Cost-efficient operation of an installation of the metal industry and of additional sub-systems of an entire system

Abstract

An entire system comprises an electrical energy store (6), as a sub-system, and additional sub-systems, at least one installation (1) of the metal industry. The sub-systems (1, 4, 6) are directly or indirectly connected to one another and to an electrical supply grid (2), for the transmission of electrical energy. Present states (Z1, Z4, Z6) of the sub-systems (1, 4, 6) and, with respect to a first time horizon (T1), a planned first draw (E2) of electrical energy from the supply grid (2) and planned first operating modes (B1, B4) of the additional sub-systems (1, 4) are known to a control device (7). On the basis of the planned first draw (E2) and the planned first operating modes (B1, B4), the control device (7) determines an expected end state (Z6') of the electrical energy store (6) in relation to the end of the first time horizon (T1). The control device (7) defines a planned second draw (E2') of electrical energy in view of the expected end state (Z6') of the electrical energy store (6) and in view of second operating modes (B1', B4') of the additional sub-systems (1, 4) which are planned for a second time horizon (T2) immediately following the first time horizon (T1) and which are known to the control device (7). The control device (7) operates the additional sub-systems (1, 4) on the basis of the planned first and second operating modes (B1, B4, B1', B4') during the two time horizons (T1, T2) and, at the same time, draws electrical energy from the supply grid (2) according to the planned first draw (E2) of electrical energy and the defined second draw (E2') of electrical energy. In order to define the planned second draw (E2') of electrical energy, the control device (7) determines, on the basis of the planned second operating modes (B1', B4'), a demand (E1', E4') for electrical energy for the operation of the additional sub-systems (1, 4) during the second time horizon (T2) and defines the second draw (E2') of electrical energy from the supply grid (2) during the second time horizon (T2) in view of the demand (E1', E4') for electrical energy for the operation of the additional sub-systems (1, 4) during the second time horizon (T2), the expected end state (Z6') of the electrical energy store (6) and a target state (Z6*) of the electrical energy store (6) which is desired for the end of the second time horizon (T2).

Description

[0001] Description

[0002] Title of the invention

[0003] Cost-efficient operation of a metal industry plant and other subsystems of an overall system

[0004] field of technology

[0005] The present invention is based on an operating method for an overall system,

[0006] - where the overall system comprises an electrical energy storage device and other subsystems as a subsystem,

[0007] - the other subsystems include a metal industry plant,

[0008] - the metal industry plant and the electrical energy storage facility for transmitting electrical energy are directly or indirectly connected to each other and to an electrical supply network,

[0009] - whereby the current states of the subsystems are known to a control device controlling the overall system.

[0010] The present invention is further based on a control program for a control device for an overall system,

[0011] - where the overall system comprises an electrical energy storage device and other subsystems as a subsystem,

[0012] - the other subsystems include a metal industry plant,

[0013] - the metal industry plant and the electrical energy storage facility for transmitting electrical energy are directly or indirectly connected to each other and to an electrical supply network,

[0014] - wherein the control program comprises machine code that can be processed by the control device,

[0015] - wherein the processing of the machine code by the control device causes the control device to control the entire system according to such an operating method.

[0016] The present invention is further based on a control device for an overall system,

[0017] - where the overall system comprises an electrical energy storage device and other subsystems as a subsystem,

[0018] - wherein the further subsystems comprise a metal industry plant, - wherein the metal industry plant and the electrical energy storage device for transmitting electrical energy are directly or indirectly connected to each other and to an electrical supply network,

[0019] - wherein the control device is programmed with such a control program, so that the control device controls the entire system according to such an operating method when executing the machine code of the control program.

[0020] The present invention is further based on an overall system,

[0021] - where the overall system comprises an electrical energy storage device and other subsystems as a subsystem,

[0022] - the other subsystems include a metal industry plant,

[0023] - the metal industry plant and the electrical energy storage facility for transmitting electrical energy are directly or indirectly connected to each other and to an electrical supply network,

[0024] - wherein the overall system comprises such a control device which, when executing the machine code of such a control program, controls the overall system according to such an operating method.

[0025] State of the art

[0026] The items mentioned are known, for example, from the article “Green Energy Supply for the Steel Industry,” Stahl und Eisen, August 2022, pages 22 to 24.

[0027] KR 2019 0136300 A describes an industrial process associated with an energy storage system. The industrial process can be a more or less complex technical process comprising several subprocesses that build on each other and interact with each other. The industrial process has various types of loads, namely loads that must always be supplied with energy, loads that can be switched off, and loads whose energy consumption is adjustable. The actual energy consumption of the various components of the industrial plant is determined. The operation of the industrial plant and the energy storage system are coordinated to minimize costs.

[0028] US 10 354297 B2 discloses an arrangement comprising a domestic consumer, an energy generator, and an energy storage device. The operation of the energy storage device can be determined taking into account the consumer's planned energy consumption. Furthermore, weather data can also be utilized. Price information for purchasing electrical energy from a supply grid and for feeding electrical energy into the supply grid can also be taken into account. It is known from TW 201 235 124 A that the energy consumption of a metal industry plant—specifically, a rolling mill—can be predicted with good accuracy given a known operating mode of the metal industry plant.

[0029] US Pat. No. 8,288,888 B2 discloses an electrolysis plant coupled to a wind farm. Additional loads and energy sources can also be present. These additional loads and energy sources can also take the form of electrical energy storage devices. The hydrogen produced by the electrolysis plant can be transferred to an affiliated chemical plant or refinery.

[0030] US 2015 / 0 051 745 A1 discloses an operating method for an overall system, in which the overall system comprises, as a subsystem, an electrical energy storage device and further subsystems. The further subsystems comprise a metal industry plant, wherein the metal industry plant and the electrical energy storage device are directly or indirectly connected to one another and to an electrical supply network for transmitting electrical energy. A control device controlling the overall system is aware of a current state of the electrical energy storage device and current states of the further subsystems, as well as, with reference to a first time horizon, planned first operating modes of the further subsystems. The control device operates the further subsystems during the first time horizon based on the planned first operating modes.

[0031] US 2023 / 0 013 847 A1 discloses an operating method for an overall system, in which the overall system comprises, as a subsystem, an electrical energy storage device and other subsystems. The other subsystems comprise a metal industry plant. The metal industry plant and the electrical energy storage device are connected directly or indirectly to one another and to an electrical supply grid for the transmission of electrical energy. A control device controlling the overall system is aware of the current state of the electrical energy storage device, the current states of the other subsystems, and, based on a first time horizon, a planned first draw of electrical energy from the supply grid and planned first operating modes of the other subsystems.The control device determines a planned second electrical energy consumption taking into account second operating modes of the further subsystems that are known to the control device and planned for a second time horizon immediately following the first time horizon. The control device operates the further subsystems during the first time horizon based on the planned first operating modes, with the control device drawing electrical energy from the supply grid during the first time horizon in accordance with the planned first electrical energy consumption and operating the further subsystems during the second time horizon based on the planned second operating modes and drawing electrical energy from the supply grid during the second time horizon in accordance with the specified second electrical energy consumption. From the technical paper “Optimal Industrial Load Control in Smart Grid”, IEEE Transactions on Smart Grid, Vol. 7, No.5, September 2016, pages 2305 to 2316, an overall system is known which comprises industrial consumers that are connected to an electrical supply grid. Components of a steelworks are cited as an example of such industrial consumers. In some embodiments, an electrical energy storage device can be present. The operation of the electrical consumers (including the electrical energy storage device) is to be optimized. The technical article thus discloses an operating method for an overall system, wherein the overall system comprises, as a subsystem, an electrical energy storage device and further subsystems, wherein the further subsystems comprise a plant in the metal industry, wherein the plant in the metal industry and the electrical energy storage device are directly or indirectly connected to one another and to an electrical supply grid for the transmission of electrical energy. The technical article further discloses predictive pricing.However, the operating modes of the other subsystems do not seem to have been determined yet, at least for the second time horizon.

[0032] US 2016 / 0291 554 A1 concerns an overall system that may include an electrical energy storage system and a metal industry plant. An energy management system is present that controls the various plant components.

[0033] Summary of the invention

[0034] In the past, the costs incurred in determining the operation of metal industry plants – including the associated energy costs – were taken into account. However, this was only done in the sense that the total electrical energy demand and the resulting electrical energy costs were taken into account. As the shift toward renewable energies progresses, the availability of electrical energy (including the temporal fluctuations in the costs incurred for electrical energy) must be considered to a much greater extent, as the availability and thus also the costs of electrical energy will be subject to significantly greater fluctuations in the future than in the past.

[0035] Decisive for the efficient use of the electrical energy storage device within the scope of the present invention are, on the one hand, the - expected - future electricity demand of the metal industry plant and, on the other hand, the - expected - future price for electrical energy drawn from the supply grid.

[0036] Although the aforementioned paper states that the metal industry plant and the electrical energy storage system are controlled and operated using an intelligent energy management system, it does not provide any further details on the implementation of the intelligent energy management system.

[0037] The object of the present invention is to create possibilities by means of which a cost-efficient operation of an overall system is achieved, which comprises as subsystems a metal industry plant and an electrical energy storage device.

[0038] The object is achieved by an operating method having the features of claim 1. Advantageous embodiments of the operating method are the subject of dependent claims 2 to 6.

[0039] According to the invention, an operating method of the type mentioned at the outset is designed in that

[0040] - wherein the control device, with respect to a first time horizon, is aware of a planned first consumption of electrical energy from the supply network and planned first operating modes of the further subsystems,

[0041] - wherein the control device determines an expected final state of the electrical energy storage device based on the planned first consumption and the planned first operating modes,

[0042] - wherein the control device determines a planned second consumption of electrical energy, taking into account the expected final state of the electrical energy storage device and second operating modes of the further subsystems known to the control device and planned for a second time horizon immediately following the first time horizon,

[0043] - wherein the control device operates the further subsystems during the first and second time horizons based on the planned first and second operating modes and draws electrical energy from the supply network during the first and second time horizons in accordance with the planned first consumption and the specified second consumption of electrical energy.

[0044] It is provided that the control device for determining the planned second purchase of electrical energy

[0045] - based on the planned second operating modes, determine the electrical energy requirement for the operation of the other subsystems during the second time horizon and

[0046] - determines the second electrical energy consumption from the supply grid during the second time horizon, taking into account the electrical energy demand for the operation of the other subsystems during the second time horizon, the expected final state of the electrical energy storage system, and a desired target state of the electrical energy storage system for the end of the second time horizon. This makes determining the planned second electrical energy consumption particularly easy. The planned second operating modes can be specified to the control device. Alternatively, they can be determined independently by the control device, for example, as part of an optimization process.

[0047] The term "subsystems," when used without further suffixes, encompasses all subsystems, both above and below, including the electrical energy storage system. The term "other subsystems," however, does not encompass the electrical energy storage system, but only the other subsystems. The first time horizon can be, for example, 24 hours. The second time horizon is generally considerably shorter than the first time horizon. It can be, for example, 1 hour or a few hours. The stated values ​​are typical. However, the present invention is not limited to the stated values ​​for the two time horizons.

[0048] It is possible for the control device to first determine the planned first consumption of electrical energy from the supply grid prior to the current execution of the operating method for the first time horizon and then, based on the planned first consumption of electrical energy, to determine the planned first operating modes of the various other subsystems. Alternatively, the reverse procedure is possible. Alternatively, it is possible for the planned first operating modes of the other subsystems to be known to the control device first (for example, because they are specified to the control device or determined by the control device) and for the control device to then determine the planned first consumption of electrical energy based on the planned first operating modes.In any case, the planned operating mode of the electrical energy storage system is derived from the specified electrical energy consumption and the corresponding planned initial operating modes of the other subsystems. The electrical energy storage system is, so to speak, the slave that obeys its masters, with the other subsystems and the specified electrical energy consumption from the supply grid being the masters.

[0049] The present invention is based on the fact that the expected price for electrical energy drawn from the grid can be determined for different periods of time in different ways. On a spot market, the price is often fixed for a relatively limited period of time, for example, only 24 hours in advance. Here, specific quantities of electricity are traded for fixed periods of time at a respective spot market price.

[0050] If, during subsequent operation of the overall system – for example, 24 hours after the purchase of a specific amount of electrical energy – the previously purchased amount of electrical energy is used, the agreed tariff will still be charged. If, on the other hand, more or less electrical energy is used, the actual price for electrical energy drawn from the supply grid depends on a variety of factors. The actual price particularly takes into account whether and, if so, at what cost additional electrical energy had to be procured by the operator of the supply grid, or whether and, if so, at what cost electrical energy purchased from the operator of the supply grid but not drawn could be used for other purposes. This creates considerable uncertainty for the operator of the overall system.It would be considerably more reliable if it could be guaranteed that, during subsequent operation of the entire system, the previously purchased amount of electrical energy—no more and no less—is actually drawn from the grid. This is precisely what the inventive approach ensures.

[0051] The current states of the subsystems can be defined as needed. They can include, in particular, "normal" operating states, operating limits, and wear states.

[0052] Specifically for the electrical energy storage device, the current state includes, in particular, the extent to which the energy storage device is charged (in percentage and / or absolute terms) and the temperature of the energy storage device's storage cells. Furthermore, the energy storage device state can also include the wear and tear of the energy storage device or parts of the energy storage device. Furthermore, the energy storage device state can, in principle, include maximum possible and currently maximum possible operating variables, such as charging and discharging currents. This also applies analogously to the actual and expected final state of the electrical energy storage device at the end of the first time horizon.

[0053] It is possible for the overall system to have only a single electrical energy storage device or for it to have multiple electrical energy storage devices, which are treated uniformly by the control device in the sense of the electrical energy storage device mentioned above. Preferably, however, the overall system comprises a further electrical energy storage device, namely as a further subsystem. Classifying the further electrical energy storage device as a further subsystem not only means that the control device knows the current state of the further electrical energy storage device and that the further electrical energy storage device is controlled by the control device.Rather, this classification also means that the control device knows the planned first and second operating modes of the additional electrical energy storage device for the first and second time horizons, and that the additional electrical energy storage device is operated accordingly. Therefore, the control device first knows the operating mode of the additional electrical energy storage device for both time horizons. Only then is the second electrical energy consumption determined for the second time horizon.For the second time horizon and limited to the two electrical energy storage devices, the sequence is therefore first the announcement of the second operating mode of the further electrical energy storage device, then the determination of the electrical energy consumption for the second time horizon and thereby for this time horizon the determination of an expected operating mode for the electrical energy storage device, which is a subsystem but not a further subsystem of the overall system.

[0054] If the additional electrical energy storage device is present, it preferably differs from the other electrical energy storage device in its possible performance limits, for example in its capacity and its maximum possible or permissible charging and discharging current (or a corresponding power). For example, the additional electrical energy storage device can have a significantly smaller storage capacity but a considerably greater maximum charging and discharging power than the other electrical energy storage device. By way of example, the values ​​​​for the additional electrical energy storage device are 10 MWh and 100 MW, and for the other electrical energy storage device the values ​​​​are 100 MWh and 25 MW. The additional electrical energy storage device can be designed, for example, as a sodium-ion battery, and the other electrical energy storage device can be designed, for example, as a redox flow battery or a sodium-sulfur battery.

[0055] The manner in which the control device is informed of the second operating mode for the additional electrical energy storage device for the second time horizon can be determined as required. In the simplest case, a specification is made by an operator. As a rule, however, it is considerably better if the control device first determines the planned second operating mode of the additional energy storage device using the planned second operating modes of the additional subsystems (now with the exception of the additional electrical energy storage device) and only then determines the planned second electrical energy consumption. The control device therefore proactively determines the planned second operating mode for the additional electrical energy storage device based on the planned second operating modes with which the other subsystems are to be operated.

[0056] During operation of the additional subsystems (usually with the exception of the additional electrical energy storage device), various types of disturbances can occur. Such disturbances, which must be taken into account, can result in the electrical energy demand of the additional subsystems (again with the exception of the additional electrical energy storage device) deviating from the energy demand according to the planned first operating modes. Therefore, the control system preferably checks during the first time horizon whether such deviations occur due to unconsidered circumstances. If the energy demand does not deviate, the control device maintains the planned first operating mode of the additional electrical energy storage device and a first operating mode of the electrical energy storage device based on the planned first consumption of electrical energy from the supply grid. If, however, the energy demand deviates,

[0057] - the control device changes the planned first operating mode of the further electrical energy storage device and / or the planned first operating mode of the electrical energy storage device so that the planned first supply of electrical energy from the supply network is maintained, and

[0058] - the control device shall only change the planned first operating modes of the other subsystems with the exception of the additional electrical energy storage device and / or the planned first consumption of electrical energy if the operating limits of the electrical energy storage device and / or the additional electrical energy storage device cannot be complied with.

[0059] The latter changes, i.e. the change in the planned initial operating modes of the other subsystems with the exception of the additional electrical energy storage device and / or the planned initial consumption of electrical energy, shall be carried out in such a way that the operating limits of the electrical energy storage device and the additional electrical energy storage device are complied with.

[0060] Even if no additional electrical energy storage device is present, malfunctions or unconsidered circumstances can naturally occur. Furthermore, it is also possible that—regardless of the reasons—the planned initial operating mode of the additional electrical energy storage device should only be changed to a lesser extent. It is therefore also possible that the control device

[0061] - during the first time horizon, checks whether, despite circumstances not taken into account, the operating limits of the electrical energy storage system are complied with during the remaining part of the first time horizon,

[0062] - in the event that the operating limits are complied with, maintain the planned first purchase of electrical energy and

[0063] - in the event that the operating limits are not complied with, the planned initial operating modes and / or the planned initial consumption of electrical energy are modified in such a way that the operating limits of the electrical energy storage device are complied with.

[0064] Possible factors not taken into account include short-term changes in the initial operating modes. The reason for such short-term changes could be, for example, malfunctions in other subsystems. Another possible reason could be that the overall system includes renewable energy generators (e.g., a wind turbine and / or a photovoltaic system) and their renewable energy generation deviates from previous assumptions. Another factor not taken into account is malfunctions in the electrical energy storage system itself.

[0065] As a result, the planned initial operating modes and / or the planned initial consumption of electrical energy may still be changed during the initial time horizon. However, this only occurs if absolutely necessary. The overall system often includes an electrolysis plant as a further subsystem. In this case, the electrolysis plant is directly or indirectly connected to the metal industry plant, the electrical energy storage system, and the electrical grid for transmitting electrical energy. Furthermore, in this case, the current states include the current state of the electrolysis plant, and the planned first and second operating modes include a respective operating mode for the electrolysis plant.

[0066] The object is further achieved by a control program having the features of claim 7. According to the invention, the processing of the machine code by the control device causes the control device to control the entire system according to an operating method according to the invention.

[0067] The object is further achieved by a control device having the features of claim 8. According to the invention, the control device is programmed with a control program according to the invention, so that the control device controls the entire system according to an operating method according to the invention when executing the machine code of the control program.

[0068] The object is further achieved by an overall system having the features of claim 9. According to the invention, the control device is designed as a control device according to the invention which, when the machine code of the control program is executed, controls the overall system according to an operating method according to the invention.

[0069] Short description of the drawings

[0070] The above-described properties, features, and advantages of this invention, as well as the manner in which they are achieved, will become clearer and more readily understood in connection with the following description of an embodiment, which is explained in more detail in conjunction with the drawings.

[0071] FIG 1 an overall system,

[0072] FIG 2 a flow chart,

[0073] FIG 3 a timeline,

[0074] FIG 4 a flow chart,

[0075] FIG 5 a communication structure,

[0076] FIG 6 a flow chart,

[0077] FIG 7 another flow chart,

[0078] FIG 8 another complete system,

[0079] FIG 9 a flow chart and

[0080] FIG 10 shows another flowchart. Description of the embodiments

[0081] According to FIG. 1, an overall system comprises a plant 1 in the metal industry. Plant 1 can have multiple components. Examples of such plants 1 are components that are technologically arranged upstream of a casting facility. Examples of such components are an iron-producing component (e.g., a DRI plant), an arc furnace, a converter, and a ladle plant. Another possible plant 1 is a hot strip mill. This plant is technologically arranged downstream of a casting facility.

[0082] Plant 1 consumes electrical energy during its operation. Plant 1 can obtain electrical energy from an electrical supply network 2, to which it is connected directly (not shown) or indirectly (for example, via a converter 3). Supply network 2 is typically a three-phase network and thus a multi-phase supply network. The three-phase network is often operated at a medium voltage in the range of 20 kV to 30 kV or at a high voltage of 110 kV.

[0083] The overall system often includes an electrolysis system 4 as a further subsystem. The invention is explained below in connection with such an embodiment. However, the electrolysis system 4 is not absolutely necessary. If it is not present, all aspects relating to the electrolysis system 4 are omitted below.

[0084] The electrolysis plant 4 also consumes electrical energy during its operation. The electrolysis plant 4 is therefore also connected to the power grid 2. The electrolysis plant 4 requires a direct current for its operation. A rectifier 5 is therefore typically arranged upstream of the electrolysis plant 4, so that only an indirect connection to the power grid 2 exists.

[0085] In some cases, plant 1 requires hydrogen for its operation. In this case, plant 1 and electrolysis plant 4 are directly or indirectly connected to each other for the transfer of hydrogen, as shown in FIG. 1. Any pumps, valves, and the like are not shown in FIG. 1.

[0086] The overall system further comprises an electrical energy storage device 6 as a subsystem. The energy storage device 6 is connected directly or indirectly to the supply grid 2 at least for absorbing electrical energy, and possibly also for emitting electrical energy. The energy storage device 6 is also connected to the system 1 and the electrolysis system 4 for emitting electrical energy. If the energy storage device 6 absorbs electrical energy, it is always drawn from the supply grid 2. If the energy storage device 6 emits electrical energy, it is used primarily to cover the needs of the system 1 and the electrolysis system 4 and only secondarily for feeding into the supply grid 2.As a result, depending on whether the electrical energy delivered by the energy storage device 6 is greater or smaller than the electrical energy consumed by the system 1 and the electrolysis system 4, electrical energy can be temporarily fed into the supply network 2 or drawn from the supply network 2.

[0087] It must be possible to adjust whether and to what extent electrical energy is supplied to the energy storage device 6, or whether and to what extent the electrical energy storage device 6 releases electrical energy. For this purpose, a bidirectionally operable converter unit is generally provided. This converter unit is not shown in FIG. 1. Rather, it is considered a component of the energy storage device 6.

[0088] The precise nature of the electrical connection between system 1, electrolysis system 4, and energy storage system 6 and the supply grid 2 is of secondary importance. In particular, rectifiers 5, inverters, and other converters 3 can be assigned to the various subsystems 1, 4, and 6 as required. However, it should be ensured that electrical energy can be transferred from energy storage system 6 to system 1 and electrolysis system 4 without going through supply grid 2.

[0089] The overall system further comprises a control device 7. The control device 7 is programmed with a control program 8. The control program 8 comprises machine code 9 which can be processed by the control device 7. Due to the programming with the control program 8, the control device 7 processes the machine code 9. The processing of the machine code 9 by the control device 7 causes the control device 7 to control the overall system according to an operating method which is explained in more detail below in connection with FIG 2. Before the operating method according to the invention is explained, however, it should be pointed out that the control device 7 is explained below as a uniform control device 7 which jointly controls the subsystems 1, 4 and 6 of the overall system. However, the control device 7 can also have its own sub-control device for controlling each of the subsystems 1, 4 and 6.In this case, appropriate information exchange and coordination must take place between the sub-control devices.

[0090] In the following, a distinction is further made between the electrical energy storage device 6 on the one hand and the further subsystems 1, 4. The “further subsystems” comprise only the basic materials industry plant 1 and, if applicable, the electrolysis plant 4, but not the electrical energy storage device 6. If, on the other hand, the term “subsystems” is used without the addition “further”, all subsystems are meant, i.e. not only the basic materials industry plant 1 and, if applicable, the electrolysis plant 4, but also the electrical energy storage device 6. According to FIG 2, a current state Z of the overall system is known to the control device 7 in a step S1. The current state Z comprises a current substate Z1, Z4, Z6 for each of the subsystems 1, 4, 6. The number of the respective current substate Z1, Z4, Z6 corresponds to the reference symbol of the respective subsystem 1, 4, 6.

[0091] For example, the partial state Z1 - assuming the presence of corresponding components of Annex 1 - can include the following quantities:

[0092] - the production progress of an iron-producing plant,

[0093] - the production progress of an arc furnace,

[0094] - a process state of a continuous casting machine,

[0095] - a temperature of a furnace upstream of a rolling mill,

[0096] - Wear conditions of work rolls of rolling mill stands,

[0097] - whether rolling passes are currently being carried out in the rolling mill's rolling stands.

[0098] The partial state Z1 can further include which materials are currently in which state in Plant 1. For example, the partial state Z1 - assuming the presence of corresponding materials in corresponding components of Plant 1 - can include the following variables:

[0099] - quantity and condition of a charge in an arc furnace or in a ladle,

[0100] - Periods of time for which rolled goods are already in a furnace,

[0101] - Temperatures of the rolled goods.

[0102] The partial state Z4 can, for example, include a temperature and a chemical composition of the electrolysis liquid of the electrolysis system 4 and a wear state of the electrolysis system 4.

[0103] The partial state Z6 includes at least the charge state of the energy storage device 6, i.e., the degree to which the energy storage device 6 is charged. The partial state Z6 can also include other variables, for example, a temperature of the energy storage device 6 or a maximum possible or permissible charging and discharging current. Furthermore, the partial state Z6 can include a wear state of the energy storage device 6.

[0104] In a step S2, the control device 7 is informed of planned first operating modes B1, B4 of the further subsystems 1, 4. According to FIG. 3, the said operating modes B1, B4 relate to a first time horizon T1. According to FIG. 3, the first time horizon T1 extends over a significant period of time, for example 20 hours, 22 hours, 24 hours or 26 hours. Of course, other periods are also possible. In a step S3, the control device 7 is also informed of a planned first consumption E2 of electrical energy from the supply network 2 for the first time horizon T1. The number “2”, which in this case has been supplemented with the letter “E”, is intended to indicate that the electrical energy is consumed from the supply network 2.

[0105] In a step S4, the control device 7 determines an expected final state Z6' of the electrical energy storage device 6. The expected final state Z6' relates to the end of the first time horizon T1. The control device 7 determines the expected final state Z6' based on the planned first reference E2 and the planned first operating modes B1, B4. As a rule, the control device 7 also determines the expected final states of the other subsystems 1, 4 in step S4. However, this is of secondary importance within the scope of the present invention.

[0106] In a step S5, the control device 7 is informed of planned second operating modes BT, B4' of the further subsystems 1, 4. The planned second operating modes BT, B4' are - see FIG. 3 - related to a second time horizon T2, which immediately follows the first time horizon T1. The second time horizon T2 is generally considerably shorter than the first time horizon T1. For example, the second time horizon T2 can be 1 hour or a few hours.

[0107] The planned second operating modes BT, B4' can be specified to the control device 7. Alternatively, they can be determined by the control device 7, based on the final states of the other subsystems 1, 4 at the end of the first time horizon T1, for example, according to an operating method as explained in detail in the older, unpublished application "Cost-efficient operation of a steel industry plant and other subsystems of an overall system" by Primetals Technologies Germany GmbH, official file number 23 151 165.0, filed with the European Patent Office on January 11, 2023.

[0108] In a step S6, the control device 7 determines a planned second electrical energy consumption E2'. This determination takes into account the expected final state Z6' of the electrical energy storage device 6 and the planned second operating modes BT, B4'.

[0109] In a step S7, the control device 7 waits for a time t0, i.e. the beginning of the first time horizon T1.

[0110] From time t0, in a step S8, the control device 7 determines the associated operating mode B6 of the electrical energy store 6 on the basis of the first operating modes B1, B4 of the further subsystems 1, 4 planned for the respective time t and the first electrical energy consumption E2 planned for the respective time t. As a result, the electrical energy store 6 thus compensates for the difference between the electrical energy requirement of the further subsystems 1, 4 on the one hand and the - specified - first electrical energy consumption E2. The compensation takes place for each time t or at least for smaller time periods of typically a maximum of 10% of the first time horizon T1. In most cases, the smaller time periods are even shorter than the second time horizon T2. ​​For example, the shorter time periods can be 15 minutes each.

[0111] In a step S9, the control device 7 controls the subsystems 1, 4, 6 for the respective time t according to the operating modes B1, B4, B6 planned or determined for the respective time t, thus operating them according to these operating modes B1, B4, B6. The control device 7 also controls the converter 3 in such a way that electrical energy is drawn from the supply network 2 according to the planned first electrical energy consumption E2.

[0112] In step S10, the control device 7 checks whether a time point t1 has been reached, i.e., the end of the first time horizon T1. If this is not the case, the control device 7 returns to step S8. Otherwise, the control device 7 proceeds to step S11.

[0113] In step S11, and thus from time t1, the control device 7 determines the associated operating mode B6' of the electrical energy store 6 based on the second operating modes BT, B4' of the further subsystems 1, 4 planned for the respective time t and the second electrical energy consumption E2' set for the respective time t. Then, in a step S12, the control device 7 controls the subsystems 1, 4, 6 for the respective time t in accordance with the operating modes BT, B4', B6' planned or determined for the respective time t. The control device 7 also controls the converter 3 in such a way that electrical energy is drawn from the supply network 2 in accordance with the set second electrical energy consumption E2'. The content of steps S11 and S12 therefore corresponds to steps S8 and S9, with the exception of the fact that they relate to a different time.

[0114] In a step S13, the control device 7 checks whether a time t2 has been reached, i.e., the end of the second time horizon T2. ​​If this is not the case, the control device 7 returns to step S11. Otherwise, the procedure of FIG. 2 is terminated.

[0115] FIG 2 shows a simplified procedure. The actual procedure is somewhat more complex. In particular, a rolling procedure is used in reality. Steps S1 to S13 are therefore repeatedly executed, with the times t0, t1, and t2 being continually adjusted and tracked, so that the second time horizon T2, in particular, always lies the same distance in the future—possibly with minor fluctuations.

[0116] For example, if—a typical case—the first time horizon T1 is 23 hours and the second time horizon T2 is 1 hour, and a 1-hour grid is used, after the initial execution of the operating method according to the invention, the operating mode of the entire system is essentially fixed for 24 hours. The period for which the operating mode of the entire system is fixed gradually decreases by 1 hour. After this hour has elapsed, the operating method is executed again, whereby the operating mode of the entire system for the now 23rd hour has been determined by the previous execution of the operating method according to the invention, and the operating mode of the entire system is newly determined for the now 24th hour.

[0117] To determine the planned second electrical energy consumption E2', i.e., the implementation of step S6, the control device 7 according to FIG. 4 first determines, in a step S21, based on the planned second operating modes B1', B4' for the further subsystems 1, 4, a requirement for electrical energy ET, E4' for the operation of the further subsystems 1, 4 during the second time horizon T2. ​​Furthermore, in a step S22, the control device 7 determines a difference ÖZ6 between the expected final state Z6' of the electrical energy storage device 6 and a desired target state Z6* of the electrical energy storage device 6 for the end of the second time horizon T2, in particular a difference between the corresponding charge states. Finally, in a step S23, the control device 7 determines the second electrical energy consumption E2' from the supply network 2 during the second time horizon T2, taking into account the values ​​determined in steps S21 and S22.In the simplest case, the control device 7 can simply calculate the sum.

[0118] 5, the control device 7 can be connected to an energy exchange 11 via the Internet 10. In this case, the control device 7 can, in a step S31, as shown in FIG. 6, determine a number of requests Ai (with i = 1, 2, 3, etc.) for the purchase of electrical energy from the supply network 2 for a number of sections of the second time horizon T2 (for example, with a length of the second time section T2 of 1 hour for four sections of one hour each). The requests Ai each comprise a desired quantity Mi of electrical energy and respective conditions Ci, for example a desired maximum price. As a rule, the requests Ai are staggered, i.e. they differ at least in the respectively assigned maximum price offered.The quantities Mi of electrical energy requested in each case are usually different from each other, but can also be the same in individual cases.

[0119] As a rule, when determining the requirements Ai, the control device 7 takes into account the expected final state Z6' of the electrical energy storage device 6 and / or the operating limits of the electrical energy storage device 6. If, for example, it must be expected that the electrical energy storage device 6 will be almost empty at the end of the first time horizon T1, a relatively large supply E2' of electrical energy must be secured for the second time horizon T2 so that the overall system can continue to operate reliably. In this case, the operator of the overall system must be prepared to pay a relatively high price for the electrical energy. If, on the other hand, it can be expected that the electrical energy storage device 6 will be almost full at the end of the first time horizon T1, only a relatively small supply E2' of electrical energy must be secured for the second time horizon T2 so that the overall system can continue to operate reliably.A very low maximum price can therefore be offered for relatively large quantities of electrical energy.

[0120] Similarly, when determining the requirements Ai, the control device 7 can take into account the operating limits of the electrical energy storage device 6. If, for example, during the second time horizon T2, the state of charge of the electrical energy storage device 6 can be changed by a maximum of 30%, it is not sensible to request an amount Mi of electrical energy that would result in a change in the state of charge of the electrical energy storage device 6 by more than 30%.

[0121] If necessary, when determining the requirements Ai, the control device 7 can also take into account an expected availability V (see FIG 1) of electrical energy that is expected for periods extending beyond the second time horizon T2. ​​The expected availability V can be specified to the control device 7 or determined by the control device 7. The determination of the expected availability V - which is ultimately a guess or estimate - can be carried out by the control device 7, if necessary, on the basis of historical data on the expected availability V, i.e., the actual availability during comparable past periods, and / or a weather forecast.By taking into account the expected availability V, it is possible, for example, to issue requests Ai that combine certain quantities Mi of electrical energy with lower maximum prices, within certain limits, if it can be expected with sufficient probability that electrical energy prices will fall shortly after the second time horizon T2. ​​This allows for some risk, so to speak.

[0122] In a step S32, the control device 7 submits the requirements Ai it has determined to the energy exchange 11. In a step S33, the control device 7 receives responses Ri for the requirements Ai. The responses Ri each contain the information as to whether or not the energy exchange 11 has promised to purchase the requested quantity Mi of electrical energy for the corresponding requirement Ai, subject to the fulfillment of the respectively assigned conditions Ci.

[0123] In a step S34, the control device 7 then accepts those requests Ai for which the purchase of the requested quantities Mi of electrical energy is promised by the energy exchange 11 subject to fulfillment of the respectively assigned conditions Ci, for the respective section of the second time horizon T2 as the second purchase E2' of electrical energy. The planned first operating modes B1, B4 are operating modes with which the corresponding subsystems 1, 4 are operated during the first time horizon T1, if possible. In practice, however, not all circumstances can be fully taken into account when determining the planned first operating modes B1, B4. Certain circumstances are always left out. For example, in the case of a rolling mill as plant 1 in the basic materials industry, a rolled product may be slightly warmer or slightly colder than planned, so that rolling forces, rolling moments and the associated demand for electrical energy vary.

[0124] The control device 7 therefore also checks during the first time horizon T1 according to FIG 7 in a step S41 whether the operating limits of the electrical energy storage device 6 (for example maximum currents or a minimum or maximum charge state) are adhered to during the remaining part of the first time horizon T1 during the actual operation of the further subsystems 1, 4 and also during operation of the electrical energy storage device 6. In other words: the planning was carried out in such a way that the operating limits are adhered to. Due to the facts not taken into account, however, the electrical energy storage device 6 is now operated differently than assumed. It is therefore now possible that despite the planning and, for example, despite certain reserves being taken into account during the planning, the operating limits of the electrical energy storage device 6 are no longer adhered to.

[0125] If the check in step S41 reveals that the operating limits are being adhered to, the control device 7 takes no further action with regard to the planned first electrical energy consumption E2. In particular, it maintains the planned first electrical energy consumption E2 unchanged. If, however, the check in step S41 reveals that the operating limits are not being adhered to, the control device 7 modifies the planned first operating modes B1, B4 in a step S42—naturally only for the future, in this case, the remaining part of the first time horizon T1. For example, a rolling speed can be adjusted or hydrogen production can be adjusted.Alternatively or additionally, in a step S43, the control device 7 changes the planned first purchase E2 of electrical energy, here too, of course, only for the future, in this case the remaining part of the first time horizon T1. For example, the control device 7 can directly purchase or return a certain amount of electrical energy from the energy exchange 11 for at least a portion of the remaining part of the first time horizon T1. In both steps S42 and S43, the measures taken are aimed at ensuring that the operating limits of the electrical energy storage device 6 are adhered to. Step S3 can be implemented analogously to the procedures in FIGS. 4 and 6.

[0126] In this case, a design was explained in which the overall system is divided into subsystems

[0127] 1, 4, 6 exclusively comprise the plant 1 of the basic materials industry, the electrolysis plant 4, and the electrical energy storage device 6. However, according to FIG. 8, the overall system can also comprise other subsystems 12, 13, 14. These subsystems 12, 13, 14, if present, are further subsystems within the meaning of the present invention.

[0128] For example, the overall system can include a hydrogen storage unit 12. The hydrogen storage unit 12 can be designed as a storage unit in the narrower sense, i.e., as a dedicated hydrogen storage unit. However, the pipeline network through which hydrogen is transported also has a certain storage capacity and can serve as a hydrogen storage unit 12. The hydrogen storage unit 12, if present, is connected directly or indirectly to the electrolysis system 4 for absorbing hydrogen and directly or indirectly to the system 1 for releasing hydrogen. Thanks to the hydrogen storage unit 12, the operation of the system 1 and the electrolysis system 4 can be designed more flexibly.

[0129] If the hydrogen storage unit 12 is present, it is possible for the hydrogen generated by the electrolysis plant 4 to be continuously fed to the hydrogen storage unit 12, and for any hydrogen required by the plant 1 to be continuously supplied by the hydrogen storage unit 12, so that the hydrogen storage unit 12 serves as a transfer station for the hydrogen. However, a direct connection between the plant 1 and the electrolysis plant 4 is also possible.

[0130] Alternatively or additionally, the overall system can comprise a power generation device 13, for example a wind turbine or a photovoltaic system. In this case, the power generation device 13 is connected directly or indirectly to the other subsystems 1, 4, 6 that absorb or emit electrical energy, as well as to the electrical supply grid 2, for the transmission of electrical energy. A converter, which is usually required for the power generation device 13, can be considered a component of the power generation device 13. It is not shown in FIG. 1. Preferably, the supply of electrical energy from the power generation device 13 to the subsystems 1, 4, 6 is possible without a detour via the supply grid 2.

[0131] If the hydrogen storage 12 and / or the power generation device 13 are present, the procedures of FIGS. 2, 4 and 6 must be extended and supplemented to take into account the corresponding initial states, operating modes, control and final states of these two subsystems 12, 13.

[0132] Above all, however, the overall system can comprise—in addition to the electrical energy storage device 6—an additional electrical energy storage device 14 as a further subsystem. For linguistic differentiation, the additional electrical energy storage device 14 will always be referred to as such hereinafter, while the electrical energy storage device 6, which has already been explained in connection with FIG. 1, will be referred to as the other electrical energy storage device 6, where necessary.

[0133] The additional electrical energy storage device 14 is directly or indirectly electrically connected to the other subsystems 1, 4, 6, etc. and to the electrical supply network 2. The additional electrical energy storage device 14 can also be operated independently of the other electrical energy storage device 6. It is therefore possible to set independently of the other energy storage device 6 whether and to what extent electrical energy is supplied to the additional energy storage device 14 or whether and to what extent the additional electrical energy storage device 14 releases electrical energy. For this purpose, the additional electrical energy storage device 14 generally has its own bidirectionally operable converter unit. This converter unit is not shown in FIG 8. Rather, it is regarded as a component of the additional electrical energy storage device 14.

[0134] Due to the presence of the additional electrical energy storage device 14, the operating mode of the overall system explained above in connection with FIG. 2 is modified. This is explained in more detail below in connection with FIG. 9.

[0135] A modification that is always present is - of course - that the procedure also takes the additional electrical energy storage device 14 into account. The control device 7 therefore also knows a current partial state Z14 for the additional electrical energy storage device 14 (see step S1 in FIG 9). Furthermore, the control device 7 knows both a planned first operating mode B14 for the first time horizon T1 (see step S2 in FIG 9) and a planned second operating mode B14' for the second time horizon T2 for the additional electrical energy storage device 14. The partial state Z14 is also evaluated analogously to the other partial states Z1, Z4, Z6, and the operating modes B14 and B14' are evaluated analogously to the other first and second operating modes B1, B4, B11, B4' of the additional subsystems 1, 4 (compare, for example, steps S8, S9, S11 and S12 in FIG 9).The current partial state Z14 can – of course for the further electrical energy storage device 14 – comprise the same quantities as the partial state Z6 of the electrical energy storage device 6.

[0136] A further modification, which is not mandatory but will generally be present, consists in the manner in which the second operating mode B14' for the further electrical energy storage device 14 is known to the control device 7. According to FIG 9, a step S51 is present between steps S5 and S6. In step S51, the control device 7 determines the planned second operating mode B14 of the further energy storage device 14 using the planned second operating modes BT, B4' of the further subsystems 1, 4 - i.e. the further subsystems 1, 4 with the exception of the further electrical energy storage device 14. If necessary, states of the further subsystems 1, 4 (including the further electrical energy storage device 14) that are expected for the transition from the first to the second time horizon T1, T2 can also be included in the determination in step S51.These states can, if necessary, be determined from the corresponding current states Z1, Z4 and the associated first operating modes B1, B4. In any case, however, the control device 7 executes step S6, in which it determines the planned second electrical energy consumption E2', only after step S51.

[0137] Due to the additional electrical energy storage device 14, the procedure of FIG. 7 can also be modified as explained below in connection with FIG. 10.

[0138] According to FIG 10, during the first time horizon T1, the control device 7 checks in a step S61 whether, during the actual operation of the further subsystems 1, 4 (with the exception of the further electrical energy storage device 14), the electrical energy requirement of the further subsystems 1, 4 deviates from an energy requirement according to the corresponding planned first operating modes B1, B4.

[0139] If the energy demand does not deviate, the control device 7 proceeds to step S62. In step S62, the control device 7 maintains the planned first operating modes B6, B14 of both electrical energy storage devices 6, 14 unchanged. The planned first operating mode B6 of the electrical energy storage device 6 was previously determined based on the planned first consumption E2 of electrical energy from the supply network 2. Thus, the control device 7 also maintains the planned first consumption E2 of electrical energy from the supply network 2 unchanged.

[0140] If, however, the energy requirement deviates, the control device 7 proceeds to step S63. In step S63, the control device 7 checks whether the planned first draw E2 of electrical energy from the supply network 2 can be maintained by modifying the planned first operating mode B14 and / or the planned first operating mode B6 - naturally taking into account the operating limits of the two electrical energy storage devices 6, 14. If the planned first draw E2 of electrical energy can be maintained, the control device 7 proceeds to step S64 in which it modifies the planned first operating mode B6 and / or the planned first operating mode B14 accordingly. However, in step S64, the control device 7 continues to maintain the planned first draw E2 of electrical energy from the supply network 2 unchanged.The first operating modes B1, B4 of the other subsystems 1, 4 will also only be changed to the extent that this is absolutely necessary due to the faults that have occurred.

[0141] By executing step S64, for example, the additional electrical energy storage device 14 can temporarily bridge the fault. If necessary, the operating mode of the other electrical energy storage device 14 can also be changed. Subsequently, the state of the additional electrical energy storage device 14 can then, for example, be brought back closer to the state it would have had without the fault. However, all of this occurs without changing the electrical energy drawn from the supply network 2.

[0142] If, however, the planned first consumption E2 of electrical energy from the supply network 2 cannot be maintained even with a change to the planned first operating mode B14 and / or the planned first operating mode B6, the control device 7 proceeds to step S65. In step S65, the control device 7 not only changes (within the scope of possibilities) the planned first operating modes B6, B14 of the two electrical energy stores 6, 14. Rather, in step S65 the control device 7 also changes the planned first consumption E2 of electrical energy from the supply network 2 and / or the planned first operating modes B1, B4 of the other further subsystems 1, 4. The change is made in such a way that the operating limits of the two electrical energy stores 6, 14 are observed.In some cases, it may be advisable to make the modification in such a way that the planned initial consumption of electrical energy E2 from grid 2 is changed as little as possible. In other cases, this may not be effective and can therefore be disregarded.

[0143] The overall system may also include other subsystems. This is not shown in FIG. 1. In this case, too, the procedures in FIGS. 2, 4, and 6 must be expanded and supplemented to take into account the corresponding initial states, operating modes, control, and final states of these subsystems.

[0144] The present invention offers many advantages. Due to the prior determination and subsequent implementation of the electrical energy supply E2' from the supply grid 2, the electrical energy costs are reliably known. In particular, participation in the internet exchange 11 can even minimize the electrical energy costs. The integration of, for example, longer-term supply contracts or a dedicated power generation facility 13 is also readily possible.

[0145] Although the invention has been illustrated and described in detail by the preferred embodiments, the invention is not limited by the disclosed examples, and other variations may be derived therefrom by those skilled in the art without departing from the scope of the invention.

[0146] 1 system

[0147] 2 Supply network

[0148] 3 inverters

[0149] 4 Electrolysis plant

[0150] 5 rectifiers

[0151] 6 energy storage

[0152] 7 Control device

[0153] 8 Control program

[0154] 9 Machine code

[0155] 10 Internet

[0156] 11 Energy Exchange

[0157] 12 hydrogen storage units

[0158] 13 Power generation facility

[0159] 14 additional energy storage units

[0160] AI requirements

[0161] B1, B4, B6, B14 first operating modes

[0162] BT, B4', B6', B14' second operating modes

[0163] Ci Conditions

[0164] ET, E4' Electrical energy requirements

[0165] E2, E2' Electrical energy consumption

[0166] Mi amounts of electrical energy

[0167] Ri Answers

[0168] S1 to S65 steps

[0169] T1 , T2 time horizons tO, t1 , t2 time points

[0170] V Availability

[0171] Z1, Z4, Z6, Z14 current states

[0172] Z6' expected final state

[0173] Z6* Target state

[0174] ÖZ6 difference

Claims

Claims 1. Operating procedures for an entire system, - wherein the overall system comprises, as a subsystem, an electrical energy storage device (6) and further subsystems (1, 4), - wherein the further subsystems (1, 4) comprise a plant (1) of the metal industry, - wherein the metal industry plant (1) and the electrical energy storage device (6) for transmitting electrical energy are directly or indirectly connected to each other and to an electrical supply network (2), - wherein a control device (7) controlling the overall system knows the current states (Z1, Z4, Z6) of the subsystems (1, 4, 6), - wherein the control device (7), with respect to a first time horizon (T1), is aware of a planned first consumption (E2) of electrical energy from the supply network (2) and planned first operating modes (B1, B4) of the further subsystems (1, 4), - wherein the control device (7) determines an expected final state (Z6') of the electrical energy storage device (6) based on the planned first reference (E2) and the planned first operating modes (B1, B4), related to the end of the first time horizon (T1), - wherein the control device (7) determines a planned second consumption (E2') of electrical energy, taking into account the expected final state (Z6') of the electrical energy storage device (6) and second operating modes (BT, B4') of the further subsystems (1, 4) known to the control device (7) and planned for a second time horizon (T2) immediately following the first time horizon (T1), - wherein the control device (7) operates the further subsystems (1, 4) during the first and second time horizon (T1, T2) based on the planned first and second operating modes (B1, B4, BT, B4') and draws electrical energy from the supply network (2) during the first and second time horizon (T1, T2) in accordance with the planned first reference (E2) and the specified second reference (E2') of electrical energy, - wherein the control device (7) determines a requirement (ET, E4') of electrical energy for the operation of the further subsystems (1, 4) during the second time horizon (T2) based on the planned second operating modes (BT, B4') in order to determine the planned second purchase (E2') of electrical energy and determines the second purchase (E2') of electrical energy from the supply network (2) during the second time horizon (T2) taking into account the requirement (ET, E4') of electrical energy for the operation of the further subsystems (1, 4) during the second time horizon (T2) and the expected final state (Z6') of the electrical energy store (6) and a desired target state (Z6*) of the electrical energy store (6) for the end of the second time horizon (T2).

2. Operating method according to claim 1, characterized in that the overall system comprises a further electrical energy storage device (14) as a further subsystem (14).

3. Operating method according to claim 2, characterized in that the control device (7) first determines the planned second operating mode (B14') of the further energy storage device (14) using the planned second operating modes (BT, B4') of the further subsystems (1, 4) with the exception of the further electrical energy storage device (14) and only then determines the planned second consumption (E2') of electrical energy.

4. Operating method according to claim 2 or 3, characterized in that the control device - during the first time horizon (T1), checks whether, due to unconsidered circumstances, the electrical energy demand of the further subsystems (1, 4), with the exception of the further electrical energy storage device (14), deviates from an energy demand according to the planned first operating modes (B1, B4), - in the event that the energy demand does not deviate, the planned first operating mode (B14) of the further electrical energy storage device (14) and a first operating mode (B6) of the electrical energy storage device (6) planned based on the planned first consumption (E2) of electrical energy from the supply network (2) are maintained, and - in case the energy demand deviates, -- primarily modifies the planned first operating mode (B14) of the further electrical energy store (14) and / or the planned first operating mode (B6) of the electrical energy store (6) so that the planned first draw (E2) of electrical energy from the supply network (2) is maintained, and only if operating limits of the electrical energy store (6) and / or of the further electrical energy store (14) cannot be complied with, the planned first operating modes (B1, B4) of the further subsystems (1, 4) with the exception of the further electrical energy store (14) and / or the planned first draw (E2) of electrical energy is modified such that the operating limits of the electrical energy store (6) and of the further electrical energy store (14) are complied with.

5. Operating method according to claim 1, 2 or 3, characterized in that the control device (7) - during the first time horizon (T1), checks whether, despite circumstances not taken into account during the remaining part of the first time horizon (T1), the operating limits of the electrical energy storage device (6) are complied with, - in the event that the operating limits are respected, maintain the planned first consumption (E2) of electrical energy and - in the event that the operating limits are not complied with, the planned first operating modes (B1, B4) and / or the planned first consumption (E2) of electrical energy are modified in such a way that the operating limits of the electrical energy storage device (6) are complied with.

6. Operating method according to one of the above claims, characterized in that - that the overall system comprises an electrolysis plant (4) as a further subsystem, - that the electrolysis plant (4) for the transmission of electrical energy is connected directly or indirectly to the plant (1) of the metal industry, the electrical energy storage device (6) and the electrical supply network (2), - that the current states (Z1, Z4, Z6) include a current state (Z4) of the electrolysis plant (4) and - that the planned first and second operating modes (B1, B4) comprise a respective operating mode (B4, B4') for the electrolysis plant (4).

7. Control program for a control device (7) for an overall system, - wherein the overall system comprises, as a subsystem, an electrical energy storage device (6) and further subsystems (1, 4), - wherein the further subsystems (1, 4) comprise a plant (1) of the metal industry, - wherein the metal industry plant (1) and the electrical energy storage device (6) for transmitting electrical energy are directly or indirectly connected to each other and to an electrical supply network (2), - wherein the control program comprises machine code (9) which can be processed by the control device (7), - wherein the processing of the machine code (9) by the control device (7) causes the control device (7) to control the overall system according to an operating method according to one of the above claims.

8. Control device for an entire system, - wherein the overall system comprises, as a subsystem, an electrical energy storage device (6) and further subsystems (1, 4), - wherein the further subsystems (1, 4) comprise a plant (1) of the metal industry, - wherein the metal industry plant (1) and the electrical energy storage device (6) for transmitting electrical energy are directly or indirectly connected to each other and to an electrical supply network (2), - wherein the control device is programmed with a control program (8) according to claim 7, so that when the machine code (9) of the control program (8) is executed, the control device controls the entire system according to an operating method according to one of claims 1 to 6.

9. Overall system, - wherein the overall system comprises as a subsystem an electrical energy storage device (6) and further subsystems (1, 4), - wherein the further subsystems (1, 4) comprise a plant (1) of the metal industry, - wherein the plant (1) of the metal industry and the electrical energy storage device (6) for transmitting electrical energy are directly or indirectly connected to each other and to an electrical supply network (2), - wherein the overall system comprises a control device (7) according to claim 8, which, when executing the machine code (9) of a control program (8) of claim 7, controls the overall system according to an operating method according to one of claims 1 to 6.

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