Method for providing an electrical supply quantity in an electrical supply system and device for carrying out the method

Abstract

Method for providing an electrical supply quantity in an electrical supply system (200) with a plurality of energy storage devices (10) for providing electrical energy per unit of time or electrical control power in a secondary application of the energy storage devices (10), wherein the electrical supply quantity is kept available with a setpoint, characterized by (i) Evaluating a large number of energy storage devices (10) each with an availability factor (V); (ii) Aggregation of energy storage devices (10) in a reserve group (100) until a predetermined setpoint of the electrical supply quantity of the reserve group (100) is reached; (iii) event-oriented modification of the composition of the reserve group (100) and / or of target operating points of the energy storage units (10) within the reserve group (100) when an event occurs that changes the availability factor (V) at at least one of the aggregated energy storage units (10), where the availability factor (V) is zero when the energy storage device (10) is in use in its primary application, further characterized in that the availability factor (V) of the selectable energy storage (10) is derived from several criteria, the criteria comprising at least: (i) an operating point of the respective energy storage device (10), wherein the operating point includes in particular the state and / or state of charge and / or charging and / or discharging power and / or temperature of the energy storage device (10); (ii) an event forecast of the probability that the state of charge of the respective energy storage device (10) will be changed, in particular reduced, within a specified period; (iii) a first utility value derived from a forecast age of the event forecast; and (iv) a second utility value derived from a time interval between two events in which the state of charge of the respective energy storage device (10) changes.

Description

State of the art

[0001] The invention relates to a method for providing an electrical supply quantity in an electrical supply system, in particular for providing electrical energy per unit of time or electrical control power, and to a device for carrying out the method.

[0002] From WO 2017 / 162 910 A1, a method and a system for providing control energy in an electrical supply system are known. For this purpose, a plurality of energy storage devices are connected to a central control unit. The energy storage devices are connected to the power grid and can absorb energy from or supply energy to the grid. Each group of energy storage devices is used for this purpose. At the beginning of a specific frequency control period, the central control unit displays a target grid frequency for the power supply system. The current status of the energy storage devices, the nominal power of each energy storage device, and / or an estimated or measured energy demand for each energy storage device are retrieved from a data source.The required levels of boost and boost control power for the power supply system to achieve the target grid frequency are estimated, and a priority is assigned to each power unit based at least on the duration of the energy storage system's current state and / or its remaining energy demand. The grid frequency is monitored, and in response to any deviation, energy storage systems are transferred according to their priority from the boost to the boost reserve when the grid frequency increases, and from the boost reserve to the boost reserve when the grid frequency decreases.

[0003] From DE 10 2016 206 256 A1, a method and a system for providing control power to an electrical power supply network with multiple energy producers and consumers, and a pool control unit, are known. This involves providing a total energy storage system consisting of multiple electric vehicles, each bidirectionally connected to the electrical power supply network and equipped with at least one energy storage device. Furthermore, the actual power output of the total energy storage system at a second time is determined at a first time prior to a second time. This actual power output is calculated as the sum of the predicted power output of a first group of electric vehicles at the second time and the predicted power output of a second group of electric vehicles at the second time.Furthermore, the determination of the maximum possible discharge power of the total energy storage system at the second time point is performed as the sum of the predicted maximum possible discharge power of the first group of electric vehicles at the second time point and the predicted maximum possible discharge power of the second group of electric vehicles at the second time point. Additionally, the determination of the guaranteed positive control power at the second time point is performed as the difference between the actual power of the total energy storage system at the second time point and the maximum possible discharge power of the total energy storage system at the second time point.

[0004] DE 10 2017 114 703 A1 also discloses a provision system for supplying electrical control power to a power supply network, comprising a first and a second device for supplying electrical power. The first device includes a first measuring device for measuring a control parameter of the power supply network and a first local control device for regulating the power supplied by the first device to the power supply network as a function of the measured control parameter. The first control device contains at least one further parameter, which represents an operating point of the second device. The first control device is configured to regulate the power supplied by the first device also as a function of the further parameter.The second device includes a second measuring device for measuring the control parameter of the power supply network and a second local control device, different from the first, for controlling power supplied by the second device to the power supply network depending on the measured control parameter, in order to increase the dynamics of the supplied power. Disclosure of the invention

[0005] The object of the invention is to create a method that allows a flexible provision of an electrical supply quantity for various secondary applications of energy storage devices.

[0006] Another task is to create a device for carrying out the procedure.

[0007] The problems are solved by the features of the independent claims. Favorable embodiments and advantages of the invention become apparent from the further claims, the description, and the drawings.

[0008] A method is proposed for providing an electrical supply quantity in an electrical supply system with a plurality of energy storage devices, in particular for providing electrical energy per unit of time or electrical control power, wherein the electrical supply quantity is kept available with a setpoint. A plurality of energy storage devices is each evaluated with an availability factor. If electrical control power is provided as an electrical supply quantity, for example for grid frequency stabilization, the selectable energy storage devices are preferably arranged in a common control area. Energy storage devices are aggregated in a reserve group until a predetermined setpoint value of the electrical supply quantity is reached.For example, aggregation occurs up to a power level that is awarded and / or requested by a transmission system operator if balancing power is provided as an electrical supply parameter. If electrical balancing power is requested as an electrical supply parameter for grid frequency stabilization, it is delivered immediately and continuously to the control area for a specified period.

[0009] If electrical energy is provided as a supply quantity per unit of time, it can, for example, be sold on a trading market. Electrical energy related to the control power is also often referred to as the capacity of the energy storage system or the reserve power plant.

[0010] The composition of the reserve group is changed in response to an event, specifically when the availability factor of an individual energy storage device within the reserve group changes, or when the energy storage device reaches or falls below a predefined minimum value of the availability factor, or reaches or exceeds a predefined maximum value of the availability factor. Alternatively, instead of changing the composition, the target values ​​of the energy storage devices currently in the reserve group can be adjusted to compensate for the impact of the event.

[0011] Availability factors for energy storage systems can vary between 0 and 1. For example, if an energy storage system is in use for its primary application, the availability factor is V=0 during that time.

[0012] The availability factor of the selectable energy storage devices is derived from several criteria, the criteria comprising at least: (i) an operating point of the respective energy storage device, wherein the operating point for batteries includes, for example, the state and / or state of charge and / or charging and / or discharging power and / or temperature; (ii) an event forecast of the probability that the state of charge of the respective energy storage device will change, in particular decrease, within a given period; (iii) a first utility value derived from a forecast age of the event forecast; and (iv) a second utility value derived from a time interval between two events in which the state of the respective energy storage device changes, in particular decreases in the case of batteries.

[0013] Event forecasting for batteries at charging stations can include one or more of the following parameters: weather forecasts, as experience shows that weather has a direct influence on the charging behavior of electric car owners as well as on the charging curves of energy storage devices, such as batteries, at different temperatures; the use of typologies for specific days of the week or time periods, as consistent charging behavior and / or charging frequency on certain days, such as weekends, weekdays, or holidays, is taken into account; forecasts for electric vehicle models, as these use very different charging durations and charging capacities; and the location of the energy storage device, whereby the use of charging stations for electric vehicles on highways differs significantly from the use of charging stations in cities.These parameters have a strong influence on the prediction of whether and, in particular, how long this event will lead to a (negative) impact on the battery or to a reduction in the availability factor of the energy storage system.

[0014] Several individual storage units can be combined to form an energy storage system, or a single storage unit can constitute an energy storage system. Energy storage systems can, for example, be storage batteries at charging stations for electric vehicles. In this case, fast charging of electric vehicles is the primary application of the energy storage system. This primary application occurs particularly when the regular grid connection power is insufficient for the charging connection of the electric car at the charging station. Providing the electrical supply as energy per unit of time or as control power is then a secondary application of the energy storage system.The secondary application of the electrical supply quantity can be prioritized depending on various framework conditions, such as whether balancing power, for example a few MW, is provided, or whether energy is offered and delivered on a trading market in terms of a unit of time, for example MWh. This can be done based on a cost-benefit analysis.

[0015] Optionally, energy storage systems in the form of storage batteries can be installed at commercial or private energy producers and / or in production processes. Alternatively or additionally, combined heat and power plants, biogas plants, pumped storage hydroelectricity, flywheel energy storage systems, and similar technologies can be used as energy storage.

[0016] The energy storage devices can be electrically connected to the power grid or at least be electrically connectable temporarily. For this purpose, they are equipped with a suitable communication device through which a control unit, preferably a central one, can control the energy storage devices accordingly. The energy storage devices can also provide the control unit with data, such as state of charge, power output, and the like. Each energy storage device is uniquely identifiable in the grid via a communication connection. Each energy storage device is preferably connected via a single communication unit and is thus uniquely identifiable by its individual identifier. The communication units can communicate, for example, via TCP / IP or a mobile network (WAN). The energy storage devices can receive control commands in this way.A control command can switch an energy storage device into "active" mode for the delivery period, in which the energy storage device provides the electrical supply quantity as a secondary application, or into "deactivated" mode if no electrical supply quantity is to be provided as a secondary application and the energy storage device is then returned to a standard mode of its primary application, for example a fast-charging mode, or a mode for so-called peak shaving, in which a consumer reduces its electricity consumption in the short term to avoid load peaks.

[0017] The forecasting of the available electrical supply and the identification of the energy storage devices capable of providing this electrical supply are essentially independent of each other and can be performed sequentially. The electrical supply can be positive or negative; that is, in the first case, the electrical supply can be provided by one or more energy storage devices in the reserve group, or in the second case, it can be absorbed by one or more energy storage devices in the reserve group.

[0018] For example, primary control power is provided decentrally via a locally installed control box containing a controller, such as a power-frequency controller. This control box measures the frequency and provides the resulting power value to the energy storage system.

[0019] The available electrical supply of energy storage systems aggregated or to be aggregated in a reserve group can be predicted with relatively high accuracy. Consequently, their electrical supply can be provided as a secondary application or called upon as needed.

[0020] In contrast, the availability of a single energy storage device or its individual projected output is very difficult, if not impossible, to predict, since, for example, an electric vehicle could arrive at a charging station at any time and either discharge the storage battery according to its primary application or charge it by delivering electrical power. Both of these events would unpredictably change the state and thus the availability of the energy storage device.

[0021] Instead of a rigid schedule forecast, according to the invention, an event causes the composition of the reserve group to change spontaneously, or even must change, if an energy storage device in the reserve group experiences an event, provided the electrical supply quantity is control power. If the electrical supply quantity is electrical energy per unit of time, the target operating point of one or more of the energy storage devices within the reserve group can be changed, or alternatively, the composition of the reserve group can be changed.

[0022] Advantageously, every energy storage system can receive a calculated availability factor in advance, which can be updated at certain intervals, for example every quarter of an hour, based on current actual data, in the case of batteries especially state of charge (SOC), charging power and / or discharging power and the like.

[0023] In the event of an incident, an attempt can first be made to compensate for the resulting change in the available electrical supply using the other energy storage devices in the reserve group. Should this prove insufficient, or should the availability factor of the energy storage device in question be insufficient, the energy storage device will be removed from the reserve group and replaced with another energy storage device that, for example, has the next highest permissible availability factor or the highest availability factor.

[0024] An availability factor is permissible if it is above or below a minimum value. This minimum value is set such that energy storage above this value is suitable for secondary applications. The specific value of this minimum can depend on various parameters and therefore vary accordingly.

[0025] In contrast to known methods where the available power for each individual energy storage unit can only be calculated and then marketed individually, it is no longer necessary to use very high safety margins or to exclude certain types of energy storage units at certain times when there is a high probability that they cannot be used for secondary applications at those specific times, for example due to charging electric cars at battery charging stations.

[0026] According to the invention, the reliably available electrical supply quantity, which can be provided and retrieved as energy related to a unit of time or control power or other electrical power, can be determined via all selectable energy storage devices, so that the total available, provideable and retrievable electrical supply quantity increases significantly.

[0027] With a favorable implementation of the method, the energy storage systems available in the supply system can be divided into selectable and non-selectable energy storage systems, whereby the non-selectable energy storage systems are not assigned an availability factor, at least temporarily. Non-selectable energy storage systems are characterized by an availability factor of zero. Selectable energy storage systems have a permissible availability factor that is above a predefined minimum value. In particular, the non-selectable energy storage systems can be temporarily omitted from their availability factor assessment. Energy storage systems may be temporarily unselectable, for example, if they are already providing balancing power or are undergoing maintenance. This division enables greater reliability of the reserve pool.The computational effort required to calculate availability factors is reduced if these are only calculated for selectable energy storage devices.

[0028] If the status of one or more energy storage devices changes from non-selectable to selectable, they can be taken into account again when calculating the availability factors.

[0029] With a favorable design of the procedure, the energy storage devices selectable in the supply system can meet at least the following selection conditions: (i) The energy storage device belongs to the common control area, provided the electrical supply quantity represents control power. (ii) The energy storage device has a permissible availability factor. This ensures, for example, that the energy storage device is not in its primary application. (iii) The energy storage device does not currently belong to the reserve group or any other reserve group. This advantageously prevents the electrical supply quantity, such as control power, from being uncontrollably diverted from one reserve group to another. (iv) An external control unit can communicate with the energy storage device, in particular to exchange data and control signals. The energy storage device is capable of communicating with a control unit.Because the energy storage device is "active," it can be assigned to a reserve group, its electrical supply can be retrieved or recorded, its operating parameters can be assigned, and so on. Energy storage devices that do not meet these selection conditions are not selectable. However, their status can be changed at a later time if the selection conditions are met at that time.

[0030] With a favorable implementation of the process, one or more energy storage devices can be removed from the reserve group if, after the initial aggregation calculation, they no longer meet one or more of the selection conditions. Conversely, one or more selectable energy storage devices with a permissible availability factor can be added to the reserve group. This allows for more power to be available for balancing, as the event-based, flexible composition of the reserve group necessitates smaller safety margins.

[0031] Alternatively, instead of a complete replacement of an energy storage system, it can be centrally determined, in particular calculated, whether a shift in operating points of one or more of the energy storage systems currently in the reserve group is sufficient to provide the quantity of electricity supplied, in particular marketed, for the supply period.

[0032] With a favorable design of the procedure, the criteria can be weighted, and the availability factor of each selectable energy storage device can be determined from the weighted criteria. Advantageously, the availability factor can vary between 0 and 1, with 1 being the best availability factor. The weighting of the criteria can be constant. Optionally, it can be provided that criteria are weighted differently at different times. The availability factor of non-selectable energy storage devices is zero. The availability factor of selectable energy storage devices is greater than zero, in particular greater than a predefined minimum value for the secondary application of the energy storage device.

[0033] With a favorable embodiment of the method, at least some of the criteria can be determined continuously or at close intervals, particularly at minute or second intervals, from the available energy storage devices. Advantageously, this can be done with all available energy storage devices for which the determination of the criteria is possible.

[0034] With a favorable implementation of the method, the operating point of the respective selectable energy storage device can be derived from a utility value of the energy storage device, which, for example, in the case of batteries, is derived from a state of charge and a ratio of usable storage capacity to a target value of the electrical supply quantity. In particular, the operating point can lie between a minimum and a maximum target value of the electrical supply quantity.

[0035] Alternatively or additionally, a utility value can be determined that assesses the distance between the start of the utility analysis and the predicted event. In particular, the utility value can increase with increasing distance from the start of the utility analysis.

[0036] Alternatively or additionally, the forecast age of the event forecast can be determined. In particular, the utility value can decrease with the age of the forecast.

[0037] Alternatively or additionally, the event interval between two charging processes of electric vehicles can be determined. In particular, the benefit can decrease with increasing time since the start of the last charging process. Charging processes of electric vehicles at a battery correspond to battery discharge processes, provided they are fast charging processes. In all other cases, experience has shown that the grid connection power is sufficient and the battery does not discharge.

[0038] In a favorable embodiment of the method, the availability factors of the energy storage systems can be generated periodically, particularly at one-minute intervals, preferably at one-quarter-hour intervals. In this way, availability factors with sufficient up-to-dateness are available. Alternatively, the availability factors of the energy storage systems can be generated on demand. Current availability factors are then available when needed.

[0039] With a favorable design of the process, the energy storage devices aggregated in the reserve group can both receive and supply electrical power. A single reserve group can therefore both provide and receive electrical power. It is not necessary to have two reserve groups, one of which could, for example, receive electrical power as balancing power and the other of which could supply it as balancing power.

[0040] With a favorable implementation of the method, energy storage systems can be aggregated into different reserve groups, which are available for providing balancing power as an electrical supply variable over varying time periods. Advantageously, reserve groups can be provided for primary reserve within seconds, and / or for secondary reserve within a few minutes, less than 10 minutes (e.g., 5 minutes), and / or for minute reserve within a quarter of an hour.

[0041] Alternatively or additionally, energy storage systems can be aggregated into reserve groups, which provide electrical energy as an electrical supply quantity based on a unit of time that is available in different time periods.

[0042] The selection of which reserve group to assign can be based, for example, on forecasts of achievable revenues per balancing power market or trading market, with the aim of maximizing revenue. Similarly, reserve groups can be designated for marketing on trading markets within a quarter of an hour. This allows for the provision of sufficient electrical supply for different demand scenarios within a power grid.

[0043] According to a further aspect of the invention, a device for carrying out a method for providing an electrical supply quantity, in particular electrical energy per unit of time or electrical control power, is proposed in an electrical supply system in which a plurality of energy storage devices are arranged. Selectable energy storage devices, i.e., those with a permissible availability factor, can be electrically aggregated into a reserve group until a predetermined setpoint value of the electrical supply quantity of the reserve group is reached.Depending on the occurrence of an event at at least one of the aggregated energy storage units that significantly alters its availability factor, the target operating point for the affected energy storage unit can be changed, or the affected energy storage unit can be removed from the reserve group and an alternative energy storage unit added to the reserve group, particularly if the electrical supply variable is control power. The target operating point of one or more energy storage units in the reserve group can be changed, particularly if the electrical supply variable is electrical energy per unit of time.

[0044] Several individual storage units can be combined to form an energy storage system, or a single storage unit can constitute an energy storage system. Storage batteries, for example, can be used as energy storage devices. In particular, storage batteries can be used as energy storage at charging stations for electric vehicles. Optionally, storage batteries can be used at commercial or private energy producers and / or in production processes. Alternatively or additionally, combined heat and power (CHP) plants or biogas plants can be used as energy storage systems.

[0045] The energy storage systems can be connected to the power grid or at least be temporarily connectable. Furthermore, each system can be equipped with a corresponding communication device, which in turn is preferably connected to a central control unit. Each energy storage system can be uniquely identifiable in the grid via a communication link. The energy storage systems can also provide the control unit with data such as state of charge, power output, and the like.

[0046] The available power of the aggregated energy storage can be predicted with relatively high accuracy, and consequently, its electrical supply capacity can be provided and called upon as needed.

[0047] More energy can be available per unit of time or in terms of control power, because smaller safety margins are needed due to the event-based flexible changing of operating points of energy storage systems or the composition of the reserve group.

[0048] Several individual storage units can be combined to form an energy storage system, or a single storage unit can constitute an energy storage system. Storage batteries, for example, can be used as energy storage devices. In particular, storage batteries can be used as energy storage at charging stations for electric vehicles. Optionally, storage batteries can be used at commercial or private energy producers and / or in production processes. Alternatively or additionally, combined heat and power (CHP) plants or biogas plants can be used as energy storage systems.

[0049] In a favorable design of the device, selectable energy storage devices can each have a communication interface for communication with a device management unit, as well as an energy storage control unit that implements control commands received via the communication interface. Because the energy storage devices can communicate, the device management unit can control the energy storage devices and, if necessary, access and aggregate them into a reserve group, which in turn can supply or draw electrical energy from the power grid as needed.

[0050] In a favorable embodiment of the device, at least one of the energy storage units can comprise one or more batteries. In particular, one or more storage batteries can be provided at charging stations. Advantageously, storage batteries that are required but rarely used can be allocated to secondary use in a reserve group. In a favorable embodiment of the device, at least one of the energy storage units can comprise one or more combined heat and power (CHP) plants. Advantageously, such plants or their storage units that are required but rarely used can be allocated to secondary use in a reserve group. drawing

[0051] Further advantages become apparent from the following description of the drawings. The drawings illustrate exemplary embodiments of the invention. The drawings, the description, and the claims contain numerous features in combination. A person skilled in the art will expediently consider the features individually and combine them into meaningful further combinations.

[0052] They show, for example: Fig. 1 schematically an embodiment of the invention in which energy storage devices are arranged in a control zone of a power supply system, some of which are grouped together in a reserve group; Fig. 2 the control zone with reserve group after Fig. 1, where an energy storage device from the reserve group is replaced based on an event; Fig. 3 energy storage devices coupled with a device management unit; Fig. 4 a flowchart with process steps for energy storage systems that provide control power; Fig. 5. A flowchart showing process steps for energy storage devices that provide energy; Fig. 6. the course of a utility value of an operating point of an energy storage device over a state, for example the state of charge of a battery; Fig. 7 the course of a utility value of an event forecast of an energy storage system over time; Fig. 8 the course of a utility value of a predicted age of an energy storage device over time; Fig. 9 the course of a utility value for the typical duration between two events of primary use of the energy storage over time. Embodiments of the invention

[0053] In the figures, similar or equivalent components are numbered with the same reference symbols. The figures merely show examples and are not to be understood as limiting.

[0054] The directional terminology used below, including terms like "left," "right," "above," "below," "in front," "behind," "after," and the like, serves only to improve the understanding of the figures and is in no way intended to limit their generality. The components and elements depicted, their interpretation, and their use may vary according to the considerations of a person skilled in the art and be adapted to the specific applications.

[0055] The Fig. 1 and Fig. Figure 2 schematically shows an embodiment of the invention in which control power is provided as the electrical supply variable to stabilize the grid frequency of the power supply system 200. In the power supply system 200, a number of available energy storage devices 10, here designated as energy storage devices 10a, 10b, 10c, 10d, 10e, 10f, 10g, 10h, 10i, 10k, 101, 10m, 10n, 10o, are arranged in a control zone 300 of a power supply system 200. The power supply system 200 supplies several consumers 250 with electrical power or energy.

[0056] Energy storage systems 10 can be composed of a network of individual storage units or of individual storage units. These energy storage systems 10 can, for example, be storage batteries, particularly those used in charging stations for electric vehicles. In this example, the primary application of the energy storage systems 10 is the charging of electric vehicles, especially fast charging. As a secondary application, the energy storage systems 10 can, for example, provide balancing power. Other types of storage that can store and release electrical energy can also be used, such as flywheel energy storage systems, combined heat and power plants, biogas plants, and the like.

[0057] Some of the energy storage devices 10a, 10b, 10c, 10d, 10e, 10f are in Fig. 1. Energy storage units 10 are grouped together in a reserve group 100. Reserve group 100 serves to supply the power supply system 200 with the electrical supply variable control power. Reserve group 100 provides control power of a predetermined level and for a predetermined time. Aggregation of energy storage units 10 into reserve group 100 occurs at least until a predetermined level of control power for reserve group 100 is reached.

[0058] The grid frequency of the 200-volt power supply system is monitored and must be kept constant within narrow limits. Control power, also called balancing energy, acts as a reserve to compensate for fluctuations in the 200-volt power supply system, specifically in the grid frequency. When balancing energy is deployed, power can be both drawn from and fed into the 200-volt power supply system. Increasing the power feed-in to compensate for a grid frequency that is too low is called positive control power, while reducing the feed-in to lower the grid frequency is called negative control power.

[0059] In response to a deviation of the grid frequency from its setpoint, e.g. 50 Hz, the reserve group 100 releases control power from the energy storage units 10a, 10b, 10c, 10d, 10e, 10f to the power supply system 200 when the grid frequency drops or receives control power when the grid frequency rises.

[0060] Reserve group 100 can, for example, represent the primary reserve, where primary control reserve (PCR) must be available within seconds. Optionally, reserve group 100 can also function as a secondary reserve (SRL) within a few minutes, for example, 5 minutes, or as a minute reserve (MRL), where control reserve must be available within a quarter of an hour. Multiple reserve groups can also be designated for primary reserve, secondary reserve, and minute reserve.

[0061] The available energy storage units 10 in the control area are divided into selectable and non-selectable energy storage units 10.

[0062] A selectable energy storage device 10 must meet several mandatory selection conditions. The energy storage device 10 must belong to the common control zone 300. The state of charge of the energy storage device 10 must currently be unchanged, i.e., it is not currently in use or has a permissible availability factor. The energy storage device 10 does not currently belong to reserve group 100 or any other reserve group. A central control unit 120 in the form of a device management unit can communicate with the energy storage device 10, in particular exchange data and control signals.

[0063] If an available energy storage unit 10 in control zone 300 does not meet all of these selection conditions, it is classified as non-selectable. The status of the non-selectable energy storage unit 10 can be changed at a later time if it then meets all selection conditions.

[0064] The selectable energy storage units 10 are each evaluated with an availability factor V, which lies between 0 and 1.

[0065] The energy storage units 10a, 10b, 10c, 10d, 10e, 10f in reserve group 100 all have, for example, an availability factor of V=1.

[0066] While the energy storage units 10g, 10h, 10l outside of reserve group 100 also have an availability factor V=1, the energy storage units 10i and 10m show an availability factor V=0.8, the energy storage units 10k and 10n show an availability factor of V=0.6 and the energy storage unit 10o shows an availability factor V=0.1.

[0067] In an alternative embodiment, some of the energy storage devices 10a, 10b, 10c, 10d, 10e, 10f are in Fig. 1 is grouped into a reserve group of 100. Reserve group 100 serves to provide electrical energy as an electrical supply quantity, based on a unit of time, and to make it available upon request. This electrical supply quantity can, for example, be offered and purchased on a trading market.

[0068] Reserve group 100 provides electrical energy at a predetermined level and within a predetermined timeframe. Energy storage units 10 are aggregated into reserve group 100 at least until a predetermined level of electrical supply for reserve group 100 is reached.

[0069] The energy (also called storage capacity) can be offered for sale on electricity trading markets, such as spot markets. This can take the form of an intraday auction on the spot market, an intraday trade on the spot market, a day-ahead auction on the spot market, a day-ahead auction on the EXAA market (Energy Exchange Austria), an Austrian electronic marketplace that is also active in the German energy market, or OTC transactions in off-exchange trading with other energy companies, brokers, and the like (OTC = Over the Counter). For this purpose, a forecast for the best price can be created, and the most favorable market can be selected using a type of "waterfall marketing."

[0070] The available energy storage devices 10 are divided into selectable energy storage devices 10 with a permissible availability factor V and non-selectable energy storage devices 10 with an availability factor V=0.

[0071] A selectable energy storage device 10 must, as is mandatory for the provision of control power, meet several selection conditions. The state of charge of the energy storage device 10 must currently be unchanged, i.e., it is not currently in use or has a permissible availability factor. The energy storage device 10 does not currently belong to reserve group 100 or any other reserve group. A central control unit 120 in the form of a device management unit can communicate with the energy storage device 10, in particular to exchange data and control signals. In this secondary application, however, the energy storage device no longer needs to belong to a common control area 300.

[0072] If an available energy storage device 10 in the power supply system 200 does not meet all of these selection conditions, it is classified as non-selectable. The status of the non-selectable energy storage device 10 can be changed at a later time if it then meets all selection conditions.

[0073] The selectable energy storage devices 10 are each evaluated with an availability factor V, which lies between 0 and 1.

[0074] The energy storage units 10a, 10b, 10c, 10d, 10e, and 10f in reserve group 100 all have an availability factor of V=1. The permissible availability factor can also be lower, provided it is above a specified minimum value.

[0075] While the energy storage units 10g, 10h, 10l outside of reserve group 100 also have an availability factor V=1, the energy storage units 10i and 10m show an availability factor V=0.8, the energy storage units 10k and 10n show an availability factor of V=0.6 and the energy storage unit 10o shows an availability factor V=0.1.

[0076] Fig. Figure 2 shows the situation when one of the energy storage devices 10 of the reserve group 100, namely energy storage device 10f, is supplied with power by a consumer 50. This event changes the availability factor V of energy storage device 10f. For example, an electric vehicle has just been connected to a charging station with energy storage device 10f for charging (consumer 50).

[0077] The composition of reserve group 100 is then changed based on events, provided the electrical supply variable is control power. Energy storage unit 10f is removed from reserve group 100, and one of the selectable energy storage units 10 located outside reserve group 100 is added to reserve group 100. For example, energy storage unit 10g replaces energy storage unit 10f.

[0078] Fig. Figure 3 shows energy storage devices 10 that are coupled to a central control unit 120 in the form of a device management unit. Each energy storage device 10 has a communication interface 130 with corresponding hardware as well as a battery control unit 132, which implements corresponding control commands from the control unit 120 and / or provides parameters of the energy storage device 10, from which the availability factor V is calculated.

[0079] The availability factor V is derived from several criteria of the available energy storage 10, which are weighted for the selectable energy storage 10 and together yield the availability factor V.

[0080] The criteria are determined at short intervals, for example in a grid of seconds, while the determination of the availability factor V can be carried out at somewhat longer intervals, for example every quarter of an hour.

[0081] Fig. Figure 4 shows a flowchart with various process steps according to the exemplary embodiment of the Fig. 1 and Fig. 2. In step S100, current data of the available energy storage devices 10 are recorded; for example, the power, state of charge, and / or temperature of the energy storage device 10 are recorded every second. The selectable energy storage devices 10 among the available energy storage devices 10 are then identified.

[0082] In step S102, the availability factor V of each selectable energy storage device 10 is calculated, in particular what power the selectable energy storage devices 10 can absorb or deliver.

[0083] In step S104, one or more reserve groups 100 are first calculated and periodically compiled from the available energy storage 10, for example, every 15 minutes. Reserve groups 100 can be subdivided according to the available control power into primary reserve (PRL), secondary reserve (SRL), minute reserve (MRL), and the like. A query is then performed in step S106, based on the results from step S104.

[0084] In step S106, it is checked whether an event has occurred at the selected energy storage devices 10 (10a, 10b, 10c, 10d, 10e, 10f) assigned to a reserve group 100. Fig. 1) has caused a change in the respective availability factor V. If this is the case (yes in the flowchart), the energy storage device in question will be 10 (10f in Fig. 2) in step S108 by an alternative selectable energy storage device 10 (10g in Fig. 2) replaced and in step S110 the new aggregation of energy storage 10 (10a, 10b, 10c, 10d, 10e, 10g in Fig. 2) in reserve group 100. The alternative energy storage device 10g, which replaces the energy storage device 10f with the changed availability factor V, receives a control signal from the control unit 120 that it is activated for reserve group 100, and the replaced energy storage device 10f receives a control signal that it is deactivated for reserve group 10.

[0085] In step S112, if there is a need, the energy storage units 10 aggregated in the relevant reserve group 100 are interconnected in such a way that the control power can be called up and the reserve group 100 can deliver or receive the available control power in the specified time.

[0086] From step S112, a query is also performed after step S106 to determine whether an event has occurred at the selected energy storage devices 10 (10a, 10b, 10c, 10d, 10e, 10f) assigned to a reserve group 100. Fig. 1) has caused a change in the respective availability factor V. If this is the case, the relevant energy storage unit 10 (10f in Fig. 2) against an alternative energy storage device 10 (10g in Fig. 2), as described above.

[0087] In step S114, the energy storage units 10 in the reserve group 100 are provided accordingly and can be controlled by the control unit 120 to receive or supply control power from the reserve group 100, whereby different reserve types PRL, SPL, MRL can be provided by the reserve group 100 as required.

[0088] Fig. Figure 5 shows a flowchart with various process steps according to an exemplary embodiment in which energy storage devices 10 do not provide control power, but rather energy as an electrical supply quantity related to a unit of time. This energy can be sold on a trading market A, B, C, D, E.

[0089] The procedure is very similar to that for standard benefits in Fig. 4 from.

[0090] In step S200, current data of the available energy storage devices 10 are recorded; for example, the power, state of charge, and / or temperature of the energy storage device 10 are recorded every second. The selectable energy storage devices 10 from among the available energy storage devices 10 are then identified.

[0091] In step S202, the availability factor V of each selectable energy storage device 10 is calculated, in particular what power the selectable energy storage devices 10 can absorb or deliver.

[0092] In step S204, one or more reserve groups 100 are first computationally compiled from the available energy storage 10 periodically, for example every 15 minutes. Before step S204, a query is performed in step S206.

[0093] In step S206, it is checked whether an event has occurred at the selected energy storage devices 10 (10a, 10b, 10c, 10d, 10e, 10f) assigned to a reserve group 100. Fig. 1) has caused a change in the respective availability factor V and, as a consequence, the availability factor V is no longer permissible. If this is the case (yes in the flowchart), step S208 checks whether the operating point of the relevant energy storage device 10 or of others in reserve group 100 can be changed, and in step S210 the operating point of the relevant energy storage device 10 and / or others in reserve group 100 is set.

[0094] In step S212, if there is a need, the energy storage units 10 aggregated in the relevant reserve group 100 are interconnected in such a way that the energy can be called up and the reserve group 100 can release or receive the available energy in relation to the unit of time within the specified time.

[0095] From step S212, a query is also performed after step S206 to determine whether an event has occurred at the selected energy storage devices 10 (10a, 10b, 10c, 10d, 10e, 10f) assigned to a reserve group 100. Fig. 1) a change in the respective availability factor V and the availability factor is no longer permissible. If this is the case, the operating point of one or more energy storage devices 10 is adjusted as described above.

[0096] However, it is also optionally possible to adjust the relevant energy storage device as described in Fig. 4 to replace with an alternative energy storage system.

[0097] In step S214, the energy storage devices 10 in the reserve group 100 are provided accordingly and can be controlled by the control unit 120 to receive or release electrical energy from the reserve group 100, whereby, depending on requirements, for example depending on a predicted achievable price for electrical energy on various trading markets, energy can be made available from the reserve group 100.

[0098] Here, A stands for an intraday auction on the spot market, B for an intraday trade on the spot market, C for a day-ahead auction on the spot market, D for a day-ahead auction on the EXAA marketplace, and E for so-called OTC transactions.

[0099] Marketing is conducted in a cascade manner, meaning that a forecast of the expected revenues from the respective marketing opportunities (balancing power, day-ahead, intraday (OTC, spot)) is generated in advance. An algorithm (revenue maximization) then decides which reserve group is offered on which market shortly before the respective bid submission deadlines. If a bid is not accepted at the required minimum cost or minimum bid prices, reserve group 100 is then offered or marketed on another market, possibly even during the day. Due to the short-term nature of changes to the composition of reserve group 100, a decision can be made at any time, even during the day, to market any available electricity supply capacity on a market other than the one already awarded a bid.

[0100] To determine the availability factor V of an energy storage device, the following are shown: Fig. 6, Fig. 7, Fig. 8 to Fig. 9. Examples of criteria for deriving an availability factor V of an energy storage system 10, for example a storage battery.

[0101] Fig. Figure 6 shows the course of a utility value N of an operating point of an energy storage device 10 over a state of charge in relative units.

[0102] A utility value analysis calculates the utility value N based on the state of charge and the ratio of the usable storage capacity to the prequalified control reserve (PQRL). The best utility value N for a storage battery as energy storage device 10 is achieved with a state of charge of 50%. The closer the operating point is to the limit values, the lower the utility value N. For example, the limit values ​​are ±0.25 x PQRL.

[0103] E NThe storage capacity of energy storage system 10 is , PQRL is the prequalified control reserve, and AP is the current operating point of energy storage system 10. For control reserve, typically only the maximum power of the connection or the energy storage system / inverter is considered, as this is essential for marketing purposes, minus the power required for recharging management. The storage capacity is only relevant in terms of the limitations of the power provision. The prequalified control reserve always refers to the maximum power and is limited either by a predefined factor (prequalified power to energy storage capacity) or by the connection power / inverter.

[0104] For example, an energy storage device 10, which can both supply and receive control power, can exhibit a parabolic curve with N(AP)=a⋅AP2+b⋅AP+c with the coefficients a, b, c a=−1(PQRL4−EN2)2 b=−a⋅EN c=1+a⋅EN24

[0105] The utility value N for this parameter is at its maximum when used for control power as an electrical supply variable, when the state of charge is at 50%. For other types of marketing, especially for electrical energy related to a unit of time, for example on trading markets, the shape of the curve may differ.

[0106] Fig. Figure 7 shows a curve of a utility value N of an event forecast of an energy storage system 10 over time t in hours.

[0107] The forecast specifies when an event is expected to occur at the charging station with energy storage unit 10. The utility analysis is started at time t0. The utility value N is calculated based on the predicted future event.

[0108] The greater the difference between the time of the event and t0, the higher the utility value N of this energy storage 10.

[0109] If PE is the prediction of an event and c is a compression, then, for example, the utility value N can be calculated as follows. N(PE)=1−ec⋅PE

[0110] Fig. Figure 8 shows a curve of a utility value N of a predicted age of an energy storage device 10 over time t in hours.

[0111] This criterion calculates the utility value N for the age of the forecast. The older the forecast for the charging station with energy storage 10, the lower the utility value N.

[0112] If PA is the age of the prognosis, for example, f(PE)=−1252PA2+1

[0113] Fig.Figure 9 shows the curve of a utility value N for the typical duration between two events of primary use of an energy storage system 10, for example, fast charging processes of electric vehicles at the energy storage system 10, over time t in hours. Here, t1 denotes the end of the last charging process, t3 is calculated as t1 plus the average duration between two charging processes since the charging station (of the energy storage system) was commissioned. t2 is defined as t0 plus the time required until the state of charge of the energy storage system is again EN / 2.

[0114] The curve between t2 and t3 is derived from the Fermi-Dirac statistics.

[0115] The utility values ​​N thus obtained are weighted and the availability factor V is determined with 0≤V≤1 for each selectable energy storage device 10.

Claims

[1] Method for providing an electrical supply quantity in an electrical supply system (200) with a plurality of energy storage devices (10) for providing electrical energy per unit of time or electrical control power in a secondary application of the energy storage devices (10), wherein the electrical supply quantity is kept available with a setpoint, characterized by (i) Evaluating a large number of energy storage devices (10) each with an availability factor (V); (ii) Aggregation of energy storage devices (10) in a reserve group (100) until a predetermined setpoint of the electrical supply quantity of the reserve group (100) is reached; (iii) event-oriented modification of the composition of the reserve group (100) and / or of target operating points of the energy storage units (10) within the reserve group (100) when an event occurs that changes the availability factor (V) at at least one of the aggregated energy storage units (10), where the availability factor (V) is zero when the energy storage device (10) is in use in its primary application, further characterized in that the availability factor (V) of the selectable energy storage (10) is derived from several criteria, the criteria comprising at least: (i) an operating point of the respective energy storage device (10), wherein the operating point includes in particular the state and / or state of charge and / or charging and / or discharging power and / or temperature of the energy storage device (10); (ii) an event forecast of the probability that the state of charge of the respective energy storage device (10) will be changed, in particular reduced, within a specified period; (iii) a first utility value derived from a forecast age of the event forecast; and (iv) a second utility value derived from a time interval between two events in which the state of charge of the respective energy storage device (10) changes. [2] Method according to claim 1, characterized by, that the energy storage devices (10) available in the supply system (200) are divided into selectable energy storage devices (10) and non-selectable energy storage devices (10), wherein the non-selectable energy storage devices (10) have an availability factor (V) of zero and the selectable energy storage devices (10) have a permissible availability factor (V) which is above a predetermined minimum value of the availability factors (V), in particular wherein an evaluation of the non-selectable energy storage devices (10) with an availability factor (V) is omitted at least temporarily. [3] Method according to claim 2, characterized by , that the energy storage devices (10) selectable in the supply system (200) must meet at least the following selection conditions: (i) the energy storage device (10) belongs to the common control area (300) if the electrical supply quantity represents a control power; (ii) the energy storage device (10) has a permissible availability factor (V); (iii) the energy storage unit (10) does not currently belong to reserve group (100) or any other reserve group; (iv) an external control device (120) can communicate with the energy storage device (10), in particular to exchange data and control signals. [4] Method according to any one of the preceding claims, further characterized by Removing one or more energy storage devices (10f) from the reserve group (100) which, after aggregation, no longer meet one or more of the selection conditions, and Adding one or more selectable energy storage devices (10g) to the reserve group (100), or Changing the target operating points of one or more energy storage devices (10) in the reserve group (100), especially if electrical energy is provided as an electrical supply quantity with respect to a unit of time. [5] Method according to any one of the preceding claims, characterized by , that the criteria are weighted and the availability factor (V) of each selectable energy storage device (10) is determined from the weighted criteria. [6] Method according to any one of the preceding claims, characterized by , that at least some of the criteria are determined on the available energy storage devices (10) continuously or at close intervals, in particular at minute intervals or at second intervals. [7] Method according to any one of the preceding claims, characterized by, that the operating point of the respective selectable energy storage device (10) is derived from a utility value of the energy storage device (10), in particular from a state of charge and a ratio of a usable storage capacity to a setpoint of the electrical supply quantity, in particular wherein the operating point lies between a minimum and a maximum setpoint of the electrical supply quantity, and / or that a utility value is determined which assesses the distance of a start (t_0) of the utility analysis to the predicted event, in particular that the utility value increases with increasing distance from the start (t_0) of the utility analysis, and / or that the forecast age of the event forecast is determined, in particular where the utility decreases with the age of the forecast, and / or that the event interval between two discharge processes of the energy storage device (10) is determined. [8] Method according to any one of the preceding claims, characterized by that the availability factors (V) of the energy storage (10) are generated periodically, in particular in a minute grid, preferably in a quarter-hour grid, or that the availability factors (V) of the energy storage (10) are generated on demand. [9] Method according to any one of the preceding claims, characterized by , that the energy storage units (10) aggregated in the reserve group (100) can both absorb and release energy. [10] Method according to any one of the preceding claims, characterized by, that energy storage (10) is aggregated into different reserve groups (100) which provide control power as an electrical supply quantity that is available in different time periods, in particular primary reserve within seconds, secondary reserve within a few minutes, minute reserve within a quarter of an hour and / or that energy storage (10) is aggregated into reserve groups (100) which provide electrical energy as an electrical supply quantity based on a unit of time that is available in different time periods. [11] Device for carrying out a method according to one of the preceding claims for providing an electrical supply quantity, in particular electrical energy per unit of time or electrical control power, in an electrical supply system (200) in which a plurality of energy storage devices (10) is arranged, characterized by , that (i) selectable energy storage devices (10) can be electrically aggregated to a reserve group (100) until a predetermined setpoint of the electrical supply quantity of the reserve group (100) is reached, (ii) depending on the occurrence of an event at at least one of the aggregated energy storage devices (10) that changes its availability factor (V), the energy storage device (10f) in question can be removed from the reserve group (100) and an alternative energy storage device (10) can be aggregated into the reserve group (100), in particular if the electrical supply quantity is control power; or that the setpoint operating point of one or more energy storage devices (10) in the reserve group (100) can be changed, in particular if the electrical supply quantity is electrical energy per unit of time. [12] Device according to claim 11, characterized by, that selectable energy storage devices (10) each have a communication interface (130) for communication with a control unit (120), and an energy storage control unit (132) which implements control commands received via the communication interface (130). [13] Device according to claim 11 or 12, characterized by , that at least one of the energy storage devices (10) comprises one or more batteries, in particular wherein one or more storage batteries are provided at charging stations. [14] Device according to any one of claims 11 to 13, characterized by , that at least one of the energy storage facilities (10) includes one or more combined heat and power plants.

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