DE102018205112A1 - Method for operating an electrical energy store for a control power supply - Google Patents

Abstract

The invention relates to a method for operating an electrical energy store (15), with which a control power delivery in a transmission network (10) is performed, wherein for a state of charge (L) of the energy store (15) has a lower working limit (31) and an upper working limit ( 30) are provided. The invention provides that in a work area (34) delimited by the working limits (30, 31), a loading limit (35) is provided for a predetermined additional load management application (13) which is independent of the control power supply, wherein the loading limit (35) on the one hand and one of the two working limits (30, 31) on the other hand a buffer area (36) is defined and results in a buffer area (36) reduced residual area (37) of the working area (34) and by a state of charge control (18) of the energy storage (15 ) with inactive load management application (13) the charge state (L) by recharging and / or discharging the energy store (15) in the remaining area (37) is maintained, and with active load management application (13) the state of charge (L) in addition to the buffer area ( 36) is guided.

Description

The invention relates to a method for operating an electrical energy store, for example a battery storage. By means of the energy storage, control power is provided in an electrical transmission network or power grid. The invention also includes a control device for a state of charge control of the energy store and an energy storage system.

For an electrical transmission network or power network is provided to stabilize the grid frequency electrical primary control power (PRL) is provided, this control power is fed in a drop in the grid frequency and subtracted in an excessive increase in the grid frequency. For such a control power supply, an electrical energy storage can be provided, which can be configured for example as a battery storage. There are also decentralized approaches. However, it must be ensured that one can rely on a control power supply of the respective energy storage system (energy storage plus associated control). Therefore, in order for an energy storage system to be approved for control power delivery, it must meet a prequalification specification. They regulate the requirements for the provision of control power by means of a power accumulator. In particular, an energy store may not be charged or discharged as desired, since for a predefined extreme case, when the grid frequency rises above a predetermined maximum value or falls below a predetermined minimum value, the energy store according to its Präqualifikationsspezifikation at least for a predetermined minimum period of time to provide a predetermined minimum power profile in a position have to be. This is only possible if the state of charge of the energy store is kept between a lower working limit and upper working limit specified by the prequalification specification. The lower working limit may only fall below in the said extreme case and the upper working limit may be exceeded only in the said extreme case.

From the US 2017/0104345 A1 It is known that an energy storage in addition to a control power delivery can still be used for the supply of a campus, that is, a local electrical network, an object network or a local balancing group. The balancing group is that part of the electrical network which is connected together with the energy storage device via the same electricity meter or connection point to that transmission network for which the energy storage device also provides control power. However, two systems do not have to be connected via the same connection point, but they can still be in the same balancing group. A balancing group can also describe an energy quantity account, for example, of an energy supplier. Here then different electricity meters are summarized in one account. The method known from the prior art requires a complex balancing of the control power and the power provided for the campus as well as the supply of energy for recharging the energy storage in order to be able to adjust a desired state of charge. Due to the complexity of this process, it could lead to a failure in the operation of the energy storage and thus to erroneous control power delivery.

The invention has for its object to make an electrical energy storage bugrobust both for the control power supply and for additional use available.

The object is solved by the subject matters of the independent claims. Advantageous embodiments of the invention are disclosed by the dependent claims, the following description and the figures.

The invention provides a method for operating an electrical energy store. The energy store can be, for example, a battery store, that is to say an arrangement of one or more electric batteries or accumulators. The energy store may additionally or alternatively be e.g. have a pumped storage plant. By means of the energy storage a control power is provided in an electrical transmission network or power grid. The control power is in particular primary control power (PRL). The method is based on the fact that the energy store is qualified for the control power supply, that is, according to a predetermined prequalification specification for a state of charge of the energy store, a lower working limit and an upper working limit are provided, by which it is guaranteed that the energy storage when they are reached is still able to provide a predetermined minimum power profile for a predetermined minimum period of time. When the lower working limit is reached, it is thus ensured that the energy store can be further discharged, ie can deliver control power, in accordance with the minimum power profile and for the minimum duration of time. The minimum power profile can be, for example, a power specification for the energy store. When the upper working limit is reached, the energy store according to the prequalification specification is still able to accommodate further control power for the minimum time duration and according to the minimum power profile.

In order to use this energy storage for another application, without jeopardizing the ability of the control power supply, the following is provided. The invention assumes that the lower working limit is smaller than the upper working limit, so that thus between the lower working limit and the upper working limit, an area results, which is referred to here as the work area and in which the state of charge can be varied without the working limits to reach. This work area is used for a predetermined additional load management application independent of the control power delivery. By load management application is meant that by means of the energy storage additional electrical power for a power supply, for example, a building or plant or a charging station is provided and / or electrical power from a power source that uses renewable energy (such as photovoltaic or wind power) is recorded. The energy store thus supplies the load management application with electrical energy and / or stores electrical energy for the load management application. The resulting energy flow corresponds to the electrical power. Since the invention can be used for both the delivery of electrical power and the absorption of electrical power, the term "charging" for charging or recharging as well as for discharging will hereafter be referred to (English: Discharging) of the energy storage used.

In the method is now provided that in the work area, ie between the lower working limit and the upper working limit, a charging limit is provided. The work area is therefore divided by the loading boundary into two parts. Accordingly, a buffer area is defined by the loading limit on the one hand and one of the two working limits on the other hand. If the loading limit is a loading limit, the buffer area is limited or defined by the loading limit and the lower working limit. If the loading limit is an unloading limit, the buffer area is limited or defined by the loading limit and the upper working limit. The buffer area corresponds to an amount of energy guaranteed for said load management application. From the loading limit to the associated working limit, as the buffer area passes through, an amount of energy in the energy store is converted (delivered or received), which is allocated or guaranteed to the load management application. The said work area between the lower and upper working limits is thus now divided into the buffer area on the one hand and, secondly, this results in a remaining area of the work area which is reduced by the buffer area.

The state of charge of the energy storage is influenced by the simultaneous control power delivery and controlled by a state of charge control. For this purpose, an energy flow or the power in and / or out of the energy storage, for example by means of power electronics, in particular a DC-DC converter or a switching converter or converter, are controlled. In an inactive load management application, namely, if there is no power requirement of the load management application, the state of charge is maintained by the state of charge control by recharging and / or discharging the energy store in said remaining area. The state of charge can therefore still vary with an inactive load management application, because the control power supply continues to run. Because at the primary control power is continuously regulated, i. the energy store (the battery) gets e.g. every second a control signal (power control signal), which it is necessary to drive. Of course, the said reloading and unloading is not simultaneous, but it is meant that both processes can take place successively, depending on which limit of the remaining region the state of charge is approaching or which limit has been reached. In the case of an active load management application, if there is a power requirement of the load management application, the state of charge is additionally fed into the buffer area by the state of charge control. In other words, the buffer area is also used.

All in all, therefore, the method will embed a load management application in the available work area between our working limit and upper working limit. The invention provides the advantage that this additional load management application can be added by the simple monitoring of an additional charging limit, so that no complex and thus error-prone monitoring of the state of charge of the energy storage is necessary. It can be used in the state of charge control, the same mechanism for reloading and unloading and monitoring, as it is also implemented in connection with the lower working limit and the upper working limit in the state of charge control anyway. Only one additional charge limit is defined. The loading limit and one of the two working limits define a buffer area, that is, they delimit it. If the load management application provides an energy supply for a power request, the buffer area is defined by the lower operating limit. If the load management application provides for a power consumption during a power request, then the buffer area is limited by the upper working limit. An energy intake can, for example, in connection with the generation of electrical power by a regenerative Energy source, such as wind and / or photovoltaic, be relevant. Here it is necessary to absorb and temporarily store the generated electrical energy.

The invention may also provide more than one reload limit for multiple load management applications. The recharge limits then accumulate depending on which of the load management applications is active.

The invention also includes embodiments that provide additional benefits.

Of course, despite the load management application, it must be ensured that the prequalification specification is guaranteed to be met or complied with, ie, when one of the working limits is reached, the predetermined minimum power profile can still be provided for the predetermined minimum period of time. An embodiment for this provides that the load management application is deactivated if the state of charge of the energy store is in the buffer area and the state of charge reaches the working limit limiting the buffer area. Thus, if the state of charge leaves the buffer area in the direction of the working limit and not in the direction of the remaining area, then the load management application is deactivated. This results in a load shedding. The energy storage is then available in an advantageous manner exclusively for the control power supply.

Said load shedding is, of course, provided only in an emergency, when the energy storage is no longer able to provide both the control power, and to provide the load management application. By recharging or discharging the state of charge control can of course counteract this load shedding. For this purpose, an embodiment provides that the charge state, in the event that it is located in the buffer area, is led back into the remaining area. For this purpose, in the event that the state of charge is in the buffer area and the state of charge reaches the working area limiting the buffer area, ie the lower or the upper working limit, and / or the load management application is inactive, in the case of the lower working limit by reloading and / or in the case of the upper working limit by discharging the energy storage then the state of charge in the remaining area is performed. Of course, this is only provided if the extreme case described at the outset does not exist, that is to say the control power supply requires that the energy store also exceeds the working limit and provides the minimum power profile. The embodiment has the advantage that the energy store is guided again into the remaining area and thus is also available again for the load management application.

Some embodiments concern the question of how the energy store can be charged or discharged. According to one of these embodiments, the recharging and / or discharging takes place by at least one power source (for example a power plant) that is different from the energy store and / or at least one power consumer being driven within a predetermined charging period during which the charging process is to take place a predetermined charging power (for charging or discharging the energy storage) with the transmission network or within the balancing group to exchange directly with the energy storage. The power source should deliver charging power to charge the energy storage can. The power consumer should absorb charging power in order to discharge the energy storage. With regard to the transmission network, this process can therefore be power-neutral. The state of charge control of the energy store sets during the charging time period a desired power flow of the energy storage offset by the said charging power. The offset corresponds to the power amount of the charging power. In other words, the operating point of the energy storage is offset or shifted. In this way, therefore, the energy store is coordinated with at least one power source and / or with at least one power consumer. The offset of the operating point takes place in such a way that the charge power delivered by a power source can flow into the energy store and charge power consumed by a power consumer can flow out of the energy store. In this case, however, the entire charging power does not have to arrive, because in the meantime part of it can be used up as a control power in the transmission network. This is then recorded as a control power provided by the energy store.

The at least one power source and / or the at least one power consumer can be controlled by providing a flexible power source and / or a flexible consumer, which can thus be controlled as required for a charging process of the energy store and is arranged in the same balancing circuit, that is to say via the same connection point as the energy store is connected to the transmission network. Thus, the charging process takes place within the balancing group and is not recorded in the transmission network. Additionally or alternatively, it can be provided that the at least one power source and / or the at least one power consumer are controlled by means of a timetable transaction of an energy exchange, in that the state of charge control signals a bid on the energy exchange in accordance with the predetermined charging power. It is thus automatically triggered a timetable business. This obliges the at least one source of power and / or the at least one power consumer to exchange the charging power during the charging period, ie during a predetermined time interval. Thus, it is ensured that then during the charging period when the target power flow is set offset by the amount of power in the energy storage in the transmission network elsewhere, that is, at least one other connection point, the at least one power source and / or the at least one power consumers one corresponding amount of charging power with the transmission network exchanges. Overall, there are three options for the charge management or the charge state control of the energy storage, namely the said stock exchange transaction and / or said driving a flexible power source and / or power consumer in the same balancing group and finally the payment of balancing energy, that is, there is no accounting of the schedule business.

During the charging process of the energy storage device, ie during the recharging or discharging, however, the control power supply for the transmission network or power grid can continue to be performed. For this purpose, the charging process of the energy storage device, that is to say the power exchange or the power transmission or the power flow of the energy storage device, is modulated or adapted in accordance with a request signal of the control power supply. Is e.g. Charging power of 10 kilowatts set and is temporarily requested during the charging process 3 kilowatts of control power, the power flow of the charging process is reduced to the remaining 7 kilowatts. An embodiment for this provides that during the said charging period by the state of charge control, a difference signal which a difference between a progress signal of the charging power (in the example 10 kilowatts) and the request signal of the control power supply (ie the required control power, in the example 3 kilowatts) signals becomes. The difference signal thus describes which part of the required control power is already provided by the charging power of the at least one controlled power source and / or the at least one controlled power consumer (in the example 3 kilowatts). However, the energy storage is responsible for this control power. Therefore, it is determined what is left of the charging power for the actual charging process (in the example, 7 kilowatts). This is expressed by the difference signal. Accordingly, a power exchange carried out between the transmission network and the energy store for recharging and / or discharging is modulated as a function of the difference signal. If there is no control power because the demand signal increases, the power exchange is throttled, so that more of the charging power in the transmission network is available as a control power. If, on the other hand, according to the request signal, less or no control power is necessary, then the energy exchange on the energy store is correspondingly increased, so that the energy store uses more of the charging power for recharging and / or discharging. In other words, a control power dynamics will continue to be provided by means of the energy storage. For example, the charging power can be provided by the at least one power source and / or the at least one power consumer with a time-constant course, while the request signal signals a time-varying control power. This temporal variation can then be compensated or compensated for by modulating the power exchange on the energy store.

Also during the load management, ie with active load management request, of course, control power is still provided. An embodiment for this provides that, when the load management application is active, a power control signal which controls the power exchange of the energy store with the transmission network and the load management application depends both on the power requirement of the load management application and on the control power demand (signaled by the load management application) said request signal) is generated. By means of the power control signal, for example, the said power electronics of the energy store can be controlled, by which the power flow of the energy store can be regulated. Advantageously, therefore, the signals are superimposed, so that the exchange of power of the energy storage of both the power requirement of the load management application and the control power requirement is justified. As a result, however, control power can be provided by means of the load management application itself if the reserve power requirement and the power requirement of the load management application at least partially offset each other. For example, if power is required for control power delivery, and the load management application consists of powering an electrical load, the embodiment co-ordinates the load management application with the transmission network such that the control power to be absorbed is consumed by the load management application. The exchange of power between the energy store and the load management application can thus also be fully or partially balance sheet with the load management application by the commercial balance sheet transfer of the service takes place. It is then provided a balance sheet exchange of electricity volumes from different meters.

For the provision of the control power, it has proven to be advantageous if the predetermined by the prequalification specification minimum period of time is in a range of 10 minutes to 60 minutes. It is preferred that the minimum duration is 30 minutes. Upon reaching the lower working limit is thus guaranteed that until the complete discharge of the energy storage at maximum demand for control power, as set for the energy storage according to the prequalification specification maximum, still passes the minimum period. The same applies to a complete charging of the energy storage when reaching the upper working limit. If the minimum period of time is at least 30 minutes, then the energy store is advantageously qualified for the German electrical energy market.

The invention also includes a control device by means of which the state of charge control can be realized in an energy store while it is being operated on an electrical transmission network. For this purpose, the control device has a computing device which is set up to carry out an embodiment of the method according to the invention. For this purpose, the computing device can be realized, for example, on the basis of at least one microprocessor and / or at least one microcontroller. The control device can be designed, for example, as a control computer for power electronics of the energy store. The method steps can be implemented, for example, as program code for the computing device, which can be stored in a data memory of the computing device.

Finally, the invention also includes the combination of an electrical energy store for operation on an electrical transmission network and of the control device according to the invention. This together results in the energy storage system according to the invention. The power electronics for adjusting the power flow in and / or out of the energy store can also be seen as part of the energy storage system. The power electronics meet the requirements of control power supply and load management.

The invention also includes the combinations of the described embodiments.

Further features of the invention will become apparent from the claims, the figures and the description of the figures. The features and combinations of features mentioned above in the description as well as the features and feature combinations mentioned below in the description of the figures and / or shown alone in the figures can be used not only in the respectively indicated combination but also in other combinations or in isolation.

• 1 eine schematische Darstellung eines Übertragungsnetzes, an welches eine Ausführungsform des erfindungsgemäßen Energiespeichersystems angeschlossen ist;
• 2 ein Diagramm zur Erläuterung der Präqualifikationsspezifikation;
• 3 ein Diagramm zur Veranschaulichung einer Ausführungsform des erfindungsgemäßen Verfahrens, das durch eine Steuervorrichtung eines Energiespeichers des Energiespeichersystems von 1 durchgeführt werden kann;
• 4 ein Flussschaudiagramm des Verfahrens;
• 5 Diagramme zur Veranschaulichung eines Ladevorgangs des Energiespeichers, wie er gemäß dem Verfahren durchgeführt werden kann.

In the following an embodiment of the invention is described. This shows:

• 1 a schematic representation of a transmission network to which an embodiment of the energy storage system according to the invention is connected;
• 2 a diagram explaining the prequalification specification;
• 3 a diagram illustrating an embodiment of the method according to the invention, by a control device of an energy storage of the energy storage system of 1 can be carried out;
• 4 a flowchart of the process;
• 5 Charts to illustrate a charging process of the energy storage, as it can be performed according to the method.

In the figures, functionally identical elements are each provided with the same reference numerals.

1 shows a transmission network 10 , which may be, for example, a public grid of the medium voltage level or high voltage level. The transmission network 10 can be supplied or operated by at least one power source Q, such as a power plant, with electrical power.

At a mains connection or connection point 11 of the transmission network 10 can be a participant or balancing group 12 be connected. A balancing group 12 can be an electrical network that sums up all those consumers and / or producers that are exclusively connected via the connection point 11 with the transmission network 10 are connected. At the connection point 11 An electricity meter can be installed which is connected to the transmission network 10 amount of energy consumed by the balancing group 12 measures or records.

In the balancing group 12 can be a load management application 13 be provided, which may be, for example, an office building or several office buildings and / or a production site (for example, a production plant) and / or at least one electric charging station for electric vehicles and / or at least one household. Additionally, in the balancing group 12 an energy storage system 14 be provided. The energy storage system 14 can be an electrical energy store 15 have, over a power electronics 16 with the connection point 11 and the load management application 13 be connected can. The energy storage 15 may for example be a battery storage. The power electronics 16 may be an energy flow or power flow in and / or out of the energy storage 15 adjust or control. For this purpose, the power electronics 16 by a control device 17 be controlled, which is a state of charge control 18 for the energy storage 15 can have. By the state of charge control 18 may be a state of charge L of the energy storage 15 be set. The state of charge control 18 For this purpose, a charge state signal describing the current charge state L can be described 20 and / or a power request signal 21 and / or a request signal 22 for a control power requirement of the transmission network 10 receive. The power request signal 21 describes a power requirement of the load management application 13 ie the requested service (utility or surplus power). The state of charge control 18 may vary depending on the power request signal 21 for the power requirement of the load management application 13 and in response to the request signal 22 for the control power demand, a power control signal 23 generate, through which the power electronics 16 can be controlled, that is by the power control signal 23 becomes the power flow of the energy store 15 controlled.

Overall, can thus in the balancing group 12 result in the following power flows: For the load management application 13 can be a direct power flow 24 from the transmission network 10 over the connection point 11 respectively. The energy storage 15 can control power with the transmission network 10 over the connection point 11 exchange, resulting in a control power delivery 25 for the transmission network 10 through the energy storage system 14 results. For recharging and / or discharging the energy storage 15 on the one hand, an internal power flow 26 between the energy storage 15 and the load management application 13 and on the other hand an external power flow 27 between the energy storage 15 and the transmission network 10 ,

1 finally shows an energy exchange B, which will be explained later in more detail.

Overall, it can be provided that by means of the energy storage 15 based on the energy storage 15 both primary control power for the transmission network 10 as well as at least partially a power request of the load management application 13 is satisfied or fulfilled.

2 explains how to do this by means of the energy storage 15 is possible. Thus the energy storage 15 Control power in the transmission network 10 he must provide a prequalification specification 28 fulfill. 2 illustrates the prequalification specification 28 graphically.

For the energy storage 15 the usage restriction applies that the full or maximum primary control power must be able to be provided at any time for at least a minimum period of, for example, 30 minutes (30-minute criterion). As a minimum power profile so can the energy storage 15 and / or the power electronics 16 nominally the highest possible power flow can be provided. The usage restriction forces provision of battery capacity or energy capacity that may only be charged / discharged at extreme grid frequency values (the extreme case). The minimum time period multiplied by the highest primary control power to be provided gives an amount of energy stored in the energy store 15 must be kept. The energy storage 15 must therefore have a minimum capacity 29 exhibit. By way of illustration, the abscissa represents a ratio V of the minimum capacity 29 to the storage capacity of the energy storage 15 specified. The minimum capacity 29 results at V = 1. On the ordinate the state of charge L is shown as it by the state of charge signal 20 can be described.

If the energy storage 15 only the minimum capacity 29 has (V = 1), the energy storage must always be charged to 50 percent (L = 50 percent). On the other hand, is the ratio V of the capacity of the energy storage to the minimum capacity 29 greater than 1, the result is an upper working limit 30 and a lower working limit 31 , In the range between the lower working limit 31 and the upper working limit 30 there is scope for action 32 within which the state of charge L can or can fluctuate, without the said 30-minute criterion or, in general, the prequalification specification 28 get hurt. For a specific energy storage 15 This always results in a concrete relationship 33 , Here then applies that between the lower working limit 31 and the upper working limit 30 a workspace 34 is available within which the state of charge L can fluctuate or can be guided.

3 illustrates again for the specific energy storage 15 the concrete relationship 33 , Shown is a progress of the state of charge L over time t , The course can be controlled by the state of charge control 18 between the lower working limit 31 and the upper working limit 30 be managed or held. It is further illustrated that the respective working limit 30 . 31 by a respective tolerance value T to the actual values for that state of charge that would actually be necessary to fulfill the prequalification specification. This will be more one Response delay of the energy storage system 14 compensated or taken into account.

To now specifically using the energy storage system 14 electrical energy for the load management application 13 can be provided that the work area 34 is divided by one between the working limits 30 . 31 lying charging limit 35 is provided or defined.

For further explanation, assume that it is the load management application 13 is an electrical load, that is, a power consumer or energy consumer. By the loading limit 35 and the lower working limit 31 this becomes a buffer area 36 defined, which corresponds to an amount of energy for the load management application 13 guaranteed or guaranteed. Accordingly, there is a residual area 37 in the workspace 34 ,

3 shows three phases of time t namely, two inactive phases 38 in which there is no power requirement of the load management application 13 is present, and a phase of a power request 39 the load management application 13 during which the load management application 13 electrical power from the energy storage 15 request what through the described power request signal 21 can be signaled. Accordingly decreases during the power request 39 the state of charge L starting from an initial state 40 ,

The state of charge control 18 can now perform two different reload strategies, depending on whether the phase 38 the inactive load management application 13 or the performance requirement 39 the load management application 13 is present.

4 FIG. 2 illustrates how the entire reserve period for the energy storage in a step S 10 is described 15 for the transmission network 10 is carried out.

Meanwhile, in one step S11 be checked if the performance requirement 39 the load management application 13 is present.

If the performance requirement 39 the load management application 13 present (in 4 symbolized by a "+" symbol), so can one step S12 the state of charge L within the workspace 34 also in the buffer area 36 be guided or fall off until the buffer area 36 limiting working limit, here the lower working limit 31 , is reached. Because the energy from the buffer area 36 is for the load management application 13 reserved. Should then still have a performance requirement 39 can be present, then the load management application 13 inactive, which means that it then fully utilizes the direct power flow 24 from the transmission network 10 or is switched off. Thus, then the state of charge L from the buffer area back into the rest area 37 be guided by reloading.

Is against it in the step S11 the load management application 13 inactive (phases 38 ), may be a recharge or a recharge 41 already done (see 3 ), if the loading limit 35 is reached. This corresponds to 4 the case symbolized by a "-" symbol. The monitoring of the state of charge L on reaching the charging limit 35 and then recharging commences corresponds to the step S13 ,

5 illustrates one way in which reloading can be done.

This can be done via the transmission network 10 connected power source Q are used. It can be made possible by the power source Q targeted electrical charging power P to request, for example, a power exchange B for buying the charging power P at the power source Q can be provided.

5 illustrates how in the step S10 even during a recharge of the energy storage 15 continue the primary control power can be provided. 5 shows over time t for different times in a diagram 42 the time course of a control power requirement for the primary control power, as indicated by the request signal 22 can be signaled. Furthermore, the power control signal 23 for controlling the power electronics 16 shown. It should be assumed here for the sake of clarity and without restriction of generality that no power requirement of the load management application 13 is present. To recharge the energy storage 15 can now on the energy exchange B a timetable business 43 with the power source Q be completed by which the power source Q for a charging period 44 committed or controlled, charging power P in the transmission network 10 feed. For the charging period 44 becomes according to diagram 42 then the operating point for the power control signal 23 by an offset 45 offset, which corresponds in terms of amount of the charging power P. This will now become part of the control power through the power source Q provided. By means of the energy storage 15 becomes only control power according to a difference signal 46 provided or with the transmission network 10 replaced. The difference signal 46 describes the difference between the request signal 22 for the control power and the charging power P.

A diagram 47 illustrates how this can be prevented that the state of charge L for example, the lower working limit 31 (Step S12 ) or the loading limit 35 (Step S13 ) crosses or falls below. It results when the respective working limit is reached 31 . 35 a stabilization 48 through the addition in the transmission network 10 fed charging power P , By shifting the operating point by the offset 45 this results in a charging process 49 (see diagram 42 ), during which the portion of the charging power not required as a control power from the transmission network 10 in the energy store 15 flows and this is thus recharged and thus the state of charge L in the remaining area 37 can be brought into it.

1. 1) Erbringung von primärer Regelleistung PRL: Ist das Lastmanagementanwendung 13 gleich 0 und der Ladezustand innerhalb des Restsignals, so ergibt sich das Leistungssteuersignal 23 aus dem Anforderungssignal 22 der Regelleistungserbringung.
2. 2) PRL plus Entladen: Ist die obere Arbeitsgrenze 30 überschritten, wird ein Entladefahrplan angesteuert, um den Ladezustand L wieder in den Arbeitsbereich zu führen. Das Leistungssteuersignal 23 ergibt sich aus dem Anforderungssignal 22 und dem Entladefahrplan.
3. 3) PRL plus Lastmanagement: Ist der Ladezustand L im Restbereich 37 und liegt eine Leistungsanforderung 39 der Lastmanagementanwendung 13 vor, so ergibt sich das Leistungssteuersignal 23 aus dem Anforderungssignal 22 für die PRL und der Leistungsanforderung 39 für die Lastmanagementanwendung 13.
4. 4) PRL plus Nachladen: Ist der Ladezustand L im Pufferbereich und liegt keine Lastmanagementanforderung vor oder ist die untere Arbeitsgrenze 31 unterschritten, so wird ein Nachladefahrplan angesteuert, wie er beispielsweise in 4 gegeben ist, und es ergibt sich das Leistungssteuersignal 23 aus PRL plus Nachladefahrplan.

Overall, this results in four operating modes:

1. 1) Provision of primary control power PRL: Is the load management application 13 equal to 0 and the state of charge within the residual signal, the power control signal results 23 from the request signal 22 the provision of control power.
2. 2) PRL plus unloading: is the upper working limit 30 exceeded, an unloading timetable is controlled to the state of charge L to return to the work area. The power control signal 23 results from the request signal 22 and the unloading timetable.
3. 3) PRL plus load management: Is the state of charge L in the rest area 37 and is a performance requirement 39 the load management application 13 before, the result is the power control signal 23 from the request signal 22 for the PRL and the performance requirement 39 for the load management application 13 ,
4. 4) PRL plus reload: If the charge state L is in the buffer area and there is no load management request or is the lower working limit 31 falls below, then a Nachladefahrplan is driven, as he, for example, in 4 is given, and there is the power control signal 23 from PRL plus reload schedule.

The unloading schedule can according to 4 be realized in that instead of positive charging power P Negative charging power is traded on the energy exchange.

Overall, this results in a state of charge control for the simultaneous provision of primary control power for a power grid or transmission network operated at a nominal grid frequency 10 and a power request from another power consumer / generator of a load management application 13 by means of an energy store 15 , This will be the transmission network 10 , the energy store 15 and the load management application 13 considered. The energy storage 15 provides continuous control power according to the requirements of the operator of the transmission system 10 , This results in the four operating modes described: PRL, PRL + unload, PRL + load management and PRL + reload. The energy storage 15 consistently complies with the prequalification specification of control power delivery, in particular the described 30 minute criterion, by defining a buffer capacity or buffer area 36 in case of using the energy storage in the mode PRL + load management (active load management application 13 with performance requirement 39 ) may be used and by premature recharge the energy storage 15 what is guaranteed by the loading limit 35 is defined or defined. If the memory is used in PRL + load management mode, this buffer capacity may be used for the buffer area 36 until reaching the working area limiting the buffer area 30 . 31 , as defined by the prequalification specification. Upon reaching this working limit 30 . 31 No more power can be provided for the load management application and the energy storage 15 is instead recharged (operating mode PRL + recharge).

Overall, this results in a division of the allowed working range of the state of charge of an energy storage in different areas and a definition of different operating modes to ensure that the requirement of the work area is not violated.

In addition to the revenues from the provision of balancing services, the system can generate additional revenues by providing power, for example for peak shaving (reducing peak load, reducing network charges) or fast charging (providing high charging power) with a battery system.

Simultaneous to the network service Control power at transmission network level, the battery can avoid peak loads in the networks and thus at the same time take over a service for the distribution system operator.

The energy storage system can be flexibly adapted by dividing the work area or the reloading limit and thus respond spontaneously to price changes on the reserve power market or to changes in demand for load management (eg more electric vehicles want to charge).

The use of a battery can greatly reduce the cost of grid connection power for the investment cost of a fast charging system.

Distribution of the permitted working range of the state of charge of energy storage in different areas. Definition of different operating modes to ensure that the condition of the work area is never violated.

Advantages of the invention are in particular the following:

In addition to the revenues from the provision of balancing power, the system can generate additional revenues by providing power, for example for peak shaving (reducing peak load and thus reducing network charges) or fast charging (in particular providing high charging power) with a battery system. Simultaneous to the network service Control power at transmission network level, the battery can avoid peak loads in the networks and thus at the same time take over a service for the distribution system operator.

The system can be flexibly adapted by dividing the work area or the reloading limits and thus respond spontaneously to price changes on the reserve power market or demand change for load management (eg more electric vehicles want to charge).

The use of a battery can greatly reduce the cost of grid connection power for the investment cost of a fast charging system. Batteries are currently very expensive. Several sources of revenue enable better profitability.

It is not necessary to aggregate several battery systems in order to provide continuous control power according to the requirements of the transmission system operators.

LIST OF REFERENCE NUMBERS

10

transmission network

11

connection point

12

Balancing group

13

Load management application

14

Energy storage system

15

energy storage

16

power electronics

17

control device

18

State of charge control

20

Charge level signal

21

Power request signal

22

request signal

23

Power control signal

24

power flow

25

Rule performance

26

power flow

27

power flow

28

Präqualifikationsspezifikation

29

minimum capacity

30

working limit

31

working limit

32

Room for maneuver

33

relationship

34

Workspace

35

charge limit

36

buffer area

37

rest area

38

phase

39

performance requirement

40

initial state

41

recharging

42

diagram

43

roadmap business

44

Charging period

45

offset

46

difference signal

47

diagram

48

stabilization

49

charging

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 2017/0104345 A1 [0003]

Claims (10)

A method for operating an electrical energy store (15), with which a control power delivery in an electrical transmission network (10) is performed, wherein according to a predetermined prequalification specification (28) for a state of charge (L) of the energy store (15) has a lower working limit (31) and an upper working limit (30) are provided, by which it is guaranteed in each case that the energy store (15) is able to provide a predetermined minimum power profile when it is reached for at least a predetermined minimum period of time, characterized in that a lower working limit ( 31) and the upper working limit (30) limited work area (34) for a predetermined, independent of the control power supply, additional load management application (13) a loading limit (35) is provided, wherein by the loading limit (35) on the one hand and one of the two working limits ( 30, 31), on the other hand, a buffer area (36) is defined, which corresponds to a guaranteed for the load management application (13) amount of energy, and thus by the buffer area (36) reduced residual area (37) of the working area (34) results and by a state of charge control (18) of the energy storage (15 ): - in the case of an inactive load management application (13), if there is no power requirement (39) of the load management application (13), the charge state (L) is maintained in the remaining area (37) by recharging and / or discharging the energy store (15), and when the load management application (13) is active, if the power request (39) of the load management application (13) is present, the charge state (L) is additionally fed into the buffer area (36). Method according to Claim 1 wherein the load management application (13) is deactivated if the state of charge (L) is in the buffer area (36) and the state of charge (L) reaches the working limit (30, 31) bounding the buffer area (36). Method according to one of the preceding claims, wherein in the event that the state of charge (L) is in the buffer area (36) and the state of charge (L) reaches the working area (30, 31) delimiting the buffer area (36) and / or the Load management application (13) is inactive, in the case of the lower working limit (31) by recharging and / or in the case of the upper working limit (30) by discharging the energy storage device (15) the state of charge (L) in the remaining area (37) is guided. Method according to one of the preceding claims, wherein the recharging and / or the discharging takes place by at least one of the energy storage (15) different power source (Q) and / or at least one power consumer is driven to within a predetermined charging time (44), a predetermined Charge power (P) with the transmission network (10) or directly to the energy storage (15) to replace, and the state of charge control (18) during the charging period (44) a desired power flow of the energy storage (15) by the amount of power of the charging power (P) offset (45 ). Method according to Claim 4 wherein the driving of the at least one power source (Q) and / or the at least one power consumer by means of a timetable business of an energy exchange (B) by the state of charge control (18) signals a bid to the energy exchange (B) according to the predetermined charging power (P) , and / or by a flexible power source and / or a flexible power consumer in the same balancing circuit (12) is driven. Method according to Claim 4 or 5 in that during the charging time period (44) by the state of charge control (18) a difference signal (46), which signals a difference between a request signal (22) of the control power supply and a charging power signal (P), is generated and between the transmission network (10 ) and the power storage (15) for the recharging and / or discharging performed power exchange in response to the difference signal (46) is modulated. Method according to one of the preceding claims, wherein, when the load management application (13) is active, a power control signal (23) which controls a power exchange of the energy store (15) with the transmission network (10) and the load management application (13) is performed by the state of charge controller (18) Dependent on the power requirement (39) of the load management application (13) as well as in response to a control power demand is generated. Method according to one of the preceding claims, wherein the predetermined by the prequalification specification (28) minimum period of time is in a range of 10 minutes to 60 minutes, in particular 30 minutes. Control device (17) for a state of charge control (18) in an electrical energy store (15) operated on an electrical transmission network (10), the control device (17) having a computing device which is adapted to carry out a method according to one of the preceding claims. Energy storage system (14) with an electrical energy store (15) for operating on an electrical transmission network (10) and with a control device (17) according to Claim 9 ,

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