A computer-implemented method for controlling the operation of at least two fuel cell systems
The method adjusts fuel cell system operations based on actual and expected health states to balance degradation, extending the service life and maintaining power output in vehicles with multiple fuel cell systems.
Patent Information
- Application Number
- JP2024571926
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2022-06-13
- Publication Date
- 2025-07-03
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
Fuel cell systems in vehicles experience degradation during use, affecting their service life, and existing methods struggle to balance the operation of multiple systems to extend their combined service life effectively.
A computer-implemented method that adjusts the operating dynamics and operating window of individual fuel cell systems based on their actual and expected health states, balancing degradation levels by reducing dynamics in weaker systems and increasing them in stronger systems.
Extends the service life of combined fuel cell systems by managing unexpected degradation through dynamic adjustments, ensuring balanced power output without adversely affecting the system's lifespan.
Smart Images
Figure 2025520323000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a computer-implemented method for controlling the operation of at least two fuel cell systems. The present invention also relates to a control unit, a propulsion system, a vehicle, a computer program, and a computer-readable medium.
[0002] The present invention can be applied to large vehicles such as trucks, buses, and construction equipment. Although the present invention is described with respect to trucks, the present invention is not limited to this particular vehicle and may also be used in other vehicles, such as wheel loaders, excavators, dump trucks, and passenger cars. The present invention is also applicable to non-vehicle applications.
Background Art
[0003] There are many different techniques for generating thrust in a vehicle. One such technique is to use electric power to drive one or more electromechanical devices of the vehicle. The electromechanical devices can be powered using a plurality of fuel cell systems.
[0004] A fuel cell is an electrochemical cell that converts chemical energy into electricity. A fuel cell generally converts the chemical energy of a fuel, which is generally hydrogen, and an oxidant, which is generally oxygen, into electricity. Therefore, a fuel cell can be used as an alternative to, or as a complement to, an electric battery. In recent years, fuel cells have been considered for powering electric vehicles such as pure electric vehicles and hybrid electric vehicles.
[0005] For example, fuel cell systems used in combination to power a vehicle are prone to degradation during use. Degradation affects the service life of the system. Therefore, it is very important to attempt to reduce the amount of degradation of the system, thereby extending the service life.
[0006] In view of the above, efforts have been made to extend the service life of such systems, and the present invention is directed to situations where at least two fuel cell systems are used to supply power. SUMMARY OF THE INVENTION
[0007] Accordingly, an object of the present invention is to provide an improved method for controlling the operation of at least two fuel cell systems, or at least a suitable alternative. In particular, an object of the present invention is to extend the service life of the combined system. Another object of the present invention is to provide an improved control unit, an improved propulsion system, an improved vehicle, a computer program and / or a computer-readable medium, or at least a suitable alternative.
[0008] According to a first aspect of the present invention, the object is at least partially achieved by the method according to claim 1.
[0009] Accordingly, a computer-implemented method for controlling the operation of at least two fuel cell systems is provided.
[0010] Each fuel cell system is adapted to operate by adjustable operating dynamics that define the operating constraints of the fuel cell system and / or within an adjustable operating window, and increasing the operating dynamics and / or the operating window is associated with an increased expected degradation of the fuel cell system, and decreasing the operating dynamics and / or the operating window is associated with a decreased expected degradation of the fuel cell system.
[0011] The method comprises obtaining the estimated actual health state of each fuel cell system, comparing the actual health states of the fuel cell systems, and if the comparison indicates a predetermined difference between the actual health states of the fuel cell systems, Identifying a first fuel cell system of at least two fuel cell systems having the lowest actual soundness state of the at least two fuel cell systems; Comparing the actual soundness state of the first fuel cell system with a determined expected soundness state of the first fuel cell system, wherein the expected soundness state is based on a history of usage conditions of the first fuel cell system; When the actual soundness state of the first fuel cell system is worse than its expected soundness state, reducing the operating dynamics and / or operating window of the first fuel cell system and increasing the operating dynamics and / or operating window of another fuel cell system; Including.
[0012] The fuel cell systems are adapted to be individually controlled. That is, the operating dynamics and / or operating window of one of the systems can be increased while the operating dynamics and / or operating window of another fuel cell system can be decreased.
[0013] As used herein, the operating dynamics of a system refer to how the operation of the system varies over time. For example, large and / or rapid variations in the operating parameters during use represent higher operating dynamics of the system compared to situations where the variations in the operating parameters are smaller and / or slower. This can also be referred to as the throughput rate of the system. As used herein, the operating window refers to the window or range during which the operating parameters are in use. As an example, the operating parameter may refer to the power output from the system. Thus, the operating dynamics can be defined as the power dynamics of a fuel cell system, for example, the rate at which a fuel cell system can transition from low power to high power or full power. Other non-limiting examples of operating parameters are voltage level, ampere level, and power throughput. As yet another non-limiting example, the operating parameter may be related to whether shutdown of the system is permitted. For example, if the fuel cell system shuts down too frequently, degradation may progress.
[0014] By providing the methods disclosed herein, i.e., by controlling the operation of a fuel cell system as disclosed herein, it is possible to achieve levels that are more similar or balanced in terms of the level of degradation of the fuel cell system. In other words, the service life of the fuel cell system can be balanced such that the service life of the combined system is increased. Further, according to the present invention, it is possible to meet, for example, the power needs required by a vehicle while not adversely affecting the service life of the combined system.
[0015] The present invention is based on the recognition that the expected healthy state based on the history of the usage conditions of a fuel cell system is not necessarily the same as the actual healthy state. The reason for this is that it may be difficult to evaluate the actual operating conditions of the fuel cell system. Therefore, during use, that is, during operation, depending on the actual operating conditions, the fuel cell system may deteriorate less or more than expected. Thus, by controlling the operation based on the above-mentioned deviation, the unexpected deterioration of the fuel cell system that is higher than the expected deterioration based on the history of the usage conditions can be managed by enabling more use of other fuel cell systems. As a result, since the service life of the combined system is based on the service life of the weakest fuel cell system, the service life of the combined system can be extended. Further, as another example, it is recognized that the actual healthy state may be different from the expected healthy state due to variations for each component of the fuel cell system. Still further, there may be noise factors that may not be considered in the actual operation when determining the expected healthy state. As disclosed herein, the influence of these noise factors may be considered by comparing the actual healthy state and the expected healthy state.
[0016] As used herein, the healthy state means the level of deterioration of the fuel cell system that affects the remaining life of the fuel cell system. For example, a 100% healthy state implies that the system is new and unused, while a 50% healthy state implies that the remaining life is 50% of the total life of the system.
[0017] Optionally, when the comparison of the actual healthy states of the fuel cell systems shows no difference between the actual healthy states of the fuel cell systems, the method includes operating the fuel cell systems with the same operating dynamics and / or within the same operating window.
[0018] Optionally, the result of the comparison between the actual healthy states of the fuel cell systems indicates a predetermined difference if the difference between them exceeds a predetermined difference threshold. This can avoid unnecessary adjustments that have little or no impact on the combined service life. The predetermined difference threshold can correspond to, for example, a 1 - 5% difference in the actual healthy state.
[0019] Optionally, if the actual healthy state of the first fuel cell system is better than its expected healthy state, the method further includes operating the fuel cell system with the same operating dynamics and / or within the same operating window. This also implicitly indicates that the service life of the combined system is extended, that is, this situation can indicate a satisfactory power distribution between the fuel cell systems.
[0020] Optionally, the decrease in the operating dynamics and / or the operating window of the first fuel cell system and the increase in the operating dynamics and / or the operating window of another fuel cell system are performed such that the combined operating dynamics and / or the combined operating window of at least two fuel cell systems remain unchanged. This can ensure that the required power output from at least two fuel cell systems is satisfied.
[0021] Optionally, the method is initiated in response to obtaining the requirements for operating all of at least two fuel cell systems. This allows the method to be initiated only when necessary, implying improvements in efficiency, reduction in the need for processing power, etc.
[0022] Optionally, the history of the usage conditions of the first fuel cell system is as follows: The power output of the operating fuel cell system, The operating dynamics of the operating fuel cell system, The power cycle frequency of the fuel cell system during operation, The ambient temperature conditions during operation, The ambient air conditions during operation, such as the contamination level, The ambient weather conditions during operation, The start / stop history, The history of the coolant temperature in the fuel cell system, The operating time, includes at least one of the above.
[0023] Optionally, during operation of the fuel cell system, the method is updated at a predetermined update frequency, for example, a frequency corresponding to a predetermined number of operating hours of at least one of the fuel cell systems. Updating at a predetermined update frequency implies a more reliable method. For example, the predetermined update frequency may be set such that the deviation between the actual healthy state and the expected healthy state does not exceed a threshold value. As yet another example, the predetermined update frequency may be set, additionally or alternatively, such that the deviation of the actual healthy state of the fuel cell system does not exceed a threshold value. The aforementioned threshold value may be, for example, within the range of 1 to 5%. For example, the predetermined update frequency may be set as a function of the deviation(s), for example, the greater the deviation(s), the higher the update frequency.
[0024] Optionally, the predetermined update frequency is variable, for example, variable with respect to at least one of the ambient temperature conditions and the ambient weather conditions. A variable update frequency implies a more flexible method, for example, enabling the update frequency to vary according to the ambient conditions. For example, the harsher the ambient conditions, the more likely it is to imply the need to increase the update frequency, and vice versa.
[0025] Optionally, the predetermined update frequency is modified during operation based on the magnitude of the difference in the actual healthy state between fuel cell systems. For example, the greater the difference in the actual healthy state between fuel cell systems, the more likely it is to imply the need to increase the update frequency, and vice versa.
[0026] According to a second aspect of the present invention, the object is at least partially achieved by the control unit according to claim 11.
[0027] Accordingly, a control unit for controlling the operation of at least two fuel cell systems is provided. The control unit is configured to execute the steps of the method according to any one of the embodiments of the first aspect of the present invention.
[0028] The advantages and effects of the second aspect are substantially the same as those of the first aspect of the present invention.
[0029] According to a third aspect of the present invention, the object is at least partially achieved by the propulsion system according to claim 12.
[0030] In this way, a vehicle propulsion system is provided. The propulsion system includes at least two fuel cell systems and further includes a control unit according to the second aspect of the present invention.
[0031] The advantages and effects of the third aspect are substantially the same as those of the first and second aspects of the present invention.
[0032] According to a fourth aspect of the present invention, the object is at least partially achieved by the vehicle according to claim 13. Thus, a vehicle including the propulsion system according to the third aspect of the present invention is provided.
[0033] According to a fifth aspect of the present invention, the object is at least partially achieved by the computer program according to claim 14. Accordingly, the computer program includes program code means for executing the steps of the method according to any one of the embodiments of the first aspect of the present invention when the program is executed on a computer, such as on a control unit according to the second aspect of the present invention.
[0034] According to a sixth aspect of the present invention, the object is at least partially achieved by a computer-readable medium according to claim 15. Thus, the computer-readable medium includes program code means for performing the steps of a method according to any embodiment of the first aspect of the present invention when the program is executed on a computer, such as on a control unit according to the second aspect of the present invention.
[0035] Further advantages and advantageous features of the present invention are disclosed in the following description and the dependent claims.
[0036] Embodiments of the present invention, given by way of example, are described in more detail below with reference to the accompanying drawings.
Brief Description of the Drawings
[0037]
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Mode for Carrying Out the Invention
[0038] FIG. 1 shows a vehicle 100 in the form of a large truck. In this case, the large truck 100 is a so-called tractor configured to tow one or more trailers (not shown). However, the present invention is applicable not only to this type of vehicle, but also to many other types of vehicles and ships, including but not limited to other trucks, buses, passenger cars, construction equipment, such as wheel loaders, dump trucks, excavators, etc.
[0039] In the illustrated embodiment, vehicle 100 includes a propulsion system 1. The propulsion system 1 may be, for example, the propulsion system 1 shown in FIG. 4, which will be further described below. Vehicle 100 further includes a control unit 110 according to an exemplary embodiment of the second aspect of the present invention.
[0040] In particular, the propulsion system 1 includes a fuel cell system FCS1 and another fuel cell system FCS2. The propulsion system 1 may include an electrical energy storage system EES, as further shown in FIG. 4. For example, the electrical energy storage system EES may be an electrical battery such as a lithium-ion battery and / or a capacitor.
[0041] Typically, such a propulsion system 1 of vehicle 1 is adapted to use the EES to compensate for the situation during operation when the fuel cell systems FCS1, FCS2 do not provide all or are not suitable for providing all of the required propulsion force, while the fuel cell systems FCS1, FCS2 contribute most to the propulsion of vehicle 1.
[0042] FIG. 2 shows a flowchart of a computer-implemented method according to an exemplary embodiment of the present invention. This method controls the operation of at least two fuel cell systems FCS1, FCS2.
[0043] Each of the fuel cell systems FCS1, FCS2 is adapted to operate by adjustable operating dynamics that define the operating constraints of the fuel cell systems FCS1, FCS2 and / or within an adjustable operating window. Increasing the operating dynamics and / or the operating window is associated with increasing the expected degradation of the fuel cell systems FCS1, FCS2, and decreasing the operating dynamics and / or the operating window is associated with decreasing the expected degradation of the fuel cell systems FCS1, FCS2.
[0044] The method is S1: Obtain the estimated actual healthy states of each fuel cell system FCS1, FCS2; S2: Compare the actual healthy states of the fuel cell systems FCS1, FCS2, and when the comparison indicates a predetermined difference between the actual healthy states of the fuel cell systems FCS1, FCS2, S3: Identify the first fuel cell system among at least two fuel cell systems FCS1, FCS2 that has the lowest actual healthy state of the at least two fuel cell systems FCS1, FCS2; S4: Compare the actual healthy state of the first fuel cell system with the determined expected healthy state of the first fuel cell system, where the expected healthy state is based on the history of the usage conditions of the first fuel cell system; S5: If the actual healthy state of the first fuel cell system is worse than its expected healthy state, reduce the operating dynamics and / or operating window of the first fuel cell system, and increase the operating dynamics and / or operating window of the other fuel cell system; including.
[0045] The first fuel cell system may be any one of the fuel cell systems FCS1, FCS2. For example, the actual healthy states of the fuel cell systems FCS1, FCS2 may be estimated by the well-known so-called electrochemical impedance spectroscopy. There are also other methods for estimating the actual healthy state, such as the comparison of polarization curves between a used fuel cell system and a new or brand-new fuel cell system. Further still, by way of example, the actual healthy state may be estimated as disclosed in any one of US8907675B2 and US10345389B2.
[0046] The expected healthy state based on the history of usage conditions may be determined, for example, by comparing the current usage amount with the maximum usage amount. For example, in a specific application, a first fuel cell system may be assumed to last for a specific operating time, such as 1000 hours. During this period, it may be assumed that the degradation characteristics are known, such as linear. Thus, for example, when the first fuel cell system has been operating for 500 hours, in linear logic, the expected healthy state should be 50%. This is an efficient approach to estimating the expected healthy state due to its simplicity. However, more advanced approaches are also possible. For example, by considering at least one of the other usage condition histories described later, any event related to the degradation of the first fuel cell system, such as ambient temperature, start / stop history, etc., a value of the expected healthy state closer to the actual healthy state can be obtained. For example, the expected healthy state based on the history of usage conditions can be determined by using tests. As an example, an empirical model can be created based on tests performed under different usage conditions, for example, based on one or more usage conditions corresponding to the history of usage conditions mentioned herein. Thereby, an improved value of the expected healthy state can be obtained.
[0047] Of one of the fuel cell systems, in this case the actual healthy state SoH over time of fuel cell system FCS1 A And the expected healthy state SoH E Examples are shown in FIG. 5. FIG. 5 represents a graph in which the healthy state is represented on the y-axis and time or years is represented on the x-axis. The dotted curve represents the actual healthy state SoH A And the solid curve represents the expected healthy state SoH E In the illustrated example, the expected healthy state SoH Eis based on the history of the usage conditions of the fuel cell system FCS1 and forms a substantially straight line. The straight line may imply, for example, that the usage conditions are substantially static during operation. For example, the power cycle frequency, ambient temperature conditions during operation, etc. may not substantially vary over time. Of course, the history of the usage conditions may vary over time additionally or alternatively, and as a result, the degradation rate may vary over time. Thereby, the expected sound state may not be clearly represented only by a straight line. The history of the usage conditions as used herein may refer to the previous usage conditions of either the fuel cell system FCS1 or FCS2.
[0048] The actual sound state SoH of the first fuel cell system FCS1 A is worse than its expected sound state SoH E An example of this case is shown by ΔFCS1 in FIG. 5. Thus, if this situation is identified by the comparison executed at S5, the operating dynamics and / or operating window of the first fuel cell system FCS1 decrease, and the operating dynamics and / or operating window of the other fuel cell system FCS2 increase.
[0049] For example, the result of the comparison between the actual sound states of the fuel cell systems FCS1 and FCS2 may show a predetermined difference if the difference between them exceeds a predetermined difference threshold. Thereby, unnecessary adjustments that have little or no impact on the combined service life can be avoided. The predetermined difference threshold may correspond to a difference of 1 to 5% in the actual sound state, for example.
[0050] Furthermore, or alternatively, a decrease in the operating dynamics and / or operating window of the first fuel cell system FCS1, and an increase in the operating dynamics and / or operating window of another fuel cell system FCS2, can be performed such that the combined operating dynamics and / or combined operating window of the at least two fuel cell systems FCS1, FCS2 remain unchanged.
[0051] The history of the usage conditions of the first fuel cell system FCS1 includes at least one of the following: The power output of the fuel cell system during operation, The operating dynamics of the fuel cell system during operation, The power cycle frequency of the fuel cell system during operation, The ambient temperature conditions during operation, The ambient air conditions during operation, such as the contamination level, The ambient weather conditions during operation, The start / stop history, The history of the coolant temperature within the fuel cell system, The operating time, and may include at least one of them.
[0052] During operation of the fuel cell systems FCS1, FCS2, the method can be updated at a predetermined update frequency, for example, a frequency corresponding to a predetermined number of operating hours of at least one of the fuel cell systems FCS1, FCS2.
[0053] Furthermore, the predetermined update frequency can be variable, for example, variable with respect to at least one of the ambient temperature conditions and ambient weather conditions.
[0054] The predetermined update frequency can be modified during operation, additionally or alternatively, based on the magnitude of the difference in the actual healthy state between the fuel cell systems FCS1, FCS2.
[0055] FIG. 3 shows another embodiment of the method according to the present invention.
[0056] Box 200 represents the case where vehicle 100 starts, i.e., turns on or operates.
[0057] The method may be initiated in response to obtaining requirements for operating all of at least two fuel cell systems FCS1, FCS2. This is represented herein by operating both fuel cell systems FCS1, FCS2.
[0058] Thus, the method may include an initial step 210 of determining the need to operate all of at least two fuel cell systems FCS1, FCS2. If the answer is "yes", the method may proceed to 220 as shown in FIG. 3.
[0059] At 220, information regarding the estimated actual health status of each fuel cell system FCS1, FCS2 is obtained. This is represented by the arrows from each fuel cell system FCS1, FCS2 to box 220.
[0060] At 220, the actual health statuses of fuel cell systems FCS1, FCS2 are compared, and if the comparison indicates a predetermined difference between the actual health statuses of fuel cell systems FCS1, FCS2, the method continues to either 240 or 250.
[0061] However, if the comparison of the actual health statuses of fuel cell systems FCS1, FCS2 indicates no difference between the actual health statuses of fuel cell systems FCS1, FCS2, the method instead continues to 230. At 230, fuel cell systems FCS, FCS2 operate with the same operating dynamics and / or within the same operating window.
[0062] The method is continued from 220 to 240 when the actual soundness state of the fuel cell system FCS1 is worse than the actual soundness state of the fuel cell system FCS2, and is continued from 220 to 250 when the actual soundness state of the fuel cell system FCS2 is worse than the actual soundness state of the fuel cell system FCS1.
[0063] At 240, the actual soundness state of the fuel cell system FCS1 is compared with the determined expected soundness state of the fuel cell system FCS1, and the expected soundness state is based on the history of the usage conditions of the fuel cell system FCS1.
[0064] In box 242, the expected soundness state of the fuel cell system FCS1 is determined. The history of the usage conditions may be obtained from a database or a memory, represented by, for example, box 244.
[0065] When the actual soundness state of the fuel cell system FCS1 is worse than its expected soundness state, the operating dynamics and / or the operating window of the fuel cell system FCS1 are decreased, and the operating dynamics and / or the operating window of another fuel cell system FCS2 are increased. This is represented by box 248 in FIG. 3.
[0066] On the other hand, when the actual soundness state of the fuel cell system FCS1 is better than its expected soundness state, the fuel cell systems FCS1 and FCS2 are operated with the same operating dynamics and / or within the same operating window. This is represented by box 246 in FIG. 3.
[0067] At 250, the actual soundness state of the fuel cell system FCS2 is compared with the determined expected soundness state of the fuel cell system FCS2, and the expected soundness state is based on the history of the usage conditions of the fuel cell system FCS2.
[0068] In box 252, the intended sound state of the fuel cell system FCS2 is determined. The history of usage conditions may be obtained from a database or memory, represented by, for example, box 254.
[0069] If the actual sound state of the fuel cell system FCS2 is worse than its intended sound state, the operating dynamics and / or operating window of the fuel cell system FCS2 are decreased, and the operating dynamics and / or operating window of another fuel cell system FCS1 are increased. This is represented by box 258 in FIG. 3.
[0070] On the other hand, if the actual sound state of the fuel cell system FCS2 is better than its intended sound state, the fuel cell systems FCS1 and FCS2 are operated with the same operating dynamics and / or within the same operating window. This is represented by box 256 in FIG. 3.
[0071] FIG. 4 schematically shows a propulsion system 1 of a vehicle according to an exemplary embodiment of the present invention. The propulsion system 1 includes a fuel cell system FCS1 and another fuel cell system FCS2. As shown, the propulsion system 1 may further include an electrical energy storage system EES. The propulsion system 1 may be, for example, a part of the vehicle 100 as shown in FIG. 1. In the illustrated embodiment, the propulsion system 1 further includes respective DC / DC converters 20, 22 for the respective fuel cell systems FCS1, FCS2. It further includes a junction box 30 and an electric machine 40 drivingly coupled to at least one traction wheel 50 of the vehicle 100. Thus, the solid lines between the components in the figure represent electrical connections, except for the line between the electric machine 40 and at least one traction wheel 50, which represents a mechanical drive connection instead. The operations of the fuel cell systems FCS1, FCS2, and the electrical energy storage system EES are controlled by a control unit 110. The control unit 110 may be further used to control the operation of the propulsion system 1, i.e., to control, for example, the electric machine 40. The fuel cell systems FCS1, FCS2 are preferably adapted to be the main contributors for providing propulsion force to at least one traction wheel 50. Thus, the electrical energy storage system EES is preferably adapted to provide additional propulsion force when the fully required power cannot be supplied by the fuel cell systems FCS1, FCS2, or when the fuel cell systems FCS1, FCS2 are not suitable for supplying the fully required power.
[0072] In this specification, the control unit 110 is an electronic control unit. It may comprise a processing circuit adapted to execute the computer programs disclosed in this specification. The control unit 110 may comprise hardware and / or software for executing the method according to the invention. In certain embodiments, the control unit 110 may be represented by a computer. The control unit 110 may be constituted by one or more separate sub-control units. Further, the control unit 110 may communicate with the propulsion system 1 using wired and / or wireless communication means. This is shown by the dashed line in FIG. 4. The control unit 110 may be part of the vehicle 100 as shown in FIG. 1. Still further, it should be noted that even if the control unit 110 is preferably a vehicle on-board control unit, the control unit 110 may additionally or alternatively be a vehicle off-board control unit, for example, a control unit that is part of a computer cloud system.
[0073] Of course, the present invention is not limited to the embodiments described above and illustrated in the drawings, but rather, as will be apparent to those skilled in the art, many variations and modifications may be made within the scope of the appended claims.
Claims
Claim 1 A computer-implemented method for controlling the operation of at least two fuel cell systems (FCS1, FCS2), each fuel cell system being adapted to operate by adjustable operating dynamics that define the operating constraints of the fuel cell system and / or within an adjustable operating window, increasing the operating dynamics and / or the operating window being associated with an increased expected degradation of the fuel cell system, and decreasing the operating dynamics and / or the operating window being associated with a decreased expected degradation of the fuel cell system, The method comprises: obtaining an estimated actual health state of each fuel cell system (FCS1, FCS2) (S1), comparing the actual health states of the fuel cell systems (FCS1, FCS2) (S2), when the comparison indicates a predetermined difference between the actual health states of the fuel cell systems (FCS1, FCS2), identifying a first fuel cell system of the at least two fuel cell systems (FCS1, FCS2) having the lowest actual health state (S3), comparing the actual health state of the first fuel cell system with a determined expected health state of the first fuel cell system, wherein the expected health state is based on a history of usage conditions of the first fuel cell system (S4), when the actual health state of the first fuel cell system is worse than its expected health state, decreasing the operating dynamics and / or the operating window of the first fuel cell system (S5) and increasing the operating dynamics and / or the operating window of the other fuel cell system (S5), The method as described above. Claim 2 When the comparison of the actual healthy states of the fuel cell systems (FCS1, FCS2) indicates no difference between the actual healthy states of the fuel cell systems (FCS1, FCS2), the method includes operating the fuel cell system with the same operating dynamics and / or within the same operating window, according to the method of claim 1.
3. The result of the comparison between the actual healthy states of the fuel cell systems (FCS1, FCS2) indicates the predetermined difference when the difference between them exceeds a predetermined difference threshold, according to the method of any one of the preceding claims.
4. When the actual healthy state of the first fuel cell system is better than its expected healthy state, the method further includes operating the fuel cell systems (FCS1, FCS2) with the same operating dynamics and / or within the same operating window, according to the method of any one of the preceding claims.
5. The decrease in the operating dynamics and / or the operating window of the first fuel cell system and the increase in the operating dynamics and / or the operating window of the other fuel cell system are performed such that the combined operating dynamics and / or the combined operating window of the at least two fuel cell systems (FCS1, FCS2) remain unchanged, according to the method of any one of the preceding claims.
6. The method is started in response to obtaining a request to operate all of the at least two fuel cell systems (FCS1, FCS2), according to the method of any one of the preceding claims.
7. The history of the usage conditions of the first fuel cell system includes at least one of the following: The power output of the fuel cell system during operation, The operating dynamics of the fuel cell system during operation, The power cycle frequency of the fuel cell system during operation, The ambient temperature conditions during operation, The ambient air conditions during operation such as the pollution level, The ambient weather conditions during operation, The start / stop history, The history of the coolant temperature within the fuel cell system, The operating time, according to the method of any one of the preceding claims.
8. During operation of the fuel cell system (FCS1, FCS2), the method is updated at a predetermined update frequency, for example, a frequency corresponding to a predetermined number of operating hours of at least one of the fuel cell systems, according to any one of the preceding claims.
9. The method according to claim 8, wherein the predetermined update frequency is variable, for example, variable with respect to at least one of ambient temperature conditions and ambient weather conditions.
10. The method according to any one of claims 8 to 9, wherein the predetermined update frequency is corrected during operation based on the magnitude of the difference in the actual soundness state between the fuel cell systems (FCS1, FCS2).
11. A control unit (110) for controlling the operation of at least two fuel cell systems (FCS1, FCS2), the control unit being configured to perform the steps of the method according to any one of claims 1 to 10.
12. A vehicle propulsion system (1) including at least two fuel cell systems (FCS1, FCS2) and further including the control unit according to claim 11.
13. A vehicle (100) including the propulsion system according to claim 12.
14. A computer program including program code means for performing the steps according to any one of claims 1 to 10 when the program is executed on a computer such as the control unit according to claim 11.
15. A computer-readable medium carrying a computer program including program code means for performing the steps according to any one of claims 1 to 10 when the program is executed on a computer such as the control unit according to claim 11.