Method of controlling an electrical power system

Abstract

The present disclosure relates to a computer-implemented method of controlling a fuel cell electric vehicle (FCEV) power system, the power system including an energy storage system and a fuel cell, in which when power consumption of the power system exceeds a power capacity of the power system, the fuel cell is connected to the energy storage system. And controlling the fuel cell to adopt a power mode when reaching the initial position of the upcoming road path.

Description

Technical Field

[0001] The present invention relates to an electric power system comprising an energy storage system and a fuel cell. In particular, the present invention relates to a method of controlling such an electric power system. The present invention also relates to a corresponding electric power system. The present invention is applicable to so-called fuel cell electric vehicles (FCEVs), in particular medium and heavy-duty FCEVs. Although the present invention will be described with respect to a heavy-duty FCEV in the form of a truck, the present disclosure is not limited to this particular vehicle, but can also be used for other FCEVs. Background Art

[0002] Electric propulsion of passenger cars is becoming a common solution to reduce the environmental impact of vehicles. Heavy vehicles such as trucks are also evolving to be able to provide electric propulsion. An electric propulsion system includes one or more electric machines that are operable to generate propulsion torque at one or more wheels of the vehicle.

[0003] However, heavy vehicles require batteries with large energy capacity to supply power to the motors in order to provide a desired operating range. Therefore, the capacity of the battery is a limiting factor for heavy vehicles.

[0004] The use of fuel cells to generate electricity during vehicle operation is one way to increase the operating range of heavy vehicles. The electricity generated by the fuel cell can be supplied directly to one or more batteries, or directly to the motor that propels the vehicle. In order to reduce the degradation of the fuel cell, the fuel cell is preferably operated to generate low levels of electricity, and ramping up and ramping down are preferably avoided. However, FCEVs should still be able to handle all types of operating conditions, and therefore there is a need to improve the operational control of such FCEV power systems. Summary of the invention

[0005] Therefore, an object of the present disclosure is to at least partially overcome the above-mentioned drawbacks.

[0006] According to a first aspect, there is provided a computer-implemented method of controlling a power system of a fuel cell electric vehicle (FCEV), the power system being operatively controlled by a processing circuit and comprising an energy storage system and a fuel cell, wherein the fuel cell is operable to adopt a cruise mode and a power mode. mode), in which the fuel cell generates electricity at a first power level in the cruise mode, and in the power mode, the fuel cell generates electricity at a second power level, the second power level being higher than the first power level, the method comprising: determining, by the processing circuit, a road topology of an upcoming road path on which the FCEV is to operate; determining, by the processing circuit, an electrical energy level of the energy storage system; determining, by the processing circuit, an electrical power level that the fuel cell can generate along the road path when the fuel cell adopts the cruise mode; determining, by the processing circuit, an electrical energy consumption of the electrical system for operating the FCEV along the upcoming road path based on the road topology; determining, by the processing circuit, an electrical energy capacity of the electrical system along the road path based on the electrical energy level of the energy storage system and the electrical power level that the fuel cell can generate when adopting the cruise mode; and when the electrical energy consumption of the electrical system exceeds the electrical energy capacity of the electrical system, controlling, by the processing circuit, the fuel cell to adopt the power mode when reaching a starting position of the upcoming road path.

[0007] Therefore, the cruise mode and the power mode should be understood as two different operating modes of the fuel cell, in which the fuel cell generates electricity at different levels. Specifically, the fuel cell generates electricity at a relatively high power level when the power mode is adopted, and generates electricity at a lower power level when the cruise mode is adopted. The cruise mode should be understood as the "sweet spot" of the fuel cell, that is, the power level at which the fuel cell operates to generate the degradation rate of the fuel is kept at the lowest level. Therefore, the fuel cell should preferably be operated in the cruise mode as much as possible. According to a non-limiting example, the fuel cell generates electricity centered at about 100 kW when the cruise mode is adopted, and generates electricity centered at about 300 kW when the power mode is adopted. It is therefore an integer multiple of three. These are merely examples and should not be interpreted as limiting the functionality of the present invention. In addition, the cruise mode and the power mode should not be interpreted as fixed power levels. Instead, the cruise mode is a mode in which the fuel cell generates electricity in a first range, and the power mode is a mode in which the fuel cell generates electricity in a second range, wherein the second range has a higher power level than the first range. Preferably, the power level at the lower limit of the second range is higher than the power level at the upper limit of the first range.

[0008] In this context, road topology should be understood as the variation of uphill and downhill slopes of the upcoming road path. Thus, the upcoming road path may include one or more uphill slopes of various angles and lengths, and one or more downhill slopes of various angles and lengths.

[0009] The present invention is based on the recognition that the fuel cell should be operated in cruise mode as much as possible, but if the fuel cell is required for the power system to adopt power mode to manage an upcoming road path without depleting the energy storage system, it is advantageous to switch to power mode before entering the upcoming road path, rather than switching to power mode during operation along the road path. Therefore, the present invention advantageously determines in advance that the power system will not be able to operate to complete the upcoming road path by controlling the fuel cell to adopt cruise mode, and thus directly switches the fuel cell to adopt power mode, rather than switching when it is determined that the energy storage system is about to run out of power. Therefore, and in accordance with an exemplary embodiment, the power level of the energy storage system can be determined for the starting position of the upcoming road path. However, before reaching the starting position, the power level of the starting position can be estimated.

[0010] It should therefore be understood that switching from cruise mode to power mode is not based on managing a steep uphill slope, i.e. adding additional power to the power system for a short period of time, but rather the power system managing the upcoming road path without depleting the energy storage system and risking ending up with no electrical energy available for further operation along the road path.

[0011] According to an exemplary embodiment, the method may also include: estimating, by the processing circuit, a change in the state of charge level of the energy storage system along the upcoming road path when the fuel cell adopts the cruise mode; and when it is determined that the state of charge level of the energy storage system drops below a predetermined threshold limit along the upcoming road path when the fuel cell is operated in the cruise mode, controlling the fuel cell to adopt the power mode when reaching the starting position by the processing circuit.

[0012] The change in state of charge level may be based on the number and inclination of uphill and downhill slopes along the upcoming road path. From this, it may be determined to what extent the energy storage system may be charged with electricity generated by the electric traction motor of the FCEV during braking on which downhill sections, and to what extent the energy storage system may supply electricity to the electric traction motor on which uphill sections.

[0013] Thus, if the state of charge level drops below a predetermined threshold limit at any location along the road route, the fuel cell preferably adopts the power mode along the entire road route.

[0014] Thus, and in accordance with an exemplary embodiment, the FCEV may include an electric traction motor configured to receive power from the electrical system during propulsion and to supply power generated by the electric traction motor to the energy storage system during braking, wherein the electrical energy capacity of the electrical system is also based on power generated by the electric traction motor along an upcoming road path.

[0015] According to an exemplary embodiment, when it is determined that the electrical energy consumption of the electrical system exceeds the electrical energy capacity of the electrical system, the processing circuit may control the fuel cell to adopt the power mode along the entire upcoming road path from the starting location to the ending location.

[0016] According to an exemplary embodiment, the method may further include: when the power consumption of the power system drops below the power capacity of the power system, controlling the fuel cell to adopt the cruise mode by the processing circuit. As described above, the degradation rate of the fuel cell is thereby reduced, and the service life of the fuel cell is increased.

[0017] According to an exemplary embodiment, the method may further include: dividing the upcoming road path into a plurality of road path segments, each road path segment being associated with a separate road topology, by the processing circuit; wherein the power consumption of the power system is determined for each road path segment. By dividing the road path into a plurality of road path segments, the computational effort of estimating the power consumption along the entire road trip is reduced compared to estimating the power consumption along the entire road path. Therefore, and according to an exemplary embodiment, the power capacity of the power system may be determined for each road path segment. The processing circuit may thereby determine for each road path segment whether the power consumption of the power system will exceed the power capacity of the power system.

[0018] According to an exemplary embodiment, the electrical energy level of the energy storage system may be determined at the starting position of each road path segment. Preferably, according to an exemplary embodiment, the method may further include: setting, by the processing circuit, a desired state of charge level of the energy storage system at the end position of the upcoming road path; determining, by the processing circuit, a desired electrical energy capacity of the electrical system for each road path segment so that the energy storage system has the desired state of charge level when reaching the end position; and controlling, by the processing circuit, the fuel cell to adopt the power mode when reaching the starting position of the upcoming road path when the determined electrical energy capacity for a certain road path segment is lower than the desired electrical energy capacity for the road path segment.

[0019] Therefore, a reverse calculation is performed based on the desired state of charge level at the end location of the upcoming road path. Therefore, the FCEV can not only operate without depleting the energy storage system, but also have the desired state of charge level when reaching the end location. If the processing circuit determines that it is not possible to adopt the cruise mode by controlling the fuel cell, the fuel cell should be controlled to adopt the power mode throughout the upcoming road path (i.e., for each road path segment) until the end location is reached.

[0020] According to a second aspect, there is provided an electric power system electrically connectable to an electric traction motor of a fuel cell electric vehicle (FCEV), the electric power system comprising an energy storage system and a fuel cell, wherein the fuel cell is operable to adopt a cruise mode and a power mode, wherein the cruise mode, the fuel cell generates electricity at a first power level, and wherein the power mode, the fuel cell generates electricity at a second power level, the second power level being higher than the first power level, wherein the electric power system further comprises a control unit, the control unit comprising a processing circuit, the processing circuit being operable to control the energy storage system and the fuel cell, the processing circuit being configured to: determine an upcoming road on which the FCEV is to operate determining a road topology of a road path; determining an electrical energy level of the energy storage system; determining an electrical power level that the fuel cell can generate along the road path when the fuel cell adopts the cruise mode; determining an electrical energy consumption of the electrical system for operating the FCEV along the upcoming road path based on the road topology; determining an electrical energy capacity of the electrical system along the road path based on the electrical energy level of the energy storage system and the electrical power level that the fuel cell can generate when adopting the cruise mode; and controlling the fuel cell to adopt the power mode when reaching a starting position of the upcoming road path when the electrical energy consumption of the electrical system exceeds the electrical energy capacity of the electrical system.

[0021] The control unit may include a microprocessor, a microcontroller, a programmable digital signal processor or another programmable device. The control unit may also include or alternatively include an application specific integrated circuit, a programmable gate array or programmable array logic, a programmable logic device or a digital signal processor. In the case where the control unit includes a programmable device (such as a microprocessor, a microcontroller or a programmable digital signal processor mentioned above), the processor may also include a computer executable code that controls the operation of the programmable device.

[0022] The expression "processing circuitry" used above should be understood to include any type of computing device, such as an ASIC, a microprocessor etc. It should also be understood that the actual implementation of such processing circuitry may be divided between more than a single device / circuit.

[0023] The effects and features of the second aspect are largely similar to those described above in relation to the first aspect.

[0024] According to a third aspect, a vehicle is provided, the vehicle comprising the system according to the second aspect.

[0025] According to a fourth aspect, there is provided a computer program comprising program code means for performing the method of any one of the embodiments described above in relation to the first aspect when the program is run on a computer.

[0026] According to a fifth aspect, a non-transitory computer-readable medium carrying a computer program is provided, the computer program comprising program code, the program means being configured to execute any one of the methods described above with respect to the first aspect when the program product is run on a computer.

[0027] According to a sixth aspect, there is provided a control unit for controlling an auxiliary system of a transport vehicle, the control unit being configured to execute the method of any one of the embodiments described above with respect to the first aspect.

[0028] Effects and features of the third, fourth, fifth and sixth aspects are largely similar to those described above with respect to the first aspect.

[0029] Further features and advantages of the present disclosure will become apparent when studying the appended claims and the following description.Those skilled in the art realize that different features of the present disclosure can be combined to create examples other than those described in the following, without departing from the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The above and further objects, features and advantages of the present disclosure will be better understood through the following illustrative and non-limiting detailed description of exemplary examples of the present disclosure, in which:

[0031] Figure 1 is a lateral side view of a fuel cell electric vehicle (FCEV) in the form of a truck according to an exemplary embodiment,

[0032] Figure 2 is a schematic diagram of an upcoming road path on which an FCEV may operate according to an exemplary embodiment,

[0033] Figure 3 is a schematic diagram of a power system of a FCEV according to an exemplary embodiment; and

[0034] Figure 4is a flowchart of a method of controlling a power system according to an exemplary embodiment. DETAILED DESCRIPTION

[0035] The present disclosure will now be described more fully hereinafter with reference to the accompanying drawings, in which illustrative examples are shown. However, the present disclosure may be embodied in many different forms and should not be construed as limited to the examples set forth herein; rather, these examples are provided for the sake of thoroughness and completeness. Throughout this specification, like reference numerals refer to like elements.

[0036] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. As used herein, unless the context clearly indicates otherwise, the singular forms "one", "a kind of" and "the" are intended to also include plural forms. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. It should also be understood that when used in this article, the terms "include" and / or "comprising" indicate the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or their groups.

[0037] 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.

[0038] 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 will be understood that when an element is referred to as being "connected" or "coupled" to another element, the element may be directly connected or directly coupled to the other element, or there may be intervening elements. In contrast, when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intervening elements.

[0039] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those of ordinary skill 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.

[0040] Specific reference Figure 1, depicting a fuel cell electric vehicle (FCEV) 10 in the form of a truck. The FCEV 10 will hereinafter be referred to only as a vehicle, and includes an electric traction motor 101 for propelling the vehicle wheels. In an exemplary embodiment, the electric traction motor 101 is arranged in the form of an electric motor. The electric traction motor 101 is arranged to receive power from an electric system 102 during propulsion, and to supply power generated by the motor 101 to an energy storage system 104 of the electric system during braking. The energy storage system 104 is preferably a high-voltage battery of the vehicle 10. As will be apparent from the disclosure below (particularly in conjunction with FIG. 5 ), the electric system 102 also includes a fuel cell 106 electrically connected to the energy storage system 104. The fuel cell 106 is configured to generate electricity upon receiving hydrogen fuel and oxygen.

[0041] The vehicle 10 also includes a control unit 114 connected to the power system 102 for controlling its operation. The control unit 114 may include a microprocessor, a microcontroller, a programmable digital signal processor, or another programmable device. The control unit may also include or alternatively include an application specific integrated circuit, a programmable gate array or programmable array logic, a programmable logic device, or a digital signal processor. In the case where the control unit 114 includes a programmable device (such as a microprocessor, a microcontroller, or a programmable digital signal processor mentioned above), the processor may also include computer executable code that controls the operation of the programmable device.

[0042] During propulsion of the vehicle 10, the fuel cell 106 generates electricity, which is supplied to the energy storage system 104, thereby charging the energy storage system 104 with electrical energy. The energy generated by the fuel cell 106 may also be supplied directly to the electric traction motor 101 during propulsion. During propulsion, electricity is also preferably supplied from the energy storage system 104 to the electric traction motor 101. Therefore, when the vehicle 10 is propelled, the energy storage system 10 steadily discharges the electrical energy consumed by the electric traction motor 101.

[0043] The fuel cell 106 is operable to adopt a cruise mode in which the fuel cell generates electricity at a first power level. When operating in the cruise mode, the power range of the electricity generated by the fuel cell 106 is, for example, between 70–130 kW, more preferably between 85–115 kW, and most preferably about 100 kW. The fuel cell 106 is also operable to adopt a power mode in which the fuel cell 106 generates electricity at a second power level. The second power level is higher than the first power level, and according to an example, the second power level may be, for example, in the range of 250–350 kW, more preferably in the range of 275–325 kW, and most preferably about 300 kW.

[0044] In order to reduce degradation of the fuel cell 106, the fuel cell 106 should preferably be operated in the cruise mode as much as possible, however, there are operating conditions where the power of the energy storage system 104 combined with the power generated by the fuel cell 106 in the cruise mode is insufficient to complete the intended task. In other words, the motor 101 may require such a high level of power to accommodate the upcoming road path that the energy storage system 104 will be depleted of power when operating the fuel cell 106 in the cruise mode. In such a case, the fuel cell 106 can be switched to the power mode. Now referring to Figure 2 An exemplary embodiment of switching to a power mode in a manner that reduces degradation of the fuel cell 106 will be described.

[0045] like Figure 2 As shown, the vehicle 10 is located at a starting position 202 and is about to operate on an upcoming road path 204. The upcoming road path 204 includes a plurality of uphill slopes and a plurality of downhill slopes. Therefore, the state of charge level of the energy storage system 104 may vary along the road path, depending on the number, length and inclination of the uphill slopes and downhill slopes, and the vehicle speed during the road path. The processing circuitry of the control unit 114 thus determines a road topology 208 of the upcoming road path 204 before initiating a mission from the starting position 202 to the ending position 206 of the upcoming road path 204. The road topology 208 may be determined based on map data from, for example, a GPS or the like that is arranged to communicate with the control unit.

[0046] In addition, the power level, i.e., the state of charge (SoC) level, of the energy storage system 104 is determined before the mission. In addition, the processing circuitry also determines the power level that the fuel cell 106 can generate during operation from the starting location 202 to the ending location 206 when the fuel cell 106 is in a cruise mode. Thus, the power capacity of the power system 102 along the road path 204 can be determined based on the power level of the energy storage system 104 and the power level that the fuel cell 106 can generate when the cruise mode is adopted. In other words, the processing circuitry can determine the power level available to the motor 101 when the vehicle 10 is operating along the road path 204.

[0047] Further, the power consumption of the power system 102 is determined based on the road topology 204. Thus, the processing circuit determines how much power the motor 101 consumes to operate the vehicle 10 along the upcoming road path. For example, the processing circuit can determine the power level supplied to the motor 101 to properly propel the vehicle along an uphill slope, as well as determine the power level generated by the motor 101 during downhill braking.

[0048] When the processing circuit determines that if the fuel cell 106 is in the cruise mode, the electrical energy consumption of the power system 102 will exceed the electrical energy capacity of the power system 102 somewhere along the road path 204, the processing circuit controls the fuel cell 106 to adopt the power mode before the vehicle leaves the starting location 202 and begins the journey along the road path 204. Therefore, the fuel cell 106 is switched to adopt the power mode for the entire road path from the starting location 202 to the ending location 206, and the risk of depleting the energy storage system 104 along the road path 204 is reduced. The inventors also unexpectedly realized that if the power mode is switched before the vehicle 10 leaves the starting location 202, the degree of degradation of the fuel cell 106 will be reduced compared to first switching to the power mode when the energy storage system 104 is depleted or determined to be depleted.

[0049] However, if the processing circuit determines that the power consumption of power system 102 will be below or will drop below the power capacity of power system 102 , fuel cell 106 is controlled to adopt a cruise mode during the entire road path 204 from starting location 202 to ending location 206 .

[0050] like Figure 2 As illustrated, upcoming road path 204 may advantageously be divided into a plurality of road path segments 210. Figure 2 , the upcoming road path 204 is divided into a first road path segment 212, a second road path segment 214, a third road path segment 216, a fourth road path segment 218, a fifth road path segment 220, a sixth road path segment 222, a seventh road path segment 224, and an eighth road path segment 226. Each road path segment 210 is associated with a separate road topology, i.e., the processing circuit determines the length and the inclination of each road path segment 210, so that the electrical energy consumption of the power system 102 for each of these road path segments 210 can be determined. In addition, the electrical energy capacity of the power system for each road path segment 210 can also be determined.

[0051] In addition, the processing circuitry may also set a desired state of charge level for the energy storage system 104 at the end location of the upcoming road path 204. In addition, a desired electrical energy capacity of the electrical system for each road path segment 210 may be determined to have a desired state of charge level upon reaching the end location. When the determined electrical energy capacity for at least one of the road path segments 210 is lower than the desired electrical energy capacity for the road path segment, the processing circuitry may thereby control the fuel cell to adopt a power mode upon reaching the start location 202 of the upcoming road path 204.

[0052] Furthermore, the power level of the energy storage system 104 is preferably determined at the starting position of each road route segment. Figure 2 In the depicted exemplary embodiment, the electrical energy level of the third road path segment 216 is determined at the starting location 230 of the road path segment, ie, at a location between the second road path segment 214 and the third road path segment 216 .

[0053] according to Figure 2 In the example of FIG. 1 , when determining the desired state of charge level at the end location 206, the desired electrical energy capacity of the power system 102 is determined for the eighth road path segment 226. From this, the desired state of charge level at the starting location 232 of the eighth road path segment 226 can be determined. Thereafter, based on the desired state of charge level at the starting location 232 of the eighth road path segment 226, the desired electrical energy capacity of the power system 102 for the seventh road path segment 224 is determined. Thus, the power system 102 can be controlled starting from the starting location 202 and continuing for each road path segment 210 to have the desired state of charge level when reaching the end location 206, and if the electrical energy capacity is insufficient to properly operate the vehicle to the end location of any of the road path segments 210, the fuel cell 106 is controlled to adopt a power mode when the vehicle 10 is at the starting location 202.

[0054] Now the last reference Figure 3 and Figure 4 The power system 102 and the method of controlling the power system are described in more detail. During operation, a road topology 208 of an upcoming road path 204 on which the vehicle 10 is to operate is determined S1. Additionally, an electrical energy level of the energy storage system 104 is determined S2.

[0055] In addition, it is determined S3 that the level of power that the fuel cell 106 can generate when the vehicle is operated along the road path 204 with the fuel cell 106 in the cruise mode. In addition, based on the road topology 208, it is determined S4 that the power consumption of the power system 102, and based on the power level of the energy storage system 102 and the level of power that the fuel cell 106 can generate when the cruise mode is adopted, it is determined S5 that the power capacity of the power system 102 along the road path 208.

[0056] If it is thereafter determined that power system power consumption exceeds power system power capacity when vehicle 10 is operating along road path 204 with fuel cell 106 in cruise mode, processing circuitry controls S6 fuel cell 106 to be in power mode prior to leaving starting location 202 .

[0057] It should be understood that the present disclosure is not limited to the examples described above and shown in the accompanying drawings; rather, those skilled in the art will recognize that many changes and modifications are possible within the scope of the appended claims.

Claims

1. A computer-implemented method of controlling a power system of a fuel cell electric vehicle (FCEV), the power system being operatively controlled by processing circuitry and comprising an energy storage system and a fuel cell, wherein the fuel cell is operable to employ a cruise mode and a power mode, wherein the fuel cell generates power at a first power level and wherein the fuel cell generates power at a second power level, the second power level being higher than the first power level, the method comprising: - determining, by the processing circuit, a road topology of an upcoming road path on which the FCEV is to operate; - determining, by the processing circuit, an electrical energy level of the energy storage system; - determining, by the processing circuit, a level of power that the fuel cell is capable of producing along the road route when the fuel cell is in the cruise mode; - determining, by the processing circuitry based on the road topology, an electrical energy consumption of the power system for operating the FCEV along the upcoming road path; - determining, by the processing circuit, an electrical energy capacity of the electrical system along the road path based on the electrical energy level of the energy storage system and the level of electrical power that the fuel cell is capable of producing when in the cruise mode; as well as - When the electrical energy consumption of the electrical system exceeds the electrical energy capacity of the electrical system, controlling the fuel cell by the processing circuit to adopt the power mode upon reaching the starting position of the upcoming road route. 2 . The computer-implemented method of claim 1 , wherein the electrical energy level of the energy storage system is determined for the starting location of the upcoming road path.

3. The computer-implemented method according to any one of claims 1 or 2, further comprising: - estimating, by the processing circuit, a change in the state of charge level of the energy storage system along the upcoming road route when the fuel cell is in the cruise mode; as well as - when it is determined that the state of charge level of the energy storage system drops below a predetermined threshold limit along the upcoming road path while operating the fuel cell in the cruise mode, controlling the fuel cell by the processing circuit to adopt the power mode when reaching the starting position.

4. A computer-implemented method according to any of the preceding claims, wherein the FCEV includes an electric traction motor configured to receive power from the electrical system during propulsion and to supply power generated by the electric traction motor to the energy storage system during braking, wherein the electrical energy capacity of the electrical system is also based on power generated by the electric traction motor along the upcoming road path.

5. A computer-implemented method according to any of the preceding claims, wherein when it is determined that the electrical energy consumption of the power system exceeds the electrical energy capacity of the power system, the processing circuit controls the fuel cell to adopt the power mode along the entire upcoming road path from the starting location to the ending location.

6. The computer-implemented method of any preceding claim, further comprising: - When the power consumption of the power system drops below the power capacity of the power system, the fuel cell is controlled by the processing circuit to adopt the cruise mode.

7. The computer-implemented method of any preceding claim, further comprising: - dividing, by the processing circuit, the upcoming road path into a plurality of road path segments, each road path segment being associated with a separate road topology; Therein the electrical energy consumption of the electrical power system is determined for each road route segment. 8 . The computer-implemented method of claim 7 , wherein the electrical energy capacity of the electrical power system is determined for each road path segment. 9 . The computer-implemented method of claim 8 , wherein the electrical energy level of the energy storage system is determined at a starting location of each road route segment.

10. The computer-implemented method of any one of claims 8 or 9, further comprising: - setting, by the processing circuit, a desired state of charge level of the energy storage system at an end location of the upcoming road route; - determining, by the processing circuit, for each road route segment, a desired electrical energy capacity of the electrical system so that upon reaching the end location the energy storage system has the desired state of charge level; as well as - when the determined electrical energy capacity for a road path section is lower than the expected electrical energy capacity for the road path section, controlling the fuel cell by the processing circuit to adopt the power mode when reaching the starting position of the upcoming road path.

11. An electric power system electrically connectable to an electric traction motor of a fuel cell electric vehicle (FCEV), the electric power system comprising an energy storage system and a fuel cell, wherein the fuel cell is operable to adopt a cruise mode and a power mode, wherein the cruise mode the fuel cell generates electricity at a first power level, and wherein the power mode the fuel cell generates electricity at a second power level, the second power level being higher than the first power level, wherein the electric power system further comprises a control unit, the control unit comprising a processing circuit, the processing circuit being operable to control the energy storage system and the fuel cell, the processing circuit being configured to: - determining a road topology of an upcoming road path on which the FCEV is to operate; - determining an electrical energy level of said energy storage system; - determining a level of power that the fuel cell is capable of producing along the road route when the fuel cell is in the cruise mode; - determining an electrical energy consumption of the power system for operating the FCEV along the upcoming road path based on the road topology; - determining the electrical energy capacity of the electrical system along the road route based on the electrical energy level of the energy storage system and the level of electricity that the fuel cell can generate when adopting the cruise mode; as well as - When the electrical energy consumption of the electrical system exceeds the electrical energy capacity of the electrical system, controlling the fuel cell to adopt the power mode upon reaching a starting position of the upcoming road route.

12. A vehicle comprising a system according to claim 11.

13. A computer program comprising program code means for performing the method according to any one of claims 1 to 10 when said program is run on a computer.

14. A non-transitory computer readable medium carrying a computer program, the computer program comprising program code for executing the method according to any one of claims 1 to 10 when the program product is run on a computer.

15. A control unit for controlling an auxiliary system of a transport vehicle, the control unit being configured to perform the method according to any one of claims 1 to 10.

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