeated on-off duty cycles during use, which involve periods of inactivity (e.g., storage or non-operating conditions) of varying lengths and temperatures. It is often desirable to be able to reliably start a fuel cell in a short period of time. For example, an automotive application may require a relatively quick and reliable start-up from a shut-down state at sub-zero ambient temperatures (e.g., well below freezing). At the same time, water management in a fuel cell at such temperatures is challenging due to the potential for freezing, which is particularly undesirable when starting at sub-zero ambient temperatures. The presence of liquid water in a fuel cell system at sub-zero temperatures is particularly undesirable because the MEA in the fuel cell system may experience degradation and damage due to freezing and expansion. In general, operation of a fuel cell at sub-freezing temperatures may result in irreversible performance losses in the fuel cell, which may seriously affect the reliability and overall life of the fuel cell. For example, the cathode catalyst may subsequently undergo structural changes, thereby deforming or even falling off or peeling off the membrane.

[0006] To cope with subfreezing ambient conditions, various fuel cell operation and storage methods have been proposed. If a fuel cell is expected to experience subfreezing temperatures, certain startup and shutdown techniques may be used. Winterization procedures, especially if performed frequently, may result in some performance degradation of the fuel cell.

[0007] Thus, despite the progress made to date, there remains a need for improved methods to properly manage fuel cell systems in and to cope with sub-zero temperature conditions. Summary of the invention

[0008] It is an object of the disclosed embodiments to address the above-mentioned need to improve techniques for managing fuel cell systems, such as in vehicles, to cope with sub-zero ambient temperatures.

[0009] Embodiments of the present disclosure provide a technique for addressing the above-mentioned needs. Specifically, a method for managing a fuel cell system in a powertrain of a vehicle is provided in a manner that considers data related to the duration of a stay of the vehicle, data related to the fuel cell system, ambient weather, and information about the driver of the vehicle to determine whether and when to perform antifreeze protection or preparation.

[0010] Aspects of the present disclosure address the above needs by providing a computer-implemented method of controlling a powertrain of a vehicle including a plurality of fuel cell systems and an electrical energy storage system that determines whether and / or when to implement freeze protection for the fuel cell systems.

[0011] The method according to an embodiment of the present disclosure allows a decision to be made on whether to perform antifreeze protection in a fuel cell system of an electric vehicle. An electric vehicle, such as a fuel cell electric vehicle (FCEV), may be stopped, parked, or unused, in which case the fuel cell system of the vehicle may be at risk of freezing. The decision may be made based at least on the duration of the vehicle's stay or parking. Other non-limiting factors may include environmental conditions, the power demand of the vehicle during the stay, the cost of hydrogen consumption associated with keeping the fuel cell system operating, and the estimated degradation cost associated with performing antifreeze protection. The method according to an embodiment of the present disclosure produces the advantage of reducing or eliminating the risk of degradation and damage to the fuel cell system, thereby improving the life and durability of the fuel cell system. This allows the operating and maintenance costs of a vehicle, such as a FCEV, including at least one fuel cell system to be reduced. In addition, the productivity and service life of the vehicle may also be improved.

[0012] According to one aspect of the present disclosure, a computer-implemented method for controlling a powertrain of a vehicle is provided, the powertrain including a plurality of fuel cell systems and an electrical energy storage system. The method includes: estimating a duration of a vehicle stop of the vehicle; determining whether antifreeze protection is required during the vehicle stop; and if it is determined that the antifreeze protection is not required, shutting down the fuel cell system without enabling the antifreeze protection.

[0013] The method may also include: if it is determined that the antifreeze protection is required, estimating a threshold time indicating the time when the cost of maintaining the fuel cell system operation exceeds the cost of shutting down the fuel cell system; and if the estimated duration of the vehicle's stay expires after the threshold time, shutting down the fuel cell system and enabling the antifreeze protection.

[0014] According to one aspect of the present disclosure, the purpose is achieved by the inventive concept disclosed herein. Here, the technical effect includes determining whether and when to perform antifreeze protection based on the duration of vehicle stay, environmental conditions and other factors, thereby improving the fuel cell system and generating the advantage of reducing the risk of degradation and damage to the fuel cell system. In this way, the life and durability of the fuel cell system will be improved. The method according to the embodiment of the present disclosure allows the following decisions to be made: shutting down the fuel cell system of the vehicle, performing antifreeze protection on the fuel cell system, maintaining one or more operations in the fuel cell system, and restarting the previously shut down fuel cell system, while considering various factors, including the estimated duration of the vehicle stay, environmental conditions, driver input, historical data, actual power demand of the vehicle and / or auxiliary devices, and the cost associated with shutting down the fuel cell system and performing antifreeze protection and the cost of maintaining one or more operations in the fuel cell system during the vehicle stay. In this way, more intelligent and accurate decisions about the fuel cell system of the vehicle can be made, which is conducive to improving the overall durability of the fuel cell system and thus extending its life.

[0015] In some examples, the method also includes determining whether there is a power demand for the vehicle during the vehicle dwell using at least the estimated duration of the vehicle dwell.

[0016] In some examples, determining whether the vehicle has a power demand during the vehicle's stay includes determining whether a driver of the vehicle is asleep in the vehicle and / or the vehicle is parked during the vehicle's stay.

[0017] In some examples, when it is determined that there is no power demand for the vehicle during the vehicle stop period, it is determined whether the antifreeze protection is needed during the vehicle stop period.

[0018] In some examples, when it is determined that the vehicle has a power demand during the vehicle stop and the electrical energy storage system can meet the power demand during the vehicle stop, it is determined whether the antifreeze protection is needed during the vehicle stop.

[0019] In certain examples, if it is determined that the vehicle has a power demand during the vehicle stop and the electrical energy storage system is unable to meet the power demand during the vehicle stop, the method further includes maintaining at least one of the fuel cell systems operating.

[0020] In certain examples, the method further includes: if the estimated duration of the vehicle stop expires before the threshold time, (1) maintaining at least one of the fuel cell systems in operation, or (2) restarting the at least one fuel cell system.

[0021] In certain examples, the at least one fuel cell system is restarted after a period of time during which the plurality of fuel cell systems were shut down.

[0022] In some examples, the method further includes selecting the at least one fuel cell system by comparing the values ​​each representing the health status of a corresponding fuel cell system in the plurality of fuel cell systems, and wherein the at least one fuel cell system has a highest value representing the health status of the at least one fuel cell system. The at least one fuel cell system may be selected to remain in operation, or the at least one fuel cell system may be selected to be restarted, for example, to keep other fuel cell systems warm.

[0023] In some examples, the threshold time is estimated using a first threshold time and a second threshold time, wherein the first threshold time is calculated for a situation where the electrical energy storage system is unable to store any power generated by the fuel cell system during the vehicle's stop, and the second threshold time is calculated for a situation where the electrical energy storage system is able to store all power generated by the fuel cell system during the vehicle's stop.

[0024] In some examples, the duration of the vehicle dwell is estimated using one or more of driver input, location information, environmental information, and historical data related to operation of the vehicle.

[0025] In some examples, whether the freeze protection is needed during the vehicle dwell period is determined using current ambient conditions and predicted ambient conditions.

[0026] According to one aspect of the present disclosure, a control unit for controlling a powertrain of a vehicle is provided, the powertrain including a plurality of fuel cell systems and an electric energy storage system, the control unit being configured to execute a method according to an embodiment of the present disclosure.

[0027] According to one aspect of the present disclosure, a powertrain is provided. The powertrain includes a plurality of fuel cell systems and an electric energy storage system. The powertrain also includes the control unit.

[0028] According to one aspect of the present disclosure, a vehicle is provided, the vehicle including the powertrain and / or communicating with the control unit.

[0029] According to one aspect of the present disclosure, a computer program product includes instructions that, when executed on at least one processor, cause the at least one processor to perform a method according to an embodiment of the present disclosure.

[0030] According to one aspect of the present disclosure, a computer-readable storage medium is provided, wherein a computer program product including instructions is stored on the computer-readable storage medium, and when the instructions are executed on at least one processor, the at least one processor executes a method according to an embodiment of the present disclosure.

[0031] Additional features and advantages are disclosed in the following description, claims and drawings. In addition, additional advantages will be apparent to those skilled in the art from this disclosure or will be recognized by practicing the disclosure as described herein. Control units, computer program products and computer readable media associated with the technical effects and corresponding advantages discussed above are also disclosed herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Various aspects of the present disclosure cited as examples will be described in more detail below with reference to the accompanying drawings.

[0033] Figure 1 A side view of an example of a vehicle including a powertrain in which methods according to aspects of the present disclosure may be implemented is shown.

[0034] Figure 2A and Figure 2B is a flow chart illustrating an example of a method for controlling a powertrain of a vehicle according to aspects of the present disclosure.

[0035] Figure 3A and Figure 3B is a flow chart illustrating another example of a method for controlling a powertrain of a vehicle according to aspects of the present disclosure.

[0036] Figure 4 is a time threshold according to various aspects of the present disclosure. tr A graph of an example of the calculation.

[0037] Figure 5 is a time threshold according to various aspects of the present disclosure. tr A graph of another example of the calculation of .

[0038] Figure 6 is a time threshold according to various aspects of the present disclosure. tr A graph of another example of the calculation of .

[0039] Fig. 7A and Figure 7B is a schematic block diagram illustrating an example of a control unit according to aspects of the present disclosure. DETAILED DESCRIPTION

[0040] Fuel cell systems are generally sensitive to low temperatures, and they need to be protected from freezing to avoid degradation or damage. A vehicle or another device including a fuel cell system may be present in an environment where the temperature drops below 0°C, sometimes even well below 0°C, and in such conditions, the risk of damage to the fuel cell increases, and thus the ability of the fuel cell to generate energy may be negatively affected. In addition, when a vehicle including a power source (which includes a fuel cell system) is stopped or parked in sub-zero temperature conditions, the ability of the vehicle to start quickly and correctly may be affected. At the same time, the vehicle is required to start normally in any ambient weather conditions, including in sub-zero temperatures.

[0041] Various methods have been developed to protect fuel cell systems from freezing during the stop of a vehicle or another device or during storage of the fuel cell. The method includes external heating, draining water before shutting down, using antifreeze, continuous operation of the fuel cell system, etc. If the antifreeze protection fails or if the fuel cell system is subsequently unable to perform antifreeze protection, irreparable damage may be caused to the fuel cell system. In addition, antifreeze preparation will bring a certain burden to the fuel cell system and cause the fuel cell system to deteriorate, which may eventually shorten the life of the fuel cell system and the host device equipped with such a system. In addition, when the fuel cell system is not fully prepared to deal with possible freezing conditions, the normal operation of the host device (such as a vehicle) that uses the fuel cell system to generate electricity is affected.

[0042] Therefore, it is desirable to ensure that freeze protection or preparation reliably occurs at the appropriate time, and it is desirable to perform freeze preparation of the fuel cell system less frequently to reduce the risk of degradation of the fuel cell system. Despite the progress and development in various methods of protecting fuel cells from damage in freezing environmental conditions, there remains a need for improved methods to properly protect fuel cell systems from freezing in near-freezing or sub-freezing temperatures.

[0043] Therefore, it is an object of embodiments of the present disclosure to provide a method to determine whether and when to perform freeze protection, for example, to take certain measures to reduce or avoid the risk of damage to the fuel cell system due to sub-zero ambient temperatures.

[0044] The object is achieved by providing a method for controlling a fuel cell system in a vehicle, the method comprising: at least based on the duration of the vehicle's stay, whether to shut down the fuel cell system without enabling antifreeze protection, shut down the fuel cell system and enable antifreeze protection, keep at least one fuel cell system in the fuel cell system operating, or restart at least one fuel cell system in the fuel cell system.

[0045] Thus, a computer-implemented method of controlling a powertrain of a vehicle is provided herein, the powertrain comprising a plurality of fuel cell systems and an electrical energy storage system. The method comprises: estimating a duration of a vehicle stay of the vehicle; determining whether antifreeze protection is required during the vehicle stay; and if it is determined that the antifreeze protection is not required, shutting down the fuel cell system without enabling the antifreeze protection. The method may also comprise: if it is determined that the antifreeze protection is required, estimating a threshold time indicating a time at which the cost of maintaining the fuel cell system in operation exceeds the cost of shutting down the fuel cell system; and if the estimated duration of the vehicle stay expires after the threshold time, shutting down the fuel cell system and enabling the antifreeze protection.

[0046] Figure 1 A side view of a vehicle 10 according to an example embodiment of the present disclosure is depicted. The vehicle 10 is shown as a truck, such as a heavy truck for towing one or more trailers (not shown). The vehicle 10 may be a fuel cell electric vehicle (FCEV). It should be understood that the present disclosure is not limited to any other specific type of vehicle, but may be used for any other type of vehicle, such as a bus, construction equipment, e.g., a wheel loader or excavator, a passenger car, an aircraft, and a marine vessel. The passenger car may be, for example, a taxi or another ride-sharing vehicle.

[0047] The present disclosure is also applicable to other applications not related to vehicles as long as a powertrain including at least a fuel cell system and an electrical energy storage system (ESS) is utilized.

[0048] like Figure 1 As schematically shown in FIG. 1 , the vehicle 10 includes a powertrain 20. The powertrain 20 may be used to power one or more electric motors (not shown) that are used to generate propulsion for the vehicle 10. The powertrain 20 may additionally or alternatively be used to power other power consuming devices (not shown) of the vehicle 10, such as an electric motor for a crane, an electric motor for a refrigerator system, an electric motor for an air conditioning system, or any other power consuming function of the vehicle 10. Thus, the powertrain 20 may additionally or alternatively be used to power a power take-off (PTO) device, which is a device that transfers the mechanical power of an electric motor to another piece of equipment. The vehicle 10 may include or be coupled or associated with one or more PTO devices.

[0049] The powertrain 20 includes at least one fuel cell unit or system 30, such as a plurality of fuel cell units or systems 30. Although not shown in detail, the fuel cell system includes two or more fuel cells, which can form a fuel cell stack together. In addition, the fuel cell system is arranged to provide the necessary supply, cooling, etc. of hydrogen fuel (H2) and air to the fuel cell, and the fuel cell system may include various components not shown herein. At least one fuel cell system 30 may include a plurality of fuel cell systems, and each fuel cell system may include its own control system, which may be communicatively connected to the control unit 40. The powertrain 20 may include a single fuel cell system, two fuel cell systems, or more than two fuel cell systems, such as three or more fuel cell systems. In addition, when a number of fuel cell units or systems are provided, the fuel cell system may be independently controlled or jointly controlled. When independently controllable, each fuel cell system may be controlled to an on state or an off state, regardless of the state of other fuel cell units. When two or more of the fuel cell systems are jointly controllable, these fuel cell systems may be jointly controlled to an on state or an off state, that is, all fuel cell systems are jointly controlled to the same state. The two fuel cell systems may be controlled dependently on each other in some cases, such that one of the fuel cell systems is controlled to be in an on state or an off state according to the state of the other fuel cell system.

[0050] The vehicle 10 also includes a control unit 40 according to an example embodiment of the present disclosure. The control unit 40 can be used to control the powertrain 20. Even though an on-board control unit 40 is shown, it should be understood that the control unit 40 can also be a remote control unit 40, that is, an off-board control unit, or a combination of an on-board control unit and an off-board control unit. The control unit 40 can be configured to control the powertrain 20 by issuing control signals and by receiving status information related to the powertrain 20. For example, the control unit 40 can be configured to control the fuel cell system 30 by issuing control signals and by receiving status information related to the fuel cell system 30. The control unit 40 can also be configured to receive information from various sensors, including one or more of a temperature sensor, a humidity sensor, and other sensors included in the vehicle 10 or associated with the vehicle. For example, the temperature sensor can be positioned so that it can measure an ambient temperature (i.e., a temperature outside and / or near the vehicle) that reflects the temperature experienced by the fuel cell system 30. The control unit 40 may also be communicatively coupled to an internal database, an external database, or a combination thereof to receive historical data related to the driver's driving patterns and other events, data about auxiliary devices of the vehicle 10, historical data about the usage of auxiliary devices, data about the current location of the vehicle 10, current and predicted environmental conditions, historical data about environmental conditions at the current location, etc. The current location of the vehicle may be determined using, for example, a global positioning system (GPS) tracking device associated with the vehicle. Information about past, current, and / or predicted environmental conditions may be received from, for example, an external weather service.

[0051] The control unit 40 may receive data regarding driver input, data from a forecast weather service, and other types of data. The control unit 40 may form part of the powertrain 20, such as Figure 1 In some implementations, the control unit 40 may be separated from the powertrain 20 .

[0052] The control unit 40 is an electronic control unit and may include processing circuitry suitable for running a computer program as disclosed herein. The control unit 40 may include hardware and / or software for executing the method according to the embodiments of the present disclosure. The control unit 40 may be represented as a computer. The control unit 40 may be composed of one or more separate sub-control units. In addition, the control unit 40 may communicate using wired and / or wireless communication.

[0053] The powertrain 20 also includes an electrical storage system (ESS) 50, which in turn may include one or more batteries for storing excess electrical energy generated by the at least one fuel cell system 30 and for providing output power from the powertrain 20. The ESS 50 is electrically connected to the fuel cell system 30. The ESS 50 may include its own control system, which is communicatively connected to the control unit 40. The ESS 50 may also be used to store energy regenerated during braking, or it may be configured to be charged by a charger such as, for example, from an external power grid.

[0054] The powertrain 20 may also include power electronics (not shown) for converting the power generated by the fuel cell unit 30 and / or provided from the ESS 50 into power available to a power consumer (such as an electric motor or another power consumer). In addition, in addition to or in lieu of what is mentioned above, the powertrain 20 may include various components such as compressors, sensors, pumps, valves, and electrical components.

[0055] Although the present disclosure is described with respect to a vehicle such as a truck, aspects of the present disclosure are not limited to this particular vehicle, but may also be used in other vehicles such as passenger cars, off-road vehicles, aircraft, and marine vehicles. The present disclosure may also be applied to marine and stationary applications such as grid-connected auxiliary generators or generators independent of the grid.

[0056] Figure 2A and Figure 2B is a flow chart of a method 200 for controlling a powertrain of a vehicle including a plurality of fuel cell systems and an electrical energy storage system according to an example. The powertrain may be, for example, Figure 1 The powertrain 20 of the vehicle 10 shown in FIG. 1 and the method 200 are described below in conjunction with a vehicle such as Figure 1 The method 200 may be performed by a controller (such as, for example, Figure 1 This is achieved by using the control unit 40 in the embodiment.

[0057] Figure 2A and Figure 2B The order of actions associated with the blocks in the figures is shown by way of example only, as the actions or steps may be performed in other orders. Optional actions are shown with dashed lines.

[0058] like Figure 2AAs shown, method 200 may start at box 202 with receipt of a vehicle shutdown request. For example, the vehicle may be shut down during a stop or parking period, collectively referred to herein as a stop. During the vehicle stop period, it is assumed herein that the engine of the vehicle is shut down. When the vehicle stops, one or more fuel cell systems of the vehicle may initially remain turned on. At some point in time, during the vehicle stop period, one or more of the multiple fuel cell systems may be turned off or turned on (e.g., reopened or restarted). In some cases, one or more of the multiple fuel cell systems may be turned on, while other fuel cell systems in the multiple fuel cell systems may be turned off.

[0059] When a vehicle shutdown request is received at box 202 and the vehicle is shut down, the vehicle's fuel cell system may be operated before and if the method according to an example of the present disclosure determines that the fuel cell system is also to be shut down. The vehicle is thus stopped.

[0060] At box 204, determine or estimate the duration of the vehicle stop or stay. The duration of the vehicle shutdown can be determined or estimated based on driver input, historical data related to the vehicle (e.g., historical data related to the vehicle's driving mode and other events (e.g., recorded in vehicle log data)), data about the current location of the vehicle, current and predicted environmental conditions, time of day, and other data. For example, an input about the duration of the vehicle stay can be received from the driver via an input device in the vehicle or an input device capable of communicating with the vehicle, the input indicating how long the vehicle is expected to stay. The input device can be provided, for example, by a display device, which can receive input from a user (such as a driver), such as, for example, touch input, keyboard input, voice input, input from various other input devices, etc. The display device can be located in various locations of the vehicle, for example, on a dashboard or a center console. In some embodiments, the display device can be a display of a mobile device of a user (such as a driver), and the driver input received via such a display device can be received remotely, and the driver is not necessarily near the vehicle. Any other type of device can be used to receive input about the duration of the vehicle stop or stay from the driver or other person.

[0061] Historical data may indicate that the vehicle is used for a certain task at certain times of the day, while at other times (e.g., at night) the vehicle is parked. As another example, it may be known that at the current location, the vehicle is typically parked for a certain amount of time. In addition, depending on the type of vehicle (e.g., taxi, public transportation vehicle, long-distance vehicle, etc.), the vehicle may experience different start-stop patterns, which may be predicted based on the vehicle's previous use and previously recorded data. As another factor, in some cases, driver shifts and laws dictating how long drivers can be on the road and / or how long they need to rest may be considered in determining the time and duration of vehicle stays, which may be different for different vehicle types. For example, in some cases, the driver may be instructed to stop for a certain duration, such as a mandatory rest.

[0062] Regardless of the specific scenario, estimate how long the vehicle is expected to be shut down.

[0063] At box 206, at least the estimated duration of the vehicle's stay is used to determine whether the vehicle has a power demand during the vehicle's stay (e.g., when the vehicle is parked). The power demand during the duration of the vehicle's stay may include a power demand for a PTO device coupled to the vehicle (such as, for example, a crane, a refrigerator, an air conditioner, a heater, etc.). The power demand may be estimated using environmental conditions, information about vehicle auxiliary devices that have been turned on, historical data about the usage of vehicle auxiliary devices, and other data. For example, when the environmental conditions include a low (e.g., sub-zero) ambient temperature, the power demand may increase, which ambient temperature may be a current and / or predicted temperature. Non-limiting examples of auxiliary devices include auxiliary batteries, mobile air conditioning systems, electric lift windows, heating systems, cranes (e.g., hydraulic cranes), etc.

[0064] In some embodiments, determining at box 206 whether the vehicle has a power demand during the vehicle's stay includes determining whether the driver of the vehicle is sleeping in the vehicle and / or whether the vehicle is parked during the vehicle's stay. The vehicle can be, for example, a taxi or another ride-sharing vehicle, and the driver of the vehicle may be sleeping in the vehicle at some time. As another example, the vehicle can be a sleeper truck or tractor, such as a long-haul truck. The vehicle can also be a heavy vehicle, for example, performing a mission, and the driver of the heavy vehicle may sleep in the vehicle when stopped and / or at night. It should be understood that sleeping can include resting or other states during the period when the vehicle is stopped (when the engine is off). If the driver is inside the vehicle, the vehicle's cabin may be heated or cooled during the period when the vehicle is stopped. Thus, Figure 2AA decision box 205 is included, in which it is determined whether the driver is sleeping in the vehicle and / or whether the vehicle is parked, which may be the case when certain energy / power requirements are to be met during the vehicle's stay. In an example, historical data about driver behavior, information about the vehicle's mission, operation of certain auxiliary devices, sensor information (e.g., using one or more sensors to monitor the driver's behavior and state), and other information may be used to determine whether the driver is sleeping in the vehicle. If it is determined at box 205 that the driver is sleeping in the vehicle and / or whether the vehicle is parked, the method 200 proceeds to box 206, in which it is determined whether the vehicle has a power demand during the vehicle's stay. The power demand of the vehicle may include the power demand of its PTO device. Although the processing at decision box 205 is shown as a separate step, it can be part of the processing at box 206.

[0065] At decision block 208, it may be determined whether the ESS can meet the power demand during the vehicle stay. In other words, it may be determined whether the ESS (such as, for example, Figure 1 Whether the ESS 50) can achieve the power requirements of the vehicle and / or PTO device.

[0066] If it is determined at decision block 208 that the ESS satisfies the estimated power demand during the vehicle dwell period, method 200 proceeds to decision block 210 where it is determined whether freeze protection is required during the vehicle dwell period. In some embodiments, it is determined whether freeze protection is required during the vehicle dwell period when it is determined that the vehicle has a power demand during the vehicle dwell period and the electrical energy storage system can satisfy or achieve the power demand during the vehicle dwell period.

[0067] In some embodiments, when it is determined that there is no power demand for the vehicle during the vehicle stop period, it can be determined at decision block 210 whether antifreeze protection is required during the vehicle stop period. Figure 2A As shown, this may occur when the driver is not in the vehicle during the stop (e.g., when the driver is not sleeping or otherwise occupying the vehicle during the stop). In other words, this may occur when it is determined at decision box 205 that the driver is not sleeping in the vehicle and / or the vehicle is not parked, as shown by dashed arrow 207.

[0068] In some embodiments, current environmental conditions and predicted environmental conditions may be used to determine whether antifreeze protection is needed during the vehicle's stay. For example, if the ambient temperature (e.g., the temperature of the exterior or other environment in which the vehicle is located) is expected to drop below 0°C during the vehicle's stay, it may be determined that antifreeze protection is needed. The predicted environmental conditions may be received from, for example, a forecasted weather service. Similarly, the current ambient temperature, which may be determined using, for example, one or more sensors, may be used to determine whether antifreeze protection needs to be enabled for the fuel cell system.

[0069] In some embodiments, a thermal model of the fuel cell system can be used and the heat loss to the surrounding environment (which is a function of the ambient temperature) can be evaluated to determine whether antifreeze protection is needed during vehicle stays. For example, the thermal model can be a verified one-dimensional or multi-dimensional thermal model that calculates the temperature of each fuel cell. It can then be evaluated whether antifreeze protection is needed by determining the terminal cell temperature within the fuel cell stack (i.e., the temperature of each fuel cell at the end plate of the fuel cell stack, which may reach freezing temperature faster than other cells in the fuel cell system). Alternatively, a lumped cell stack model can be used and the mass average fuel cell stack temperature can be determined to evaluate whether antifreeze protection is needed. The model used can operate, for example, based on an ambient temperature input from a forecast weather service, a measured ambient temperature input obtained from a temperature sensor outside the fuel cell system, or a measured temperature input obtained from a temperature sensor inside the fuel cell system (e.g., within a coolant loop). In some cases, a thermal model may be generated as described, for example, in Henao, N. et al. (“PEMFC low temperature startup for electric vehicle,” IECON 2012 - 38th Annual Conference of the IEEE Industrial Electronics Society, 2012, pp. 2977-2982); Amamou, A. et al. (“Thermal Management Strategies for Cold Start of Automotive PEMFC,” 2015 IEEE Vehicle Power and Propulsion Conference (VPPC), 2015, pp. 1-6); and Khandelwal, M. et al. (“One-dimensional thermal model of cold-start in a polymer electrolyte fuel cell stack,” Journal of Power Sources, 2007, Vol. 172, pp. 816-830). In Henao, N., et al. (2012), an energy management strategy using a lumped mass fuel cell stack thermal model was proposed and experimentally validated. The strategy estimates the ideal time to start heating the fuel cell stack during cold start operation assuming the initial fuel cell temperature is known. Similar lumped models can also be used to estimate the time when the fuel cell stack reaches critical temperature, as done in Amamou, A., et al. (2015), where such a model was created to compare cold start strategies.In certain implementations, the model described in Khandelwal, M. et al. (2007) can be used, which simulates individual battery behaviors in a one-dimensional transient model.

[0070] If it is determined at decision box 210 that antifreeze protection is not required, the fuel cell system can be shut down at box 212 without enabling antifreeze protection. Antifreeze protection may not be required when the power demand of the vehicle and / or its auxiliary devices (e.g., PTO device) can be met by the electrical energy storage device. In some embodiments, antifreeze protection may not be required if there is no power demand for the vehicle and / or its auxiliary devices (e.g., PTO) during the vehicle's stay. For example, if the ambient temperature is not expected to drop below 0°C, or if it is expected to drop below 0°C within a time period that is not expected to cause a risk of freezing of the fuel cell system, antifreeze protection may not be required.

[0071] If it is determined at decision block 210 that freeze protection is required, method 200 proceeds to estimate at block 214 a threshold time t after which the cost of maintaining the fuel cell system in operation exceeds the cost of shutting down the fuel cell system. tr . This can also be referred to as the break-even point between the so-called "keep warm" strategy and the "thaw at start" cold start strategy. When the fuel cell system is turned off, it does not provide any output power and does not consume any fuel. When the fuel cell unit is turned on, it consumes fuel, such as hydrogen (H2), and it supplies output power, which can be stored in the electrical energy storage system. Therefore, when the fuel cell system remains in operation, the costs associated with the consumption of the fuel cell rise. At the same time, the costs also rise when the fuel cell system is turned off, because in this case, the risk of freezing of the fuel cell system increases. The power stored in the electrical energy storage system is consumed to perform antifreeze protection, subsequently thawing the fuel cell system and bringing it to a suitable temperature before starting it. The vehicle can be heated using an electric heating assembly and / or any other heating device available on the vehicle or accessible to the vehicle. For example, a hydrogen heater, such as a catalytic heater, can be used, in which case the cost will be different. In addition, if an external power source is used, the cost will be different.

[0072] Threshold time t trThe estimation may be performed using a first threshold time and a second threshold time, wherein the first threshold time may be calculated for a situation or scenario where the electrical energy storage system is unable to store any power generated by the fuel cell system during the vehicle stop period, and the second threshold time may be calculated for a situation or scenario where the electrical energy storage system is able to store all of the power generated by the fuel cell system during the vehicle stop period. The first threshold time and the second threshold time may be determined using information about an initial state of charge (SoC) and capacity of an electrical energy storage system such as a battery. For example, the first threshold time may be calculated for a scenario where the SoC is 100% at the beginning of the stop period, and the second threshold time may be calculated for a scenario where the SoC is 0% at the beginning of the stop period. With respect to t tr For more details on the calculation of Figure 4 Description.

[0073] Next, at decision block 216 it is determined whether the estimated duration of the vehicle stop is within a threshold time t tr Therefore, at box 216, it is determined whether the estimated duration of the vehicle stay is longer than the time period at which the cost of keeping the fuel cell system operating exceeds the cost of shutting down the fuel cell system. In other words, at the threshold time t tr After expiration, it becomes more costly to keep one or more of the fuel cell systems operating than to shut down the fuel cell systems.

[0074] If the estimated duration of the vehicle stop is within the threshold time t tr After the expiration, at box 218, method 200 includes shutting down the fuel cell system and enabling antifreeze protection. In addition, in some cases, if the estimated duration of the vehicle stay is equal to the threshold time t tr , method 200 may similarly include shutting down the fuel cell system and enabling freeze protection.

[0075] Freeze protection can include the use of external heaters, antifreeze solutions, draining water before shutting down, and other techniques. The specific freeze protection method can depend on the characteristics of the powertrain, fuel cell system, and other factors.

[0076] In some embodiments, enabling freeze protection includes selecting a freeze protection method that is a method suitable for the fuel cell system.

[0077] If the estimated duration of the vehicle dwell expires before the threshold time, method 200 includes maintaining at least one of the fuel cell systems in operation, as indicated by block 220. In some embodiments, if it is determined that the vehicle has a power demand during the vehicle dwell, and the electrical energy storage system is unable to meet the power demand during the vehicle dwell (e.g., Figure 2A), the method 200 similarly proceeds to frame 220, which includes maintaining at least one of the fuel cell systems in operation. At least one of the fuel cell systems can be maintained in operation to keep the remaining fuel cell systems warm, thereby preventing freezing.

[0078] In some embodiments, maintaining at least one fuel cell system of a plurality of fuel cell systems of a vehicle in operation includes determining which fuel cell system to maintain in operation. The state of health of each of the fuel cell systems of the vehicle may be used for this purpose. Thus, at least one fuel cell system may be selected at block 222 by comparing values ​​each representing the state of health of a corresponding fuel cell system of the plurality of fuel cell systems, wherein at least one fuel cell system has the highest value representing the state of health of the at least one fuel cell system. Thus, at least one fuel cell system having the highest value representing its state of health (SoH) is selected.

[0079] The value representing the SoH of a fuel cell system (or the value of the SoH) can be determined in a number of ways. For example, the polarization curve of the fuel cell system can be evaluated. The polarization curve (which shows the voltage output of the fuel cell system at a given current density load) can be used to analyze the fuel cell degradation process. As the fuel cell system ages, the polarization curve of the fuel cell system changes. Therefore, as the fuel cell system ages, for the same current, the voltage drops, and this can give an indication of the SoH value of the fuel cell system.

[0080] Furthermore, in some examples, numerical techniques and / or machine learning may be used to estimate or predict the SoH value of a fuel cell system using data regarding the conditions in which the fuel cell system operates. For example, a history of operating conditions of a fuel cell system may be used to predict the SoH value of a fuel cell system.

[0081] Figure 2B Based on an example Figure 2A Another flow chart of a method 200 for controlling a powertrain including a plurality of fuel cell systems and an electrical energy storage system. Figure 2B In more detail, the various aspects of the present disclosure are shown in FIG. tr calculation and use.

[0082] like Figure 2B As shown, method 200 may determine at block 211 that freeze protection is required and / or that the ESS does not meet power requirements during vehicle parking. For example, Figure 2A The "yes" arrow appearing in decision box 210 in FIG. 2 represents a situation in which it is determined that antifreeze protection is required.

[0083] In some embodiments, if freeze protection is required, Figure 2B The time period t is calculated or estimated at blocks 214 and 215. tr (threshold time) and t0 (initial closing time). The intersection point is t tr indicates that after this time, it is more cost-effective to shut down the fuel cell system and perform antifreeze protection rather than keep the fuel cell system operating. tr , the fuel cell system is shut down and antifreeze protection is activated. If the vehicle stays for less than t tr , then at least one fuel cell system can remain operational to keep the other fuel cell systems warm to prevent freezing.

[0084] In an embodiment of the present disclosure, t can be estimated based on a comparison of the hydrogen consumption cost that will be incurred when the fuel cell system is kept in operation (including the degradation cost for keeping the fuel cell system in operation) and the expected degradation cost that will occur when antifreeze protection is performed. tr and t0. When the vehicle needs to move, the fuel cell system is restarted.

[0085] Figure 4 is a threshold time t when the vehicle does not have any energy / power demand during the vehicle stop period tr The graph 400 shows the change of hydrogen consumption of the fuel cell system over time. tr The estimation may be performed using a first threshold time t1 and a second threshold time t2. The first threshold time t1 may be calculated for a scenario where the electric energy storage system cannot store any power generated by the fuel cell system during the vehicle stop period, and the second threshold time t2 may be calculated for a scenario where the electric energy storage system can store all power generated by the fuel cell system during the vehicle stop period. Figure 4 As shown, the threshold time t tr is between a first threshold time t1 and a second threshold time t2. The first threshold time t1 and the second threshold time t2 are two extreme values ​​calculated based on scenarios in which the ESS (e.g., battery) cannot obtain or store any power generated from the fuel cell system (i.e., the ESS cannot be charged) and in which the ESS can obtain or store all or the entire power generated from the fuel cell system during the dwell / vehicle parking duration, respectively. When the battery can no longer obtain any power, the power may be dissipated, for example, to heat the cabin space of the vehicle or dissipated in other ways, for example, via a brake resistor that can dissipate excess energy.

[0086] Figure 4The horizontal lines in show cost thresholds R1 and R2 used to calculate the first threshold time t1 and the second threshold time t2. R1 represents an acceptable threshold when the ESS cannot store any power generated from the fuel cell system (i.e., the ESS cannot be charged), while R2 represents an acceptable threshold when the ESS can store all the power from the fuel cell system for charging. The principle behind this is that if the ESS (such as a battery) can be charged with the power generated from the fuel cell system, a higher hydrogen consumption cost can be accepted to keep the system operating because the charged battery compensates for this cost when the vehicle needs to move next time.

[0087] The R1 threshold when the battery cannot be charged can be determined using the energy required for antifreeze preparation and thawing of the fuel cell system after freezing. In addition, to calculate the R1 threshold, degradation due to startup and drainage is considered.

[0088] According to the charge state of the ESS when the vehicle is parked, the threshold time t tr It can be located between the first threshold time t1 and the second threshold time t2. Therefore, Figure 4 shows the threshold time t tr is between t1 and t2, and its position relative to the first threshold time t1 and the second threshold time t2 may vary according to the charge state of the ESS (such as a battery) at the time of initial parking. For example, if the battery is exhausted or nearly exhausted, the threshold time t tr As another example, if the battery is fully charged, the threshold time t tr The first threshold time t1 may be approached. Assuming that the fuel cell system is running or operating at a constant power level, the shape of the hydrogen consumption line or graph can be considered to be linear. However, the slope of the hydrogen consumption graph and the shape of the graph (e.g., curve) may vary depending on environmental conditions and fuel cell system operation.

[0089] In some cases, the threshold time t tr It can be called that the time from when the vehicle is turned off and stays is extended until the threshold time t tr The time period for expiration. Figure 4 The graph 400 is shown as a straight line graph passing through the points (t1, R1) and (t2, R2). tr The point where the vertical line (parallel to the y-axis) intersects is the point in time when shutting down the fuel cell system and performing antifreeze protection is as cost-effective as keeping the fuel cell system operating. However, at the threshold time t tr At a later point in time, it may be more cost-effective to shut down the fuel cell system and perform freeze protection rather than keep the fuel cell system operating. trAt previous points in time, shutting down the fuel cell system and performing freeze protection may not be as cost effective as keeping the fuel cell system operating.

[0090] In some embodiments, at least one fuel cell system of the vehicle's powertrain may be restarted after a certain period of time during which the plurality of fuel cell systems are shut down. The certain period of time may be denoted as t0, which may be, for example, Figure 2B . Thus, the fuel cell system of the vehicle's powertrain may be restarted before the ambient temperature drops to a point where freezing may occur, or the fuel cell system may be restarted before the fuel cell system itself reaches freezing temperatures. For example, this may be the case where the ambient temperature around a parked vehicle is high during the day, such as above 0°C (e.g., at least 5°C, or another temperature above zero), but drops below freezing during the night. This may be the case when the ambient temperature around the parked vehicle is high during the day, such as above 0°C (e.g., at least 5°C, or another temperature above zero). Figure 5 , which shows the threshold time t when the vehicle does not have any energy / power demand during the vehicle stop period. tr Another graph 500 of the calculation of . Graph 500 shows the variation of hydrogen consumption of a fuel cell system over time.

[0091] exist Figure 5 In the example shown in FIG. , the additional time t0 is also included in the threshold time t tr The time t0 represents the time when the fuel cell system is shut down. At time t0, the previously shut down fuel cell system is restarted, and the hydrogen consumption cost starts to increase after this time t0. The first threshold time t1 and the second threshold time t2 and other calculations of R1 and R2 are the same as Figure 4 However, in Figure 5 In the example, the thresholds R1 and R2 used to calculate t1 and t2 may be lower than Figure 4 in order to take into account the increased degradation that may occur due to restarting of the fuel cell system.

[0092] Figure 5 A straight line graph 500 is shown passing through points (t1, R1) and (t2, R2). The graph 500 is related to the time t1 passing through the threshold value. tr The point where the vertical line (parallel to the y-axis) intersects is the point in time when shutting down the fuel cell system and performing antifreeze protection is as cost-effective as keeping the fuel cell system operating. However, at the threshold time t tr At a later point in time, it may be more cost effective to shut down the fuel cell system and perform freeze protection rather than keep the fuel cell system operating.

[0093] Figure 6 The threshold time t for calculating the energy / power demand of the vehicle during the vehicle stop period is shown.tr 600 and a second graph 602. The first graph 600 and the second graph 602 are each shown as changes in hydrogen consumption of a fuel cell system over time. More specifically, both graphs represent the hydrogen consumed to keep the system warm and prevent freezing. Heat is a byproduct of power generation by the fuel cell system, and when a certain amount of power is generated, a certain amount of heat is also generated. This heat can be used to keep the system warm. Graph 600 shows a situation where there is no power demand, while graph 602 shows a situation where there is a power demand. If the vehicle has a power demand that is met by the fuel cell system, the cost of hydrogen consumption required to keep the fuel cell system operating to prevent freezing may be lower over time. The basic principle is that some hydrogen consumption is considered to achieve the energy and power needs of the vehicle.

[0094] like Figure 6 As shown, it can be assumed that, for example, the fuel cell system consumes hydrogen according to the first line diagram 600 while providing a certain first power amount (e.g., 10 kW). However, a certain second power amount (e.g., 5 kW, which Figure 6 600) to achieve the power demand of the vehicle, so that the actual hydrogen consumption rate used only for antifreeze protection is only considered as part of the total hydrogen consumption. Using the example values ​​and given that the first power amount is greater than the second power amount, the power consumed by the antifreeze protection can be considered as the remaining power, that is, the first power amount minus the second power amount (in this example, the antifreeze protection is 10 kW-5 kW=5 kW). If the power demand of the vehicle (for example, when the driver is sleeping in the vehicle or when power output is required) is greater than the power required by the fuel cell system to keep itself warm (for example, the second power amount is 15 kW instead of 5 kW), then the vehicle power / energy demand can be considered to be greater than the first power amount represented in graph 600. In this case, continuing with this example, the second line graph 602 can coincide with the x-axis, and the fuel cell system will operate to achieve the power / energy demand of the vehicle without any additional antifreeze protection costs (for example, 10 kW-15 kW<0 kW, so the additional power required for antifreeze protection is 0 kW). In this case, i.e., when the fuel cell system is running to achieve the power demand of the vehicle, heat for heating the system is generated as a byproduct, which can be referred to as free net electricity generation, i.e., without additional cost. Therefore, the hydrogen consumption used only for heating the fuel cell system will be zero. This will cause the second line graph 602 to coincide with the x-axis, because the additional hydrogen consumption for antifreeze protection is zero. However, it should be noted that in this case the hydrogen consumption itself is not zero, but the hydrogen consumption used to heat the fuel cell system is zero.

[0095] Figure 6A straight line graph 602 is shown passing through points (t1, R1) and (t2, R2). Graph 602 and the time after the threshold value t tr The point where the vertical line (parallel to the y-axis) intersects is the point in time at which shutting down the fuel cell system and performing freeze protection is as cost-effective as keeping the fuel cell system operating. tr At a later point in time, it may be more cost effective to shut down the fuel cell system and perform freeze protection rather than keep the fuel cell system operating.

[0096] Return to reference Figure 2B , similar to Figure 2A In the process shown in FIG. 2 , a determination is made at decision block 216 as to whether the estimated duration of the vehicle stop is within a threshold time t tr If this is the case, then at box 218, method 200 includes shutting down the fuel cell system and enabling freeze protection. In some embodiments, enabling and executing freeze protection includes selecting a freeze protection method that is suitable for the fuel cell system.

[0097] If the estimated duration of the vehicle stop is within the threshold time t tr If the timeout period has expired before the timeout period has expired, the method 200 may include (1) maintaining at least one of the fuel cell systems in operation, or (2) restarting at least one of the fuel cell systems. Figure 2A , the option of maintaining at least one fuel cell system in operation is shown at box 220. Alternatively, Figure 2B At block 219 of the embodiment, it may be determined whether at least one fuel cell in the fuel cell system needs to be restarted after time t0. Figure 2B As further shown in FIG. 2 , the process at box 219 may also be performed after the fuel cell system has been shut down and freeze protection has been enabled at box 218 .

[0098] At decision block 221, it may be determined whether at least one fuel cell in the plurality of fuel cell systems needs to be restarted after time t0. If it is determined that at least one fuel cell system needs to be restarted, the at least one fuel cell system may be restarted at block 223. Alternatively, if it is determined that at least one fuel cell system does not need to be restarted, the fuel cell system may remain shut down at block 225.

[0099] Figure 3A and Figure 3B is a flow chart that together illustrates another example of a method 300 for controlling a powertrain of a vehicle that includes multiple fuel cell systems and an electrical energy storage system. Figure 3A and Figure 3B Method 300 is similar to Figure 2A and Figure 2BMethod 200. Method 300 may be performed by a controller unit (such as, for example Figure 1 The control unit 40) is used to execute.

[0100] Figure 3A and Figure 3B The order of the actions associated with the blocks in the diagram is shown by way of example only, as the actions or steps may be performed in other orders. Figure 3A and Figure 3B It is not indicated in the , but one or more actions may be optional.

[0101] exist Figure 3A In the method 300, at box 302, the method 300 includes receiving a vehicle parking / shutdown request. For example, the driver may shut down the vehicle. If the vehicle is an autonomous or semi-autonomous vehicle, the vehicle may shut down automatically.

[0102] At block 304, a duration of time that the vehicle was stationary after the vehicle was shut down is determined. This may be performed using at least driver input, location data (e.g., the vehicle's global positioning system (GPS) location), and historical data (which may include historical data about the driver, vehicle operation, use of auxiliary devices of the vehicle, etc.).

[0103] At decision box 305, it may be determined whether the driver is sleeping in the vehicle and / or whether there are any PTO applications associated with the vehicle, such as a PTO device. If it is determined whether the driver is sleeping in the vehicle and / or whether there are PTO applications, it may be further determined at box 306 that the vehicle has energy / power demand (referred to herein as power demand) during the vehicle's stay (e.g., when the vehicle is parked). The power demand for the duration of the vehicle's stay may include power demand for PTO devices connected to or mounted on the vehicle (such as, for example, a crane, refrigerator, air conditioner, heater, etc.). The power demand may be estimated using environmental conditions, the duration of the vehicle's stay (determined at box 304), information about vehicle auxiliary devices that have been turned on, historical data about the use of vehicle auxiliary devices, and using other data. Non-limiting examples of auxiliary devices include auxiliary batteries, mobile air conditioning systems, electric lift windows, heating systems, cranes (e.g., hydraulic cranes), etc.

[0104] After determining that the vehicle has a power demand during the vehicle stop, the method 300 can proceed to box 308, where it can be determined whether the ESS can meet or achieve the power demand during the vehicle stop. If it is determined that the ESS can meet the power demand of the vehicle during the vehicle stop, the method 300 can proceed to box 310, where it is determined whether it is necessary to protect multiple fuel cell systems of the vehicle from freezing during the vehicle stop. However, if it is determined that the ESS cannot meet the power demand of the vehicle during the vehicle stop, the method 300 can proceed to box 320, where the method 300 includes: (1) based on the vehicle power demand during the vehicle stop, keep one or more fuel cell systems in the multiple fuel cell systems running or operating; and (2) if it is necessary to keep one of the multiple fuel cell systems operating (or turned on), select the fuel cell system with the highest value representing the health status of the fuel cell system in the multiple fuel cell systems to keep the other fuel cell systems warm.

[0105] like Figure 3A As shown, after decision block 310, method 300 continues at Figure 3B For the sake of clarity, Figure 3B The decision box is shown again in Figure 3B As shown, a determination as to whether freeze protection of multiple fuel cell systems of a vehicle is required during a vehicle dwell period may be performed based on environmental conditions (eg, using data obtained from a predictive weather service), which may be current or predicted conditions.

[0106] If it is determined that freeze protection is not required, the fuel cell system may be shut down (as indicated by block 312 ) and freeze protection may not be enabled.

[0107] If it is determined that antifreeze protection is required, the threshold time t may be calculated at block 314 tr and the closing time t0. These can also be Figure 2B Next, at decision block 316, it may be determined whether the estimated duration of the vehicle stop is greater than a threshold time t tr (ie, expires after the threshold time.) If this is the case, then at box 318, method 300 includes shutting down the fuel cell system and performing freeze protection. The fuel cell system may be heated before or at its next startup.

[0108] If it is determined at decision block 316 that the estimated duration of the vehicle stop is less than the threshold time t tr(i.e., expires before the threshold time), the method 300 may proceed to block 322, where the method 300 includes: (1) selecting a fuel cell system having a higher state of health (SoH) value from the plurality of fuel cell systems and maintaining its operation / operation or restarting it after time t0, or (2) using at least one fuel cell system in operation from the plurality of fuel cell systems to keep other fuel cell systems in the plurality of fuel cell systems warm. Thus, the process may include using data about the state of health of the plurality of fuel cell systems of the powertrain of the vehicle, such as Figure 3B shown.

[0109] In order to perform the method steps described herein, the control unit 40 may be configured to perform the above-mentioned steps in conjunction with Figure 2A , Figure 2B , Figure 3A and Figure 3B The control unit 40 may include, for example, Fig. 7A and Figure 7B The arrangement depicted in .

[0110] like Fig. 7A As shown, the control unit 40 may include an input and output interface 700, which is configured to communicate with any necessary components and / or entities of the embodiments herein, for example, receiving system status from the ESS 50, receiving location information, weather information, information about driver input, any type of historical data, information about at least one auxiliary device of the vehicle, information about the use of at least one auxiliary device of the vehicle, and any other information. The input and output interface 700 may include a wireless and / or wired receiver (not shown) and a wireless and / or wired transmitter (not shown). The input and output interface 700 may include a transmitter, a receiver, a transceiver, and / or one or more antennas. The control unit 40 may be located in any suitable position of the vehicle 10. The control unit 40 may use the input and output interface 700 to control and communicate with sensors, actuators, subsystems, and interfaces in the vehicle 10 using any one or more of a controller area network (CAN), an Ethernet cable, Wi-Fi, Bluetooth, and other network interfaces. The control unit 40 may be configured to communicate with one or more external services, databases, and / or controllers via wireless communication technology.

[0111] The methods described herein may be performed by processing circuitry (e.g., one or more processors such as Fig. 7AThe processing circuit 760 of the control unit 40 depicted in FIG))) together with computer program code for performing the functions, actions and steps of the embodiments herein. The computer program code can be provided as a computer program medium, for example, in the form of a computer readable storage medium, which carries computer program code or computer executable instructions, which are used to perform methods according to embodiments of the present disclosure when loaded into the control unit 40 and executed by the processing circuit 760. An example of a computer readable storage medium can be in the form of a memory stick or any other suitable medium that can store machine readable data. The computer program code can also be provided as program code on a server and downloaded to the control unit 40.

[0112] The control unit 40 may also include a memory 770, which includes one or more memory units. The memory 770 includes instructions that can be executed by the processing circuit 760 of the control unit 40. The memory 770 is arranged to store, for example, information, data, etc. to perform the method herein when executed in the control unit 40. The control unit 40 may additionally obtain information from an external memory.

[0113] In some embodiments, the computer program product 780 includes instructions (e.g., software code portions) that, when executed on at least one processor (e.g., on the processing circuit 760), cause the at least one processor to perform the method steps described herein as performed by the control unit 40.

[0114] In some embodiments, the computer readable storage medium 790 stores a computer program product 780. The computer readable storage medium 790 may be, for example, a disk, a universal serial bus (USB) stick, etc. The computer readable storage medium 790 may store thereon a computer program product 780 that includes program code or instructions that, when executed on at least one processor (e.g., processing circuit 760), cause the at least one processor to perform methods according to embodiments herein.

[0115] like Figure 7B As shown in FIG. 7 , the control unit 40 may include a receiving unit 702. The control unit 40, the processing circuit 760 and / or the receiving unit 702 may be configured to receive or detect a vehicle shutdown request.

[0116] The control unit 40 may further include an estimation unit 704. The control unit 40, the processing circuit 760 and / or the estimation unit 704 may be configured to estimate the duration of a vehicle stop of the vehicle. The duration of the vehicle stop may be estimated using one or more of driver input, location information, environmental information, and historical data related to the operation of the vehicle.

[0117] The control unit 40 may further include a determination unit 706. The control unit 40, the processing circuit 760, and / or the determination unit 706 may be configured to determine whether antifreeze protection is needed during the vehicle's stay. In some cases, whether antifreeze protection is needed during the vehicle's stay may be determined using current environmental conditions and predicted environmental conditions. In some implementations, the estimation unit 704 and the determination unit 706 may be part of the same unit.

[0118] The control unit 40 may also include a shut down unit 708. If it is determined that antifreeze protection is not required, the control unit 40, the processing circuit 760 and / or the shut down unit 708 may be configured to shut down the fuel cell system without enabling antifreeze protection. Thus, when it is determined that antifreeze protection is not required, antifreeze protection is not performed on the fuel cell system. However, the shut down unit 708 of the control unit 40 may generally be able to control the fuel cell system and / or other components of the powertrain or vehicle to perform antifreeze protection on the fuel cell system when it is determined that antifreeze protection is required.

[0119] The control unit 40, the processing circuit 760 and / or the estimation unit 704 may also be configured to estimate a threshold time indicating a time when the cost of keeping the fuel cell system operating exceeds the cost of shutting down the fuel cell system, such as the threshold time t tr The threshold time may be estimated using a first threshold time and a second threshold time. The first threshold time may be calculated for a situation where the electric energy storage system cannot store any power generated by the fuel cell system during a vehicle stop, and the second threshold time may be calculated for a situation where the electric energy storage system can store all power generated by the fuel cell system during a vehicle stop.

[0120] The control unit 40 , the processing circuit 760 , and / or the shutdown unit 708 may also be configured to shut down the fuel cell system and enable freeze protection if it is determined that the estimated duration of the vehicle stop has expired after a threshold time.

[0121] The control unit 40 may also include a power estimation unit 710. The control unit 40, the processing circuit 760, and / or the power estimation unit 710 may be configured to use at least the estimated duration of the vehicle's stop to determine whether the vehicle has a power demand during the vehicle's stop. Determining whether the vehicle has a power demand during the vehicle's stop may include determining whether the driver of the vehicle is sleeping in the vehicle and / or whether the vehicle is parked during the vehicle's stop. The control unit 40, the processing circuit 760, and / or the power estimation unit 710 may be configured to use various other information (such as, for example, information about auxiliary devices of the vehicle, current and / or predicted environmental conditions, and other information) to determine whether the vehicle has a power demand during the vehicle's stop.

[0122] The control unit 40, the processing circuit 760 and / or the determination unit 706 may be configured to determine whether antifreeze protection is required during the vehicle stop, wherein when it is determined that the vehicle has no power demand during the vehicle stop, it is determined whether antifreeze protection is required during the vehicle stop. In an embodiment, when it is determined that the vehicle has a power demand during the vehicle stop and the power demand can be achieved during the vehicle stop, it is determined whether antifreeze protection is required during the vehicle stop.

[0123] The control unit 40 may further include a fuel cell system control unit 712. The control unit 40, the processing circuit 760, and / or the fuel cell system control unit 712 may be configured to keep at least one fuel cell system in the fuel cell system operating if the control unit 40, the processing circuit 760, and / or the power estimation unit 710 determines that the vehicle has a power demand during the vehicle stop and the power demand cannot be met during the vehicle stop.

[0124] The control unit 40, the processing circuit 760 and / or the fuel cell system control unit 712 may be configured to: if the estimated duration of the vehicle stop is within the threshold time t tr If the timeout period has expired before, then (1) at least one of the fuel cell systems is maintained in operation, or (2) at least one of the fuel cell systems is restarted.

[0125] In a certain example, at least one fuel cell system may be restarted after a certain period of time when the multiple fuel cell systems are shut down. The control unit 40, the processing circuit 760 and / or the fuel cell system control unit 712 may be configured to restart the multiple fuel cell systems.

[0126] The control unit 40 may further include a selection unit 714. The control unit 40, the processing circuit 760, and / or the selection unit 714 may be configured to select at least one fuel cell system by comparing values ​​each representing a health state of a corresponding fuel cell system in a plurality of fuel cell systems, wherein at least one fuel cell system has a highest value representing a health state of at least one fuel cell system. The at least one fuel cell system may be selected to remain in operation, or the at least one fuel cell system may be selected to be restarted, for example, to keep other fuel cell systems warm. In some examples, at least one fuel cell system may be selected to be restarted after a certain period of time when the plurality of fuel cell systems are shut down. The fuel cell system may be selected from two or more fuel cell systems. If the vehicle includes one fuel cell system, the fuel cell system is selected.

[0127] The units in the control unit 40 may be composed of Fig. 7A708. The processing circuit 760 shown in is executed. It should be understood that the units in the control unit 40 are shown as examples because one or more of the units can be parts of the same unit, or one or more of the units can have sub-units. For example, in some embodiments, the fuel cell system control unit 712 and the shutdown unit 708 can be parts of the same unit of the controller 40. In addition, one or more of the fuel cell system control unit 712, the shutdown unit 708, and the selection unit 714 can be parts of the same unit. In some embodiments, one or more of the estimation unit 704, the determination unit 706, and the power estimation unit 710 can be parts of the same unit.

[0128] It should be understood by those skilled in the art that the units in the control unit 40 described above may refer to a combination of analog and digital circuits, and / or one or more processors configured with software and / or firmware, for example, stored in the control unit 40, which, when executed by the corresponding one or more processors, may perform the method according to the embodiments of the present disclosure. One or more of these processors and other digital hardware may be included in a single application specific integrated circuit (ASIC), or several processors and various digital hardware may be distributed over several separate components, whether packaged separately or assembled into a system on a chip.

[0129] The operational steps described in any of the exemplary aspects herein are described to provide examples and discussion. These steps may be performed by hardware components, may be embodied in machine executable instructions to cause a processor to perform these steps, or may be performed by a combination of hardware and software. Although a specific order of method steps may be shown or described, the order of the steps may be different. In addition, two or more steps may be performed simultaneously or partially simultaneously.

[0130] The terms used herein are only used for the purpose of describing specific aspects and are not intended to limit the present disclosure. As used herein, the singular forms "a", "an" and "the" are intended to also include plural forms, unless the context clearly indicates otherwise. As used herein, the term "and / or" includes any and all combinations of the associated listed items. It should also be understood that the terms "include" and / or "comprise" when used herein clearly indicate the presence of the features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0131] It should be understood that although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, without departing from the scope of the present disclosure, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element.

[0132] Relative terms such as "below" or "above", or "upper" or "lower", or "horizontal" or "vertical" may be used herein to describe the relationship of one element to another element, as shown in the figures. It should be understood that these terms and those discussed above are intended to cover different device orientations in addition to the orientations depicted in the figures. It should be understood that when an element is referred to as being "connected to" or "coupled to" another element, the element may be directly connected or coupled to the other element or there may be intervening elements. In contrast, when an element is referred to as being "directly connected to" or "directly coupled to" another element, there are no intervening elements.

[0133] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those commonly understood by those skilled in the art to which the present disclosure belongs. It should also be understood that, unless otherwise clearly defined herein, the terms used herein should be interpreted as meanings consistent with their meanings in the context of this specification and the relevant art, and should not be interpreted in an idealized or overly formal sense.

[0134] It should be understood that the present disclosure is not limited to the aspects described above and shown in the accompanying drawings; rather, the skilled person will recognize that many changes and modifications may be made within the scope of the present disclosure and the appended claims. In the drawings and description, various aspects have been disclosed for illustrative purposes only and not for limiting purposes, and the scope of the inventive concept is set forth in the above claims.

Claims

1. A computer-implemented method of controlling a powertrain (20) of a vehicle (10), wherein the powertrain includes a plurality of fuel cell systems (30) and an electrical energy storage system (50), the method comprising: estimating (204) a duration of a vehicle stop of the vehicle; determining (210) whether antifreeze protection is required during the period when the vehicle is stationary; as well as If it is determined that the antifreeze protection is not required, shutting down (212) the fuel cell system without enabling the antifreeze protection.

2. The method of claim 1, further comprising: If it is determined that the freeze protection is required, estimating (214) a threshold time indicative of a time at which a cost of maintaining the fuel cell system in operation exceeds a cost of shutting down the fuel cell system; as well as If the estimated duration of the vehicle stop expires after the threshold time (216), the fuel cell system is shut down and the freeze protection is enabled (218).

3. The method of claim 2, further comprising: At least the estimated duration of the vehicle dwell is used to determine ( 206 ) whether the vehicle has a power demand during the vehicle dwell.

4. The method of claim 3, wherein determining whether the vehicle has a power demand during the vehicle stop includes determining (205) whether a driver of the vehicle is sleeping in the vehicle and / or whether the vehicle is parked during the vehicle stop. 5 . The method according to claim 3 , wherein when it is determined that the vehicle has no power demand during the vehicle stop period, it is determined whether the antifreeze protection is required during the vehicle stop period.

6. The method of claim 3 or 4, wherein when it is determined that the vehicle has a power demand during the vehicle stop and the electric energy storage system can meet the power demand during the vehicle stop, it is determined whether the antifreeze protection is required during the vehicle stop.

7. The method according to claim 3 or 4, further comprising: If it is determined that the vehicle has a power demand during the vehicle stop and the electrical energy storage system cannot meet the power demand during the vehicle stop, at least one of the fuel cell systems is maintained (220) in operation.

8. The method according to any one of claims 2 to 7, further comprising: If the estimated duration of the vehicle stop expires before the threshold time, (1) at least one of the fuel cell systems is maintained in operation, or (2) the at least one fuel cell system is restarted.

9. The method of claim 8, wherein the at least one fuel cell system is restarted after a certain period of time during which the plurality of fuel cell systems are shut down.

10. A method as described in any one of claims 7 to 9, further comprising selecting (222) at least one fuel cell system by comparing values ​​each representing a health status of a corresponding fuel cell system among the multiple fuel cell systems, and wherein the at least one fuel cell system has a highest value representing the health status of the at least one fuel cell system.

11. The method of any one of claims 1 to 10, wherein the threshold time is estimated using a first threshold time and a second threshold time, wherein the first threshold time is calculated for a situation where the electrical energy storage system is unable to store any power generated by the fuel cell system during the vehicle stop, and the second threshold time is calculated for a situation where the electrical energy storage system is able to store all power generated by the fuel cell system during the vehicle stop.

12. The method of any one of claims 1 to 11, wherein the duration of the vehicle dwell is estimated using one or more of driver input, position information, environmental information, and historical data relating to operation of the vehicle.

13. The method of any one of claims 1 to 12, wherein whether the antifreeze protection is required during the vehicle's stationary period is determined using current ambient conditions and predicted ambient conditions.

14. A control unit (40) for controlling a powertrain (20) of a vehicle (10), the powertrain comprising a plurality of fuel cell systems (30) and an electrical energy storage system (50), the control unit (40) being configured to perform the method according to any one of claims 1 to 13.

15. A powertrain (20) comprising a plurality of fuel cell systems (30) and an electrical energy storage system (50), the powertrain (20) further comprising a control unit (40) as claimed in claim 14.

16. A vehicle (10) comprising a powertrain (20) as claimed in claim 14 and / or communicating with a control unit (40) as claimed in claim 15.

17. A computer program product comprising instructions which, when executed on at least one processor, cause the at least one processor to perform the method of any one of claims 1 to 13.

18. A computer readable storage medium having stored thereon a computer program product comprising instructions which, when executed on at least one processor, cause the at least one processor to perform the method of any one of claims 1 to 13.

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