Method for controlling power assembly

Abstract

To provide a method for controlling a power assembly including a fuel cell unit and an electric energy storage system with high cost efficiency.SOLUTION: A method executes: a step S1 at which electric power demand for power supply from a power assembly is predicted; and a step S2 at which costs associated with controlling the power assembly is calculated according to at least two different control scenarios. Two different control scenarios includes a first control scenario for turning off a fuel cell unit, and a second control scenario for turing on the same. At a step 3, costs associated with ability of the power assembly, costs associated with fuel consumption and costs associated with degradation of a fuel cell when electric power is supplied to each of control scenarios according to the predicted electric power demand are calculated, and the calculated costs are compared. At a step 4, one of two control scenarios is selected, and at a step 5, the power assembly is controlled according to the selected control scenario.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a method for controlling a power assembly including one or more fuel cell units and an electrical energy storage system. The present invention further relates to a power assembly, a control unit, a vehicle, a computer program, and a computer-readable medium.

[0002] The present invention will be described with respect to trucks, but the present invention is not limited to this particular vehicle and can also be used in other vehicles such as passenger cars and off-road vehicles. The present invention can also be applied in stationary applications such as ships and grid-connected or grid-independent generators.

Background Art

[0003] Fuel cell systems can be used as an alternative or complement to electric batteries for powering electric vehicles, but can also be used in stationary applications such as grid-connected and grid-independent generators.

[0004] When a fuel cell system operates at a low current density, the polarization cell voltage of the fuel cell increases, which in turn adversely affects the durability of the fuel cell. To prevent deterioration of the fuel cell, an operating maximum polarization cell voltage is set, which effectively means that the minimum operating power of the fuel cell is limited. Thus, in certain situations, such as when a vehicle powered by a fuel cell system is traveling downhill, the fuel cell system may operate at a power higher than necessary considering the vehicle's power demand. In that case, the surplus power generated by the fuel cell system can be stored in the battery. However, when the battery reaches its maximum state of charge (SoC), the power generated by the fuel cell system may instead be dissipated and thus wasted.

[0005] To avoid energy dissipation, control strategies exist that are based on which fuel cell systems to turn off when the battery's SoC is relatively high and power demand is low. US2016 / 0046204 discloses a method for controlling a vehicle's fuel cell system, in which the fuel cells are controlled to be on or off depending on the vehicle's predicted power demand and the battery's SoC. However, turning fuel cells on and off involves fuel cell degradation, thus negatively impacting the fuel cell's lifespan. [Overview of the project]

[0006] The main object of the present invention is to provide a method for controlling a power assembly including a fuel cell unit and an electrical energy storage system, the method being an improvement over known methods in at least some embodiment. More specifically, the object is to provide an improved method for cost-effective control of a power assembly in at least some embodiment.

[0007] At least the main objective is achieved by the method described in claim 1.

[0008] Thus, a computer implementation method for controlling a power assembly is provided. The power assembly includes a fuel cell unit and an electrical energy storage system for storing surplus electrical energy generated by the fuel cell unit. The power assembly may include two or more fuel cell units, for example, at least two independently operating fuel cell units, i.e., fuel cell units that can be controlled independently of each other to be on or off. This method provides To forecast power demand for power supplied from power assemblies across the forecast horizon, The calculation of the costs associated with controlling the power assembly according to at least two different control scenarios during the predicted horizon, wherein the at least two different control scenarios include a first control scenario for turning off the fuel cell unit and a second control scenario for turning on the fuel cell unit, and for each of the control scenarios, the associated costs are at least The costs associated with the expected capacity or inability of the power assembly to supply power according to the predicted power demand, Costs associated with fuel consumption, The costs associated with fuel cell degradation, Calculations that include, The goal is to compare the calculated costs of at least two control scenarios and obtain a comparison result. Based on the comparison results, select at least one of the two control scenarios. This includes controlling the power assembly according to the selected control scenario.

[0009] The cost of at least two control scenarios is calculated in parallel, with the fuel cell unit turned on in one scenario and the fuel cell unit turned off in the other. By doing so, the most useful cost scenario in terms of cost and capacity can be selected. The negative effects of turning the fuel cell unit on and off, such as the costs incurred due to fuel cell unit degradation, can be balanced, as herein states, with the negative effects of operating the power assembly with the fuel cell unit turned on despite relatively low power demand, such as increased fuel consumption.

[0010] The most useful control scenario is usually the one with the lowest overall cost, but costs can be weighted, for example, so that the cost of non-compliance with predicted power demand is weighted more heavily than the cost of higher fuel consumption, or vice versa. In vehicles, such weighting can be based, for example, on the selected driving mode or preferences set by the vehicle user, such as the driver or fleet operator.

[0011] For example, the most useful control scenario might be one in which the power assembly can supply output power according to the predicted power demand, and the calculated costs associated with fuel consumption and fuel cell degradation are as low as possible. Therefore, if the power assembly is in all of at least two control scenarios in which it can supply the predicted output power, the control scenario with the lowest calculated costs for fuel consumption and fuel cell degradation can be selected. However, if the power assembly can only supply the predicted output power in one of the compared control scenarios (typically with the fuel cell turned on), the costs associated with the power assembly's inability to supply output power according to the predicted power demand in the other control scenarios may be relatively higher. Such costs can also be called the costs of power derating. In vehicles, power derating may result in a decrease in vehicle speed, which may incur costs associated with a certain delay. However, in some cases, the vehicle may become unable to climb a hill, in which case the costs of power derating may be unacceptably high.

[0012] For cost calculations, input parameters may include fuel consumption at idle, fuel cell degradation during starting and / or stopping, fuel price, fuel cell unit price, fuel cell unit efficiency, and fuel cell voltage cycle degradation cost.

[0013] The prediction horizon may be set in terms of time. Alternatively, if the power assembly is configured to power the vehicle, the prediction horizon may be set in terms of distance. The prediction horizon may be a fixed value or may vary depending on the expected stability of the operating conditions, for example. For example, if the power assembly is located inside the vehicle, the prediction horizon may be relatively long if the vehicle is traveling on a known route, such as a previously traveled route, under known traffic conditions, while it may be set relatively short if the vehicle is traveling along a route that is new to the vehicle. The prediction horizon may also be set depending on the data capacity of the memory used to store the data required for the prediction and / or the data generated in the prediction, for example.

[0014] This method may preferably be performed continuously, for example, at a specific update frequency. As a result, the control of the power assembly may be continuously updated according to the selected control scenario.

[0015] When a fuel cell unit is turned off, it neither supplies any power nor consumes any fuel. When a fuel cell unit is turned on, it consumes fuel such as hydrogen (H2) and supplies power. This power may be used by power-consuming parts of the vehicle, such as electric motors, or it may be stored in an electrical energy storage system. Therefore, the costs associated with fuel cell consumption occur when the fuel cell is turned on.

[0016] Optionally, in the second control scenario, the ratio between the power supplied by the electrical energy storage system and the power supplied by the fuel cell unit is allowed to vary over the predicted horizon. Thus, the power sharing between the electrical energy storage system and the fuel cell unit may be allowed to vary, for example, in response to the predicted power demand.

[0017] Optionally, a power assembly includes at least two fuel cell units, each of which is independently controllable to an ON state (turning the fuel cell unit on) and an OFF state (turning the fuel cell unit off). The at least two control scenarios include multiple control scenarios, each one of which corresponds to a unique combination of the ON(n) and OFF(n) states of at least two fuel cell units. Thus, each fuel cell unit is controllable to one of two states. Consequently, the number of available combinations, and therefore the number of possible control scenarios, increases with the number of individually controllable fuel cell units. For a fuel cell system with n fuel cell units, there are a total of 2 n A number of control scenarios are possible. For example, if a fuel cell system includes two fuel cell units, a total of four control scenarios are possible, and therefore at least two of the control scenarios include the first, second, third, and fourth control scenarios. The proposed method makes it possible to take into account differences in operating costs between fuel cell units, such as different fuel cell operating costs due to differences in the age and / or dimensions of different fuel cell units.

[0018] If the power assembly is optionally operated with the fuel cell unit turned off, calculating the costs associated with controlling the power assembly according to the second control scenario includes calculating the costs associated with starting the fuel cell unit. Starting the fuel cell unit, as used herein, is intended to turn on the fuel cell unit and bring it up to power. This is correlated, on the one hand, to fuel costs and on the other hand, to the degradation costs of the fuel cell unit.

[0019] If the power assembly operates with the fuel cell unit turned on, optionally, calculating the cost associated with controlling the power assembly according to the first control scenario includes calculating the cost associated with shutting down the fuel cell unit. By shutting down the fuel cell unit, this specification intends to turn off the fuel cell unit with reduced power. Generally, the shutdown corresponds to the degradation cost of the fuel cell unit.

[0020] Optionally, in at least the first control scenario, the expected capacity or incapacity of a power assembly to supply power according to the predicted power demand is determined by obtaining the system state of the electrical energy storage system and calculating the capacity or incapacity based on the obtained system state. The system state may include, for example, the temperature, state of charge (SoC), state of health (SoH), and power capacity for charging or discharging of the electrical energy storage system. These system states are relevant to determining whether an electrical energy storage system, typically including one or more batteries, can meet the predicted power demand. The system state may be received, for example, from a battery management unit or another control unit of the electrical energy storage system.

[0021] Optionally, the costs associated with at least one of each of the two control scenarios further include the costs associated with the expected degradation of the electrical energy storage system. Such costs may arise due to high battery temperatures within the electrical energy storage system, as well as high battery throughput within the electrical energy storage system resulting from the operation of the electrical energy storage system at high power and / or high charge / discharge current (C rate).

[0022] Optionally, the method further includes determining whether at least one predetermined condition is met, and the cost calculation for at least two different control scenarios is performed only if at least one predetermined condition is met. If at least one predetermined condition is not met, the cost for a single control scenario may be calculated. This has the advantage of saving computational power when it is not necessary to calculate the costs for two control scenarios, for example, when it is clear that the power assembly needs to operate with the fuel cell either turned on or off. The method according to this embodiment is most useful when the power assembly includes a single fuel cell unit or several fuel cell units that are commonly controlled to be on or off. When the power assembly includes several independently controllable fuel cell units, the costs for multiple control scenarios may be calculated in parallel, and the computational power saved by omitting one of them may be negligible. The at least one predetermined condition may include one or more conditions relating to the SoC threshold(s), time threshold(s), and / or power demand threshold(s) of the electrical energy storage system.

[0023] Optionally, at least one of the predetermined conditions includes both the first and second predetermined conditions. If the first predetermined condition is not met, the cost calculation is performed only for the first control scenario. If the second predetermined condition is not met, the cost calculation is performed only for the second control scenario.

[0024] Optionally, when the power assembly is operating with the fuel cell unit turned on, at least one predetermined condition is considered to be satisfied when the state of charge of the electrical energy storage system exceeds a first threshold level. The first threshold level may be set to a level below which the electrical energy storage system is expected to be unable to supply sufficient output power for typical expected power demands. Thus, when below the first threshold level, it cannot be expected that the power assembly can meet the predicted power demand when the fuel cell unit is turned off. Thereby, computing power can be saved simply by calculating the cost for continuous operation with the fuel cell unit turned on. When calculating the cost for continuous operation with the fuel cell unit turned on, the power split between the fuel cell unit and the electrical energy storage system may be allowed to vary over the prediction horizon.

[0025] Optionally, when the power assembly is operating with the fuel cell unit turned off, at least one predetermined condition is considered to be satisfied when the state of charge of the electrical energy storage system is below a second threshold level. The second threshold level may be set to a state of charge (SoC) at which the electrical energy storage system can normally supply output power according to the predicted power demand by itself, i.e., with the fuel cell unit turned off. As long as the SoC is above the second threshold level, only the cost for continuous operation with the fuel cell unit turned off is calculated.

[0026] Optionally, the power assembly is adapted to supply power contributing to the propulsion of the vehicle, and predicting the power demand is receiving vehicle-related information including at least one of traffic information for the predicted driving route of the vehicle during the prediction horizon, terrain information for the predicted driving route, topographic information for the predicted driving route during the prediction horizon, weather information for the predicted driving route during the prediction horizon, and vehicle gross weight information, and In order to predict the power demand over a prediction horizon, using the received vehicle-related information is included.

[0027] One or more of the aforementioned vehicle-related information can contribute to an appropriate prediction of the power demand.

[0028] According to a second aspect, the aforementioned object is achieved by a control unit for controlling a power assembly, and the control unit is configured to perform the method according to the first aspect. The control unit should be understood as an electronic control unit.

[0029] According to a third aspect, the aforementioned object is achieved by a power assembly including one or more fuel cell units and an electrical energy storage system for storing surplus electrical energy generated by the one or more fuel cell units, and the power assembly further includes a control unit according to the second aspect.

[0030] According to a fourth aspect, a vehicle including the power assembly according to the third aspect is provided, and the power assembly is adapted to supply power that contributes to the propulsion of the vehicle.

[0031] According to a fifth aspect, a computer program is provided, which includes program code means for performing the method according to the first aspect when the program is executed on a computer. The computer may be a control unit according to the second aspect.

[0032] According to a sixth aspect, a computer-readable medium holding a computer program is provided, and the computer program includes program code means for performing the method according to the first aspect when the program is executed on a computer. The computer may be a control unit according to the second aspect.

[0033] Further advantages and favorable features of the present invention are disclosed in the following description and dependent claims.

[0034] A more detailed description of the embodiments of the present invention cited as examples is given below with reference to the attached drawings. [Brief explanation of the drawing]

[0035] [Figure 1] This is a schematic side view of the vehicle. [Figure 2] This is a schematic diagram of a power assembly according to an embodiment of the present invention. [Figure 3] This is a flowchart illustrating an embodiment of the method of the present invention. [Figure 4a] This is a schematic block diagram illustrating a control unit according to an embodiment of this specification. [Figure 4b] This is a schematic block diagram illustrating a control unit according to an embodiment of this specification. [Modes for carrying out the invention]

[0036] A more detailed description of the embodiments of the present invention cited as examples is given below with reference to the attached drawings.

[0037] Figure 1 shows a side view of a vehicle 100 according to an embodiment of the present invention. Here, vehicle 100 is a truck, more specifically, a heavy-duty truck for towing one or more trailers (not shown). While a heavy-duty truck 100 is shown, it should be noted that the present invention is not limited to this type of vehicle and may be used for any other type of vehicle, such as buses, construction machinery (e.g., wheel loaders and excavators), passenger cars, and marine vessels. The present invention can also be applied to other applications unrelated to vehicles, as long as a power assembly including a fuel cell unit and an electrical energy storage system (ESS) is used.

[0038] The vehicle 100 includes a power assembly 1. The power assembly 1 is used here to power one or more electric motors (not shown) used to form the propulsion force for the vehicle 100. In addition to or instead of thereto, the power assembly 1 may be used to power other power-consuming functions (not shown) of the vehicle 100, such as an electric motor for a refrigerator system, an electric motor for an air conditioning system, or any other power-consuming function of the vehicle 100.

[0039] Vehicle 100 further includes a control unit 5 according to an embodiment of the present invention. Therefore, the control unit 5 is used to control the power assembly 1. While an onboard control unit 5 is shown, it should be understood that the control unit 5 may also be a remote control unit 5, i.e., an offboard control unit, or a combination of an onboard and an offboard control unit. The control unit 5 may be configured to control the power assembly 1 by issuing control signals and receiving status information related to the power assembly 1. The control unit 5 may constitute part of the power assembly 1.

[0040] The control unit 5 is an electronic control unit and may include processing circuits adapted to execute a computer program disclosed herein. The control unit 5 may include hardware and / or software for performing the method according to the present invention. In one embodiment, the control unit 5 may represent a computer. The control unit 5 may consist of one or more separate sub-control units. In addition, the control unit 5 may communicate using wired and / or wireless communication means.

[0041] Figure 2 shows a schematic diagram of a power assembly 1 according to an embodiment of the present invention. The power assembly 1 may be used, for example, in a vehicle 100 as shown in Figure 1.

[0042] The power assembly 1 includes at least one fuel cell unit, in this specification a first fuel cell unit 2 and a second fuel cell unit 3. Each fuel cell unit 2, 3 may include one or more fuel cells, typically several fuel cells, although these are not illustrated in detail. A fuel cell may also be referred to as a fuel cell stack, and a fuel cell stack may include several hundred fuel cells. Furthermore, each fuel cell unit is configured to provide the fuel cell with hydrogen fuel (H2) and necessary supplies such as air and cooling. Each fuel cell unit 2, 3 may include its own control system, which may be communicatively connected to a control unit 5. In the illustrated embodiment, the power assembly 1 includes two fuel cell units 2, 3, but alternatively, it may include a single fuel cell unit or more than two fuel cell units, such as three or more fuel cell units. Furthermore, if several fuel cell units are provided, the fuel cell units may be independently controllable or commonly controllable. If independently controllable, each fuel cell unit may be controlled to be on or off regardless of the state(s) of the other fuel cell units(s). If two or more fuel cell units are commonly controllable, they are commonly controllable to either an ON or OFF state, meaning all fuel cell units are commonly controlled to the same state. Two fuel cell units may be controlled dependently, such that, in some cases, one of the fuel cell units is controlled to either an ON or OFF state depending on the state of the other fuel cell unit.

[0043] The power assembly 1 further includes an ESS4. The ESS4 itself may include one or more batteries for storing surplus electrical energy generated by the fuel cell units 2 and 3, and for supplying output power from the power assembly 1. The ESS4 is electrically connected to the fuel cell units 2 and 3. The ESS4 may include its own control system, which is communicably connected to the control unit 5. The ESS4 may also be used to store energy regenerated during braking, or may be configured to be charged by a charger from an external power grid or the like.

[0044] The power assembly 1 may further include power electronics (not shown) for converting the power generated by the fuel cell units 2, 3 and / or the power supplied from the ESS 4 into power usable by a power consumption unit 6 such as an electric motor or other power consumption unit. In addition to or instead of what has been described above, the power assembly 1 may also include various components such as a compressor, sensors, pumps, valves, and electrical components.

[0045] Figure 3 shows a method for controlling a power assembly, such as the power assembly 1 illustrated in Figure 2, according to an embodiment of the present invention. This method can be performed by a control unit 5.

[0046] In the first step S1, the power demand for power supplied from power assembly 1 over a forecast horizon, such as a forecast period range, is predicted. If power assembly 1 is adapted to supply power that contributes to the propulsion of vehicle 100, step S1 predicting the power demand is: Receiving vehicle-related information including at least one of the following for the predicted route of 100 vehicles in the predicted horizon: traffic information for the predicted route, terrain information for the predicted route, topographic information for the predicted route in the predicted horizon, weather information for the predicted route in the predicted horizon, and total vehicle weight information. This may include using the received vehicle-related information to forecast power demand across a predicted horizon.

[0047] In the second step S2, the costs associated with controlling the power assembly 1 according to at least two different control scenarios during the predicted horizon are calculated. The costs may be monetary costs. The at least two different control scenarios include a first control scenario in which both fuel cell units 2 and 3 are turned off and no output power is provided, and a second control scenario in which fuel cell units 2 and 3 are turned on and output power is provided. For each of the control scenarios, the associated costs include at least the costs associated with the expected capacity or incapacity of the power assembly 1 to supply power according to the predicted power demand, the costs associated with the fuel consumption of fuel cell units 2 and 3, and the costs associated with the degradation of the fuel cells. The illustrated power assembly 1 includes two independently controllable fuel cell units 2 and 3, and the costs associated with four different control scenarios are calculated in parallel. Specifically, these are a first control scenario in which both fuel cell units 2 and 3 are turned off, a second control scenario in which both fuel cell units 2 and 3 are turned on, a third control scenario in which the first fuel cell unit 2 is turned on and the second fuel cell unit 3 is turned off, and a fourth control scenario in which the second fuel cell unit 3 is turned on and the first fuel cell unit 2 is turned off.

[0048] When power assembly 1 is operating with fuel cell units 2 and 3 turned off, calculating the costs associated with controlling power assembly 1 according to a second control scenario, i.e., a scenario in which both fuel cell units 2 and 3 are turned on, may include calculating the costs associated with starting the first fuel cell units 2 and 3. These costs may include both the costs incurred due to fuel cell degradation during startup and the fuel costs.

[0049] When power assembly 1 is operating with both fuel cell units 2 and 3 turned on, calculating the costs associated with controlling power assembly 1 according to the first control scenario, i.e., the scenario in which both fuel cell units 2 and 3 are turned off, may include calculating the costs associated with shutting down fuel cell units 2 and 3. These costs may include both the costs incurred due to fuel cell degradation during shutdown and the fuel costs.

[0050] In at least a first control scenario in which fuel cell units 2 and 3 are turned off, the expected capacity or incapacity of the power assembly supplying power according to the predicted power demand may be determined by acquiring system states such as the battery state of ESS4 and calculating the capacity or incapacity based on the acquired system states. System states such as SoC and ESS temperature may indicate the capacity of ESS4 to supply output power according to the predicted power demand. The system state(s) of ESS4 may be determined by the ESS4 control system and communicated to the control unit 5. The cost associated with the expected capacity or incapacity is calculated, for example, from the expected delay due to the incapacity of power assembly 1 supplying power according to the predicted power demand when fuel cell units 2 and 3 are turned off, i.e., when only ESS4 is used for power supply.

[0051] The costs associated with each control scenario may further include the costs associated with the expected degradation of ESS4 over the predicted horizon.

[0052] In the third step S3, the calculated costs of at least two control scenarios are compared to obtain a comparison result. In a typical embodiment, the costs of all four control scenarios are compared.

[0053] In the fourth step S4, one of at least two control scenarios is selected based on the comparison results. Typically, the control scenario that is most beneficial from a cost standpoint is selected; that is, the control scenario with the lowest total cost in terms of fuel costs, fuel cell degradation, and the ability or inability to supply power according to the predicted power demand.

[0054] In the fifth step, S5, the power assembly 1 is controlled according to the selected control scenario.

[0055] This method may include an optional step S0 (marked with a dashed line) that determines whether at least one predetermined condition is met. If the predetermined condition is met, step S2 is performed to calculate the costs for at least two different control scenarios. If the predetermined condition is not met, the costs are not calculated for all possible cost scenarios. Instead, the costs may be calculated for a single control scenario, such as only the first or second control scenario.

[0056] For example, when power assembly 1 is operating with both fuel cell units 2 and 3 turned on, at least one predetermined condition may be set such that it is considered satisfied when the SoC of ESS4 is above a first threshold level. If the SoC is below the first threshold level, it may be undesirable or even impossible to turn off fuel cell units 2 and 3. Therefore, if the SoC value received from the control system of ESS4 is below the first threshold level, the cost is calculated only for a second control scenario in which fuel cell units 2 and 3 remain turned on. The at least one predetermined condition may also include a condition relating to predicted power demand, such as a first power demand threshold level below which the cost is calculated for both the first and second control scenarios, and below which the condition is considered satisfied. A combination of SoC and power demand thresholds may be used to determine whether at least one predetermined condition is satisfied.

[0057] Alternatively, when the power assembly 1 is operating with the fuel cell units 2 and 3 turned off, at least one predetermined condition may be set such that it is considered to be met when the SoC of the ESS4 is below a second threshold level. As long as the SoC is above the second threshold level, the ESS4 is expected to be able to supply sufficient output power without turning on the fuel cell units 2 and 3. Therefore, the cost is calculated only for the first control scenario in which the fuel cell units 2 and 3 remain turned off. In this specification, the second threshold level is set to a value higher than the first threshold level.

[0058] If at least one predetermined condition further includes a condition related to the predicted power demand, in which case it may be considered satisfied if the power demand exceeds a second power demand threshold level. Thus, if the power demand exceeds the second power demand threshold level, the costs for both the first and second control scenarios are calculated. The at least one predetermined condition may further include a condition related to time, and if the power assembly 1 operates with fuel cells 2 and 3 turned off for a period exceeding a time threshold, the predetermined condition is considered satisfied, and the costs for both the first and second control scenarios are calculated.

[0059] To perform the steps described herein, the control unit 5 may be configured to perform one or more of the steps S0 to S5 described above, and / or any other example or embodiment described herein. The control unit 5 may include, for example, the configuration shown in Figures 4a and 4b.

[0060] The control unit 5 includes an input / output interface 500 configured to communicate with any necessary components and / or entities of the embodiments herein, for example, receiving system status from the ESS4, traffic information, terrain information, topography information, weather information, and gross vehicle weight information. The input / output interface 500 may include a wireless and / or wired receiver (not shown) and a wireless and / or wired transmitter (not shown). The control unit 5 may be located in any suitable location within the vehicle 100. The control unit 5 may use the input / output interface 500 to control and communicate with sensors, drive units, subsystems, and interfaces within the vehicle 100 by using one or more of the following network interfaces: a controller area network (CAN), an Ethernet cable, Wi-Fi, Bluetooth, and other network interfaces.

[0061] The control unit 5 is configured to use the prediction unit 501 to predict the power demand for power supply from the power assembly 1 across the prediction horizon, based on data received via the interface 500.

[0062] The control unit 5 may also be configured to determine, by the determination unit 502, whether or not at least one predetermined condition is met.

[0063] The control unit 5 is further configured, by the computing unit 503, to calculate the costs associated with controlling the power assembly 1 according to at least two different control scenarios during the predicted horizon.

[0064] The control unit 5 is further configured to use the comparison unit 504 to compare the calculated costs of at least two control scenarios and obtain a comparison result.

[0065] The control unit 5 is further configured to select one of at least two control scenarios based on the comparison results by the selection unit 505, and to control the power assembly 1 according to the selected control scenario by the control unit 506.

[0066] The methods described herein may be implemented through a processor, such as the processor 560 of the processing circuit in the control unit 5 shown in Figure 4a, or one or more processors, along with computer program code for performing the functions and operations of the embodiments described herein. The aforementioned program code may also be provided as a computer program medium, for example, in the form of a data computer-readable medium that holds the computer program code for performing the steps of the methods described herein when loaded into the control unit 5. One such computer-readable medium may be in the form of a memory stick. The computer program code may also be provided on a server as pure program code, or it may be downloaded into the control unit 5.

[0067] The control unit 5 may further include a memory 570 which includes one or more memory units. The memory 570 contains instructions that can be executed by the processor in the control unit 5. The memory 570 is configured to be used to store, for example, information, data, control scenarios, costs, etc., in order to perform the methods described herein when executed in the control unit 5.

[0068] In some embodiments, the computer program 580 includes instructions that, when executed by a computer, for example, at least one processor 560, cause at least one processor of the control unit 5 to perform the method steps described above.

[0069] In some embodiments, the computer-readable storage medium 590 includes each computer program 580. The computer-readable storage medium 590 may also include program code for performing the method steps described above when the program product is executed on a computer, for example, on at least one processor 560.

[0070] As those skilled in the art will see, the units within the aforementioned control unit 5 may refer to a combination of analog and digital circuits, and / or one or more processors, each consisting of software and / or firmware (for example, stored within the control unit 5) executed by each of the aforementioned processors or one or more processors. One or more of these processors, along with other digital hardware, may be included in a single application-specific integrated circuit configuration (ASIC), or multiple processors and various digital hardware may be distributed among several separate components, whether individually packaged or assembled within a system-on-a-chip.

[0071] It should be understood that the present invention is not limited to the embodiments illustrated in the drawings above. Rather, as those skilled in the art will see, many changes and modifications may be made within the scope of the appended claims.

Claims

1. A computer implementation method for controlling a power assembly (1), wherein the power assembly (1) includes fuel cell units (2, 3) and an electrical energy storage system (4) for storing surplus electrical energy generated by the fuel cell units (2, 3), and the method is: (S1) Predicting the power demand for power supplied from the power assembly (1) across the predicted horizon, (S2) Calculate the costs associated with controlling the power assembly (1) during the predicted horizon according to at least two different control scenarios, wherein the at least two different control scenarios include a first control scenario for turning off the fuel cell units (2, 3) and a second control scenario for turning on the fuel cell units (2, 3), and for each of the control scenarios, the associated costs are at least The costs associated with the expected capacity or incapacity of the power assembly (1) that supplies power in accordance with the predicted power demand, Costs associated with fuel consumption, The costs associated with fuel cell degradation, Calculating the aforementioned costs, including (S2), The calculated costs of each of the at least two control scenarios are compared (S3) to obtain a comparison result, Based on the comparison results, select one of the at least two control scenarios (S4), Controlling the power assembly (1) according to the selected control scenario (S5), Methods that include...

2. The method according to claim 1, wherein, in the second control scenario, the ratio between the power provided by the electrical energy storage system (4) and the power provided by the fuel cell units (2, 3) is permitted to vary over the predicted horizon.

3. The power assembly (1) includes at least two fuel cell units (2, 3), and each of the at least two fuel cell units (2, 3) is independently controllable to an ON state, which turns the fuel cell unit (2, 3) ON, and an OFF state, which turns the fuel cell unit (2, 3) OFF. The method according to claim 1, wherein the at least two control scenarios include a plurality of control scenarios, and each of the control scenarios is associated with a unique combination of ON states and OFF states of the at least two fuel cell units (2, 3).

4. The method according to claim 1, wherein, when the power assembly (1) is operating with the fuel cell units (2, 3) turned off, calculating the cost associated with controlling the power assembly (1) according to the second control scenario includes calculating the cost associated with starting the fuel cell units (2, 3).

5. The method according to claim 1, wherein, when the power assembly (1) is operating with the fuel cell units (2, 3) turned on, calculating the cost associated with controlling the power assembly (1) according to the first control scenario includes calculating the cost associated with shutting down the fuel cell units (2, 3).

6. The method according to claim 1, wherein, in at least the first control scenario, the expected capacity or incapacity of the power assembly (1) that supplies power according to the predicted power demand is determined by obtaining the system state of the electrical energy storage system (4) and calculating the capacity or incapacity based on the obtained system state.

7. The method according to claim 1, wherein the costs associated with each of the at least two control scenarios further include the costs associated with the expected degradation of the electrical energy storage system.

8. The method further includes determining whether at least one predetermined condition is met, The method according to claim 1, wherein the calculation of the cost for the at least two different control scenarios is performed only if the at least one predetermined condition is met.

9. When the power assembly (1) is operating with the fuel cell units (2, 3) turned on, the charge state of the electrical energy storage system (4) is considered to be above a first threshold level, and / or, The method according to claim 8, wherein, when the power assembly is operating with the fuel cell units (2, 3) turned off, the at least one predetermined condition is considered to be met when the charge state of the electrical energy storage system (4) is below a second threshold level.

10. The power assembly (1) is adapted to supply electricity that contributes to the propulsion of the vehicle (100), and the power demand is to be predicted. Receiving vehicle-related information including at least one of the following: traffic information for the expected route of the vehicle (100) in the predicted horizon, terrain information for the expected route, topographic information for the expected route in the predicted horizon, weather information for the expected route in the predicted horizon, and total vehicle weight information. To predict the power demand across the aforementioned forecast horizon, the received vehicle-related information is used, The method according to claim 1, including the method described in claim 1.

11. A control unit (5) for controlling a power assembly (1), the control unit (5) is configured to perform the method according to any one of claims 1 to 10.

12. A power assembly (1) comprising one or more fuel cell units (2, 3) and an electrical energy storage system (4) for storing surplus electrical energy generated by the one or more fuel cell units (2, 3), further comprising the control unit (5) according to claim 11.

13. A vehicle (100) comprising a power assembly (1) according to claim 12, wherein the power assembly (1) is adapted to supply electricity that contributes to the propulsion of the vehicle (100).

14. A computer program (580) comprising program code means for performing the method described in any one of claims 1 to 10 when the program (580) is executed on a computer.

15. A computer-readable medium (590) holding a computer program (580), wherein the computer program (580) includes program code means for performing the method according to any one of claims 1 to 10 when the program is executed on a computer.

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