Device with storage and regenerative energy generator and method for operating the same

Abstract

The invention relates to a device comprising a storage (2) for electrical energy for output to a power grid (9) and a regenerative energy generator (1), wherein the regenerative energy generator (1) has a power control unit (10) with an input for a target power output and controls the power generation by the regenerative energy converter (13), and also a charge controller (20) for the storage (2) is provided, which sets a minimum regulating energy to be provided and outputs a signal for a target state of charge (SoC) of the storage (2). In order to achieve a better utilization of the storage, a correction unit (4) is connected to the charge controller (10), which continuously adjusts the signal for the target state of charge (SoC), and a sequence control unit (5) is provided, which is actuated by the correction unit (4) and influences the power control unit (10) of the regenerative energy generator in accordance with the output value of the correction unit (4).

Description

TECHNICAL FIELD

[0001] The invention relates to a device for energy generation and storage. The device comprises a regenerative energy generator, in particular a wind power plant and / or a photovoltaic plant, and an electrical energy store. BACKGROUND

[0002] In order to ensure a high supply reliability, the power grid must have the ability to quickly compensate for the difference between power generation on the one hand and power consumption on the other hand. The electrical power required for this is referred to as regulating power. Positive regulating power is required in order to be able to compensate for a sudden deficiency in power generation, for example a power plant shutting down. In the case of negative regulating power, the situation is exactly the opposite, here the power generation is too great in relation to the power consumption, so that power generation must be reduced. In both cases, the regulating power quickly and within a limited time period overcomes the excess supply of power or the power deficiency, i.e. this is done until other reserve power generation can be started or power generators can be obtained from the power grid. In this case, the limited time period can be understood to mean what varies from country to country, usually a time period in the range between 15 and 60 minutes.

[0003] In conventional power grids, electrical power is mainly generated by means of conventional power plants, which usually have synchronous generators driven by turbines. An excess supply or a deficiency of electrical power (active power) can be seen by a change in the grid frequency. Thus, such a change in the grid frequency is based on the fact that in the case of a lack of active power in the power grid (too little power generation), the synchronous generator, due to its construction type, slows down, or in the case of too much active power (power generation is too great for the consumption), the synchronous generator is unloaded and thereby speeds up. This slowing down or speeding up is counteracted by the large inertia of the rotating parts of the synchronous generator, including the drive turbine coupled to the synchronous generator. Therefore, conventional synchronous generators act compensatorily with respect to changes in active power from home. This action only occurs in the time range of a few seconds, so that power grids with mainly conventional power plants also depend on regulating energy.

[0004] However, in power grids, more and more conventional power plants with large synchronous generators are being replaced by smaller decentralized power plants, the feedable power of which depends on a primary energy supply (for example the wind speed). Examples of this are often facilities for regenerative energy generation from renewable energy sources, in particular wind power plants or wind farms or photovoltaic plants. Regenerative energy generation power plants can only provide regulating energy depending on the primary energy supply, and must be operated below the possible power (down-regulation) when positive regulating power should be provided.

[0005] On the other hand, however, the inherent necessity of providing the regulating power is entirely to ensure the provision of this regulating power. On the one hand, this regulating power must be able to ensure that it is fed for a certain period of time (typically a period of 30 minutes) when required, and it must be able to ensure that it is provided for a certain period of time (typically a period of one week in Germany for the provision).

[0006] Conventional power plants can generally meet this need to ensure provision from a domestic perspective, whereas this is mostly not the case for regenerative energy generation facilities. In particular, regenerative energy generation facilities lack sufficiently reliable forecasts for the required period of time (period of time for ensuring provision of regulating power), and these facilities also often cannot (or only very limitedly) provide positive regulating power (if the wind is insufficient, more power cannot be fed in).

[0007] In order for regenerative energy generation facilities to still participate in the provision of regulating power, these regenerative energy generation facilities are increasingly assigned electrical storage. However, the provision of storage is expensive and the utilization thereof is sometimes not optimal. Typically, these storages are operated with a state of charge of approximately 50% in order to have not only an upward reserve for absorbing power (negative regulating power) but also a downward reserve for outputting additional power (positive regulating power). By this means, the size of the storage is designed to be twice the size that is actually required for the regulating energy to be provided.

[0008] In order to reduce the expenses required for this to a minimum, it is known to reduce the storage by providing an energy converter (EP 3 148 036 A1). This energy converter is configured to appear as an additional consumer and thus dissipate power, in particular in the case of negative regulating power, so that this power does not have to be absorbed in the storage. By this means, the storage can be operated with a higher state of charge (ideally 100%) and thus the result is a smaller size. This advantage is counteracted by the following disadvantages: additional elements are required to dissipate the excess energy; furthermore, this dissipation of electrical energy is a waste of energy that is to be avoided as a result of the lack of storage possibility. SUMMARY

[0009] The task on which the invention is based is to avoid this disadvantage and to achieve a better utilization of the storage.

[0010] The solution according to the invention consists in the features of the apparatus and the method for operating the apparatus. Advantageous refinements are the subject matter of other embodiments.

[0011] In the case of an arrangement comprising a storage for electrical energy for output to a power grid and a regenerative energy generator, wherein the regenerative energy generator has a power control unit which has an input for a target power output and controls the power generation by the regenerative energy converter, and an energy converter for converting a regenerative primary energy into electrical energy, and a charge controller for the storage is also provided, which sets a minimum regulating energy to be provided and outputs a signal for a target state of charge of the storage, it is provided according to the invention that a correction unit is connected to the charge controller, which continuously adjusts the signal for the target state of charge, and a sequence control unit is provided, which is actuated by the correction unit and influences the power control unit of the regenerative energy generator in accordance with the output value of the correction unit.

[0012] Firstly some used terms are explained.

[0013] A regenerative generator is a facility which has an energy converter for generating electrical energy from a regenerative primary energy. This includes in particular wind power plants, photovoltaic plants or solar thermal power plants. Typical for these facilities is that the primary energy cannot be directly controlled (whether there is wind and how strong, whether there is sunshine and how strong, etc.).

[0014] The storage is at least configured to store or release electrical energy generated by the energy generator and to output electrical energy to the power grid or to take electrical energy from the power grid.

[0015] The idea on which the invention is based is that, instead of keeping the state of charge of the storage fixed (for example to 50% or to 100%) while the regulating energy is ready, the state of charge of the storage is dynamically adjusted by means of a correction unit, wherein the regenerative energy generator is influenced in accordance with the correction and the target power of the regenerative energy generator is changed accordingly. Thus, the negative regulating energy to be provided is dynamically divided between the storage on the one hand and the regenerative energy generator on the other hand. If, for example, the wind is strong, the state of charge of the storage can be increased by means of the correction unit, because in the case of strong wind and thus high power of the wind power plant, the negative regulating power required if necessary can be achieved by throttling of the wind power plant, without the storage having to be used for this. That is, the storage does not need to have much space available accordingly, that is to say the storage can be charged significantly above 50%. It has been recognised by the invention that this can be achieved by a combination of two measures, namely on the one hand the dynamic construction of the target state of charge at the storage, in combination with the change of the target power of the regenerative energy generator from the storage by means of the sequence controller. In this way, by means of the sequence controller, the regenerative energy generator becomes an "assistant" of the storage. This is exactly the opposite of the situation which has been common hitherto in the prior art.

[0016] The advantages achieved thereby are considerable. On the one hand, not only is the provision of regulating power improved, but additionally the capacity of the storage can now be used for delaying the provision of the generated electrical energy, i.e. for so-called production shifting. This time shifting, also referred to as "production shifting", is of great significance in terms of grid operation, since by means of it a shift in the power feed can be achieved from the grid point of view. By means of this, demand peaks can be met, i.e. such situations which are particularly suitable for an energy deficit in the grid and thus for an energy which is particularly important in the grid. This can enable the regenerative energy generator equipped in accordance with the application to achieve new fields of use, in particular to participate in the free trade of electricity on the so-called electricity market.

[0017] That is to say, in accordance with the application, the energy storage is used twice, i.e. on the one hand for providing regulating energy (as hitherto), but in addition also for carrying out "production shifting" to meet demand peaks (electricity market). By means of this, the storage is utilised significantly better, and for this no expensive expansion of the storage capacity itself is necessary. The application achieves this by means of the clever use and manipulation of the storage itself and the regenerative energy generator connected thereto. Here, it is always ensured that the required regulating energy is immediately available on request. In this case, preferably a measure for the available primary power is applied as an input parameter to the correction unit, which measure can in particular be a forecast (prediction) of the available primary power. A particular advantage is that this prediction can be shorter than the period of time in which the provision of regulating power is ensured. That is to say, the prediction period can be shorter than the securing period (also referred to above as "required period"). This is a particularly advantageous aspect of the application.

[0018] Suitably, the sequence controller influences the power control unit of the regenerative energy generator, such that this power control unit is in a master / slave relationship with the correction unit of the storage. In this case, the correction unit is the master and the power control unit of the regenerative energy generator is correspondingly the slave. By means of this, it can be achieved that, for example, in the case of sufficient wind, the storage can be completely charged, and by means of the sequence controller then not the negative regulating power is caused by the storage, but by the wind power plant being regulated. If it is predicted that, for example, in the subsequent period of time (for example 48 hours) there will not only be sufficient wind, but also periods of a tendency to an excess supply of energy in the grid, then in accordance with the application the storage can be charged (and outputs comparatively little power to the grid), in order to discharge the storage at a later point in time only when there is a demand peak in the grid (in exchange for a corresponding remuneration), and here too always sufficient regulating power is prepared.

[0019] Advantageously, the correction unit is configured for a plurality of input parameters. In particular, further parameters are: a forecast value for the available primary power (wind strength or insolation strength); a forecast value for the power demand in the power grid; a minimum value for the regulating power to be provided; the storage capacity and the power; the target regulating power; and / or the state of charge of the storage. With this large number of input parameters for the correction unit, a better prediction or adaptation of the state of charge of the storage can be achieved (and accordingly also a corresponding power setting of the regenerative energy generator by the sequence controller). Suitably, at least for some of the input parameters, additionally statistical characteristic quantities, in particular for the confidence interval, are applied. By this, a more refined adaptation and a higher reliability can be achieved, in particular in the area of the prediction of the power production (wind forecast or insolation forecast). The corresponding applies to the prediction of the demand situation in the power grid.

[0020] Suitably, the correction unit has an optimization device which is configured to determine the signal for the target state of charge by means of an optimization module from the input parameters. By means of an optimization calculation known per se, the optimum target state of charge of the storage can thus be determined with respect to the input parameters, and the power to be output by the regenerative energy generator can also be determined accordingly by the sequence controller. Suitably, in the optimization module, a gradient method, a neural network or an evolutionary algorithm is implemented as optimization method. Such optimization methods are known per se and thus do not need to be explained in more detail in the present case.

[0021] The input parameters are preferably dependent on time, i.e. variable over time. This relates in particular to the forecast of the available primary power but also of the demand situation in the power grid. Preferably, the correction unit is also configured such that it evaluates the input parameters in a time staggered manner. By this, a dynamic process in the determination of the target state of charge can be realized, and thus a more accurate adaptation to the respectively changed conditions can be achieved.

[0022] According to a particularly preferred embodiment of the application, weighting factors are also provided for at least one of the input parameters, more precisely in particular for the power demand in the power grid and / or the generated power. Optionally, the weighting factors can differ depending on the sign (for positive or negative). With the weighting factors, a measure of the importance of the input parameters can be set respectively, wherein the measure can also change over time. By this, the importance of a particular parameter at a particular point in time can be represented. This is particularly advantageous in the context of yield management of regenerative energy generation, wherein the weighting factors can represent the prices to be achieved (for example on the power market). Weighting is a valuable means in the optimization.

[0023] With regard to the target power output of the regenerative energy generator, it is advantageously provided that a reference signal for the target power output is applied from the outside. However, it is also possible to provide that the reference signal is generated internally, in particular by means of a frequency static characteristic. In the latter case, for example, the regenerative energy generator increases its power output in the event of a frequency drop (below the normal value) and reduces its power output in the event of a frequency rise (above the normal value). In this way, a self-regulation can be achieved which is essentially similar to the self-regulation of synchronous generators in conventional power plants.

[0024] The operation of the device according to the application will subsequently be outlined with reference to the example of a wind power plant as a regenerative energy generator. In the event of sufficient primary energy being available (because the wind is strong enough), the positive and negative regulation power can essentially be provided not only by the wind power plant itself but also by the storage. It is generally applicable that the choice of the division between the generator and the storage should ensure on the one hand the minimum regulation power (positive and negative) being provided at all times and on the other hand being as efficient and economical as possible. In the event of no primary energy being available or only insufficient primary energy being available (for example in the event of no wind), it should be ensured that the minimum regulation power provided is available using the storage alone. It is known that this is achieved by setting a defined state of charge, for example 50% in the event of symmetrical primary regulation power (positive and negative being equally large) being required. Since the regulation power must be ready at any point in time, it is necessary for the state of charge to be set and achieved in this way. In other words, it is sufficient, and indeed necessary, to predict no wind in order to approach the state of the storage as the wind decreases.

[0025] As mentioned above, the application can achieve all this. By choosing different optimization algorithms and, if necessary, by optional further input parameters, such as the uncertainty of such weighting factors for the energy fed (for example market price forecasts) or such parameters taking into account the storage efficiency or the storage self-discharge (and thereby more likely penalizing excessively long storage times), the performance can be improved.

[0026] The application also relates to a corresponding method. For a more detailed explanation, reference is made to the above description. BRIEF DESCRIPTION OF DRAWINGS

[0027] Subsequently, the application is described in more detail with reference to embodiments in accordance with the accompanying drawings. In which:

[0028] Figure 1 An overview of a wind power plant with a storage according to one embodiment of the application is shown;

[0029] Figure 2An overview of a solar power plant with a storage according to a further embodiment of the application is shown;

[0030] Figure 3 A schematic block diagram for controlling the storage and the wind power plant is shown;

[0031] Figure 4 a, b, c show diagrams on operating characteristics of the wind power plant; and

[0032] Figure 5 A diagram of the yield is shown. DETAILED DESCRIPTION

[0033] The wind power plant, generally designated by reference numeral 1, together with the storage 2 forms a device according to an embodiment of the application.

[0034] The wind power plant 1 itself is conventionally constructed. It has a tower 15, at the upper end of which a nacelle 11 is arranged pivotably in azimuth direction. At the end side of the nacelle a rotor 12 is rotatably arranged, which drives a generator 13 by means of a (not shown) rotor shaft, which cooperates with a converter 14 to generate electric power. The electric power thus generated is conducted via internal lines (not shown) to a plant transformer 16 and via a connection line 17 to a collection grid, mostly within the wind farm. The storage 2 is also connected to the connection line 17. Further wind power plants 1 of the wind farm can also be connected, which are basically constructed in the same way and are suitably connected to the common storage of the wind farm; however, they can also each have their own storage 2. The electric energy thus generated is conducted via a wind farm transformer 18 to a transfer point 19, from which it is fed into the public grid 9. The operation of the wind power plant 1 is controlled by an operating controller 10. In this respect, all of this is conventional and thus need not be further explained. It should be noted that a plurality of wind power plants operating according to the application need not necessarily be combined in a wind farm, but can also be arranged independently of one another.

[0035] The storage 2 is a basically conventional electric accumulator, which has, inter alia, a plurality of batteries, but alternative storage technologies such as compressed air, liquid air, hydrogen or pumped hydro storage can also be provided. The operation of the storage 2 is controlled by a charging controller 20. This sets, inter alia, the desired state of charge (SoC - State of Charge) which the storage 2 should assume. The storage 2 is used, inter alia, to compensate for fluctuations in the power output of the wind power plant 1 or to output or absorb additional power on request, in general to provide regulating power. All of this is known per se and thus need not be further described.

[0036] It should be noted that in the embodiments described here the storages 2 are respectively assigned to the wind power plant 1 and arranged outside this wind power plant. This is not mandatory. In this way, inter alia, the storages 2 can also be arranged within the wind power plant 1 or centrally in the collection grid, as is Figure 1 illustrated in Fig. 1 by the hatched lines.

[0037] In Fig. 1 a wind power plant 1 is shown as a regenerative energy generator. The wind power plant 1 comprises a plurality of wind turbines 10, which are connected to a power grid 2 via connection lines 17. The wind power plant 1 is connected to a storage 2 via a connection line 18. The storage 2 is connected to the power grid 2 via a connection line 19. Figure 2 In Fig. 2 another embodiment of the invention is shown. In this other embodiment, instead of a wind power plant 1, photovoltaic units 1' are provided as regenerative energy generators, which are connected to one another and to the storage 2' via connection lines 17'. The photovoltaic units 1' do not require rotating parts like wind wheels or rotating generators, the photovoltaic units convert the radiation power applied by the sun 99 directly into electrical power. Both the wind power plant 1 and the photovoltaic plant 1' have in common that the respective primary source (wind or sunlight) cannot be controlled and can only be predicted to a limited extent. There is a significant uncertainty with regard to the power output.

[0038] The invention is then explained by way of example with a regenerative energy generator having the primary "wind". The corresponding applies to other regenerative energy generators, like inter alia photovoltaic units 1'.

[0039] In order to improve the power performance and to additionally use the storage 2 for other system services like power generation delay in addition to providing regulating power, the invention provides a device 3 consisting of a correction unit 4 and a sequence control unit 5. The regulating power P R to be provided is applied as a main input variable to the correction unit 4. The correction unit calculates a control signal for the state of charge SoC therefrom and applies this control signal at the output of the correction unit to the charge controller 20 of the storage 2.

[0040] Further input data are applied to the correction unit 4, more precisely inter alia prediction data regarding the actual primary energy (in this case: wind) V W and regarding the predicted energy requirement V B . Also applied are the following data: at least the power P min to be provided (positive and negative), the confidence interval σ for different parameters and, if necessary, further parameters like storage capacity and power, target regulating power and state of charge of the storage. Also applied are weighting factors W i with which the energy or power provision and delivery can be weighted in terms of time. For this purpose, a time module is also provided in the correction unit 4.

[0041] The correction unit 4 also has an optimization device in which an optimization method, for example a gradient method known per se, is implemented.

[0042] The correction unit 4 cooperates with the storage 2 and its charge controller 20 as follows:

[0043] If the supply of primary energy (wind) is only very small, it must still be ensured that the minimum regulation power provided can be made available with the aid of the storage 2. For this purpose, the storage 2 needs a certain state of charge, which it approaches in a defined manner. In this way, for example in Germany, the primary regulation power must be provided symmetrically, the state of charge (SoC) being 50%. This approach must be carried out predictively, since at any point in time the regulation power must be ready. For this purpose, in particular, a forecast value V W In this case, the storage 2 is only used to ensure the provision of primary regulation power as required.

[0044] If, on the other hand, there is sufficient primary energy (i.e. the wind is strong enough), the (ensured) positive and negative regulation power can not only be provided by the storage 2 but also by the wind power plant 1. Now, the correction unit 4, together with the sequence control unit 5, carries out the division of the power between the wind power plant 1 and the storage 2, so that at all times the minimum regulation power is ensured, but on the other hand the storage 2 can also be used as extensively as possible for other system services for the grid 9, such as power generation delay (production shifting).

[0045] The sequence control unit 5 obtains reference signals for the target power. Preferably, these reference signals are applied by a frequency-static characteristic 51 which is configured to specify a lower target power if the grid frequency is above the nominal value (plus standard tolerance) and a higher target power if the grid frequency is below the nominal value (again taking into account the standard tolerance).

[0046] In addition, the sequence control unit 5 exchanges signals with the charge controller 20 about the actual power output of the wind power plant 1 and about the actual state of charge of the storage 2.

[0047] This is explained by way of example with a wind farm having a plurality of wind power plants and a nominal power of 4 MW in total and a storage capacity of 2 MWh in total and a storage power of 2 MW in total. In the event of a low supply of primary energy, in particular in the absence of wind, the storage 2 must be kept in a charged state of 1 MWh, that is to say 50% of its storage capacity. This guarantees that the guaranteed regulating power of 1 MW can be provided at any time for a sufficiently long period of time. - However, if the wind is sufficiently strong, the storage 2 can also be fully charged. In this case, a negative regulating power can be induced by regulating the wind power plant 1. If, for example, it is expected for the next period of time (48 hours) that not only will there be sufficient wind but also that there will be a period of low energy demand and low energy prices, the weighting factor will be small and the storage can then be charged at a time of low prices, taking the weighting factor into account, in order to then discharge the storage again at a time of higher prices (generation postponement). The sequence control unit 5 induces the wind power plant 1 to adapt its respective power generation and, for example, to throttle the power generation in the event of a negative regulating power and thereby to relieve the storage 2 of the load which it must correspondingly absorb. In this way, not only is the wind power plant 1 and the storage 2 which exist better utilized, but additional earnings are also achieved. In this case, it is still ensured in accordance with the application that there is always sufficient regulating power available.

[0048] The result is visualized in Figure 4 a), b) and c). In Figure 4 a), the actual power generation of the wind power plant 1 which is set on the basis of the wind conditions (arranged on the left-hand side of the y-axis of Figure 4 a) as a standard) is shown by a thick solid line, and the charge state of the storage 2 (arranged on the right-hand side of the y-axis of Figure 4 a) as a standard) is shown by a thin solid line. A period of one week (equalling 168 hours, of which only the first 150 hours are shown) is considered. In Figure 4 b), the weighting factor (here in the form of the settlement price on the electricity market) is shown. In Figure 4 c), the power reserves available are shown, more precisely the power reserves to be guaranteed are shown by horizontal dashed lines and the power reserves actually present are shown by solid lines, more precisely for positive power reserves (above) and negative power reserves (below), respectively.

[0049] In Figure 4a) In the middle by a dotted line over a time range of 100-150 h the prediction data for the following wind change process are shown (the actually derived, but at this point not yet known actual change process is shown by a dashed line). From the charge state of the storage 2, which is shown by a thin line, it is seen that the storage 2 is charged differently by the correction unit 4 according to the application in times of sufficient wind, more precisely mainly according to the (predicted) weighting factor. If there is only little wind, the charge state is essentially maintained at the regular value of 50% (corresponding to 1 MWh), in times of strong wind it approaches a higher charge state.

[0050] In Figure 4 In c) the power reserves available at any point in time are shown. As can be well seen, the positive reserve is always 1 MW or more (equal to or above the upper dashed line), and the same applies to the negative reserve, which is always on the other side of -1 MW. It is seen that the guaranteed values (horizontal dashed lines) of 1 MW positive and 1 MW negative regulating power are always adhered to. The power used for "production shifting" is shown by the hatched area.

[0051] Thus, advantages are derived not only for the operational safety and power supply of the power grid 9, but also from the revenue perspective of the operator of the wind power plant. Figure 5 The additional revenues achievable by the additionally provided system services within the framework of the power generation delay are shown (see hatched area). This additional revenue is of absolute importance, in particular in the context of the application, in which no additional storage is required, but the existing storage is used better in the core.

Claims

1. An arrangement comprising a storage (2) for electrical energy for output to a power grid (9) and a regenerative energy generator (1), wherein the regenerative energy generator (1) has a power control unit (10) with an input for a target power output and is set up for controlling the power generation by an energy converter (13) for converting a regenerative energy source into electrical energy, and a charging controller (20) is provided for the storage (2), and a correction unit (4) is provided, which is set up for outputting a signal for a target state of charge of the storage (2), wherein the correction unit (4) is set up to be connected to the charging controller (20) and to modify the signal for the target state of charge continuously, characterized in that the charging controller (20) is set up to adjust a minimum regulating energy to be provided by the storage (2) for maintaining a minimum regulating power at all times for compensating for a difference between power generation and power consumption in the power grid (9), and a sequence control unit (5) is provided, which is set up to be operated by the correction unit (4) and to influence the power control unit (10) of the regenerative energy generator (1) in accordance with the output value of the correction unit (4) such that a dynamic build-up of the target state of charge of the storage (2) is combined with a change in the target power output of the regenerative energy generator (1) from the storage (2) by means of the sequence control unit (5). The sequence control unit (5) is set up to influence the power control unit (10) such that the power control unit is in a master / slave relationship with the correction unit (4) of the storage, wherein the correction unit (4) is the master.

2. The apparatus of claim 1, wherein, The arrangement is set up to apply a measure for an available primary power as an input parameter to the correction unit (4), wherein the target state of charge is reduced when the available primary power decreases and is increased when the available primary power increases.

3. The apparatus of claim 1 or 2, wherein, The arrangement is set up to apply a predicted value for the available primary power as an input parameter to the correction unit (4).

4. The apparatus of claim 3, wherein, The correction unit (4) is set up to modify the signal for the target state of charge in accordance with the available primary power.

5. The apparatus of claim 3, wherein, The correction unit (4) is configured for a plurality of input parameters, wherein further parameters are: a predicted value for the demand for electrical power in the power grid; a minimum value of the power to be maintained; a storage capacity and a power; a target regulating power; and / or a state of charge of the storage.

6. The apparatus of claim 3, wherein, The arrangement is set up to apply an additional statistical characteristic variable. The arrangement is set up to apply an additional statistical characteristic variable for a confidence interval.

7. The apparatus of claim 6, wherein, The correction unit (4) has an optimization device, which is configured to determine the signal for the target state of charge by means of an optimization module in dependence on the input parameters.

8. The apparatus of claim 7, wherein, In the optimization device, a gradient method, a neural network or an evolutionary algorithm is implemented as an optimization method.

9. The apparatus of claim 3, wherein, ​ 10. The apparatus of claim 9, wherein, ​ 11. The apparatus of claim 3, wherein, The input parameters are time-shifted.

12. The apparatus of claim 11, wherein, The correction unit (4) is set up to evaluate the input parameters as a function of time.

13. The apparatus of claim 3, wherein, A weighting factor is provided for at least one of the input parameters.

14. The apparatus of claim 13, wherein, The weighting factor is provided for the predicted power demand and / or the generated power in the power grid.

15. The apparatus of claim 13, wherein, The weighting factor is provided separately for positive and negative.

16. The apparatus of claim 1 or 2, wherein, The device is set up to either externally apply a reference signal for the target power output or to internally generate a reference signal for the target power output.

17. The apparatus of claim 16, wherein, The reference signal for the target power output is externally applied or internally generated by means of a frequency-static characteristic (51).

18. A method for operating a device comprising a storage for electrical energy for output to a power grid and a regenerative energy generator, wherein the regenerative energy generator has a power control unit with an input for a target power output and controls the power generation by an energy converter for converting a renewable energy source into electrical energy, and a charging controller is provided for the storage, and a correction unit is provided, which outputs a signal for a target state of charge of the storage, wherein the method comprises continuously modifying the signal for the target state of charge by means of the correction unit connected to the charging controller, characterized in that The method furthermore comprises changing the power generated by the regenerative energy generator by means of a sequence control unit, which is operated by the correction unit and influences the power control unit of the regenerative energy generator as a function of the output value of the correction unit, wherein the charging controller (20) is set up to adjust a minimum regulating energy to be provided by the storage (2) for maintaining a minimum regulating power at any time for compensating for a difference between power generation and power consumption in the power grid (9) such that a dynamic build-up of the target state of charge of the storage (2) is combined with a change in the target power output of the regenerative energy generator (1) by means of the sequence control unit (5) starting from the storage.

19. The method of claim 18, wherein using a device according to any one of claims 2 to 17.

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