EP4278421A1

EP4278421A1 - Method and control device for controlling load flows between a plurality of energy systems

Info

Publication number: EP4278421A1
Application number: EP22708465.4A
Authority: EP
Inventors: Arvid Amthor; Stefan JESSENBERGER; Sebastian Schreck; Sebastian THIEM
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 2021-03-05
Filing date: 2022-02-09
Publication date: 2023-11-22
Also published as: CN116964886A; EP4054045A1; WO2022184393A1; AU2022228605A1

Abstract

The invention relates to a method for controlling load flows between a plurality of energy systems (2) via an electrical network (4) by means of a control device (1) common to the energy systems (2), wherein a power associated with a load flow can be provided by each of the energy systems (2) at at least one network node of the electrical network (4), the method comprising at least the following steps: - (S1) determining first powers which are provided for the load flows, on the basis of data which are transmitted from the energy systems (2) to the control device (1) and comprise information regarding a maximum power which can be provided by the relevant energy system at the relevant network node; - (S2) ascertaining a network-node-resolved control power which is internal with respect to the electrical network (4), on the basis of the determined provided first powers as well as on the basis of provided network boundary conditions of the electrical network (4); - (S3) taking into account the control power ascertained at the network nodes by accordingly reducing or increasing the maximum powers which can be provided at this network node by the energy systems (2); - (S4) determining provided second powers on the basis of the reduced or increased maximum powers which can be provided; and - (S5) controlling the load flows according to the determined second powers. The invention also relates to a control device (1) for carrying out the method.

Description

description

Method and control device for controlling load flows between several energy systems

The invention relates to a method according to the preamble of patent claim 1 and a control device according to the preamble of patent claim 14.

Energy systems, for example city districts, municipalities, industrial plants, industrial buildings, office buildings and/or residential buildings, can exchange energy with one another in a decentralized, ie local, manner, for example by means of a power grid (electrical grid). In this case, energy systems typically have one or more energy subsystems, for example a building. The energy subsystems each include a number of energy systems that are provided for generating energy, consuming energy or storing energy.

The decentralization of the energy supply gives rise to the fundamental technical problem of efficiently distributing the locally generated energy and, in particular, also consuming it locally. In other words, technical regulation or control of the distribution of the generated, consumed and/or stored energy is required. Such a control can be made possible by means of a control device of a local energy market platform.

In other words, a local energy market is technically realized by the local energy market platform forming a control device. Such a local energy market platform/control device for exchanging electrical energy is known, for example, from document EP 3518369 A1. In principle, the local energy market platform enables the most efficient local distribution of the energy generated, consumed and/or stored in the overall system. Optimization methods (optimization) are used to determine control variables that are as optimal as possible. In other words, the technical control on which efficient energy distribution is based is represented by a target function on which optimization is based. The local energy market platform determines the technical values required for control by solving the optimization problem, ie by making the target function extremal. Here, the target function is associated with the overall system, ie with all energy systems and/or energy subsystems participating in the energy exchange. Typically, the total energy consumption, the total emissions or the total costs or a weighted combination of the variables mentioned are used as the target function.

In principle, the share of volatile, difficult to predict feed-in of renewable energies, for example from photovoltaics and/or wind power plants, as well as the share of decentralized consumers, for example from electric cars and/or heat pumps, is increasing.

Electrical networks and their network operators are faced with additional technical challenges. In particular, they must react to short-term, unforeseen generation or consumption fluctuations by using flexibility (balancing capacity) so that grid bottlenecks can be avoided and system stability (grid frequency, voltage stability) is ensured. Since the grid frequency is the global size of the European and other interconnected grids, the technical function not only has to be ensured in one's own energy system, but also flexibility, i.e. control power, has to be made available to higher-level grids or grid levels. The present invention is based on the object of providing a method for controlling load flows between a plurality of energy systems via an electrical network which is improved with regard to network bottlenecks.

The object is achieved by a device having the features of independent patent claim 1 and by a method having the features of independent patent claim 14 . Advantageous refinements and developments of the invention are specified in the dependent patent claims.

The method according to the invention for controlling load flows between a plurality of energy systems via an electrical network by means of a control device which is common to the energy systems, with a power associated with a load flow being able to be provided at least at one network node of the electrical network by the energy systems, in particular being provided flexibly in terms of time , is, comprises at least the following steps:

- Determination of first powers provided for the load flows based on data transmitted from the energy systems to the control device, which data include information about a maximum power that can be provided by the respective energy system at the respective network node;

- Determining a control power that is internal to the electrical network and resolved in terms of network nodes, based on the determined intended first powers and based on provided network boundary conditions of the electrical network;

- Taking into account the control power determined at the network node by correspondingly reducing or increasing the maximum power that can be provided at this network node by the energy systems;

- Determining intended second services based on the reduced or increased maximum services that can be provided; and

- Control of the load flows according to the determined second services. The method according to the invention and/or one or more functions, features and/or steps of the method according to the invention and/or one of its configurations can be computer-aided. In particular, the optimization is carried out with the aid of a computer. For example, the optimization problem is solved numerically.

In the present case, the term power includes active power and/or reactive power.

From a structural perspective, the IPCC Fifth Assessment Report in particular defines an energy system as: "All components related to the production, conversion, supply and use of energy." The energy system is in particular a building, for example an office building and/or a residential building, an industrial plant, a campus, a district, a municipality and/or the like.

The energy system includes, in particular, power generators, energy storage devices, in particular battery storage devices, combined heat and power systems, in particular combined heat and power plants, gas boilers, diesel generators, electric boilers, heat pumps, compression refrigeration machines, absorption chillers, pumps, district heating networks, energy transfer lines, wind turbines or wind turbines, photovoltaic systems - Taik plants, biomass plants, biogas plants, waste incineration plants, industrial plants, conventional power plants and/or the like, as operating resources.

The energy systems are connected to the electrical grid, for example via a respective grid connection point. The energy systems can exchange energy or power within a time range via the electrical network. Here, generation can be distinguished from consumption by means of the sign of the power. In the present case, the provision of a service or energy is understood to mean energy generation and/or energy consumption, in which case energy is also Storage that feeds energy from the electrical network for charging and/or feeds energy into the electrical network when discharging are also included. In other words, a positive or negative power is provided in a time range, that is to say, in summary, a power is provided. The assignment of the sign of the power to energy generation (supply into the electrical network) and to energy consumption (extraction from the electrical network) depends on the meter system used.

With regard to the energy systems, the control device is a common or central device. It is designed to control the energy exchanges or load flows between the energy systems via the electrical network. In this case, no direct control is required. It is sufficient if the control device transmits control data intended for control to the respective energy systems. This control data is received, for example, by edge devices of the energy systems and converted into control signals for the energy systems of the respective energy system. However, direct control of the power engineering systems can be provided. As a result, the energy systems of the energy systems that feed energy or power into or out of the electrical network, and thus in this sense the load flows between the energy systems, are controlled by the central control device. For this purpose, the control device can thus be designed for data exchange with the energy systems.

The electrical network has a number of network nodes. A network node is assigned to the feed-in or feed-out of an energy system. In other words, the positive or negative power of an energy system is provided at a network node of the electrical network. From the services provided, it can be determined which power flows from a network node via a line to a further network node of the electrical network or is exchanged. In other words, this creates the load flows between the energy systems. The load flows between the energy systems are thus controlled by the (performance) control of the energy-technical installations or the energy systems.

In the present case, the terms power and energy are considered to be equivalent and interchangeable, since an energy is always associated with a power within a time range.

In a first step of the method according to the invention, the first powers provided for the load flows are determined based on data transmitted from the energy systems to the control device, which data includes information about a maximum power that can be provided by the respective energy system at the respective network node .

In other words, the control device calculates the first powers that could form the basis of the actual load flows between the energy systems. This can be seen as a first prediction or as a first simulation of the load flows. In other words, the control device calculates a first forecast for the load flows, ie for a future time range, for example for the next 15 minutes. In this case, the first prediction or the first simulation can calculate the load flows in such a way that the electrical network is not overloaded by the load flows. The first prediction is thus calculated using the information about the maximum amount of energy that the respective energy system can provide or intends to provide in the stated time range. In this case, providing can in turn be feeding in or feeding out with regard to the electrical network. The information about the respective maximum amount of energy that can be provided is provided from the energy systems, for example by respective edge devices and/or a control unit or regulating unit of the energy-related systems the control device transmits the actual power flows in advance.

The transmitted maximum power that can be provided can be viewed as predictions of the energy systems with regard to their operation. Thus, after this first step, it is not yet ensured that the capacity limits of the electrical network are sufficient to actually provide the service. A control power may therefore be required at the network nodes, which is determined and taken into account in the following steps according to the present invention.

In a second step of the method according to the invention, a control power that is internal and node-resolved with respect to the electrical network is determined based on the determined intended first powers and based on the provided network boundary conditions of the electrical network.

For this purpose, the network boundary conditions of the electrical network are provided, for example by a network operator of the electrical network. By determining the first powers, the control platform is symbolically known which load flow takes place between which network nodes. The electrotechnical boundary conditions for the power of the electrical grid are known from the grid boundary conditions provided, so that an overload of a line of the electrical grid can be determined by the control device from the first power provided and the grid boundary conditions. In other words, the control device knows which first power is to be exchanged via which line of the electrical network from which network node to which network node and which maximum power (network boundary conditions) the provided line has. Lines that may be overloaded or lines close to their load limit can be identified by comparing the maximum powers with the first powers provided. With this knowledge, the control device determines an internal control power (positive or negative) for each network node participating in the load flows, so that the electrical network is not overloaded by the load flows in one or more areas or is operated close to its load limit, for example at more than 80 percent. The grid boundary conditions include the specified respective load limits. This is done for each network node affected (and known) by the load flows, i.e. resolved for each network node.

In a third step of the method according to the invention, the control power determined at the network node is taken into account by a corresponding reduction or increase in the maximum power that can be provided at this network node by the energy systems.

For each participating or loaded network node, the control device knows the maximum power or amount of energy that can be provided at the respective network node by the respective energy system or its energy-related installations. In other words, it is known which energy system intends to provide which maximum energy/power for the load flows at which network node. Furthermore, it is known from one of the preceding steps of the method according to the invention which control power is required at the respective network node to comply with the network boundary conditions. According to the invention, provision is therefore made for the control power to be taken into account by subtracting this from the maximum powers of the energy systems that can be provided at the network node. Depending on the sign of the control power and the maximum power that can be provided, the maximum power that can be provided is reduced or increased. In other words, new powers that can be provided and that have been corrected with regard to the respective control power are determined as a result.

In a fourth step of the method according to the invention, provided second services are based on the reduced ed or increased maximum services that can be provided.

In other words, the first step of the method according to the invention is carried out again with the control power-corrected maximum power that can be provided. It is thus symbolically assumed that the energy systems would have transmitted the control power-corrected maximum power that could be provided to the control device. As a result, the load flows between the energy systems are determined as optimally as possible by the control device, taking into account the internally required control power. The determination or the calculation of the second services can in turn be viewed as a second prediction for the load flows or a second simulation of the load flows.

In a fifth step of the method according to the invention, the load flows are controlled according to the determined second powers.

For example, for this purpose the determined second powers in the sense of target values are transmitted by the control device to the respective energy systems. In other words, the information about the planned services (second services) for the load flows is transmitted to the respective energy systems in the form of data. These can be received by an edge device and/or a control unit of one or more energy systems of the respective energy system and converted into control signals of the corresponding energy systems of the energy system. The power engineering systems provide the power according to the determined second powers for the electrical network. This results in the load flows that are controlled according to the second services.

In this sense, the central control device with regard to the energy systems can control the load flows. An advantage of the method according to the invention is the dynamic combination of energy exchanges and the provision of reserve power. In this sense, the electrical network can thus be operated more independently of a network that is superordinate to the electrical network, since the reserve power required for operating the electrical network is provided within the network as far as possible. This is particularly advantageous in the case of volatile feeders or generators, for example for photovoltaics and/or wind power plants that are connected to the electrical grid.

Furthermore, the method according to the invention can be carried out dynamically, ie at intervals of one day, one hour, 15 minutes and/or 5 minutes. This is possible because the control device, by transmitting the respective maximum amount of energy that can be provided (or the information about it), knows when and in terms of network technology where which energy system intends to provide power, ie feed in or feed out.

The method according to the invention is dynamic in the sense that, in contrast to static methods, a fixed control power is not provided, but rather this is determined dynamically and as a function of the transmitted planned maximum amounts of energy/power for each network node. In other words, the control power is determined and taken into account adaptively, i.e. depending on the planned feed-in and feed-out for each network node.

The control device according to the invention for controlling load flows between several energy systems via an electrical network comprises a communication unit and a computing unit, the communication unit being designed to receive data that contains information about a maximum through the respective energy system at the respective network node - Include rideable power to receive. The control device according to the invention is characterized in that the arithmetic unit is designed for this - to determine the first services provided for the load flows based on the maximum services that can be provided at the respective network node;

- to determine an internal and node-resolved control power with regard to the electrical network based on the determined intended first powers and based on provided network boundary conditions of the electrical network;

- to take account of the control power determined at the network node by correspondingly reducing or increasing the maximum power that can be provided at this network node by the energy systems;

- intended second services based on the reduced or increased maximum services that can be provided; to investigate; and

- To control the load flows according to the determined second services.

Similar and equivalent advantages and configurations of the control device according to the invention result in relation to the method according to the invention.

According to an advantageous embodiment of the invention, an external control power provided for an electrical network which is higher in relation to the electrical network is additionally taken into account in accordance with the internal control power.

In other words, the electrical network as a whole can provide control power (positive or negative) for a higher-level network. This can also be done for each network node, so that one or more network nodes, possibly different, contribute to the external control reserve.

Furthermore, future requirements for electrical networks (known in Germany under the term Redispatch 2.0) are complied with by the method according to the invention. the The provision of control power (flexibility) from the electrical network for higher-level network levels or higher-level networks is ensured, while the use of flexibility and energy in the internal electrical network is also optimized, in this case by the control device.

In an advantageous development of the invention, the external control power and/or a network topology is transmitted to the control device by a control unit of the higher-level network.

In other words, the external control power and/or the network topology, which can include the electrical network and/or the network that is higher than this, is transmitted to the control device by the network operator of the higher-level network. Alternatively or additionally, the network topology of the electrical network can be transmitted to the control platform by the network operator of the electrical network. As a result, the network boundary conditions and the network nodes of the control platform are advantageously known.

According to a preferred embodiment of the invention, the first powers are determined by means of a first optimization method based on a first target function, taking into account the network boundary conditions, with the first powers being the variables of the first target function.

In other words, a first mathematical optimization is carried out to determine the first powers. Here, the first objective function, which quantifies a property to be optimized with regard to the load flows, is extremalized, ie minimized or maximized. The first services are the variables of the first target function, so that they are determined or their values are calculated by extremizing the first target function. The first objective function is extremalized taking into account the constraints. In the present case, the ancillary the optimization problem, the network boundary conditions are taken into account so that they are taken into account in the first optimization. In other words, the solution of the first optimization problem, which corresponds to the first performances, respects the constraints. The first target function can be the total energy conversion, the primary energy use, the total carbon dioxide emissions and/or the total costs with regard to the load flows.

In an advantageous development of the invention, a sequence of the energy systems is defined according to which sequence the reduction or increase in the power that can be provided at one of the network nodes takes place based on the first optimization.

In other words, the reserve power determined for this network node can typically be made available for a network node by a number of energy systems. In order to determine which energy system is to be used first or which energy systems are to be used at all for the balancing power, the contributions can be determined which energy system has to the result (value of the target function) of the optimization problem. If the target function is minimized, the energy system with the lowest contribution is used first for the control power, ie this is subtracted from the maximum amount of energy that can be provided by this system. The energy system with the next higher contribution is then used, so that a sequence of the energy systems that corresponds to the above sequence is formed until the required balancing power is completely covered. For example, the energy systems are arranged according to their specific carbon dioxide emissions. Furthermore, an arrangement (sequence) of the energy systems according to the specific fees (flexibility costs) associated with the provision of the control reserve is possible.

According to an advantageous embodiment of the invention, the second power is determined by means of a second operational Timing method based on a second objective function, taking into account the network boundary conditions, with the second services being the variables of the second objective function.

In other words, the second powers, like the first powers already preferred, are determined or calculated by means of an optimization. The optimizations can each be viewed as simulations or predictions or forecasts with regard to the load flows, since these each show the load flows and the associated first or second services for a future time period within which the load flows are then based on the second services actually take place, calculate. In other words, the optimization methods are also simulation methods. The difference between the first services (first optimization) and second services (second optimization) is that the second services take into account the network node-resolved control power within the meaning of the present invention. The explanations above about the first optimization can also be used for the second optimization. The first and second target functions are preferably the same. In other words, the first and second optimization methods are based on the same target functions. However, the secondary conditions are fundamentally different, since the secondary conditions of the second optimization include the maximum amounts of energy that can be provided, reduced or increased by the respective control power.

The secondary condition of the second optimization thus includes the maximum amounts of energy that can be provided, corrected for the control power. The constraint of the first optimization includes the maximum amounts of energy that can be made available transmitted from the energy systems.

In an advantageous development of the invention, the network boundary conditions include maximum line capacities for a a load flow from one network node to another network node.

This maximum power capacity (maximum power) or the information about the respective maximum power and/or connection capacity (maximum connection power) can be transmitted by the energy systems to the control platform and taken into account in the optimisations. Advantageously, the first and second services as solutions of the respective optimization thereby respect the technical boundary conditions, which are characterized by the maximum line or connection capacities.

According to an advantageous embodiment of the invention, the internal control power required at a network node is determined using a risk factor from the maximum power capacity.

The risk factor can also be described as the utilization factor of the respective service. As a result, it can advantageously be identified or determined when a line is considered to be loaded. For example, the risk factor is 80 percent of the maximum performance capacity. Depending on the load, more or less balancing power is required at the respective network node.

For example, more is to be fed in at a network node i than consumed. The network node i thus supplies the network node j (high consumption) via the line i→j. If this line were therefore close to its maximum power capacity (limit capacity), this can be counteracted according to the present invention by, for example, power being additionally fed in at network node j (control power) and/or the load being reduced. It is thus determined for which node there is a need for internal control services (requirement for flexibility). This can then be determined by the risk factor m mentioned, for example by P _k = μ P _{i,j,t, max} can be calculated, where P _{i,j,t, max} denotes the maximum power capacity of the line i → j. The risk factor can be defined by a network operator of the electrical network and transmitted to the control device, for example. The control power determined by the control device can also be transmitted to the grid operator.

In an advantageous development of the invention, the data transmitted to the control platform includes information about a maximum connected load of the respective energy systems.

As a result, the respective maximum connected load (connected capacity) of the energy systems can be taken into account in the optimizations by the control device. The information about the maximum connection lines can preferably be transmitted to the control device together with the information about the respective maximum amount of energy that can be provided.

According to an advantageous embodiment of the invention, the power that can be provided, which is reduced or increased according to the specific control power, is associated with consumption that can be shifted over time, generation that can be shifted over time, and/or with provision by an energy store of the respective energy system - ed.

As a result, it can advantageously be avoided that powers that cannot be shifted in time are used for the control power. If the respective energy systems transmit an identification of their respective intended maximum amount of energy that can be provided as being shiftable or not shiftable over time, the control device can preferably take into account the powers that can be shifted over time within the optimization for the provision of the control power. In other words, the energy Systems transmit information to the control device about power/energy quantities that can be shifted over time, for example within a respective time range. The powers that can be shifted over time are preferably taken into account for the provision of the reserve power.

In an advantageous development of the invention, the control device is used to control the load flows within a local energy market.

Advantageously, this allows control power to be taken into account within a local energy market. The control device according to the present invention and/or one of its configurations is particularly suitable for the operation of local energy markets, since this essentially allows for network-internal regulation of the electrical network by means of the control power determined and provided by the energy systems independent of a higher-level network. Within the framework of a local energy market, the energy systems can also transmit information about a specific fee (fee per kilowatt hour) for the intended maximum amount of energy that can be provided. Thus, in the context of a local energy market, the transmitted data can also be referred to or viewed as an offer or bid.

If the control device is used for a local energy market, the target functions are preferably the total costs associated with the load flows, which are formed from the first or second service (variables) and the respective associated fee.

The control device particularly preferably forms a local energy market platform. The control device can preferably be cloud-based. According to a preferred embodiment of the invention, the method according to the invention or the method according to an embodiment of the present invention is carried out for a coming day, in particular for the next day.

Particularly with regard to a local energy market, this advantageously enables day-ahead trading that takes reserve power into account.

In an advantageous development of the invention, the method according to the invention or the method according to an embodiment of the present invention is carried out repeatedly in time periods of one day, one hour, 15 minutes and/or 5 minutes.

Particularly with regard to a local energy market, this advantageously enables intra-day trading that takes reserve power into account.

Further advantages, features and details of the invention result from the exemplary embodiments described below and from the drawings. The following are shown schematically:

FIG. 1 shows an overview of an overall system on which the present invention or one of its configurations is based; and

FIG. 2 shows a flowchart of the method for controlling load flows according to an embodiment of the present invention.

Identical, equivalent or equivalent elements can be provided with the same reference symbols in one of the figures or in the figures. FIG. 1 shows a possible overall system in a schematic form, which can form the basis of a method according to an embodiment of the present invention.

The overall system shown comprises at least two energy systems 2, for example two buildings, a central control device 1 with respect to the energy systems 2 and a control unit 3 of an electrical network.

The energy systems 2 can exchange energy or power via the electrical network. These load flows are controlled between the energy systems 2 by the control device 1 . To this end, data or information can be exchanged between the energy systems 2 and the control device 1, between the control device 1 and the control unit 3 of the electrical network, and between the energy systems 2 and the control unit 3 of the electrical network. These data exchanges are symbolized in FIG. 1 by the respective arrows.

The energy systems 2 each include an edge device, which enables data exchange and thus communication with the control device 1 . Furthermore, the edge devices can be designed for communication with the control unit of the electrical network 4 and thus with the network operator.

The edge devices are designed to receive data relating to the control of energy systems 23 of the respective energy system from the control device 1 and to process them additionally. The edge devices 21 forward this received and optionally processed data to the control unit 22 of the respective power engineering installation 23 . As a result, the power engineering systems 23 are controlled in accordance with the data transmitted by the control device 1 to the edge devices 21 . Finally, since the energy systems 23 a power for the electrical network via the network connection point of the associated Provide energy system 2, the load flows between the energy systems 2 are thus controlled by the central control device 1. For example, the edge devices 23 are embodied as energy management devices. The edge devices 23 also form a communication interface to the control device 1 .

The control device 1 is particularly preferably designed as a local energy market platform. As part of a local energy market, offers or bids for the services/energy quantities that the respective energy system intends to contribute to one or more of the load flows are transmitted by the edge devices 23 to the local energy market platform 1 . To control the load flows, the control device 1 or the local energy market platform 1 thus collects the bids of all participating energy systems 2 symbolically. In this sense, the energy systems 2 can also be referred to as participants.

Furthermore, network boundary conditions and other requirements of the electrical network, for example its network topology and, with regard to the electrical network, external reserve power requirements (external flexibility requirements or requirements of higher-level networks or higher network levels) are transmitted by the control unit 3 to the control device 1 transmitted.

The energy systems 2 can include energy subsystems, which are then treated as energy systems within the meaning of the present invention or one of its configurations.

FIG. 2 shows a flow chart of a method according to an embodiment of the present invention.

In the following exemplary embodiment, the method or the control device 1 for controlling load flows between a plurality of energy systems 2 is included of a local energy market. In this case, the control device 1 can be designed as a local energy market platform.

The energy systems 2 form the participants in terms of a local energy market, ie they intend to participate in one of the load flows. The load flows are again exchanged via an electrical network to which the energy systems 2 are connected.

Furthermore, a control unit 3 of a network operator of the electrical network is involved in the method, so that the control unit can exchange data or information with the control device 1 and the energy systems 2 . The data exchanges or information exchanges are identified by the arrows 101, . . . , 105.

The method according to the present embodiments has at least five steps S1,...,S5. In the present case, steps S1, . . . , S5 are carried out by the control device 1. In other words, the control device 1 is designed to carry out the steps S1,...,S5.

In a step preceding the steps S1, . . . , S5, the energy systems 2 transmit information about their maximum amount of energy that can be provided [kWh] or power, information about an associated minimum or maximum fee [fee/kWh] and in addition, an associated maximum connected load to the control device 1. This can be done for a specified point in time or time range t. A maximum fee is transmitted for consumption and a minimum fee for generation. Furthermore, types of generation and consumption that can be shifted can be marked as shiftable or transmitted. In summary, this data/information transmitted to the control device 1 can be used as a bid or offer for the Participation of the respective energy system 2 can be viewed in one of the load flows.

In particular, three offers (flexibility offers) can be distinguished with regard to services that can be postponed.

A first flexibility offer is characterized by consumption that can be shifted over time for a time range. A maximum amount of energy to be obtained, a possibly time-dependent connected load and a maximum charge for the consumption are transmitted to the control device 1 in the form of data/information for the stated time range.

A second flexibility offer is characterized by a temporally shiftable generation for a time range. A maximum amount of energy to be generated, a possibly time-dependent connected load and a minimum payment for the generation are transmitted to the control device 1 in the form of data/information for the stated time range.

A third flexibility offer is characterized by the use of an energy store of one of the energy systems 2 for a time range. A maximum storage capacity, a maximum charging and minimum discharging capacity of the energy store (possibly time-dependent), a charging and discharging efficiency (possibly time-dependent) and a minimum fee for the use of the energy store are sent to the control device 1 transmitted in the form of data/information.

In summary, at least each participating energy system transmits a maximum amount of power/energy that can be provided to the control device 1 for a specified time range. In a first step S1 of the method, the first services provided by the control device 1 for the load flows are based on data/offers transmitted from the energy systems 2 to the control device 1, which provide information about a maximum that can be provided by the respective energy system 2 at the respective network node Include performance, determined. The transmission of the above data is marked with the 101 marker.

The intended first services are determined by means of a mathematical optimization. The optimization or the optimization problem is preferably based on a target function of the form whereby the first service (variable) to be determined for a planned transmitted consumption (English: bid) and an associated transmitted minimum fee, the first service (variable) to be determined for a planned transmitted consumption (English: Ask) and the associated maximum fee (English: discharge/charge; abbreviated dch/ch) the first performance (variable) for an intended and transmitted use of an energy storage device and an associated minimum de- applies to the use of the energy store, in particular a battery store. The power flowing through a line i→j is denoted by , where for this a fee (network fee) should also be provided for can.

In other words, they are the decision variables (variables) determined by the first optimization. The variables correspond to the intended first services of the subscriber k at the network node n at the time t or within the time period marked t. Furthermore, the present one with a generation associated performance is evaluated positively and a performance associated with consumption is evaluated negatively within the target function, with the present target function or its

value is minimized. This will make the variables or their values, which correspond to the first services, are determined.

Furthermore, the optimization problem has the following constraints: for all network nodes n and points in time t within a time range T.

Furthermore, the secondary conditions and used. correspond to this the maximum power that can be provided in each case transmitted from the energy systems 2 to the control device 1 or the maximum power that can be provided in each case within a time interval Δt. As a result, this transmitted data is taken into account in the optimization.

For energy storage (flexibility of the first kind) the additional constraint becomes used, this being shown without indices for network nodes and subscribers for reasons of clarity.

For shiftable loads (flexibility of the second kind for shiftable consumption or shiftable generation) are given by the constraint marked. For a line flow or load flow from a network node i to a further network node j of the electrical network, the network boundary conditions P _i,j = - P _j,i and P _i,j ≤

P _{i,j,t, max} required. In this case, P _i,j,t,max can be transmitted to the control device 1 by the energy systems 2 and/or by a network operator of the electrical network 4, for example by a control unit 3 of the electrical network 4, and/or be determined by a network model known to the control device 1 . The transmission of the network boundary conditions of the electrical network 4 by the control unit 3 of the electrical network 4 is symbolized by the arrow 102 .

In a second step S2 of the method, a control power that is internal to the electrical network and broken down into network nodes is determined based on the determined intended first powers and based on the provided network boundary conditions of the electrical network 4 .

In other words, the second step 2 determines the flexibility requirement of the electrical network 4 for the first powers provided for each of the network nodes. In other words, after the first step S1, by means of which the first services were calculated based on the transmitted data/bids, which power should flow via which line and which network node, so that knowledge of the network boundary conditions (maximum power capacity) tät) it is clear whether a line is overloaded by the planned load flow, which corresponds to the associated first service. A line can be marked as overloaded from as little as 80 percent of its maximum load.

In other words, within the second step S2 it is calculated which network nodes or which lines are expected to be operated close to their capacity limit. Since the result of the first optimization problem (first performances) is based on predictions of the individual energy systems 2 or subscribers (transmitted maximum amount of energy/power that can be made available), it is not certain whether the capacity limits are sufficient for the actual performance. Highly utilized lines, for example P _{i,j, t} ≥ α * P _{i,j,t, max} with 0 ≤ α ≤ 1, indicate an internal need for flexibility within the electrical network 4 network area under consideration. The internal flexibility requirement (control power) can be provided by the control device 1 and/or the control unit 3 of the electrical network 4, ie by the network operator.

Furthermore, a risk factor m can be provided for determining the control power or the flexibility requirement, ie this control power P _Flex,k is determined according to P _Flex,k =μ·P _i,j,t,max , for example with μ = 0.2.

In a third step S3 of the method, the control power determined at the network node is taken into account by a corresponding reduction or increase in the maximum power that can be provided by the energy systems 2 at this network node.

In other words, the maximum powers/energies that can be provided, which were transmitted from the energy systems 2 to the control device 1 and on which the first optimization problem was based, are corrected by the reserve power determined and required in the second step S3. A portion of the maximum power that can be provided by the energy systems 2 is therefore provided as reserve power. For example, an intended consumption at a network node is reduced and/or the feed provided at a network node is increased. This symbolically fictitious maximum available power, corrected for the control power, is then used for a second optimization.

In other words, instead of the transmitted maximum power that can be provided, which was used in the first optimization to determine the required control power, in the second optimization the required control power is Use corrected maximum power that can be provided.

The specific control power can be allocated to the energy systems 2 according to a defined and/or determined order 42 in the above-mentioned sense. In other words, it is determined which energy system 2 makes which contribution to a control power that is required and determined at a network node. This sequence is symbolized in the figure by the diagram of step S3, with, for example, the control reserve in kilowatt hours (kWh) on the abscissa of the diagram and the fees associated with the provision of the respective control reserve of energy systems 2nd on the ordinate are connected. In other words, the energy systems 2 can be arranged with regard to their charges for providing the control reserve or with regard to their carbon dioxide emissions for providing the control reserve (sequence 42). In the context of a local energy market, based on knowledge of the transmitted data, for example in the form of bids, the control device 1 of the local energy market can determine a network-node-specific or network-node-resolved payment function or carbon dioxide emission function for the provision of control power with the energy systems 2 or their associated energy systems being arranged in ascending order according to their fees or their carbon dioxide emissions for the provision of the control reserve or the flexibility requirement (sequence 42). The specific need for flexibility and, if applicable, the fee function or the carbon dioxide emission function can be transmitted from the control device 1 to the control unit 3 of the electrical network 4 . This is indicated by the arrow 103.

In a fourth step S4 of the method, provided second services are based on the reduced or increased maximum services that can be provided determined by the second optimization. Here, the same objective function is used for the first optimization. However, for the second optimization, the transmitted maximum power/energy quantities that can be provided are not or as a constraint of form used, but the available power/energy quantities corrected by the control reserve or · This increases the internal control reserve requirement taken into account in the second optimization. Furthermore, an external control power requirement of a network that is higher than the electrical network 4 can also be taken into account. The control unit 3 of the electrical network 4 can determine which internal and/or external control power requirement is actually taken into account. In particular, the external control power requirement is determined by the control unit 3 of the electrical network and is transmitted to the control device 1 for consideration. This is symbolized by the arrow 104.

In a fifth step S5 of the method, the load flows between the energy systems 2 or between the energy systems of the energy systems 2 are controlled according to the determined second powers. This ensures that the determined internal control reserve requirement and, if applicable, the external control reserve requirement are provided by the actual load flows, for example the next day (symbolized by the arrow 105). First of all, it can be checked which energy system is connected to which network node. It can then be determined whether the respective energy system is ready for use or available. Then the energy systems that are ready for use or available are prioritized according to the determined order 42 and controlled by local control units in such a way that they provide the power in the intended time range according to their associated and determined second power. If an error is detected within the procedure mentioned, the procedure if necessary, be repeated taking into account current measured values or the amounts of energy already provided (real-time optimization). As a result of the present method, within the framework of a local energy market, trading in electrical energy corrected by the technically required reserve capacity is made possible. Although the invention has been illustrated and described in detail by the preferred exemplary embodiments, the invention is not restricted by the disclosed examples, and other variations can be derived therefrom by a person skilled in the art without departing from the protective scope of the invention.

Reference List

1 control device

2 Power system 3 Control unit

4 electrical network

21 edge device

22 control unit

23 Appendix 42 sequence

101 arrow 102 arrow

103 arrow

104 arrow 105 arrow

S1 first step

S2 second step

S3 third step

S4 fourth step S5 fifth step

Claims

patent claims

1. A method for controlling load flows between a plurality of energy systems (2) via an electrical network (4) by means of a control device (1) that is common to the energy systems (2), with the energy systems (2) each having a load flow associated power can be provided at least at one network node of the electrical network (4), comprising at least the following steps:

- (S1) Determination of the first powers provided for the load flows based on data transmitted from the energy systems (2) to the control device (1), which includes information about a maximum power that can be provided by the respective energy system at the respective network node sen

- (S2) determining an internal and network node-resolved control power with regard to the electrical network (4) based on the determined intended first services and based on provided network boundary conditions of the electrical network (4);

- (S3) taking into account the control power determined at the network node by correspondingly reducing or increasing the maximum power that can be provided at this network node by the energy systems (2);

- (S4) determination of intended second services based on the reduced or increased maximum services that can be provided; and

- (S5) control of the load flows according to the determined second services.

2. The method as claimed in claim 1, characterized in that an external control power provided for an electrical network which is higher in relation to the electrical network (4) is additionally taken into account in accordance with the internal control power.

3. The method according to claim 2, characterized in that the external control power and / or a network topology a control unit (3) of the higher-level network is transmitted to the control device (1).

4. Method according to one of the preceding claims, characterized in that the determination of the first powers is carried out by means of a first optimization method based on a first target function taking into account the network boundary conditions, the first powers being the variables of the first target function are.

5. The method according to claim 4, characterized in that a sequence (42) of the energy systems (2) is defined based on the first optimization, according to which sequence the reduction or increase in the power that can be provided at one of the network nodes takes place.

6. The method as claimed in one of the preceding claims, characterized in that the second performance is determined using a second optimization method based on a second objective function, taking into account the network boundary conditions, the second performance being the variables of the second objective function are.

7. The method according to any one of the preceding claims, characterized in that the network boundary conditions include maximum line capacities for a load flow from one network node to another network node.

8. The method according to claim 7, characterized in that the internal control power required at a network node is determined using a risk factor from the maximum power capacity.

9. The method according to any one of the preceding claims, characterized in that the data include information about a maximum connected load of the respective energy systems (2).

10. The method according to any one of the preceding claims, charac- terized in that the services that can be provided, which are reduced or increased according to the specific control power, with consumption that can be shifted over time, generation that can be shifted over time and/or with provision by an energy store of the respective Energy system (2) are associated.

11. Method according to one of the preceding claims, characterized in that the control device (1) is used for controlling the load flows within a local energy market.

12. Method according to one of the preceding claims, characterized in that this is carried out for a coming day, in particular for the next day.

13. Method according to one of the preceding claims, characterized in that it is carried out repeatedly in time intervals of one day, one hour, 15 minutes and/or 5 minutes.

14. Control device (1) for controlling load flows between a plurality of energy systems (2) via an electrical network (4), comprising a communication unit and a computing unit, wherein the communication unit is designed to transmit data containing information about a through the respective - GE energy system (2) at the respective network node include maximum available power to receive, characterized in that the computing unit is designed to do so

- to determine the first services provided for the load flows based on the maximum services that can be provided at the respective network node;

- A control power internal to the electrical network (4) and broken down into network nodes based on the determined intended first services and based on the provided network boundary conditions of the electrical network

(4) to determine; - to take into account the control power determined at the network node by a corresponding reduction or increase in the maximum power that can be provided at this network node by the energy systems (2); - intended second services based on the reduced or increased maximum services that can be provided; to investigate; and

- To control the load flows according to the determined second services.

15. Control device (1) according to claim 14, characterized in that it is designed as a local energy market platform.