Method for operating a power supply system, computer program, computer-readable data carrier and power supply system

Abstract

The invention relates to a method (10) for operating an energy supply system (12) with at least one fuel cell unit (14, 16, 18, 20), wherein in at least one method step at least one control signal is generated to set an operating state of the at least one fuel cell unit (14, 16, 18, 20). It is proposed that the operating state to be set by the control signal be determined, in particular in advance, depending on a given load profile (22).

Description

State of the art

[0001] A method for operating an energy supply system having at least one fuel cell unit has already been proposed, wherein in at least one method step at least one control signal for setting an operating state of the at least one fuel cell unit is generated. Disclosure of the invention

[0002] The invention is based on a method for operating an energy supply system with at least one fuel cell unit, wherein in at least one method step at least one control signal for setting an operating state of the at least one fuel cell unit is generated.

[0003] It is proposed that the operating state to be set by the control signal be determined, in particular in advance, depending on a predetermined load profile. The method is preferably carried out by a computing unit, which may be part of the energy supply system, for example as an edge controller or as a control unit of the at least one fuel cell unit, or which is connected to the energy supply system via a public or private data network, in particular the Internet. A "computing unit" should be understood in particular as a unit with an information input, an information processing unit, and an information output. The computing unit advantageously has at least one processor, a memory, input and output means, further electrical components, an operating program, control routines, control routines, and / or calculation routines.Components of the computing unit can be arranged on a common circuit board and / or in a common housing or provided by a distributed system.

[0004] The load profile preferably specifies a power requirement of a load to be met by the energy supply system as a function of time. The power requirement is preferably an electrical power requirement. Additionally or alternatively, the power requirement can be a thermal power requirement. The load profile preferably comprises a power requirement over a period of at least several hours, preferably at least one day, more preferably over at least one week, in particular over at least one month or at least one year. A temporal resolution of the load profile is preferably at least one specification per hour, particularly in time periods with non-constant power requirements. The computing unit preferably limits the number of control signals generated to the at least one fuel cell unit to a maximum of one control signal per ten-minute period of the load profile.

[0005] For the method, the computing unit is preferably connected to the control unit of the at least one fuel cell unit via data transmission, for example, wired or wireless, in particular radio wave-based. The control unit is preferably designed to set the operating state of the fuel cell unit. The computing unit preferably sends the control signal for setting the operating state to the control unit of the fuel cell unit.Setting the operating state can include starting up the at least one fuel cell unit, modulating the at least one fuel cell unit, shutting down the at least one fuel cell unit, switching the at least one fuel cell unit to standby mode at a designated operating temperature of the at least one fuel cell unit or at a standby temperature of the at least one fuel cell unit that deviates from the designated operating temperature, or the like. The computing unit preferably links the control signal to a time parameter that indicates when the control signal is sent to the at least one fuel cell unit and / or when an instruction contained in the control signal is to be executed by the control unit.The computing unit preferably creates a time schedule from a plurality of control signals depending on the load profile, in particular in temporal correlation with the load profile. The computing unit can process the time schedule element by element, in particular send the control signals to the control unit depending on the respective time parameter, or send the time schedule in full or in sections, for example by day, week, month, or the like, to the control unit for automatic processing by the control unit. If the energy supply system comprises a plurality of independently operable, in particular modulatable, fuel cell units, the control unit preferably determines a distribution of the power requirement among the different fuel cell units and preferably determines individual control signals for the different fuel cell units.

[0006] The schedule preferably specifies that the at least one fuel cell unit be switched off or placed into standby mode if the load profile includes a time period with a power demand below an efficiency threshold, for example, on non-working days. Below the efficiency threshold, the energy supply system obtains any remaining power demand, for example, from a public electricity grid, a public district or local heating network, or the like. Preferably, the computing unit decides to switch off the at least one fuel cell unit if the duration of the time period with the power demand below an efficiency threshold exceeds a minimum shutdown time.The minimum shutdown time is preferably at least longer than a start-up duration of the at least one fuel cell unit, in particular at least 1 hour longer, preferably at least 4 hours longer, particularly preferably at least 8 hours longer than the start-up duration. The time schedule preferably specifies that the at least one fuel cell unit is started up in good time, taking into account the start-up duration, before the load profile has a period with a power requirement above the efficiency threshold, for example at the start of the week. The computing unit can use as the start-up duration a time period from switch-on until a stable operating point of the at least one fuel cell unit is reached, or a duration from switch-on until at least a positive net power is reached by the at least one fuel cell unit.

[0007] The fuel cell unit preferably comprises at least one fuel cell, preferably at least one stack of fuel cells or a combination of stacks of fuel cells. The at least one fuel cell is preferably designed as a solid oxide fuel cell, a molten carbonate fuel cell, a polymer electrolyte membrane fuel cell, or the like.

[0008] "Intended" should be understood in particular to mean specifically programmed, designed, and / or equipped. The fact that an object is intended for a specific function should be understood in particular to mean that the object fulfills and / or performs this specific function in at least one application and / or operating state.

[0009] The inventive design advantageously allows operation of the energy supply system to be individually adapted to each user. In particular, waiting times until the energy supply system is ready for use and / or standby times of the energy supply system, even when there is no power demand, can be advantageously kept to a minimum.

[0010] It is further proposed that, in at least one method step of the method, the operating state to be set is determined as a function of the operating efficiency of the at least one fuel cell unit. Preferably, the computing unit executes an optimization function to determine the operating state to be set, in particular the distribution of the power demand. The optimization function preferably maximizes the efficiency of the energy supply system; in particular, the optimization function minimizes the operating costs of the energy supply system while covering the load profile.The optimization function is preferably dependent on a current operating state of the at least one fuel cell unit, a state of wear of the at least one fuel cell unit, a modulation capability of the at least one fuel cell unit, a fuel consumption by the at least one fuel cell unit and in particular on a fuel price, on costs of an alternative energy source, for example a public power grid, on a commissioning duration of the at least one fuel cell unit, on costs for maintaining the at least one fuel cell unit in standby mode, in particular at the intended operating temperature, or the like. The configuration according to the invention advantageously allows the energy supply system to be operated cost-effectively.

[0011] It is further proposed that in at least one method step of the method, the operating state to be set is determined as a function of the availability of at least one further energy source, in particular one designed differently from the at least one fuel cell unit. The further energy source is preferably a generator unit, in particular a renewable generator unit. Preferably, the further energy source comprises at least one photovoltaic system and / or a wind turbine. Preferably, the distribution of the power requirement by the computing unit also includes the further energy source in addition to the at least one fuel cell unit. Preferably, the computing unit checks whether and to what extent the further energy source is available before sending the control signal to the at least one fuel cell unit.Preferably, the computing unit updates the control signal to the at least one fuel cell unit depending on the availability of the additional energy source. The inventive design allows the at least one fuel cell unit and the additional energy source to be advantageously operated complementarily to cover the load profile. In particular, an excess of provided energy can advantageously be kept low.

[0012] It is further proposed that use of the at least one further energy source to cover the load profile is preferred over power provision by the at least one fuel cell unit. Preferably, the energy source, in particular the further energy source or the at least one fuel cell unit, whose operating costs are lowest is preferred. Preferably, power provided by the further energy source is used first to cover the power requirement. Preferably, the at least one fuel cell unit is operated, in particular only when the further energy source only partially covers the power requirement. If the at least one fuel cell unit has to be operated to cover the power requirement, it is preferably set by the computing unit to the maximum of the smallest necessary modulation and the smallest adjustable modulation.Due to the design according to the invention, fuel consumption by the at least one fuel cell unit can be advantageously kept low.

[0013] It is further proposed that in at least one method step of the method, an environmental parameter is detected or queried in order to determine the operating state to be set. Preferably, the computing unit uses the environmental parameter to determine whether and to what extent the additional energy source will be available. In particular, the computing unit uses the environmental parameter to predict power provision by the additional energy source. The environmental parameter is, for example, a detected or predicted solar radiation, a probability of rain, a detected or predicted wind speed, or the like. The energy supply system preferably comprises an environmental parameter determination unit, which detects the environmental parameter using a sensor element and / or queries it using a data interface from a public or private data network, in particular the Internet.For example, the computing unit switches the at least one fuel cell unit from a switched-off state to standby mode or to an active operating state with minimal modulation if a risk assessment, dependent on the environmental parameter, for insufficient power provision by the additional energy source rises above a threshold value. The inventive design advantageously allows the timing of the control signals to be precisely planned. In particular, the risk or extent of an oversupply, in particular an unnecessary startup of the at least one fuel cell unit, or an undersupply, in particular a failure of the at least one fuel cell unit to be started up in a timely manner in the event of a failure of the additional energy source, can be advantageously kept low by the energy supply system.

[0014] It is further proposed that, in at least one method step of the method, the operating state to be set is determined as a function of a charge state of an energy storage device of the energy supply system. The energy storage device is designed, for example, as a battery or supercapacitor. A capacity of the energy storage device is preferably designed to maintain the power requirement of a load connection and / or load disconnection of the at least one fuel cell unit alone. Preferably, the energy storage device stores excess energy from the at least one fuel cell unit and / or the additional energy source. Preferably, the computing unit prefers the additional energy source over the energy storage device in order to cover the power requirement.Preferably, the computing unit prefers the energy storage device to the at least one fuel cell unit in order to cover the power requirement, for example when a remaining power requirement is below a minimum modulation of the at least one fuel cell unit, for example when the state of charge can completely replace an operating cycle from switching on to switching off the at least one fuel cell unit, for example when recharging of the energy storage device by the additional energy source is likely.In some embodiments, particularly depending on the load profile, the time schedule includes targeted charging of the energy storage device by the at least one fuel cell unit, particularly when the at least one fuel cell unit is already in operation, for example in order to be able to shut down the at least one fuel cell unit prematurely before the end of the power requirement or to restart it with a delay after shutdown. The embodiment according to the invention advantageously allows fuel consumption by the at least one fuel cell unit to be kept low. In particular, a period of time during which the fuel cell unit maintains its state, particularly in the active state or in the passive state, can advantageously be selected to be long.In particular, short-term power demand peaks or drops can be compensated by the energy storage device without the operating state of at least one fuel cell unit having to be changed.

[0015] It is further proposed that in at least one method step of the method, the at least one control signal is determined by a digital twin of the energy supply system. The digital twin is preferably implemented on the computing unit, alternatively on an external server. The digital twin preferably comprises a digital representation of the at least one fuel cell unit, the further energy source and / or the energy storage device. The digital representation of an object preferably comprises a state of wear and / or age, an efficiency, a characteristic reaction time to a change, in particular to a change in operating points, to commissioning, to decommissioning, to a change in the state of charge or the like. The computing unit preferably uses the digital twin to create the optimization function.The computing unit with the digital twin is preferably designed as a server, in particular as a cloud-based service. The inventive design allows the optimization function and / or the distribution of power requirements to be advantageously set up or determined precisely, in particular in a system-specific manner.

[0016] It is further proposed that, in at least one method step of the method, the at least one control signal or a further control signal is determined by an edge controller of the energy supply system. The edge controller preferably determines the distribution of the power demand. The computing unit is preferably designed as an edge controller. Alternatively, the edge controller is interposed between the computing unit and the control unit of the at least one fuel cell unit. The inventive design advantageously allows the data volume of the energy supply system to be kept low.

[0017] Furthermore, a computer program comprising instructions that, when executed by a computing unit, in particular the one already mentioned, cause the computing unit to execute a method according to the invention is proposed. The inventive design makes it possible to provide a computer program by means of which the energy supply system can be operated advantageously in an efficient and cost-effective manner.

[0018] Furthermore, a computer-readable data carrier is proposed on which a computer program is stored, comprising instructions that, when executed by a computing unit, cause the computing unit to execute a method according to the invention. The data carrier can be designed, for example, as a hard disk, a USB mass storage device, a memory card, or the like. The inventive design makes it possible to provide a computer-readable data carrier that can be used to advantageously operate the energy supply system efficiently and cost-effectively.

[0019] Furthermore, an energy supply system with at least one, in particular the one already mentioned, fuel cell unit and with at least one, in particular the one already mentioned, computing unit for implementing a method according to the invention is proposed. The energy supply system preferably comprises a plurality of fuel cell units. The energy supply system preferably comprises the at least one further energy source, in particular a photovoltaic system. The computing unit can be designed as a local computing unit, as a server, as an edge controller, or the like. The energy supply system preferably comprises the environmental parameter determination unit. The embodiment according to the invention makes it possible to provide an advantageously efficient and cost-effective energy supply system.

[0020] The method according to the invention, the computer program according to the invention, the computer-readable data carrier according to the invention, and / or the energy supply system according to the invention are not intended to be limited to the application and embodiment described above. In particular, the method according to the invention, the computer program according to the invention, the computer-readable data carrier according to the invention, and / or the energy supply system according to the invention can, in order to fulfill a functionality described herein, have a number of individual elements, components, units, and method steps that differs from the number stated herein. Furthermore, in the value ranges specified in this disclosure, values ​​within the stated limits are also to be considered disclosed and can be used arbitrarily. Drawings

[0021] Further advantages will become apparent from the following description of the drawings. The drawings illustrate an exemplary embodiment of the invention. The drawings, the description, and the claims contain numerous features in combination. Those skilled in the art will also expediently consider the features individually and combine them into useful further combinations.

[0022] They show: Fig. 1 a schematic representation of an energy supply system according to the invention and Fig. 2 a schematic representation of a method according to the invention. Description of the embodiment

[0023] Fig. 1 shows an energy supply system 12. The energy supply system 12 comprises at least one fuel cell unit 14, 16, 18, 20. The energy supply system 12 comprises at least one computing unit 28. The computing unit 28 comprises a computer-readable data carrier on which a computer program is stored, which comprises instructions which, when the computer program is executed by the computing unit 28, cause the computing unit 28 to carry out a method 10 which is described in Fig. 2. The computing unit 28 preferably comprises a digital twin of the energy supply system 12. The computing unit 28 comprises, for example, at least one server of a public or private data network on which the digital twin is implemented. Alternatively, the computing unit 28 is designed as a local computing unit, which is arranged, for example, in a building, a room and / or a housing of the energy supply system 12, in which in particular the at least one fuel cell unit 14, 16, 18, 20 is also arranged. The local computing unit 28 is preferably designed as an edge controller of the energy supply system 12. The computing unit 28 preferably comprises at least one data interface for receiving and / or inputting a load profile 22. The load profile 22 preferably indicates a required power as a function of time.The load profile 22 preferably extends over at least one day, preferably over several days, in particular over at least one week.

[0024] The energy supply system 12 preferably comprises at least one further energy source 24. The further energy source 24 is particularly preferably embodied as a photovoltaic system. The energy supply system 12 preferably comprises an environmental parameter determination unit 30. The environmental parameter determination unit 30 is preferably provided to determine an environmental parameter. The environmental parameter determination unit 30 comprises, for example, at least one sensor element for detecting the environmental parameter. Additionally or alternatively, the environmental parameter determination unit 30 comprises at least one data interface for querying the environmental parameter and / or a further environmental parameter from an external source. The external source can be, for example, a server of a public or private data network, a sensor element of a local area network, or the like.

[0025] The energy supply system 12 preferably comprises an energy storage device 26 for storing energy provided by the at least one fuel cell unit 14, 16, 18, 20 and / or the further energy source 24.

[0026] Fig.2 shows a flowchart of the method 10 for operating the energy supply system 12. The method 10 preferably comprises a data determination step 32. In the data determination step 32, at least the load profile 22 is preferably queried and / or updated. The environmental parameter determination unit 30 determines the environmental parameter in the data determination step 32. The computing unit 28 preferably processes the environmental parameter in a schedule creation step 34 of the method 10 in order to determine the operating state to be set. The computing unit 28 processes the environmental parameter, in particular to evaluate and / or predict the availability of the at least one further energy source 24.

[0027] The method 10 preferably includes schedule creation 34. In schedule creation 34, an operating state of the at least one fuel cell unit 14, 16, 18, 20, to be set by a control signal, is determined, in particular in advance, as a function of the predetermined load profile 22. In schedule creation 34, the computing unit 28 determines the operating state to be set as a function of an operating efficiency of the at least one fuel cell unit 14, 16, 18, 20. In schedule creation 34, the computing unit 28 determines the operating state to be set as a function of an availability of the at least one additional energy source 24. In schedule creation 34, the computing unit 28 prefers the use of the at least one additional energy source 24 to cover the load profile 22 over power provision by the at least one fuel cell unit 14, 16, 18, 20.During schedule creation 34, the computing unit 28 determines the operating state to be set depending on a charge state of the energy storage device 26 of the energy supply system 12. In particular, the computing unit 26 links the control signal to a time parameter that indicates when the control signal is transmitted to the at least one fuel cell unit 14, 16, 18, 20 and / or when the fuel cell unit 14, 16, 18, 20 should process the control signal. The time parameter can be configured, for example, as an execution time, in particular a time, and / or as a time period, in particular as the remaining time period until the intended transmission or intended processing of the control signal.

[0028] The method 10 comprises, in particular, a time comparison 36 depending on the configuration of the time parameter. If the computing unit 28 determines in the time comparison 36 that a time for transmitting the control signal has arrived, it preferably executes a control step 38 of the method 10. If the computing unit 28 determines in the time comparison 36 that a time for transmitting the control signal has not yet arrived, it preferably executes an update of the data determination step 32. In the control step 38, the computing unit 28 generates the at least one control signal for setting an operating state of the at least one fuel cell unit 14, 16, 18, 20. The computing unit 28 preferably transmits the control signal in the control step 38 to the at least one fuel cell unit 14, 16, 18, 20.

Claims

[1] Method (10) for operating an energy supply system (12) with at least one fuel cell unit (14, 16, 18, 20), wherein in at least one method step at least one control signal for setting an operating state of the at least one fuel cell unit (14, 16, 18, 20) is generated, characterized by that the operating state to be set by the control signal is determined, in particular in advance, as a function of a predetermined load profile (22). [2] Method (10) according to claim 1, characterized by that in at least one method step the operating state to be set is determined as a function of an operating efficiency of the at least one fuel cell unit (14, 16, 18, 20). [3] Method (10) according to claim 1 or 2, characterized byin that in at least one method step the operating state to be set is determined as a function of the availability of at least one further energy source (24), in particular one which is designed differently from the at least one fuel cell unit (14, 16, 18, 20). [4] Method (10) according to claim 3, characterized by that the use of the at least one further energy source (24) to cover the load profile (22) is preferred over power provision by the at least one fuel cell unit (14, 16, 18, 20). [5] Method (10) according to one of the preceding claims, characterized by that in at least one method step an environmental parameter is recorded or queried in order to determine the operating state to be set. [6] Method (10) according to one of the preceding claims, characterized bythat in at least one method step the operating state to be set is determined as a function of a charge state of an energy store (26) of the energy supply system (12). [7] Method (10) according to one of the preceding claims, characterized by that in at least one method step the at least one control signal is determined by a digital twin of the energy supply system (12). [8] Method (10) according to one of the preceding claims, characterized by that in at least one method step the at least one control signal or a further control signal is determined by an edge controller of the energy supply system (12). [9] Computer program comprising instructions which, when the computer program is executed by a computing unit (28), cause the computing unit (28) to carry out a method (10) according to one of the preceding claims. [10] Computer-readable data carrier on which a computer program is stored, which comprises instructions which, when the computer program is executed by a computing unit (28), cause the computing unit (28) to carry out a method (10) according to one of claims 1 to 8. [11] Energy supply system (12) with at least one fuel cell unit (14, 16, 18, 20) and with at least one computing unit (28) for carrying out a method (10) according to one of claims 1 to 8.

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