Method for operating a fuel cell system

Abstract

The invention relates to a method for operating a fuel cell system (100), in particular a vehicle (200), by means of a control unit (FCCU) comprising: - Providing (110), by the control unit (FCCU), a respective heating current (I i,k ) to a heater of a number (n) of heaters of the fuel cell system (100) in a second calculation step (k), wherein the heating currents (I i,k ) in total a total heating current (I ges,k ) result, - Forecast (120), by the control unit (FCCU), of the total heating current (I ges,k+1 ) for a third calculation step (k+1) following the second calculation step (k) depending on the total heating current (I ges,k ) of the second calculation step (k) and - Operation (130), by the control unit (FCCU), of the fuel cell system (100) depending on the total heating current (I ges,k+1 ) of the third calculation step (k+1). The invention further relates to a fuel cell system (100), a computer program product, a computer-readable data carrier, a control unit (FCCU) and a system (200).

Description

[0001] The invention relates to a method with the features of the independent method claim, a fuel cell system with the features of the independent device claim, a computer program product with the features of the independent patent claim relating to a computer program product, a computer-readable data carrier with the features of the independent patent claim relating to a computer-readable data carrier, a control unit with the features of the independent patent claim relating to a control unit, and a system with the features of the independent patent claim relating to a system.

[0002] Fuel cell systems are known to be used in systems such as (motor) vehicles to provide (electrical) power.

[0003] However, the current state of the art has disadvantages. For example, a cold start of such fuel cell systems may not be possible or may only be possible within certain temperature ranges. A cold start may be impossible, limited, and / or delayed at temperatures below freezing (of water). For instance, components of the fuel cell system may not function (fully) under these conditions, such as being frozen. Furthermore, heaters (e.g., low-voltage electric heaters) and / or temperature control devices may be unavailable and / or cannot be operated safely. For example, excessive electrical currents (from the heaters) can cause damage. It is also possible that different heaters cannot be operated simultaneously because, for example, the current consumption limits of a single heater, particularly the total current, are exceeded.This means that certain heaters may not function (directly), which in particular delays the entire period until a (potential) start-up. Components may include sensors and / or actuators. Sensors may, especially at low temperatures, generate no or incorrect measurement data, which can prevent (efficient) operation of the fuel cell system. It may also be the case that actuators do not function at all or do not function as intended (and / or predictably) at low temperatures.

[0004] It is therefore an object of the present invention to overcome at least one of the disadvantages described above, at least partially. In particular, it is an object of the invention to enable faster heating and / or starting of a fuel cell system. It may also be an object to reduce wear and / or increase safety. It may also be provided to enable improved operation and / or heating of one or more heaters.

[0005] The foregoing problem is solved by a method with the features of the independent method claim, a fuel cell system with the features of the independent device claim, a computer program product with the features of the independent patent claim relating to a computer program product, a computer-readable data carrier with the features of the independent patent claim relating to a computer-readable data carrier, a control unit with the features of the independent patent claim relating to a control unit, and a system with the features of the independent patent claim relating to a system. Further features and details of the invention will become apparent from the dependent claims, the description, and the drawings.Features and details described in connection with the method according to the invention naturally also apply in connection with the fuel cell system according to the invention and / or in connection with the computer program product according to the invention and / or in connection with the computer-readable data carrier according to the invention and / or in connection with the control unit according to the invention and / or in connection with the system according to the invention, and vice versa, so that the disclosure relating to the individual aspects of the invention always refers to each other. In particular, advantages described within the scope of the first, second, third, fourth, fifth and / or sixth aspects also apply to the first, second, third, fourth, fifth and / or sixth aspects.

[0006] The above problem is solved according to a first aspect by a method for operating a fuel cell system, in particular a system (according to the sixth aspect) and / or vehicle by a control unit (according to the fifth aspect), comprising: - Providing, by the control unit, a respective heating current to a heater of a (total) number of heaters of the fuel cell system in a second calculation step, wherein the heating currents (in particular for a respective [first, second and / or third] calculation step) sum to a (respective) total heating current, - Predicting (calculating), by the control unit, the total heating current for a third calculation step following the second calculation step (in time and / or directly), depending on the total heating current of the second calculation step, and in particular the total heating current of a first calculation step, especially one immediately preceding and / or earlier than the second calculation step, and - Operation, by the control unit, of the fuel cell system depending on the total heating current of the third calculation step.

[0007] The method can be (at least partially) computer-implemented. Operation can include, in particular, control and / or regulation, preferably using a control unit (see below). The described actions or features of the method can be performed in the sequence shown and, in particular, can be performed repeatedly. Preferably, the method can be used to control and / or regulate a fuel cell system according to the second aspect. A control unit according to the fifth aspect can particularly preferably be used for (activating) control and / or regulation. The control unit can perform the corresponding actions or features and / or initiate activation, preferably to implement the actions.

[0008] The fuel cell system can have at least one, preferably several (in particular a plurality, e.g., 10) heaters. Each heater can be specific for and / or arranged on or in a (functionally essential) component of the fuel cell system (also known as a balance-of-plant [BoP] component), in particular comprising a sensor (e.g., temperature sensor, pressure sensor, mass flow sensor) and / or actuator (e.g., valve, heat exchanger, fan) of the fuel cell system. The heater can, for example, be a foil heater, which is specifically configured to heat a component (e.g., a gas line). Alternatively or additionally, the heater can, for example, be a cartridge heater, which is specifically configured to heat a component. For example, a heating current can be converted into heat resistively or due to ohmic losses in the heater.This allows the heater and / or the component to be heated and / or the temperature of the heater and / or the component to be increased. This allows, for example, a target temperature and / or (desired) operating temperature (of the fuel cell system, the fuel cell stack and / or the [respective] components) to be reached. Preferably, this enables defrosting and / or thawing.

[0009] The calculation steps can be performed by the control unit. These calculation steps can be discrete and / or performed by the control unit at discrete time points, e.g., every 10 ms. It can be provided that heating occurs at the first, second, third, and / or each calculation step by supplying a total heating current and / or individual heating currents to the heater(s). The profile or value of each heating current can be predefined by the control unit and / or transmitted to it (e.g., by a predefined control command). Preferably, the control unit and / or the heaters are configured to bring the fuel cell system (as a whole) into an operating state and / or heat it to a temperature that enables stable and / or low-wear operation.For this purpose, it may be possible to use the heaters to bring the component(s) of the fuel cell system to a suitable temperature as quickly and / or with minimal wear as possible (e.g. at least 5 °C or more).

[0010] The provision, by the control unit, of a specific heating current to a heater of a (total) number of heaters in the fuel cell system in a second calculation step, whereby the heating currents (especially for each [first, second, and / or third] calculation step) sum to a (respective) total heating current, can involve outputting and / or supplying the heater(s) with corresponding heating currents specific to the second calculation step (or time). For example, the heating currents can be predefined and / or output by the control unit. The control unit can measure and / or determine the heating current(s) in each case. In other words, it can be provided that the control unit supplies a (respective) heating current and / or total heating current to the heater(s) at each calculation step (at a specific time).The system provides the heaters (in particular a first, second, and / or third heating current). The first heating current (or total heating current) may be specific to the first calculation step and / or first time point. The second heating current (or total heating current) may be specific to the second calculation step and / or second time point. The third heating current (or total heating current) may be specific to the third calculation step and / or third time point. The first and / or second calculation time point may already be completed. Preferably, the third calculation step may be performed directly and / or immediately after the second calculation step and may include, in particular, an expected and / or predicted total heating current and / or the respective heating currents of the heaters (see below).

[0011] The prediction (calculation) by the control unit of the total heating current for a third calculation step following the second calculation step (in time and / or directly), depending on the total heating current of the second calculation step, and in particular the total heating current of a first calculation step, especially one immediately preceding and / or earlier than the second calculation step, can include determining a likely total heating current and / or individual heating currents. In other words, it can be calculated which total heating current and / or which individual heating currents are expected to be present for the third calculation step and / or at the third point in time.

[0012] The operation of the fuel cell system by the control unit, depending on the total heating current of the third calculation step, can include operating, in particular controlling and / or regulating, the fuel cell system. The total heating current (determined by forecasting) can be used as the basis for this. Preferably, the operation can prevent exceeding a (too) high total heating current and / or individual heating currents (see below). In other words, the control unit can be designed to prevent the occurrence of safety-critical and / or (excessively) wear-inducing operating conditions.

[0013] Within the scope of the invention, it can be advantageous that the forecasting is (also) carried out depending on the total heating current of a first calculation step, wherein in particular the first calculation step, the second calculation step and the third calculation step have temporally successive discrete points in time, wherein in particular the third calculation step is specific for a future and / or forecasted point in time.

[0014] The first calculation step can include an initial and / or start step. It is also possible for the first, second, and / or third calculation steps to be (later) consecutive calculation steps. Accordingly, the procedure or the calculation steps can be performed iteratively or continuously. The second calculation step can be a current and / or just-updated calculation step. Therefore, the second calculation step can be specific to a second point in time (present or just past). The first calculation step can include a previous, prior, and / or last calculation step (e.g., 10 ms before the second point in time).

[0015] Accordingly, the first calculation step can be specific to a (past) first point in time, which in particular precedes the second point in time. At the first calculation step, or at the first point in time specific to the first calculation step, a (first) total heating current and / or a respective (first) heating current (or heating currents) can be provided (or have been provided). The third calculation step can be a (temporally) future, subsequent, and / or predicted calculation step. Accordingly, the third calculation step can be specific to a (future and / or next) third point in time, which in particular follows the second point in time. At the third calculation step, or at the third point in time specific to the third calculation step, a (third) total heating current and / or a respective (third) heating current (or heating currents) can be provided.In other words, the third calculation step can be specific to forecasting the total heating current and / or the individual heating currents in the future. The actual calculation or forecasting can take place before the third point in time (e.g., immediately after the second point in time).

[0016] Within the scope of the invention, it is conceivable that the provisioning, forecasting and operation can be carried out during a cold start of the fuel cell system, particularly at temperatures below freezing.

[0017] Within the scope of the invention, it may be provided that the forecasting includes extrapolation, in particular linear extrapolation, wherein the total heating current of the third calculation step I ges,k∓1 (see equation 1 below) is calculated by summing - of the total heating current I ges,k of the second calculation step and - the difference in the total heating current Iges,k of the second calculation step, and in particular of the total heating current I ges,k-1 of the first calculation step.

[0018] Therefore, it can be calculable and / or the following can hold true (Equation 1): Iges,k+1=Iges,k+(Iges,k−Iges,k−1)

[0019] Accordingly, for, preferably successive, calculation steps, the (third) total heating current, which is particularly important for the The third calculation step and / or specific point in time can be determined (continuously). This allows for the advance or forecasting of the total heating current that will be present (in the future and / or next) or would be present (if no intervention is made during operation).

[0020] It is conceivable that at least two, three, or more calculation steps, and / or further calculation steps, are performed. Accordingly, a forecast can include at least one further and / or fourth calculation step, which is specifically for a calculation step or point in time that lies further in the future. In other words, the index k can be increased by 1, based on the data already calculated, particularly from the third calculation step. This allows for particularly early operation and / or reaction to a (potential) surge in electricity demand.

[0021] It is also conceivable that the operation of the fuel cell system by the control unit, depending on the total heating current of the third calculation step, includes the provision of a limited total heating current, in particular where the limited total heating current is less than the total heating current of the third calculation step determined by forecasting.

[0022] In the simplest case, the limited total heating current can be reduced compared to the (predicted) total heating current from the third calculation step. The limited total heating current can be set to a value that is lower than or identical to the current limit for the total heating current. This can increase safety and / or reduce wear. At the same time, it can be ensured that excessive heating, particularly due to high total heating currents and / or individual heating currents, is not prevented too early or too severely. Thus, heating can advantageously be achieved (as quickly as possible).

[0023] It is also conceivable that the provision of a limited total heating current is carried out if the total heating current of the third calculation step exceeds and / or would exceed a current limit for the total heating current, in particular a predefined one (if this were actually provided).

[0024] Alternatively, it can be provided that a predefined and / or planned total current and / or corresponding individual heating currents are supplied, particularly if the current limit for the total heating current is not exceeded. This allows for (comparatively) rapid heating.

[0025] Within the scope of the invention, it is optionally possible that the provision of a limited total heating current includes an even distribution of the current limit value for the total heating current into each limited heating current at the heaters, in particular at the third calculation step and / or at the third time.

[0026] In the simplest case, this allows for the provision of equal (limited) heating currents to each heater. This enables a simple, robust, and / or safe limitation of the total heating current, which advantageously requires minimal computing power. For example, a current limit of 10 A could be implemented. The total heating current can then be set to a (maximum) 10 A. With 10 heaters, each heater could therefore be provided with a heating current of 1 A. This ensures safety at future and / or third-party times. Advantageously, this approach avoids providing excessive and / or wear-inducing currents.

[0027] Furthermore, the invention may provide that the provision of a limited total heating current includes dividing the current limit for the total heating current into limited heating currents specific to the respective heater, which are in particular specific for a maximum current consumption of the respective heater at maximum power and constant operating voltage.

[0028] This allows for the provision of a specific heating current or heating current limit. Different limits can thus be set for different heaters and / or components. This increases safety and further reduces the overall heating time.

[0029] With regard to the present invention, it is conceivable that the division could involve weighting over a linear deviation between a target temperature T. soll,i(of the i-th component) and an actual temperature T ist,i (the i-th component) of the respective heater, in particular a component of the fuel cell system specific to the heater.

[0030] The fuel cell system can have a number n of heaters and / or components. Therefore, the following can be calculated and / or the following can apply (Equation 2): fi=Tset,i−Tcomp,i∑i=1n(Tset,i−Tcomp,i)

[0031] This can f i Each has a weighting factor specific to the i-th heater and / or the i-th component. This weighting factor can be (comparatively) large if the actual temperature is (still) far from the target temperature. Conversely, the weighting factor can be (comparatively) small if the actual temperature is (already) close to the target temperature.

[0032] Therefore, especially within the framework of equation 2, it can be calculated and / or the following can hold true (equation 3): Ii,k,b,spez=fi∗Iges,lim

[0033] In this case I i,k,b,spez The specific limited heating current of each heater is preferably weighted according to the weighting factor. This advantageously enables particularly fast and / or efficient heating. The desired (operating) temperature of the fuel cell system can be reached (particularly) quickly, since components that were previously heated less intensely are heated more intensely and thus preferably do not delay reaching the operating temperature.

[0034] Furthermore, it is conceivable that the division could involve weighting based on a squared deviation between a target temperature T. soll,i and an actual temperature T ist,iof the respective heater, in particular a component of the fuel cell system specific to the heater.

[0035] The fuel cell system can have a number n of heaters and / or components. Therefore, the following can be calculated and / or the following can apply (Equation 4): fi=(Tset,i−Tcomp,i)2∑i=1n(Tset,i−Tcomp,i)2

[0036] This can f iEach i-th heater and / or component has a specific weighting factor. This weighting factor can be (comparatively) large if the actual temperature is (still) far from the target temperature. Conversely, it can be (comparatively) small if the actual temperature is (already) close to the target temperature. Therefore, squaring the weighting factor can significantly influence large differences between the target and actual temperatures. The actual temperature can be measured, for example, by one or more temperature sensors, which are typically located on and / or within the heater, component, and / or fuel cell system.

[0037] Therefore, particularly within the framework of equation 4, it can be calculated and / or the following can hold true (equation 5): Ii,k,b,spez=fi∗Iges,lim

[0038] J can i,k,b,spezThe specific limited heating current of each heater is preferably weighted according to the weighting factor. This advantageously enables particularly fast and / or efficient heating, especially compared to linear weighting. The desired (operating) temperature of the fuel cell system can thus be reached (particularly) quickly, since components that were previously heated less intensely are heated more intensely and therefore preferably do not delay reaching the operating temperature.

[0039] It can also be provided that, as an alternative or in addition to the total heating current or the individual heating currents, the respective power is determined and / or predicted. If the heaters are controlled via power, the power consumption of the heaters for the next calculation step can also be predicted using an (empirical and / or simulated) model (e.g., a PT1 filter) of the controlled power. The power can be limited accordingly by a power limit (for the total power and / or individual power limits). For example, the limited power of a heater P can be lim,i depending on a performance limit for the total performance P lim via the weighting factor (see above) and / or be calculable via: Plim,i=fi∗Plim

[0040] The above problem is solved according to a second aspect by a fuel cell system according to the invention comprising: - a control unit (in particular according to the fourth aspect) which is set up to implement the procedure according to the first aspect, and - at least one or a number of heaters of the fuel cell system, which are specifically designed to heat at least one component (see above) of the fuel cell system.

[0041] This results in the same advantages with regard to a fuel cell system according to the second aspect as have already been described with regard to a method according to the first aspect.

[0042] The above problem is solved according to a third aspect by a computer program product according to the invention, comprising instructions which, when the computer program product is executed by a computer, cause it to implement the method according to the first aspect.

[0043] This results in the same advantages with regard to a computer program product according to the invention as have already been described with regard to a method according to the first aspect and / or a fuel cell system according to the second aspect.

[0044] The above problem is further solved according to a fourth aspect by a computer-readable data carrier according to the invention, in which instructions are stored which, when executed by a computer, cause it to carry out the method according to the first aspect.

[0045] This results in the same advantages with regard to a computer-readable data carrier according to the invention as have already been described with regard to a method according to the first aspect and / or a fuel cell system according to the second aspect and / or a computer program product according to the third aspect.

[0046] The above problem is further solved according to a fifth aspect by a control unit according to the invention, comprising a computing unit and a storage unit in which instructions are stored which, when at least partially executed by the computing unit, carry out a method according to the first aspect.

[0047] The control unit, particularly the processing unit, may be configured to execute and / or initiate the process steps, for example, by controlling the fuel cell system and / or its (above-mentioned) components and / or sensors. The control unit can send control signals to corresponding actuators of the fuel cell system to adjust them. The control unit can also receive sensor signals from sensors of the fuel cell system, such as temperature sensors, which are taken into account in the process, particularly during control and / or regulation. Based on this, for example, a current temperature can be determined.

[0048] The control unit can have or provide a (respective) current output and / or connection for each heater (e.g., via a separate [physical] heating cable) to supply it with a specific heating current. The control unit can be designed as the central and / or sole control unit of the fuel cell system. Alternatively or additionally, a pilot control unit and / or inter-control unit can be provided, each with a connection for each heater to supply a heating current. The pilot control unit and / or inter-control unit can be connected to the (central) control unit via a bus.

[0049] This results in the same advantages with regard to a control unit according to the invention as have already been described with regard to a method according to the first aspect and / or a fuel cell system according to the second aspect and / or a computer program product according to the third aspect and / or a computer-readable data carrier according to the fourth aspect.

[0050] The above problem is further solved according to a sixth aspect by a system according to the invention comprising a fuel cell system according to the second aspect and / or a control unit according to the fifth aspect.

[0051] A system can include a (residential) building, industrial building, power plant, storage plant, vehicle, shipbuilding structure, aircraft or other system with, in particular, increased energy requirements.

[0052] It may be particularly preferable to provide for a (essentially) stationary (immobile) application of the fuel cell system.

[0053] This results in the same advantages with regard to a system according to the invention as have already been described with regard to a method according to the first aspect and / or a fuel cell system according to the second aspect and / or a computer program product according to the third aspect and / or a computer-readable data carrier according to the fourth aspect and / or a control unit according to the fifth aspect.

[0054] Further advantages, features, and details of the invention will become apparent from the following description, in which several embodiments of the invention are described in detail with reference to the drawings. The features mentioned in the claims and in the description can be essential to the invention individually or in any combination. The following are shown schematically: Fig. 1 a method for operating a fuel cell system and Fig. 2 a fuel cell system.

[0055] The figures use identical reference numerals for the same technical features, even for different embodiments.

[0056] Fig. Figure 1 shows a method for operating a fuel cell system 100, in particular a vehicle 200, by means of a control unit FCCU, comprising: - Provide 110, through the control unit FCCU, of a respective heating current I i,k to a heater of a number n of heaters of the fuel cell system 100 in a second calculation step k, where the heating currents I i,k in total a total heating current I ges,k result, - Forecast 120, by the FCCU control unit, of the total heating current J ges,k+1 for a third calculation step k+1 following the second calculation step k as a function of the total heating current I ges,k of the second calculation step k and the total heating current I ges,k-1 of a first calculation step k-1, and - Operating 130, through the control unit FCCU, of the fuel cell system 100 depending on the total heating current I ges,k+1 of the third calculation step k+1.

[0057] Within the scope of the invention, it can be advantageous that the first calculation step k-1, the second calculation step k and the third calculation step k+1 have temporally successive discrete points in time, wherein in particular the third calculation step k+1 is specific for a future and / or predicted point in time.

[0058] Within the scope of the invention, it is conceivable that the provisioning 110, the forecasting 120 and the operation 130 are carried out during a cold start of the fuel cell system 100, particularly at temperatures below freezing.

[0059] Within the scope of the invention, it may be provided that the forecasting 120 comprises an extrapolation 121, in particular linear extrapolation, wherein the total heating current I ges,k+1 the The third calculation step, k+1, is calculated by summing. - of the total heating current I ges,k of the second calculation step k and - the difference in the total heating current I ges,k of the second calculation step k and the total heating current I ges,k-1 of the first calculation step k-1.

[0060] It is also conceivable that the operation of the fuel cell system 100 by the control unit FCCU depends on the total heating current I ges,k+1 of the third calculation step k+1 a provision 131 of a limited total heating current I ges,k+1,b includes, in particular, the limited total heating current I ges,k+1,b is lower than the total heating current I determined by forecasting 120 ges,k+1 of the third calculation step k+1.

[0061] It is also conceivable that providing 131 of a limited total heating current I ges,k+1,b is carried out when the total heating current I ges,k+1 of the third calculation step k+1 a current limit value I, in particular a predefined one ges,lim for the total heating electricity consumption.

[0062] Within the scope of the invention, it is optionally possible that the provision 131 of a limited total heating current I ges,k+1,b an even distribution of 132 of the current limit I ges,lim for the total heating current on individually limited heating currents I i,k,b includes the stokers.

[0063] Furthermore, it may be provided within the scope of the invention that the provision 131 of a limited total heating current I ges,k+1,b a division 133 of the current limit I ges,lim for the total heating current on heating currents specific to the respective heater I i,k,b,spez , which are specifically designed for maximum power consumption of the respective heater at maximum power and constant operating voltage.

[0064] With regard to the present invention, it is conceivable that the division 133 involves weighting 134 over a linear deviation between a target temperature T. soll,iand an actual temperature T ist,i of the respective heater, in particular a component of the fuel cell system 100 specific to the heater.

[0065] Furthermore, it is conceivable that the division 133 could result in a weighting 135 over a squared deviation between a target temperature T. soll,i and an actual temperature T ist,i of the respective heater, in particular a component of the fuel cell system 100 specific to the heater.

[0066] Fig. Figure 2 shows a system 200, for example a vehicle 200, comprising a fuel cell system 100, comprising: - a control unit FCCU, which is configured to execute the procedure according to the first aspect and / or Fig. 1 to implement, and - a number n of heaters of the fuel cell system 100, which are specifically designed to heat (at least) one component of the fuel cell system 100.

[0067] The FCCU control unit can have a processing unit CU and a storage unit MU, in which instructions are stored which, if at least partially executed by the processing unit CU, carry out the procedure according to the first aspect and / or according to Fig. 1. The FCCU control unit can be integrated into the fuel cell system 100.

Claims

[1] Method for operating a fuel cell system (100), in particular a fuel cell system (100) of a vehicle (200), comprising a control unit (FCCU): - Providing (110), by the control unit (FCCU), a respective heating current (I i,k ) to a heater of a number (n) of heaters of the fuel cell system (100) in a second calculation step (k), wherein the heating currents (I i,k ) in total a total heating current (I ges,k ) result, - Forecast (120), by the control unit (FCCU), of the total heating current (I ges,k+1 ) for a third calculation step (k+1) following the second calculation step (k) depending on the total heating current (I ges,k ) of the second calculation step (k) and - Operation (130), by the control unit (FCCU), of the fuel cell system (100) depending on the total heating current (I ges,k+1 ) of the third calculation step (k+1). [2] Method according to claim 1, characterized by , that the forecasting (120) depends on the total heating current (I ges,k-1 ) of a first calculation step (k-1) is performed, wherein in particular the first calculation step (k-1), the second calculation step (k) and the third calculation step (k+1) have temporally successive discrete points in time, wherein in particular the third calculation step (k+1) is specific for a future and / or predicted point in time. [3] Method according to claim 1 or 2, characterized by , that the provisioning (110), forecasting (120) and operation (130) are carried out during a cold start of the fuel cell system (100), especially at temperatures below freezing. [4] Method according to any one of the preceding claims, characterized by, that the forecasting (120) includes extrapolation (121), in particular linear extrapolation, wherein the total heating current (I ges,k+1 ) of the third calculation step (k+1) is calculated by summing - of the total heating current (I ges,k ) of the second calculation step (k) and - the difference in the total heating current (I ges,k ) of the second calculation step (k), and in particular of the total heating current (I ges,k-1 ) of the first calculation step (k-1). [5] Method according to any one of the preceding claims, characterized by , that the operation (130) of the fuel cell system (100) by the control unit (FCCU) depends on the total heating current (I ges,k+1 ) of the third calculation step (k+1) a provision (131) of a limited total heating current (I ges,k+1,b ) includes, in particular the limited total heating current (I ges,k+1,b) is less than the total heating current determined by forecasting (120) (I ges,k+1 ) of the third calculation step (k+1). [6] Method according to the preceding claim 5, characterized by , that the provision (131) of a limited total heating current (I ges,k+1,b ) is carried out when the total heating current (I ges,k+1 ) of the third calculation step (k+1) a current limit value, in particular a predefined one (I ges,lim ) for the total heating current exceeds. [7] Method according to claim 5 or 6, characterized by , that the provision (131) of a limited total heating current (I ges,k+1,b ) an even distribution (132) of the current limit (I ges,lim ) for the total heating current to each limited heating current (I i,k,b ) includes the stokers. [8] Method according to claim 5 or 6, characterized by , that the provision (131) of a limited total heating current (I ges,k+1,b) a division (133) of the current limit (I ges,lim ) for the total heating current to heating currents specific to the respective heater (I i,k,b,spez ), which are specifically designed for maximum power consumption of the respective heater at maximum power and constant operating voltage. [9] Method according to claim 8, characterized by , that the division (133) is a weighting (134) over a linear deviation between a target temperature (T soll,i ) and an actual temperature (T ist,i ) of the respective heater, in particular a component of the fuel cell system specific to the heater (100). [10] Method according to claim 8, characterized by , that the division (133) results in a weighting (135) over a squared deviation between a target temperature (T) soll,i ) and an actual temperature (T ist,i) of the respective heater, in particular a component of the fuel cell system specific to the heater (100). [11] Fuel cell system (100), comprising: - a control unit (FCCU) configured to implement the method according to any of the preceding claims, and - a number (n) of heaters of the fuel cell system (100), which are specifically designed to each heat at least one component of the fuel cell system (100). [12] Computer program product comprising instructions which, when the computer program product is executed by a computer, cause it to implement the method according to any one of the preceding claims 1 to 10. [13] Computer-readable data carrier in which instructions are stored which, when executed by a computer, cause it to carry out the method according to any one of the preceding claims 1 to 10. [14] Control unit (FCCU) comprising a computing unit (CU) and a storage unit (MU) in which instructions are stored which, when at least partially executed by the computing unit (CU), perform a method according to any one of the preceding claims 1 to 10. [15] System (200), in particular vehicle (200), comprising a fuel cell system (100) according to claim 11 and / or a control unit (FCCU) according to claim 14.

Images