Computer-implemented method for controlling a plurality of sites of a distributed energy storage system
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2026-01-22
- Publication Date
- 2026-08-13
Smart Images
Figure FI2026050025_13082026_PF_FP_ABST
Abstract
Description
COMPUTER- IMPLEMENTED METHOD FOR CONTROLLING A PLURALITY OF SITES OF A DISTRIBUTED ENERGY STORAGE SYSTEMTECHNICAL FIELD
[0001] The present disclosure relates to distributed energy storage systems, and more particularly to a computer-implemented method for managing a plurality of sites of a distributed energy storage system, a computing device, a distributed energy storage system, and a computer program product .BACKGROUND
[0002] A distributed energy storage (DES) system can comprise a plurality of sites and each site can comprise at least one battery unit . The DES system can be used for, for example, participating in power grid frequency balancing. For example, when working in national frequency reserve markets, the market operator can require each participant to deliver a selected amount of frequency balancing capacity for the market during the time of resource activation. Further, the maker operator can require the participants to monitor various information about the DES system.SUMMARY
[0003] This summary is provided to introduce a selection of concepts in a simplified form that are furtherdescribed below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subj ect matter, nor is it intended to be used to limit the scope of the claimed subj ect matter .
[0004] It is an obj ective to provide a computer-implemented method for managing a plurality of sites of a distributed energy storage system, a computing device, a distributed energy storage system, and a computer program product . The foregoing and other obj ectives are achieved by the features of the independent claims . Further implementation forms are apparent from the dependent claims, the description and the figures .
[0005] According to a first aspect, a computer-implemented method for controlling a plurality of sites of a distributed energy storage system, the method comprising : obtaining samples from the plurality of sites according to a first sampling rate, wherein the samples comprise at least a delivered power grid frequency balancing capacity of each site in the plurality of sites; and in response to obtaining a signal for activating fast-response power grid frequency balancing for a first subset of sites in the plurality of sites : applying a second sampling rate for the first subset of sites, wherein the second sampling rate is higher than the first sampling rate; participating in the fast-response power grid frequency balancing using the first subset of sites; and obtaining samples from the first subsetof sites according to the second sampling rate during the fast-response power grid frequency balancing.
[0006] In an implementation form of the first aspect, the method further comprises, in response to obtaining a signal for deactivating the fast-response power grid frequency balancing for the first subset of sites, applying the first sampling rate for the first subset of sites and obtaining samples from the first subset of sites according to the first sampling rate .
[0007] In another implementation form of the first aspect, the method further comprises, in response to a site being removed from the first subset of sites during the fast-response power grid frequency balancing, applying the first sampling rate to the removed site and obtaining samples from the removed site according to the first sampling rate .
[0008] In another implementation form of the first aspect, the method further comprises obtaining samples from sites not in the first subset of sites according to the first sampling rate during the fast-response power grid frequency balancing.
[0009] In another implementation form of the first aspect, the first sampling rate is lower than once every ten seconds and the second sampling rate is higher than once every ten seconds .
[0010] In another implementation form of the first aspect, the method further comprises obtaining interpolated samples by interpolating the samples obtained fromthe first subset of sites according to the second sampling rate .
[0011] In another implementation form of the first aspect, the method further comprises, before the obtaining the signal for activating the fast-response power grid frequency balancing for the first subset of sites, reserving the first subset of sites for the fastresponse power grid frequency balancing.
[0012] In another implementation form of the first aspect, the obtaining the signal for activating the fast-response power grid frequency balancing for the first subset of sites comprises : performing power grid frequency measurements; and determining, based on the power grid frequency measurements, that the fast-response power grid frequency balancing for the first subset of sites should be activated.
[0013] In another implementation form of the first aspect, method further comprises : obtaining a signal for activating a slow-response power grid frequency balancing for a second subset of sites in the plurality of sites; and obtaining samples from the second subset of sites according to the first sampling rate during the slow-response power grid frequency balancing.
[0014] In another implementation form of the first aspect, the obtaining the signal for activating the slow-response power grid frequency balancing for the second subset of sites comprises receiving a slow-response power grid frequency balancing activation signal from a transmission system operator of the power grid.
[0015] According to a second aspect, a computing device comprises at least one processor and at least one memory including computer program code, the at least one memory and the computer program code being configured to, with the at least one processor, cause the computing device to perform the method according to the first aspect .
[0016] According to a third aspect, a distributed energy storage system comprises the computing device according the second aspect and a plurality of sites coupled to a power grid.
[0017] In an implementation form of the third aspect, at least one site in the plurality of sites comprises a component comprising a register, wherein a sampling rate of the register is lower than the second sampling rate and the site is configured to : sequentially obtain a data series from the register; interpolate the sequentially obtained data series, thus obtaining an interpolated data series; and transmit at least a part of the interpolated data series in a sample .
[0018] According to a fourth aspect, a computer program product comprises program code configured to perform the method according to the first aspect when the computer program product is executed on a computer .
[0019] Many of the attendant features will be more readily appreciated as they become better understood by reference to the following detailed description considered in connection with the accompanying drawings .DESCRIPTION OF THE DRAWINGS
[0020] In the following, example embodiments are described in more detail with reference to the attached figures and drawings, in which:
[0021] Fig. 1 illustrates a flow chart representation of a method according to an embodiment;
[0022] Fig. 2 illustrates a schematic representation of a site according to an embodiment;
[0023] Fig. 3 illustrates a schematic representation of a site according to another embodiment;
[0024] Fig. 4 illustrates a schematic representation of a plurality of sites according to an embodiment;
[0025] Fig. 5 illustrates a schematic representation of samples according to an embodiment;
[0026] Fig. 6 illustrates a schematic representation of samples according to another embodiment;
[0027] Fig. 7 illustrates a schematic representation of a computing device according to an embodiment;
[0028] Fig. 8 illustrates a schematic representation of a distributed energy storage system according to an embodiment ;
[0029] Fig. 9 illustrates a signalling diagram according to an embodiment; and
[0030] Fig. 10 illustrates a schematic representation of a data log according to an embodiment .
[0031] In the following, like reference numerals are used to designate like parts in the accompanying drawings .DETAILED DESCRIPTION
[0032] In the following description, reference is made to the accompanying drawings, which form part of the disclosure, and in which are shown, by way of illustration, specific aspects in which the present disclosure may be placed. It is understood that other aspects may be utilised, and structural or logical changes may be made without departing from the scope of the present disclosure . The following detailed description, therefore, is not to be taken in a limiting sense, as the scope of the present disclosure is defined by the appended claims .
[0033] For instance, it is understood that a disclosure in connection with a described method may also hold true for a corresponding device or system configured to perform the method and vice versa. For example, if a specific method step is described, a corresponding device may include a unit to perform the described method step, even if such unit is not explicitly described or illustrated in the figures . On the other hand, for example, if a specific apparatus is described based on functional units, a corresponding method may include a step performing the described functionality, even if such step is not explicitly described or illustrated in the figures . Further, it is understood that the features of the various example aspects described herein may be combined with each other, unless specifically noted otherwise .
[0034] Fig. 1 illustrates a flow chart representation of a method according to an embodiment .
[0035] According to an embodiment, a computer-implemented method 100 for controlling a plurality of sites of a distributed energy storage system comprises obtaining 101 samples from the plurality of sites according to a first sampling rate, wherein the samples comprise at least a delivered power grid frequency balancing capacity of each site in the plurality of sites .
[0036] Herein, the delivered power grid frequency balancing capacity of each site may comprise the amount of power, in for example kilowatts, the site is providing to the power grid or consuming from the power grid for power grid frequency balancing. Each sample may comprise the delivered power grid frequency balancing capacity during a time interval corresponding to the sample, such as between the sample and a previous sample .
[0037] Herein, a site may also be referred to as a physical site, a node, a unit, a distributed energy resource, an asset, a battery site, or similar .
[0038] For example, each site or at least some of the sites may be embodied in a base station of a telecommunication network.
[0039] The distributed energy storage (DES) system may also be referred to as a virtual power plant (VPP) , a virtual power plant system, or similar .
[0040] The samples obtained from sites may further comprise activated up / down frequency balancing capacity, maintained up / down frequency balancing capacity,and / or a power baseline . Activated power may refer to how much physical power goes in or out from the site to the power grid. Maintained capacity may refer to how much power can be provided to the power grid at each time stamp . For example, less power may be activated than what can be provided. Power baseline may refer to the zero point of the power . For example, in residential buildings, there can be a basic power consumption and this power consumption can be considered as the zero point . When power is activated for power grid frequency balancing, it may be in relation to this zero point .
[0041] Any quantities in the samples can be obtained by the site by, for example, measuring power consumption of various components of the site, measuring electrical current flowing to / from a battery of the site, and / or measuring electrical currents at various measurement points in the site .
[0042] The method 100 may further comprise, in response to obtaining a signal for activating fast-response power grid frequency balancing for a first subset of sites in the plurality of sites : applying 102 a second sampling rate for the first subset of sites, wherein the second sampling rate is higher than the first sampling rate .
[0043] The fast-response power grid frequency balancing may also be referred to as a first power grid frequency balancing use case, a first power grid frequency balancing mechanism, a first power grid frequency balancing service, or similar .
[0044] The applying 102 the second sampling rate for the first subset of sites may comprise, for example, transmitting instructions to the first subset of sites instructing the first subset of sites to transmit samples according to the second sampling rate .
[0045] In some embodiments, the signal for activating the fast-response power grid frequency balancing can cause an event in the DES system that triggers the start of the fast monitoring . After the event, the fast monitor samples can be obtained from the sites participating in the fast-response power grid frequency balancing at a fast rate . When the fast-response power grid frequency balancing is no longer active, another event can cause the fast monitoring to terminate .
[0046] The method 100 may further comprise participating 103 in the fast-response power grid frequency balancing using the first subset of sites .
[0047] For example, the participating 103 in the fastresponse power grid frequency balancing using the first subset of sites may comprise performing fast-response power grid frequency balancing using the first subset of sites .
[0048] The method 100 may further comprise obtaining 104 samples from the first subset of sites according to the second sampling rate during the fast-response power grid frequency balancing.
[0049] For example, after instructions have been transmitted to the first subset of sites instructing the first subset of sites to transmit samples according tothe second sampling rate, the first subset of sites can be configured to transmit samples according to the second sampling rate . For example, a request can be transmitted to the first subset of sites instructing the first subset of sites to transmit samples according to the second sampling rate and the first subset of sites can respond to the request with samples .
[0050] According to an embodiment, the method 100 further comprises, in response to obtaining a signal for deactivating the fast-response power grid frequency balancing for the first subset of sites, applying the first sampling rate for the first subset of sites and obtaining samples from the first subset of sites according to the first sampling rate .
[0051] For example, when the fast-response power grid frequency balancing is no longer needed, the first sampling rate can be applied for the first subset of sites and samples can be obtained from the first subset of sites according to the first sampling rate .
[0052] The applying the first sampling rate for the first subset of sites may comprise, for example, transmitting instructions to the first subset of sites instructing the first subset of sites to transmit samples according to the first sampling rate .
[0053] In other embodiments, the applying the first sampling rate for the first subset of sites may comprise, for example, transmitting requests for samples to the first subset of sites according to the firstsampling rate . Each site in the first subset of sites can respond to each request with a sample .
[0054] Similarly, in some embodiments, the applying the first / second sampling rate for the first / second subset of sites may comprise, for example, transmitting requests for samples to the first / second subset of sites according to the first / second sampling rate . Each site in the first / second subset of sites can respond to each request with a sample .
[0055] Herein, power grid frequency balancing may comprise up regulation and / or down regulation. Up regulation can comprise a site feeding power to the power grid by, for example, increasing power production of the site and / or decreasing power consumption of the site . Alternatively, the site can be taken off the power grid so that the site does not consume power from the power grid. Down regulation can comprise a site taking power from the power grid by, for example, decreasing power production of the site and / or increasing power consumption of the site . For example, power production can be increased in relation to a power baseline and / or power consumption can be increased in relation to a power baseline .
[0056] Frequency balancing of a power grid may be arranged for example using automatic Frequency Restoration Reserve (aFRR) capacity market . aFRR is a centralized automatically activated reserve . Its activation is based on a power change signal calculated on the base of the frequency deviation in a synchronized area, such as theNordic synchronized area . Its purpose is to return the frequency of the power grid to the nominal value .
[0057] There is also a new energy market, Picasso, where the activation signal in the aFRR market is based on energy bids, not capacity bids . Capacity bids are used as an incentive to bid energy because once a participant bids capacity they should bid the same amount also in energy. It is also possible to bid more energy than capacity, but not the other way around.
[0058] Frequency balancing of electric grid may also be arranged using, for example, Frequency Containment Reserve for Normal Operation (FCR-N) or Frequency Containment Reserve for Disturbances (FCR-D) that are active power reserves that are automatically controlled based on the frequency deviation. Their purpose is to contain the frequency during normal operation and disturbances . FCR is an active power reserve that is automatically controlled based on the frequency deviation. FCR may be Frequency Containment Reserve for Normal Operation, FCR-N, or Frequency Containment Reserve for Disturbances, FCR-D. Their purpose is to contain the frequency during normal operation and disturbances .
[0059] The fast-response power grid frequency balancing may comprise, for example, FCR-D.
[0060] A balancing service may refer to, for example, FCR-D, FCR-N, fast frequency reserve (FFR) , or any other service the DES system can participate in to perform power grid frequency balancing.
[0061] DES systems may need to monitor their delivered power grid frequency balancing capacity periodically in order to, for example, report the delivered capacity to the transmission system operator (TSO) . With many sites, the amount of data used for such monitoring can grow very large as it increases linearly with the number of sites in the DES system.
[0062] Fast-response power grid frequency balancing services, such as FCR-D, can require a fast sampling rate, such as in the low seconds . This can mean that if every site was sampled every second, there could be an unmanageable amount of data .
[0063] Different power grid frequency balancing services like aFRR and FCR-D can require different sampling rates for telemetry feedback to the TSO. For example, aFRR can require a sampling rate of once per minute and FCR-D can require a sampling rate of once per second. However, as FCR-D may be activated rarely, such as once a month for 15 minutes, it can be unnecessary to sample the delivered capacity at a rate of once a second for the rest of that time period when the fast-response power grid frequency balancing is not activated.
[0064] The method 100 can enable dynamic altering of the sampling rate of the sites of the DES system according to the activation of fast-response power grid frequency balancing. This can, for example, reduce the amount of data that needs to be transmitted between the sites and, for example, a central controller and / or reduce the amount of data that needs to be stored.
[0065] It should be appreciated that at least some of the operations of the method 100 may be performed in various orders . For example, operations 102 and 103 may be performed in different order and / or at least partially in parallel . For example, due to the requirements of the fast-response power grid frequency balancing, it may not be possible to wait operation 102 to be finished before performing operation 103.
[0066] Fig. 2 illustrates a schematic representation of a site according to an embodiment .
[0067] Each site 200 can comprise at least one power source 201. The power source 201 can be, for example, electrically coupled to the power grid. For example, the at least one power source 201 may comprise a rectifier . Alternatively or additionally, the power source 201 may comprise some other type of power source, such as at least one renewable energy power source . For example, the power source 201 may comprise at least one solar panel, at least one wind turbine, and / or similar .
[0068] In some embodiments, each site 200 in the plurality of sites may comprise at least one battery unit 203 and a rectifier for charging the at least one battery unit 203 using power from the power grid and / or each site 200 in the plurality of sites comprises an inverter 206 for feeding power to the power grid from the at least one battery unit 203. For example, if the site 200 comprises a direct current (DC) system, such as in the embodiment of Fig. 2, the at least one power source 201 can comprise at least one rectifier for converting thealternating current (AC) to DC compatible with the site 200. For example, the at least one rectifier can convert 230-volt AC to 48-volt DC . In other embodiments, the at least one battery unit 203 may use have higher voltages, such as 350 - 800V, and the rectifier can be used to step up the voltage from the power grid. The at least one power source 201 can be used to drive a site load 202. The at least one power source 201 can also be used to provide power to the at least one battery unit 203.
[0069] In other embodiments, the at least one battery unit 203 may comprise alternatively or additionally, for example, a capacitor, a supercapacitor, and / or similar .
[0070] According to an embodiment, the at least one battery unit comprises at least one battery and / or at least one supercapacitor .
[0071] For example, in the embodiment of Fig . 2, the at least one battery unit 203 comprises a main battery 204 and a secondary battery 205. The secondary battery 205 can be connected, for example, in parallel with the main battery 204 for bi-directional charging. However, the secondary battery 205 and the main battery 204 may not be connected electrically parallel in the traditional sense . Rather, the secondary battery 205 may have its own DC-DC converter and the current between the batteries may be AC . When the secondary battery 205 is connected, it can provide additional current to the site 200 on demand to meet the site load 202 or inverter 206 requirements .
[0072] The rectifier can be "partly" used if the terminal voltage of the rectifier is set slightly lower than the battery voltage . In such a configuration, some current is drawn to the site load 202 from the rectifier and some from the at least one battery unit 203.
[0073] In sites operating on AC, the rectifier may be replaced with another type of component and the site load 202 can operate using AC . However, the at least one battery unit 203 typically operates using DC and the inverter 206 can be used between the at least one battery unit 203 and the site load 202. Other components, such as DC-DC converters may also be utilized.
[0074] The at least one battery unit 203 can be used to drive the site load 202 when being controlled to, and to receive charge from the power source 201 during recharge periods .
[0075] The site load 202 can comprise, for example, various equipment consuming power, the type of the equipment can be essentially anything consuming electricity. If the power source 201 is partly pushing current to the site load 202, the frequency balancing capacity for up regulation of the site 200 may not be equal to its power consumption but less .
[0076] For example, the site 200 may be embodied in a base station of a telecommunication network. The telecommunication equipment may consume power in order to provide telecommunication services via the base station. The at least one battery unit 203 can be used for powerredundancy and / or load shifting of the base station in addition to power grid frequency balancing.
[0077] The site 200 can further comprise at least one inverter 206 that can be electrically coupled to the at least one battery unit 203 and to the power grid. The at least one inverter 206 can be used to feed electricity back to the power grid from the at least one battery unit 203.
[0078] According to an embodiment, at least one site in the plurality of sites 200 comprises a component comprising a register, wherein a sampling rate of the register is lower than the second sampling rate and the site is configured to : sequentially obtain a data series from the register; interpolate the sequentially obtained data series, thus obtaining an interpolated data series; and transmit at least a part of the interpolated data series in a sample .
[0079] In some embodiments, at least one site in the plurality of sites 200 may comprise at least one component comprising at least one fast register, wherein a sampling rate of the at least one fast register is higher than or equal to the second sampling rate and the site is configured to : sequentially obtain at least one data series from the at least one fast register; and transmit at least a part of the at least one data series in a s amp 1 e .
[0080] Herein, a register may refer to any data storage of a component comprising data indicating an operational parameter value of the component . For example,a register of an inverter may comprise the active power of the inverter .
[0081] In some embodiments, it may not be possible for the site 200 to obtain information from components of the site 200 according to the second sampling rate . This may be due to, for example, the implementation details of the hardware of the components . Further, some components can comprise fast registers and / or slow registers that can be read at different intervals . For example, one inverter can comprise a register indicating the active power of the inverter that can be read at one second intervals . Another inverter may further comprise slow registers indicating, for example, solar power and / or site power consumption that can be read only at four second intervals . If the second sampling rate is higher than once every four seconds, the site 200 may be able to transmit data from the fast registers in the samples but the slow registers cannot be read often enough for the second sampling rate . In such cases, the site 200 may perform interpolation on data obtained from the slow registers .
[0082] For example, if the second sampling rate is once per second and a slow register of an inverter can be read once every four seconds, the data series may comprise at least two samples sequentially obtained from the registered. The site can interpolate three samples between each two samples sequentially obtained from the registered. The site 200 can then transmit a data point from the interpolated data series each second.
[0083] Fig. 3 illustrates a schematic representation of a site according to another embodiment .
[0084] Any disclosure in relation to the embodiment of Fig. 2 may also apply to the embodiment of Fig. 3.
[0085] The embodiment of Fig. 3 may represent, for example, a site implemented in a residential building. In such embodiments, the power source 201 , such as the power grid can be used to charge the at least one battery unit 203 via a rectifier and power can be fed to the power grid from the at least one battery unit 203 via an inverter . The site load 202 can be powered via power from the power source 201, such as the power grid.
[0086] Fig. 4 illustrates a schematic representation of a plurality of sites according to an embodiment .
[0087] The embodiment of Fig. 4 illustrates a plurality of sites 300 with two subsets of sites, the first subset of sites 301 and a second subset of sites 302. The plurality of sites 300 may further comprise sites that are not in the first subset of sites 301 or in the second subset of sites 302. Further, sites can be reassigned from the first subset of sites 301 to the second subset of sites 302 and from the second subset of sites 302 to the first subset of sites 301. Further, sites that are not in any subset of sites can be assigned to the first subset of sites 301 or to the second subset of sites 302 and sites form the first subset of sites 301 or from the second subset of sites 302 can be reassigned to not be in any subset of sites .
[0088] The first subset of sites 301 and the second subset of sites 302 can be disjoint sets . Thus, when a site is in the first subset of sites 301, the site cannot be in the second subset of sites 302 and when a site is in the second subset of sites 302, the site cannot be in the first subset of sites 301.
[0089] According to an embodiment, the method 100 further comprises, in response to a site being removed from the first subset of sites during the fast-response power grid frequency balancing, applying the first sampling rate to the removed site and obtaining samples from the removed site according to the first sampling rate .
[0090] For example, when sites are selected to be included in the first subset of sites 301, sites in the first subset of sites 301 can be monitored and samples can be obtained from the first subset of sites 301 according to the second sampling rate . When a site is removed from participating in the fast-response power grid frequency balancing, and thus removed from the first subset of sites 301, samples may no longer be obtained from the site according to the second sampling rate .
[0091] When a site is removed from the first subset of sites 301, the site can be, for example, moved to the second subset of sites 302 or not be added to any subset of sites .
[0092] For example, in response to determining all sites in the first subset of sites 301 are not needed for the fast-response power grid frequency balancing,some sites can be removed from the first subset of sites 301. For example, if a frequency deviation from a target frequency, such as 50 Hertz, is reduced during the fastresponse power grid frequency balancing it can be determined that all sites in the first subset of sites 301 are not needed for the fast-response power grid frequency balancing. For example, if the frequency deviation from the target frequency of 50 Hertz is reduced to 0.3 Hertz from 0.5 Hertz, it can be determined that all sites in the first subset of sites 301 are not needed for the fast-response power grid frequency balancing.
[0093] According to an embodiment, the method 100 further comprises obtaining samples from sites not in the first subset of sites 301 according to the first sampling rate during the fast-response power grid frequency balancing .
[0094] The sites not in the first subset of sites 301 can comprise, for example, the sites in the second subset of sites 302 and / or sites not in the first subset of sites 301 and not in the second subset of sites 302.
[0095] According to an embodiment, the method 100 further comprises, before the obtaining the signal for activating the fast-response power grid frequency balancing for the first subset of sites, reserving the first subset of sites for the fast-response power grid frequency balancing.
[0096] For example, the first subset of sites 301 can be reserved for the fast-response power grid frequency balancing before the fast-response power grid frequencybalancing is activated. The reserving may comprise, for example, configuring the first subset of sites 301 to have sufficient state of charge for the fast-response power grid frequency balancing.
[0097] According to an embodiment, the method 100 further comprises : obtaining a signal for activating a slow-response power grid frequency balancing for a second subset of sites in the plurality of sites; and obtaining samples from the second subset of sites according to the first sampling rate during the slow-response power grid frequency balancing.
[0098] The slow-response power grid frequency balancing may comprise, for example, aFRR.
[0099] The slow-response power grid frequency balancing may also be referred to as a second power grid frequency balancing use case, a second power grid frequency balancing mechanism, a second power grid frequency balancing service, or similar .
[0100] In some embodiments, the fast-response power grid frequency balancing and the slow-response power grid frequency balancing may be performed at least partially simultaneously. For example, first the slow-response power grid frequency balancing may be activated. Then, while the slow-response power grid frequency balancing is active, the fast-response power grid frequency balancing may also be activated.
[0101] For example, the DES system may be capable of running a plurality of power grid frequency balancingservices at the same time . For example, the first plurality of sites may be use for FCR-D while the second subset of sites may be used for aFRR.
[0102] In some embodiments, the second subset of sites may also be used for non-f requency balancing applications, such as load shifting, intraday trading etc .
[0103] In some embodiments, some sites in the plurality of sites 300 can also be reserved for other power grid frequency balancing services and / or user for other power grid frequency balancing services .
[0104] Fig. 5 illustrates a schematic representation of samples according to an embodiment .
[0105] According to an embodiment, the first sampling rate is lower than once every ten seconds and the second sampling rate is higher than once every ten seconds .
[0106] For example, in the embodiment of Fig. 5, a first plurality of samples 401 according to the first sampling rate and a second plurality of samples 402 according to the second sampling rate are illustrated. In the embodiment of Fig. 5, there are ten samples in the second plurality of samples 402 for each sample in the first plurality of samples 401. For example, the first sampling rate can be once every ten seconds and the second sampling rate can be once every second or the first sampling rate can be once every hundred seconds and the second sampling rate can be once every ten seconds . These values are only exemplary and, in other embodiments, the first sampling rate and the second sampling rate may have different values .
[0107] In some embodiments, the first sampling rate can be lower than once every 30 seconds and the second sampling rate can be higher than once every ten seconds . In some embodiments, the first sampling rate can be lower than once every 30 seconds and the second sampling rate can be higher than once every five seconds .
[0108] In other embodiments, the first sampling rate may be, for example, once every minute and the second sampling rate may be once every second. In other embodiments, the first sampling rate may be, for example, once every ten seconds and the second sampling rate may be once every second.
[0109] Herein, a higher sampling rate means that a higher number of samples are obtained per a time interval . Similarly, a smaller sampling rate means that a smaller number of samples are obtained per a time interval . Herein, some sampling rates may be expressed in the form of "once every x second" and / or "once every y minutes" for convenience . Alternatively, these could be expressed as "1 / x samples per second" and / or "1 / y samples per minute" . For example, "once per second" could be expressed as "one sample per second", "once every five seconds" could be expressed as "1 / 5 samples per second", "once every ten seconds" could be expressed as "1 / 10 samples per second", "once every 30 seconds" could be expressed as "1 / 30 samples per second", and "once every minute" could be expressed as "one sample per minute" .
[0110] Fig. 6 illustrates a schematic representation of samples according to another embodiment .
[0111] According to an embodiment, the method 100 further comprises obtaining interpolated samples by interpolating the samples obtained from the first subset of sites according to the second sampling rate .
[0112] For example, in the embodiment of Fig. 6, a first plurality of samples 501 according to the first sampling rate and a second plurality of samples 502 according to the second sampling rate are illustrated. In the embodiment of Fig. 6, there are ten samples in the second plurality of samples 502 for each sample in the first plurality of samples 501. Further, every other sample in the second plurality of samples 502 is an interpolated sample, indicate by the dashed lines . Thus, the second sampling rate can be five times the first sampling rate even though there are ten samples in the second plurality of samples 502 for each sample in the first plurality of samples 501.
[0113] By interpolating samples, network traffic due to the samples can be reduced while still obtaining samples at a sufficient sampling rate .
[0114] The samples obtained from the first subset of sites can be interpolated using, for example, linear interpolation, polynomial interpolation, spline interpolation, or any other interpolation method.
[0115] Fig. 7 illustrates a schematic representation of a computing device according to an embodiment .
[0116] According to an embodiment, a computing device 600 comprises at least one processor 601 and at least one memory 602 including computer program code, the at least one memory 602 and the computer program code configured to, with the at least one processor 601, cause the computing device 600 to perform the method 100.
[0117] The computing device 600 may comprise at least one processor 601. The at least one processor 601 may comprise, for example, one or more of various processing devices, such as a co-processor, a microprocessor, a digital signal processor (DSP) , a processing circuitry with or without an accompanying DSP, or various other processing devices including integrated circuits such as, for example, an application specific integrated circuit (ASIC) , a field programmable gate array (FPGA) , a microprocessor unit (MCU) , a hardware accelerator, a special-purpose computer chip, or the like .
[0118] The computing device 600 may further comprise a memory 602. The memory 602 may be configured to store, for example, computer programs and the like . The memory 602 may comprise one or more volatile memory devices, one or more non-volatile memory devices, and / or a combination of one or more volatile memory devices and nonvolatile memory devices . For example, the memory 602 may be embodied as magnetic storage devices (such as hard disk drives, magnetic tapes, etc . ) , optical magnetic storage devices, and semiconductor memories (such as mask ROM, PROM (programmable ROM) , EPROM (erasable PROM) , flash ROM, RAM (random access memory) , etc . ) .
[0119] The computing device 600 may further comprise other components not illustrated in the embodiment of Fig. 7. The computing device 600 may comprise, for example, an input / output bus for connecting the computing device 600 to other devices .
[0120] When the computing device 600 is configured to implement some functionality, some component and / or components of the computing device 600, such as the at least one processor 601 and / or the memory 602, may be configured to implement this functionality. Furthermore, when the at least one processor 601 is configured to implement some functionality, this functionality may be implemented using program code comprised, for example, in the memory.
[0121] The computing device 600 may be implemented at least partially using, for example, a computer, some other computing device, or similar .
[0122] Fig. 8 illustrates a schematic representation of a distributed energy storage system according to an embodiment .
[0123] According to an embodiment, a distributed energy storage (DES) system 700 comprises the computing device 600 and a plurality of sites 200 coupled to a power grid 701 .
[0124] Each site 200 in the plurality of sites may be electrically coupled to the power grid 701. For example, each site 200 may be configured to feed power to the power grid 701 and / or take power from the power grid 701 to perform power grid frequency balancing.
[0125] Each site 200 in the plurality of sites may be coupled to the computing device 600. Each site 200 in the plurality of sites may be communicatively coupled to the computing device 600. For example, each site 200 may be configured to communicate with the computing device 600 via the internet or any other telecommunication network. The computing device 600 may be configured to control each site 200 in the plurality of sites according to the method 100.
[0126] Each site 200 in the plurality of sites may be located at a different geographical location.
[0127] Fig. 9 illustrates a signalling diagram according to an embodiment .
[0128] According to an embodiment, the obtaining the signal for activating the fast-response power grid frequency balancing for the first subset of sites comprises : performing power grid frequency measurements; and determining, based on the power grid frequency measurements, that the fast-response power grid frequency balancing for the first subset of sites should be activated .
[0129] The determining, based on the power grid frequency measurements, that the fast-response power grid frequency balancing for the first subset of sites should be activated can comprise, for example, in response to a measured frequency of the power grid deviating from a target frequency more than a preconfigured threshold, determining that the fast-response power grid frequencybalancing for the first subset of sites should be activated. For example, in response to the measured frequency of the power grid deviating more than 0.5 Hertz from a target frequency of 50 Hertz, it can be determined that the first subset of sites should be activated.
[0130] The fast-response power grid frequency balancing can be activated by the computing device 600 and the computing device 600 can transmit instructions to adjust the sampling rate to the second sampling rate to the sites involved in the fast-response power grid frequency balancing. The second sampling rate can be used as long as the fast-response power grid frequency balancing is activated. When the fast-response power grid frequency balancing is no longer active, the computing device 600 can transmit a signal to the sites so that the fast monitor is terminated and only the slow monitor continues to execute according to the first sampling rate .
[0131] For example, the computing device 600 may be configured to perform power grid frequency measurements . For example, the computing device 600 may further comprise equipment for measuring the power grid frequency and the computing device 600 may be configured to perform power grid frequency measurements using such equipment . The computing device 600 may be configured to, for example, perform power grid frequency measurements periodically.
[0132] The computing device 600 may determine, based on the power grid frequency measurements, that the fastresponse power grid frequency balancing for the firstsubset of sites should be activated. The computing device 600 may, for example, transmit a fast-response power grid frequency balancing activation signal 801 to the first subset of sites . In response to the fastresponse power grid frequency balancing activation signal 801, the first subset of sites can start to transmit samples according to the second sampling rate to the computing device 600.
[0133] For example, in the embodiment of Fig. 9, the computing device transmits a fast-response power grid frequency balancing activation signal 801 to a first site 200_l . The first site 200_l can belong to the first subset of sites . The first site 200_l can start to participate in the fast-response frequency balancing and transmit samples 802 to the computing device 600 according to the second sampling rate as instructed by the fast-response power grid frequency balancing activation signal 801 .
[0134] Although only the first site 200_l is illustrated in the embodiment of Fig. 9, all disclosure herein in relation to the first site 200_l may apply to all sites in the first subset of sites .
[0135] In some embodiments, the fast-response power grid frequency balancing activation signal 801 may comprise instructions for the first subset of sites to start transmitting samples according to the second sampling rate . In other embodiments, the computing device 600 can, for example, transmit a separate signal comprising instructions for the first subset of sites tostart transmitting samples according to the second sampling rate .
[0136] The computing device 600 may determine, based on, for example, the power grid frequency measurements, that the fast-response power grid frequency balancing is no longer needed. Based on this, the computing device 600 may transmit a fast-response power grid frequency balancing deactivation signal 803 to the first subset of sites . In response to the fast-response power grid frequency balancing deactivation signal 803, the first subset of sites can start to transmit samples according to the first sampling rate to the computing device 600.
[0137] It should be appreciated that, in the embodiment of Fig. 9, the first site 200_l may transmit samples according to the first sampling rate before receiving the fast-response power grid frequency balancing activation signal 801 and after receiving the fast-response power grid frequency balancing deactivation signal 803 although such samples are not illustrated in the embodiment of Fig. 9.
[0138] According to an embodiment, the method 100 further comprises : obtaining a signal for activating a slow-response power grid frequency balancing for a second subset of sites in the plurality of sites; and obtaining samples from the second subset of sites according to the first sampling rate during the slow-response power grid frequency balancing.
[0139] According to an embodiment, the obtaining the signal for activating the slow-response power grid frequency balancing for the second subset of sites comprises receiving a slow-response power grid frequency balancing activation signal from a transmission system operator of the power grid.
[0140] For example, in the embodiment of Fig. 9, the computing device 600 receives a signal for activating a slow-response power grid frequency balancing 804 from a transmission system operator (TSO) 810. Based on the signal for activating a slow-response power grid frequency balancing 804, the computing device 600 can determine that the second subset of sites should be activated for the slow-response power grid frequency balancing. For example, the second subset of sites may be reserved for the slow-response power grid frequency balancing. In the embodiment of Fig . 9, the computing device 600 transmits a slow-response power grid frequency balancing activation signal 805 to a second site 200_2 belonging to the second subset of sites . In response to the slow-response power grid frequency balancing activation signal, the second site 200_2 can transmit samples 806 according to the second sampling rate to the computing device 600.
[0141] Although only the second site 200_2 is illustrated in the embodiment of Fig. 9, all disclosure herein in relation to the second site 200_2 may apply to all sites in the second subset of sites .
[0142] In some embodiments, the second subset of sites can transmit samples according to the second sampling rate to the computing device 600 even before the slow-response power grid frequency balancing activation signal . The slow-response power grid frequency balancing activation signal or some separate signal may instruct the second subset of sites to continue to transmit samples according to the second sampling rate to the computing device 600. Alternatively, the second subset of sites can continue to transmit samples according to the second sampling rate to the computing device 600 without any separate instructions .
[0143] Although the fast-response power grid frequency balancing and the slow-response frequency balancing are illustrated as sequential in the embodiment of Fig . 9, the fast-response power grid frequency balancing and the slow-response frequency balancing may also be active at the same time in some embodiments . Thus, the computing device 600 can receive the samples 802 transmitted by the first site 200_l and the samples 806 transmitted by the second site 200_2 in an interleaved manner .
[0144] According to an embodiment, the method 100 further comprises : obtaining a signal for deactivating a slow-response power grid frequency balancing for the second subset of sites in the plurality of sites; and obtaining samples from the second subset of sites according to the first sampling rate after the slow-response power grid frequency balancing.
[0145] According to an embodiment, the obtaining the signal for deactivating the slow-response power grid frequency balancing for the second subset of sites comprises receiving a slow-response power grid frequency balancing deactivation signal from a transmission system operator of the power grid.
[0146] The computing device 600 may, for example, be configured to store the samples obtained from the plurality of sites in a non-volatile memory. The computing device 600 may further be configured to perform other processing, such as interpolation, based on the samples as disclosed herein. For example, the TSO 810 may request for the samples at a later time .
[0147] Fig. 10 illustrates a schematic representation of a data log according to an embodiment .
[0148] In the data log of Fig. 10, first three samples are obtained during aFRR. The sampling rate is once every two minutes during these samples . Then, FCR-D is activated, which is indicated by an event at 07 : 01 : 30 in the data log. Two samples are obtained during FCR-D and one sample is generated by interpolating the two obtained samples . The sampling rate is once every two seconds during these samples, but due to the interpolation, a sample is stored every second. Then, FCR-D is deactivated, which is indicated by another event in the data log at 07 : 01 : 33. After FCR-D is deactivated, samples are again obtained according to the once every two minutes sampling rate of aFRR. It should be appreciated that aFRR can be active during FCR-D but no aFRR samplesare obtained during FCR-D in the embodiment of Fig. 10 due to the short duration of FCR-D and the low sampling rate of aFRR.
[0149] Any range or device value given herein may be extended or altered without losing the effect sought . Also any embodiment may be combined with another embodiment unless explicitly disallowed.
[0150] Although the subj ect matter has been described in language specific to structural features and / or acts, it is to be understood that the subj ect matter defined in the appended claims is not necessarily limited to the specific features or acts described above . Rather, the specific features and acts described above are disclosed as examples of implementing the claims and other equivalent features and acts are intended to be within the scope of the claims .
[0151] It will be understood that the benefits and advantages described above may relate to one embodiment or may relate to several embodiments . The embodiments are not limited to those that solve any or all of the stated problems or those that have any or all of the stated benefits and advantages . It will further be understood that reference to ' an' item may refer to one or more of those items .
[0152] The steps of the methods described herein may be carried out in any suitable order, or simultaneously where appropriate . Additionally, individual blocks may be deleted from any of the methods without departingfrom the spirit and scope of the subj ect matter described herein. Aspects of any of the embodiments described above may be combined with aspects of any of the other embodiments described to form further embodiments without losing the effect sought .
[0153] The term ' comprising' is used herein to mean including the method, blocks or elements identified, but that such blocks or elements do not comprise an exclusive list and a method or apparatus may contain additional blocks or elements .
[0154] It will be understood that the above description is given by way of example only and that various modifications may be made by those skilled in the art . The above specification, examples and data provide a complete description of the structure and use of exemplary embodiments . Although various embodiments have been described above with a certain degree of particularity, or with reference to one or more individual embodiments, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the spirit or scope of this specification .
Claims
CLAIMS :
1. A computer-implemented method ( 100) for controlling a plurality of sites of a distributed energy storage system, the method ( 100) comprising:obtaining ( 101 ) samples from the plurality of sites according to a first sampling rate, wherein the samples comprise at least a delivered power grid frequency balancing capacity of each site in the plurality of sites; andin response to obtaining a signal for activating fast-response power grid frequency balancing for a first subset of sites in the plurality of sites :applying (102 ) a second sampling rate for the first subset of sites, wherein the second sampling rate is higher than the first sampling rate;participating ( 103) in the fast-response power grid frequency balancing using the first subset of sites; andobtaining ( 104 ) samples from the first subset of sites according to the second sampling rate during the fast-response power grid frequency balancing.
2. The computer-implemented method ( 100) according to claim 1, the method further comprising:in response to obtaining a signal for deactivating the fast-response power grid frequency balancing for the first subset of sites, applying the firstsampling rate for the first subset of sites and obtaining samples from the first subset of sites according to the first sampling rate .
3. The computer-implemented method ( 100) according to claim 1 or claim 2 , the method further comprising, in response to a site being removed from the first subset of sites during the fast-response power grid frequency balancing, applying the first sampling rate to the removed site and obtaining samples from the removed site according to the first sampling rate .
4. The computer-implemented method ( 100) according to any preceding claim, the method further comprising obtaining samples from sites not in the first subset of sites according to the first sampling rate during the fast-response power grid frequency balancing.
5. The computer-implemented method ( 100) according to any preceding claim, wherein the first sampling rate is lower than once every ten seconds and the second sampling rate is higher than once every ten seconds .
6. The computer-implemented method ( 100) according to any preceding claim, the method further comprising obtaining interpolated samples by interpolating the samples obtained from the first subset of sites according to the second sampling rate .
7. The computer-implemented method ( 100) according to any preceding claim, the method further comprising, before the obtaining the signal for activating the fast-response power grid frequency balancing for the first subset of sites, reserving the first subset of sites for the fast-response power grid frequency balancing .
8. The computer-implemented method ( 100) according to any preceding claim, wherein the obtaining the signal for activating the fast-response power grid frequency balancing for the first subset of sites comprises :performing power grid frequency measurements; anddetermining, based on the power grid frequency measurements, that the fast-response power grid frequency balancing for the first subset of sites should be activated.
9. The computer-implemented method ( 100) according to any preceding claim, the method further comprising :obtaining a signal for activating a slow-re-sponse power grid frequency balancing for a second subset of sites in the plurality of sites; and obtaining samples from the second subset of sites according to the first sampling rate during the slow-response power grid frequency balancing.
10. The computer-implemented method ( 100) according to claim 9, wherein the obtaining the signal for activating the slow-response power grid frequency balancing for the second subset of sites comprises receiving a slow-response power grid frequency balancing activation signal from a transmission system operator of the power grid.
11. A computing device ( 600) comprising at least one processor ( 601 ) and at least one memory ( 602 ) including computer program code, the at least one memory ( 602 ) and the computer program code configured to, with the at least one processor ( 601 ) , cause the computing device ( 600) to perform the method ( 600) according to any preceding claim.
12. A distributed energy storage system (700) comprising the computing device ( 600) according to claim 11 and a plurality of sites (200) coupled to a power grid ( 701 ) .
13. The distributed energy storage system (700) according to claim 12, wherein at least one site in the plurality of sites (200) comprises a component comprising a register, wherein a sampling rate of the register is lower than the second sampling rate and the site is configured to :sequentially obtain a data series from the register;interpolate the sequentially obtained data series, thus obtaining an interpolated data series; and transmit at least a part of the interpolated data series in a sample .
14. A computer program product comprising program code configured to perform the method according to any of claims 1 - 10 when the computer program product is executed on a computer .