Method and device for determining a retrieval sequence of operating reserves from a plurality of installations for providing a total operating reserve
Patent Information
- Application Number
- EP2023734151
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-06-20
- Filing Date
- 2023-06-13
- Publication Date
- 2025-02-19
AI Technical Summary
The increasing proportion of volatile renewable energy sources and the loss of conventional power plants have made it challenging for decentralized energy producers and consumers to participate effectively in control power markets, particularly due to low output levels and complex coordination requirements for maintaining grid stability.
A method and device that utilize an aggregator unit to determine the retrieval sequence of control services from multiple small electrical systems connected to a power grid, where each system transmits registration and current performance data to ensure the sum of available control services meets the required total control power, allowing for efficient aggregation and trading on control power markets.
This approach enables better integration of decentralized producers and consumers into balancing power markets, effectively utilizing small systems to provide control power, tapping previously unused capacities, and ensuring grid stability by optimizing the retrieval order of control services.
Smart Images
Figure 1.1
Abstract
Description
[0001] Description
[0002] Method and device for determining a call-up sequence of control power from several plants to provide a total control power
[0003] The invention relates to a method according to the preamble of patent claim 1 and a device according to the preamble of patent claim 12.
[0004] To maintain system stability (grid frequency) within power grids, a constant balance between consumed and supplied power must be ensured. In order to respond to fluctuations in generation and consumption in real time, control power capacities are maintained that can be accessed at different speeds, for example, primary, secondary, and tertiary control, as well as minute reserve power. To date, control power has primarily been provided by large power plants, which can dynamically adjust their output according to specifications.
[0005] Due to an increasing proportion of volatile, difficult-to-predict feed-in of renewable energies, for example from photovoltaic systems and wind turbines, and the elimination of conventionally operated large power plants, for example nuclear power plants, coal-fired power plants and / or gas-fired power plants, the demand for control power is increasing, which must be provided by decentralized energy producers or consumers, in particular decentralized producers, for example heat pumps, electric vehicles and energy storage systems, to ensure grid stability.
[0006] When procuring control power on the market, transmission system operators put out to tender the required positive and negative control power (primary, secondary, tertiary). In Germany, the minimum bid size is one megawatt. This prevents decentralized producers / consumers from participating in established control power markets, as these typically have insufficient capacity. Participation is therefore only possible through aggregation by an aggregator.
[0007] Furthermore, strict prequalification procedures are required for participation in the control power market, particularly with regard to call-up time, response time, ramps, and setpoint jumps. At the time the control power is requested by the grid operator, the aggregator must ensure that the guaranteed capacity can be called up in compliance with the technical requirements. The assured call-up of flexibility (control power) by a large number of small plants (capacity less than 1 MW) therefore requires more complex coordination than the call-up of control power from a few large power plants.
[0008] The object of the present invention is to provide a method and a device for providing and coordinating control power by several small systems.
[0009] The object is achieved by a method having the features of independent patent claim 1 and by a device having the features of independent patent claim 12. Advantageous embodiments and further developments of the invention are specified in the dependent patent claims.
[0010] The method according to the invention for determining a retrieval sequence of control powers from several electrical Installations k that are connected to a power grid, by means of an aggregator unit, whereby for a specified period of time the aggregator unit receives a surcharge for providing a required total control power for the Power grid is characterized by the following steps:
[0011] - transmitting registration data to the aggregator unit by each of the installations k, wherein the respective registration data contains at least one availability A k,tof the respective plant k to provide an available control power as well as a respective minimum power draw;
[0012] - Transmission of a current performance to the aggregator gate unit through each of the systems k; and
[0013] - Determination of the call-up sequence of the plants k by the aggregator unit under the constraint that the sum of the respective available control powers is equal to the required total control power is, whereby each of the available control services by a difference between the respective current power and the respective minimum power tion is specified.
[0014] In principle, the power can be active power and / or reactive power. The active power of each system is preferably less than or equal to one megawatt (small-scale systems).
[0015] 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 embodiments can be computer-aided. For example, the method is carried out by the aggregator unit, which is designed as a computing device for carrying out the method.
[0016] The aggregator unit may include a processing unit for determining the call-off sequence. Furthermore, the aggregator unit aggregates the individual control powers of the plants into a common control power offer, which can be traded on control power markets. The aggregator unit receives a bid for a requested total control power, which is based on previous offers by the aggregator unit on the control power market.
[0017] The subject of the present invention is the call sequence that determines when which plant contributes to the provision of control power and thus to the required provision of the total control power. According to the present invention, an improved call sequence is provided in this regard.
[0018] In a first step of the process, each of the participating installations transmits respective registration data to the aggregator unit. The registration data includes at least information about availability A k,t of the respective plant k to provide an available control power as well as a respective minimum power •
[0019] This means that the aggregator unit knows symbolically which plant is generally available at which times, and what power (minimum power) is required for the operation of the plant. The respective powers and quantities are generally time-dependent and can, for example, be available as a time series within the specified time range. The registration data thus includes status information of the respective plant. In this case, the availability can be a basic availability
[0020] A k with values of zero and one and a planned availability A k,t , also with values of zero and one.
[0021] In a second step of the process, a current power is supplied to the aggregator unit by each of the plants. gen k is transmitted to the aggregator unit. In other words, the aggregator unit is informed about the current power generated or consumed by the respective system, i.e., the power fed into or fed out of the power grid. This is necessary because the difference between the current power and the minimum power can generally be used as available control power. The current power is recorded as a measured value or in the form of measurement data.
[0022] In a third step of the process, the call-up sequence of the plants is determined. The call-up sequence is determined under the constraint that the sum of the available control power of the individual plants equals the required total control power. This ensures that the control power (total control power) guaranteed on the control power market by the aggregator unit or the aggregator is delivered, i.e., is made available to the power grid or the power grid operator. Furthermore, this constraint ensures that not too much control power is provided, but that only as much flexibility of the plants is used as is necessary to cover the guaranteed control power demand.Here, the available control power of each plant is determined by the difference between the respective current power and the respective minimum power required for the operation of the plant. In other words, the flexibilities of the individual plants are used to provide the available control power. The determination of the call-up sequence is therefore carried out under technically advantageous constraints, namely that the required total control power is provided by the plant in aggregate and that the current flexibility of each plant is used for this purpose. The determination of the call-up sequence can be carried out using a mathematical optimization method based on a specified objective function. These constraints are then used as boundary conditions or constraints of the optimization. The optimization is typically carried out numerically, i.e., computer-aided.
[0023] This method enables the improved integration of decentralized producers / consumers into a control power market. Furthermore, the plants, especially small plants with a capacity of less than or equal to one megawatt, can be used to provide control power. Thus, electric vehicles, charging stations, heat pumps, and / or photovoltaic systems, in particular, can be used to provide control power via the aggregator unit. For each type of plant, a specific objective function or a specific term within an overall objective function can be used in the optimization described above.
[0024] Furthermore, a grid operator can use the collected data to determine at which nodes in the grid additional flexibility could or should be added.
[0025] The present invention thus makes it possible to tap into previously unused control power capacities within the power grid (distribution network). This compensates for lost control power capacities from large power plants.
[0026] The aggregator unit according to the invention for determining a retrieval sequence of control services of several electrical installations k that are connected to a power grid, whereby for a specified period of time the aggregator unit receives a surcharge for providing a required total control power for the power grid is characterized in that the aggregator unit is designed to:
[0027] - to receive and / or request registration data through each of the systems k, wherein the respective registration data contains at least one availability A k,t the respective plant k (102) to provide an available control power and a respective minimum performance mark;
[0028] - a current performance to receive and / or request from each of the facilities k; and
[0029] - the order of call-up of the plants k under the constraint that the sum of the respective available control powers is equal to the total control power required is to be determined, whereby each of the available control services by a difference in the respective current performance and the respective minimum power This results in advantages and / or configurations of the aggregator unit according to the invention that are equivalent and have the same effect as the method according to the invention.
[0030] According to an advantageous embodiment of the invention, •
[0031] In other words, the available control power of one of the plants k is determined by the difference between the current power (measured value) and the minimum power required for its operation. This advantageously ensures that the plant can continue to operate and still provide control power (available control power). The current power is preferably recorded as a measured value by a measuring unit.
[0032] In an advantageous development of the invention, the constraint is defined by , where μ k,t to are binary variables that determine whether the plant k is intended to provide its available control power at time t.
[0033] The binary variables μ k,tare determined when determining the retrieval order. These essentially determine the retrieval order. In other words, μ k,t a binary decision variable that defines the selection of plant k (operating resources) for providing load shedding. The transmitted basic availability and / or the transmitted current availability of the respective plants are determined using the factor A k,t taken into account. The constraint thus ensures that the sum of the individual available control powers results in the promised, assured, or required total control power.
[0034] According to a particularly advantageous embodiment of the invention, the systems k are designed as charging stations for electric vehicles, in particular electric cars. The method according to the invention is particularly suitable for integrating charging stations for electric vehicles into a control power market.
[0035] In an advantageous development of the invention, the registration data include a current state of charge SOC k,t of an electric vehicle at the respective charging station k.
[0036] This advantageously allows the charging status of each vehicle to be taken into account when determining the retrieval sequence. In particular, this can prevent electric vehicles with a low charging status from not being charged or from being charged only slightly, or from the battery charging status no longer being sufficient for the planned trip.
[0037] According to an advantageous embodiment of the invention, the retrieval sequence is determined by means of an optimization method, wherein the objective function is minimized.
[0038] An optimization method is a mathematical optimization in which an objective function is minimized or maximized.
[0039] By minimizing or maximizing, the values of the variables are determined in the best possible way, i.e., with respect to the objective function. In this case, μ k,t the variables of the objective function Z to be determined.
[0040] These establish or form the retrieval sequence, as this determines when which facility is used to provide control power. The objective function models the technically advantageous situation that charging stations with longer availability or whose electric vehicle has a higher state of charge are prioritized for the provision of control power, i.e., they are higher up in the resulting retrieval sequence. In other words, the objective function ensures that the charging stations are determined (symbolically drawn) whose state of charge of the electric vehicles connected to them for charging has the smallest deviation from the full state of charge (SOC k,t = 1).
[0041] Alternatively or in addition to the determination using the optimization method, a look-up table can be used. For example, vehicles with a low state of charge are assigned a low decision value EW1. Similarly, vehicles with only a small maximum throttleable power receive a small decision value EW2. The charging stations with very high decision values are then identified, with the decision value calculated, for example, as EW1 x EW2.
[0042] In an advantageous development of the invention, the objective function is extended by a safety summand.
[0043] In other words, the objective function preferably includes such a safety factor. This advantageously ensures that if a facility becomes unavailable in the time between the last calculation of the call sequence and the transmission of the call signal from the grid operator, for example, if a charging process has been terminated, another facility is included in the control power call.
[0044] According to an advantageous embodiment of the invention, the respective available control power is determined according to the tel retrieval sequence by a grid control unit of the power grid for control.
[0045] In other words, the total available control power of the plants is advantageously called up for grid control by the grid operator or a grid control unit of the power grid according to the determined call-up sequence. The plants thus provide their available control power by feeding in or feeding out at the time determined according to the call-up sequence. For this purpose, the grid control unit can preferably transmit a corresponding call-up signal to the respective plants k and / or to the respective control units, which convert the call-up signal into setpoints for the respective plant k.
[0046] This advantageously ensures that the basic control of the power grid continues to be carried out by the grid control unit. The request signal from the grid control unit can be converted into setpoints or target signals for the respective systems by the respective control units (edge devices).
[0047] In an advantageous further development of the invention, the total control power is allocated through a control power market.
[0048] In other words, the aggregator unit is advantageously integrated into a control power market.
[0049] According to an advantageous embodiment of the invention, the determination of the retrieval sequence is repeated according to specified time ranges.
[0050] In other words, the process repeats itself according to specified time ranges, so that, for example, a retrieval sequence is determined again for every day, for every hour or for every 15 minutes.
[0051] Further advantages, features, and details of the invention will become apparent from the exemplary embodiments described below and from the drawing. The figure shows a schematic sequence of a method according to one embodiment of the present invention.
[0052] Similar, equivalent, or equivalently functioning elements may be provided with the same reference numerals in the figure. The figure shows a schematic method according to an embodiment of the present invention. A temporal progression of the method is sketched along the ordinate. The respective integrated units / systems / devices are plotted along the abscissa.
[0053] A respective event and / or trigger is identified by the reference number 101.
[0054] The figure shows systems 102 connected to a common power grid. The systems 102 can feed energy into and / or out of the power grid. In particular, the systems 102 are designed as charging stations for electric vehicles.
[0055] The figure also shows control units 103 (edge devices) of the respective systems 102. The control units 103 are designed to control their associated system 102. A respective agent unit 104 can configure the connection of the respective system 102 to an aggregator unit 105. In this case, the respective agent unit 104 transmits registration data, for example, status information of the systems, to the aggregator unit 105.
[0056] Furthermore, the figure shows a control power market 105 and a grid control unit 107 of a grid operator of the electricity grid.
[0057] The overall process shown is divided by the dashed line into a trading phase and a real-time phase. The subject of the present invention is the real-time phase, i.e., the technical implementation of the contracts negotiated during the trading phase for the provision of control power on the control power market 106.
[0058] During the trading phase, the grid operator tenders a specific amount of control power (reference numeral 10). The aggregation unit 105 submits a specific bid to the control power market 106 (reference numeral 10'). Based on this bid, the control power market determines a market result, which is transmitted to the aggregation unit 105. This award of the total control power required by the aggregation unit 105 is identified by the reference numeral 200. The trading phase, which precedes the real-time phase, thus determines the control power required by the aggregation unit 105.
[0059] In the real-time phase, the required total control power must be provided by the aggregation unit 105. For this purpose, the aggregation unit 105 uses the systems 102, which ultimately provide the total control power for the aggregation unit 105. Which of the systems 102 provides which control power at which time is determined by a call-up sequence. According to the invention, the call-up sequence is determined by the aggregation unit 105.
[0060] To determine the retrieval sequence, registration data and measurement data are transmitted from the systems 102 to the aggregation unit 105 in a first step. The transmission of the registration data is identified by the reference numeral 201.
[0061] The transmission of the measurement data, in particular the current performance of the systems 102, takes place according to a second step and is identified by the reference number 202.
[0062] In a third step, the aggregation unit 105 determines or calculates the retrieval sequence according to the present invention and / or one of its embodiments (reference numeral 12). This determines which of the systems 102 provides which power at which time to provide the required total control power.
[0063] The actual retrieval of the total control power available according to the determined retrieval sequence is carried out by a retrieval signal from the grid control unit 107, which it transmits to the aggregation unit 105. The retrieval signal is identified by reference numeral 204, and the retrieval of the control power by reference numeral 14.
[0064] Based on the call signal 204, the aggregation unit 105 transmits a corresponding call signal 204 to the respective control units 103. The control units 103 convert the respective call signal 104 into setpoints for the regulation / control of the respective systems 102. The setpoints are transmitted to the systems 102 (reference numeral 205). Based on the transmitted setpoints, the actual service provision then takes place according to the determined call sequence. The service provision is identified by reference numeral 15.
[0065] During or after the power provision 15, the systems 102 transmit measurement data regarding their power to the aggregator unit 105 and to the grid control unit 107. This is again identified by the reference numeral 201. Based on the measurement data or power data transmitted to the grid control unit 107, the latter can perform a validation 17. This advantageously ensures that the required total control power has been provided and, in addition, it can be determined which of the systems 102 has provided which actual contribution.
[0066] The method mentioned can be repeated, as indicated by the circular arrow, cyclically with a fixed sampling rate and / or event-based, for example by an electric vehicle arriving at one of the charging stations 102.
[0067] Although the invention has been illustrated and described in detail by the preferred embodiments, the invention is not limited by the disclosed examples, and other variations may be derived therefrom by those skilled in the art without departing from the scope of the invention.
[0068] 10 Tender for control power requirements
[0069] 10' bidding
[0070] 11 Registration
[0071] 12 Determination of the retrieval sequence
[0072] 13 Activation of control power
[0073] 14 Calling up the control power
[0074] 15 Provision of services
[0075] 16 End of service provision
[0076] 17 Validation
[0077] 101 Event / Trigger
[0078] 102 Appendix
[0079] 103 Control unit
[0080] 104 Agent Unit
[0081] 105 Aggregator unit
[0082] 106 Control power market
[0083] 107 Grid control unit
[0084] 200 surcharge
[0085] 201 Transmission of registration data
[0086] 202 Transmission of measurement data
[0087] 204 Retrieval signal
[0088] 205 Transmission of target values
Claims
Patent claims 1. Method for determining (12) a call-up sequence for control services from several electrical installations k (102), which are connected to a power grid, by means of an aggregator unit (105), wherein for a specified time range the aggregator unit (105) adds a surcharge (200) for providing a required total control power for the power grid, characterized by the steps: - Transmission (11, 201) of registration data to the aggregate unit (105) by each of the systems k (102), wherein the respective registration data includes at least one availability A k,t the respective plant k (102) for the provision of available control power as well as a respective minimum Performance mark; - Transmit (11, 202) a current performance to the aggregator unit (105) by each of the plants k (102); and - Determining (12) the call-up sequence of the systems k (102) by the aggregator unit (105) subject to the constraint that the sum of the respective available control powers equal to the required total control power iisstt,, whereby each of the available standard services through a difference between the respective current performance and the respective A minimum performance level is specified.
2. Method according to claim 1, characterized in that it is.
3. Method according to claim 1 or 2, characterized in that the constraint is determined by is, where μ k,t The binary variables to be determined each define whether the plant k (102) is ready to provide its available control power at time t. is to see.
4. Method according to one of the preceding claims, characterized in that the systems k (102) are designed as charging stations for electric vehicles.
5. Method according to claim 4, characterized in that the registration data includes a current state of charge (SOC). k,t include the charging of an electric vehicle at the respective charging station k.
6. Method according to claim 5, characterized in that the retrieval sequence is determined by means of an optimization method, wherein the target function is minimized in the optimization method.
7. Method according to claim 6, characterized in that the objective function is extended by a safety summand.
8. Method according to one of the preceding claims, characterized in that the respective available control power is determined according to the determined call-off sequence by a- a network control unit (107) of the power grid is called upon for control (14, 204, 205).
9. Method according to claim 8, characterized in that the network control unit (107) receives a corresponding call signal (204) to the respective systems k (102) and / or to the respective control units (103) which convert the call signal (204) into setpoints (205) for the respective system k (102), transmitted.
10. Method according to one of the preceding claims, characterized in that the surcharge (200) of the total regular power is made by a regular power market (106).
11. Method according to one of the preceding claims, characterized in that the determination (12) of the run-off sequence is repeated according to specified time intervals.
12. Aggregator unit (105) for determining (12) a call-up sequence of control power from several electrical installations k (102) connected to a power grid, wherein for a defined time period the aggregator unit (105) applies a surcharge (200) for providing a required total control power for the power grid, characterized in that the aggregator unit (105) is designed to: - To receive and / or request registration data through each of the facilities k (102) (11, 201), wherein the respective registration data includes at least one availability A k,t the respective plant k (102) for the provision of available control power as well as a respective minimum power mark; - a current power output of each of the plants k (102) to receive and / or request; and - the call-up sequence of the systems k under the constraint that the sum of the respective available control powers equals the required total control power is to be determined (12), wherein each of the available control powers is determined by a difference between the respective current power and the respective minimum power. determined is.