Control of grid components of power grids

Abstract

Disclosed are methods, apparatus, and systems for controlling grid components of an electric power grid, each configured to consume power from and / or supply power to the electric power grid according to a respective predefined function that receives as input a received power flow characteristic value. The method includes obtaining a value of a characteristic of power flow in the electric power grid, modifying the obtained value by inputting the obtained value to a mapping function that maps the predefined function to a controller function to generate a modified power flow characteristic value, and transmitting the modified power flow characteristic value to the grid component to control the grid component to consume power from and / or supply power to the electric power grid according to the controller function. Methods and apparatus for providing the modified power flow characteristic values are also disclosed.

Description

[Technical Field]

[0001] The present invention relates to methods, apparatus, and systems for controlling one or more grid components of an electric power grid. [Background technology]

[0002] The generated electricity is distributed to consumers through an electricity distribution network or grid. Electricity grids typically operate at a uniform nominal grid frequency throughout the grid's synchronized area. For example, mains electricity in the UK operates at a nominal 50Hz AC frequency. Grid operators are typically obliged to maintain the grid frequency within predefined limits. For example, the UK electricity system should be kept within 1% of the nominal 50Hz grid frequency.

[0003] Large-capacity power plants, such as nuclear or fossil-fuel power plants, use rotating generators with relatively large rotating parts that are powered to rotate at relatively high speeds, many times the nominal grid frequency (so-called spinning generators). During normal operation, these rotating generators store a relatively large amount of kinetic energy in the weight and speed of the spinning turbines. Smaller-scale providers, such as wind or solar power plants, often use DC-connected inverters to supply power at the nominal grid frequency and typically store much less kinetic energy, or even no kinetic energy at all.

[0004] Changes in the balance between grid power supply and consumption (e.g., when total supply cannot meet consumption during periods of high demand, or when supply from a generator or interconnection fails) cause changes in the load on the generators, which in turn change the rotational speed of the rotating generators and, accordingly, the operating frequency of the grid.

[0005] It is also desirable to maintain other power flow characteristics of the grid, such as voltage, within specified limits, which ensures reliable operation of grid-connected units.

[0006] An electric power grid can utilize auxiliary services to support the stability of power flows in the grid. Ancillary services can include grid components configured to consume and / or source power from the electric power grid, the operation of which can be controlled to help maintain power flow characteristics within specified limits.

[0007] For example, frequency control or dynamic suppression ancillary services can be used to ensure that grid frequency remains within specified limits. Such services can include grid components connected to a power grid that can control the grid's power consumption and / or power supply to help maintain the grid frequency within specified limits. When grid frequency decreases from a nominal value, the grid components can be controlled to either decrease power consumption from the power grid or increase power supply to the power grid, thereby restoring the frequency to the nominal value. Specifically, this decrease in power consumption and / or increase in power supply reduces the load on the rotating generator, causing it to rotate faster, resulting in an increase in grid frequency. Conversely, when grid frequency increases from a nominal value, the grid components can be controlled to either decrease power supply to the power grid or increase power consumption from the power grid, thereby restoring the frequency to the nominal value. Specifically, this decrease in power supply and / or increase in power consumption increases the load on the rotating generator, causing it to rotate slower, resulting in a decrease in grid frequency.

[0008] To provide ancillary services, each grid component of an ancillary service can be preprogrammed with how the grid component should operate in response to a particular grid characteristic value. For example, a grid component of a frequency ancillary service may be preprogrammed to begin supplying a certain amount of power to the grid when the grid frequency drops 0.03 Hz below its nominal value. In general, grid components can be preprogrammed to consume and / or supply power from the grid according to a predefined function, which receives a power flow characteristic value as an input.

[0009] Occasionally, it may be desirable to change the function by which a grid component consumes / sources power from the grid. For example, while a grid component may be pre-programmed to begin providing a certain amount of power to the grid when the grid frequency is 0.03 Hz below nominal, it may be discovered or determined that it would actually be more beneficial to grid stability if the grid component were programmed to begin providing a certain amount of power to the grid when the grid frequency is (for example) 0.015 Hz below nominal. This can be achieved by reprogramming each grid component with the new function. However, reprogramming each grid component to operate according to the new function is time-consuming and expensive to accomplish, particularly because each grid component requires some degree of technical intervention, followed by conformance testing to ensure that the technical intervention correctly meets the revised function parameters. Furthermore, due to the time required to reprogram and retest each grid component, the desired change may only be implemented relatively slowly, which may limit the usefulness and / or functionality of the service to changing needs for managing the stability of the power system.

[0010] It would be desirable to mitigate at least some of these drawbacks. Summary of the Invention

[0011] According to a first aspect of the present invention, there is provided a method of controlling one or more grid components of an electric power grid, each grid component configured to consume power from and / or supply power to the electric power grid, each grid component configured to receive a respective power flow characteristic value from a controller and to consume power from and / or supply power to the electric power grid according to a respective predefined function, the predefined function receiving the received power flow characteristic value as an input, the method comprising: obtaining, at the controller, measurement data indicative of one or more measurements of characteristics of power flow in the electric power grid; modifying the obtained power flow characteristic value by inputting the obtained power flow characteristic value to a mapping function that maps the predefined function to a controller function to generate modified power flow characteristic values; and transmitting the modified power flow characteristic value to the one or more grid components, thereby controlling the one or more grid components to consume power from and / or supply power to the electric power grid according to the controller function.

[0012] Optionally, the predefined function defines a first trigger point for the power flow characteristic value at which the respective grid component is triggered to consume power from and / or supply power to the power grid, and the controller function defines a second trigger point for the power flow characteristic value different from the first trigger point, and upon sending the modified power flow characteristic value to the one or more grid components, the one or more grid components are triggered to consume power from and / or supply power to the power grid when the obtained power flow characteristic value is at the second trigger point.

[0013] If desired, modifying the obtained power flow characteristic values is responsive to detected and / or predicted changes in grid conditions of the power network.

[0014] Optionally, the method includes dynamically varying the modification of the obtained power flow characteristic values in response to one or more detected and / or predicted changes in grid conditions of the power network.

[0015] Optionally, the grid conditions include the inertia, short circuit ratio, fault level and / or system strength of the power grid, and / or the frequency, voltage, current, reactive power, one or more oscillations, one or more harmonics, and / or phase angle of the electricity flowing within the power grid.

[0016] Optionally, the grid condition includes one or more oscillations in electricity flowing within the power grid, and dynamically varying the modification includes varying the modification to dampen one or more of the oscillations.

[0017] Optionally, modifying the obtained power flow characteristic values is responsive to reaching a point in time within the time schedule, and / or the method includes dynamically varying the modification of the obtained power flow characteristic values in response to reaching one or more points in time within the time schedule.

[0018] Optionally, the method includes transmitting, to one or more grid components, in addition to the modified power flow characteristic value, a reparameterization signal configured to cause each of the one or more grid components to modify one or more parameters of a predefined function according to which the grid component is configured to consume power from and / or supply power to the power grid.

[0019] Optionally, each of the one or more grid components has a plurality of selectable predefined functions according to which the respective grid component is configurable to consume power from and / or supply power to the power grid, and the method includes transmitting to the one or more grid components, in addition to the modified power flow characteristic value, a selection signal configured to cause each of the one or more grid components to respectively select a predefined function from the plurality of predefined functions, whereby the respective grid component is configured to consume power from and / or supply power to the power grid according to the selected predefined function.

[0020] There may be multiple grid components as needed.

[0021] Optionally, the method includes selecting a first group of one or more of the plurality of grid components and transmitting the modified power flow characteristic value to each grid component in the selected first group.

[0022] Optionally, the method includes selecting a second group of one or more of the plurality of grid components; and transmitting a second modified power flow characteristic value to each grid component of the second group of grid components, the second modified power flow characteristic value being obtained by inputting the obtained power flow characteristic value into a second mapping function that maps a predefined function to a second controller function, thereby controlling the grid components of the second group to consume power from and / or supply power to the power grid in accordance with the second controller function.

[0023] Optionally, selecting the first group of one or more grid components and / or selecting the second group of one or more grid components is based on an area in which the grid components are located.

[0024] Optionally, there may be a plurality of grid components in a first group, and the grid components selected to belong to the first group may be located in the same area as one another, and / or there may be a plurality of grid components in a second group, and the grid components selected to belong to the second group may be located in the same area as one another.

[0025] Optionally, the first and / or second group of grid components are selected based on at least one power flow condition in the region in which the grid components of the respective group are located.

[0026] If desired, the first group and / or the second group of grid components are selected based on the area in which the grid components of the respective group are located being an area in which a response to changing grid conditions in the power grid is determined to be necessary or likely to be effective.

[0027] Optionally, obtaining one or more power flow characteristic values includes, at the controller, obtaining a plurality of measurements of the power flow characteristic values obtained at a respective plurality of different locations in the power grid, and combining the plurality of measurements to determine the obtained power flow characteristic value.

[0028] Optionally, the power flow characteristics are indicative of the inertia, short circuit ratio, fault level, and / or system strength of the power grid, and / or one or more of the frequency, voltage, current, reactive power, one or more oscillations, one or more harmonics, and / or phase angle of the electricity flowing within the power grid.

[0029] Where appropriate, power consumed from and / or supplied to the power grid by one or more grid components is real power and / or reactive power.

[0030] Optionally, the power consumed from and / or supplied to the power grid by one or more grid components is reactive power. Optionally, at least the controller function includes a dead band for the power flow characteristic value, such that the one or more grid components are controlled to consume power from and / or supply power to the power grid only if the obtained power flow characteristic value is outside the dead band.

[0031] Optionally, each grid component is configured to receive respective values of a plurality of power flow characteristics from the controller and consume power from and / or supply power to the power grid in accordance with a respective at least one predefined function, the at least one predefined function receiving as input the received values of the plurality of power flow characteristics, obtaining measurement data including obtaining data indicative of one or more measurements of each of the plurality of characteristics of power flow in the power flow grid, modifying the obtained power flow characteristic values including modifying the obtained value of each of the plurality of power flow characteristics by inputting the obtained value of each of the plurality of power flow characteristics to at least one mapping function that maps the at least one predefined function to the at least one controller function to generate modified values of each of the plurality of power flow characteristics, and transmitting the modified power flow characteristic values includes transmitting the modified values of the plurality of power flow characteristics to one or more grid components, thereby controlling the one or more grid components to consume power from and / or supply power to the power grid in accordance with the at least one controller function.

[0032] According to a second aspect of the present invention, there is provided a method for providing a modified power flow characteristic value, the method comprising: obtaining, at a first entity, measurement data indicative of one or more measurements of characteristics of power flow in an electric power grid, wherein one or more grid components are configured to consume power from and / or supply power to the electric power grid according to a first function based on the received power flow characteristic values; determining a second function, different from the first function, for controlling the one or more grid components to consume power from and / or supply power to the electric power grid; modifying the obtained power flow characteristic value by inputting the obtained power flow characteristic value to a mapping function that maps the first function to the second function to generate a modified power flow characteristic value; and outputting the modified power flow characteristic value.

[0033] Optionally, the method includes providing the modified power flow characteristic values to one or more components of a model of the power grid, thereby simulating power flow behavior within the grid resulting from transmitting the modified power flow characteristic values to the one or more grid components.

[0034] Optionally, obtaining measurement data includes obtaining measurement data indicative of one or more measurements of each of a plurality of characteristics of power flow in the power grid, the one or more grid components each configured to consume power from and / or supply power to the power grid according to at least one first function based on the received values of the plurality of power flow characteristics, determining a second function includes determining at least one second function different from the at least one first function for controlling the one or more grid components to consume power from and / or supply power to the power grid, the second function being different from the at least one first function, modifying the obtained power flow characteristic values includes modifying the obtained values of the plurality of power flow characteristics by inputting the obtained values of the plurality of power flow characteristics to at least one mapping function that maps the at least one first function to the at least one second function to generate modified values of the plurality of power flow characteristics, and outputting the modified power flow characteristics includes outputting the modified values of the plurality of power flow characteristics.

[0035] According to a third aspect of the present invention there is provided an apparatus configured to carry out a method according to the first or second aspect.

[0036] According to a fourth aspect of the present invention there is provided a computer program comprising instructions which, when executed by a computer, cause the computer to carry out a method according to the first or second aspect.

[0037] According to a fifth aspect of the present invention there is provided a system comprising an apparatus according to the third aspect and one or more grid components.

[0038] Further features and advantages of the present invention will become apparent from the following description of preferred embodiments of the invention, given by way of example only, made with reference to the accompanying drawings. [Brief explanation of the drawings]

[0039] [Figure 1] FIG. 1 is a flow diagram illustrating a method according to an example. [Figure 2] FIG. 1 is a schematic diagram illustrating a power grid according to an example. [Figure 3A] 10 is a graph illustrating a predefined function according to an example. [Figure 3B] 10 is a graph illustrating a controller function according to an example. [Figure 3C] 10 is a graph illustrating a mapping function according to an example. [Figure 4] 10 is a graph illustrating a plot of grid frequency as a function of time according to an example. [Figure 5] 10 is a graph illustrating a plot of grid frequency as a function of time according to an example. [Figure 6] FIG. 1 is a schematic diagram illustrating a portion of a power grid according to an example. [Figure 7] FIG. 1 is a schematic diagram illustrating a system according to an example. [Figure 8] FIG. 1 is a flow diagram illustrating a method according to an example. [Figure 9] 1 is a schematic diagram illustrating an apparatus according to an example. DETAILED DESCRIPTION OF THE INVENTION

[0040] Referring to Figure 1, a method for controlling one or more grid components of a power grid is shown according to an example. As described in more detail below with reference to Figures 2-3C, each grid component 222 is configured to consume power from and / or source power to the power grid 200. Further, each grid component 222 is configured to receive a respective power flow characteristic value v from a controller 205 and to consume power P from and / or source power to the power grid 200 according to a respective predefined function 550, the predefined function 550 receiving the received power flow characteristic value v as an input. In broad overview, the method includes, in the controller 205: - in step 102, obtaining measurement data indicative of one or more measurements v of characteristics of power flow in the power network 200; - in step 104, modifying the obtained power flow characteristic values v by inputting them into a mapping function 554 that maps a predefined function 550 to a controller function 552 to generate modified power flow characteristic values v'; In step 106, transmitting the modified power flow characteristic value v′ to one or more grid components 222, thereby controlling the one or more grid components 222 to consume power P from and / or supply power to the power grid in accordance with the controller function 552.

[0041] This may allow one or more grid components 222 to consume power from and / or supply power to power grid 200 in accordance with controller function 552, but without having to reprogram grid component 222 with controller function 552, which would be time-consuming and resource-intensive. Thus, this may allow operation of grid component 222 in accordance with controller function 552 to be implemented relatively quickly and efficiently. Rapid implementation of controller function may allow for improved availability and / or functionality of auxiliary services provided by one or more grid components 222. For example, allowing rapid implementation of controller function 552 may allow for improved responsiveness of responses provided by grid component 220 to changing grid conditions, thus providing improved auxiliary services.

[0042] As previously discussed, the method is for controlling one or more grid components 222 of an electric power network 200. Referring to Figure 2, an electric power network 200 is shown according to an example.

[0043] Electricity is typically delivered from suppliers, such as power plants, to consumers, such as homes and businesses, via an electrical power distribution network or grid 200. In the example of Figure 2, electrical power grid 200 includes a transmission grid 202 and a distribution grid 204.

[0044] The power grid 202 is connected to a generator 206, which may be, for example, a nuclear power plant or a gas-fired power plant, which transmits large amounts of electrical energy at very high voltages (typically on the order of hundreds of kV) through transmission lines (such as overhead lines) to the power grid 204.

[0045] The power transmission grid 202 is connected to the power distribution grid 204 via a transformer 208 which converts the power supply to a lower voltage (typically on the order of 50 kV) for distribution on the power distribution grid 204 .

[0046] The power distribution network 204 is connected via a substation 210, which further includes a transformer for converting the power to a lower voltage, to a local network that supplies power to power consumers connected to the power network 200. The local network may include a network of domestic consumers, such as a city network 212, that supplies power to domestic appliances in private residences 213 that consume relatively small amounts of power, on the order of a few kW. The private residences 213 use electric vehicles, battery storage, heat pumps, air conditioners, and solar power generation systems 215 to supply relatively small amounts of power for consumption by the appliances in the residences or for supplying power to the grid. The local network may also include industrial facilities, such as factories 214, where larger equipment operating in the industrial facilities consumes more power, on the order of a few kW to MW. The local network may also include a network of small-scale generators, such as battery storage, solar power plants, and wind power plants 216, that supply power to the power grid.

[0047] For simplicity, only one power transmission grid 202 and one power distribution grid 204 are shown in FIG. 2 , but in reality a typical power transmission grid 202 may supply power to multiple power distribution grids 204, and one power transmission grid 202 may be interconnected with one or more other power transmission grids 202.

[0048] Electrical power in the power grid 200 flows as alternating current (AC) at the system frequency, sometimes called the grid frequency (usually 50 or 60 Hz depending on the country). The power grid 200 operates at a synchronized frequency, such that the frequency is substantially the same at each point on the grid.

[0049] Grid 200 may include one or more DC interconnects 217 that provide direct current (DC) connections between power grid 200 and other power grids. Typically, DC interconnects 217 are connected to the conventional high-voltage transmission grid 202 of power grid 200. DC interconnects 217 provide DC links between various power grids, and power grid 200 defines regions that operate at specific synchronized grid frequencies that are not affected by changes in the grid frequencies of other power grids. For example, the UK power grid is connected to the continental European synchronized grid via a DC interconnection.

[0050] The power grid 200 may include one or more measurement devices 220 for measuring power flow characteristics v within the power grid 200. For example, the measurement device 220 may include a phasor measurement unit (PMU) that may be configured to measure one or more of the frequency, voltage, current, power, reactive power, and phase angle of electricity flowing within the power grid. As another example, the measurement device 220 may include other types of measurement devices, such as a power meter or a digital fault recorder (DFR). The DFR may be configured to sample and record power flow characteristics of electricity flowing through the power grid, including, but not limited to, harmonics, frequency, and voltage levels. For example, the DFR may sample data captured by a protective relay in the power grid. As another example, the one or more measurement devices 220 may include measurement devices configured to measure power flow characteristics of power lines, such as EMF (electromagnetic force), and dynamic line rating measurement devices, such as thermal, vibration, current sensors, and radar and / or optical sensors. For example, a thermal sensor may measure the temperature of the power line, which may indicate the current flowing through the power line. As another example, optical sensors can measure the current and / or voltage of electrical energy flowing through power lines, for example, using the Pockels effect. Other measurement devices may also be used, such as measurement devices configured to measure synchrophasors and / or wave points of electricity flowing within a power grid. Other measurement devices may also be used.

[0051] The grid 200 may include one or more grid components 222 .

[0052] Grid component 22 may, for example, form part of auxiliary services (e.g., dynamic control auxiliary services) of power grid 200 and support the stability of power flows in the grid, e.g., help to keep power flow characteristics within specified limits. For example, during peak power consumption periods, or if, for example, generator 206 experiences a fault, the amount of power consumed may exceed the amount of power generated. In this case, the grid frequency may begin to drop. In such a case, frequency auxiliary services grid component 220 is triggered to supply power to grid 200, e.g., help to restore the grid frequency to a nominal value.

[0053] In any event, each grid component 222 is configured to consume power from and / or supply power to power grid 200. Additionally, each grid component 222 is configured to receive a respective power flow characteristic value from controller 205 and to consume power from and / or supply power to power grid 200 according to a respective predefined function 550, which receives the received power flow characteristic value as an input (described in more detail below with reference to FIG. 3A ).

[0054] In some examples, the power flow characteristics may indicate, but are not limited to, the inertia, short circuit ratio, fault level, and / or system strength of the power grid, and / or one or more of the frequency, voltage, current, reactive power, one or more oscillations, one or more harmonics, and / or phase angle of the electricity flowing within the power grid.

[0055] For example, the power flow characteristic may indicate the frequency of electricity flowing into the power grid 200. For example, the power flow characteristic may be the frequency of electricity flowing into the power grid 200, or the deviation of the frequency from a nominal value, such as 50 Hz. In this case, the predefined function may include, for example, a trigger value for the grid frequency (or deviation) below which the grid component 222 supplies power to the grid 200, thereby causing the grid frequency to return to the nominal value.

[0056] In some examples, the power flow characteristic may represent one or more of the voltage, current, phase angle, and reactive power of electricity flowing in the power grid. The phase angle Φ may describe the phase shift that exists between the voltage and the current. The reactive power may be given by the product of the voltage, the current, and sin(Φ). For example, the power flow characteristic may be the voltage (or reactive power, or phase angle) of electricity flowing in the grid 200 (or a portion thereof, e.g., the power distribution network 204). In this case, the predefined function may include, for example, a trigger value for the voltage (or reactive power, or phase angle) below which a grid component supplies reactive power to the grid 200 (or a portion thereof), thereby causing the voltage (or reactive power, or phase angle) to return to its nominal value.

[0057] In some examples, power flow characteristics may indicate the inertia of electricity flowing within a power grid. Power grid inertia is a measure of the amount of kinetic energy stored in the power grid and affects the rate at which the operating frequency of the power grid changes in response to changes in the balance of power supply and consumption within the power grid. For example, a rotary generator with a rotating turbine having a relatively large mass can store a relatively large amount of kinetic energy and therefore provide a relatively large inertia. In this case, the predefined function may include, for example, an inertia trigger value below which grid components that can provide a relatively large inertia are activated, thereby increasing the inertia of the grid or a particular portion of the grid to a nominal or desired value. As another example, each generator in a group of relatively small generators may have a predefined function that may include, for example, an inertia trigger value below which each generator is configured to supply power to the power grid in a synchronized manner. While the inertia provided by each individual small generator is not particularly large, synchronizing the power supply and inertia provided by the group of small generators to the power grid can increase the inertia of the power grid or a particular portion of the power grid to a nominal or desired value.

[0058] In some examples, the power flow characteristic may indicate one or more oscillations in the electricity flowing within the power grid 200. For example, there may be one or more oscillations in the frequency of the power grid. For example, oscillations in the frequency of the power grid may occur between different regions of the power grid 200 or may be the result of overcompensation, for example, by other auxiliary service units. For example, the power flow characteristic value may be the amplitude of the oscillations. The grid component 222 may provide oscillations related to the power supplied to or consumed by the grid 200 and may dampen the frequency oscillations. In this case, the predefined function may include, for example, a trigger value for the oscillation amplitude, above which the grid component provides oscillations in the power consumed from or provided to the grid 200 to dampen the frequency oscillations, thereby reducing the amplitude of the frequency oscillations.

[0059] In some examples, the power flow characteristics may indicate one or more harmonics of the electricity flowing within the power grid 200. For example, one or more harmonics may be present relative to a reference grid frequency. The grid component 222 may consume power from and / or supply power to the power grid in a manner that reduces harmonics in the grid 200. As one example, the grid component 222 may include a harmonic filter that consumes power by routing unwanted harmonic currents to ground. For example, the harmonic filter may include a resonant circuit connected in series or parallel with the grid to route harmonic currents to ground. In this case, the predefined function may include, for example, a set of harmonic amplitudes or trigger values that, when exceeded, cause the grid component 222 to activate the harmonic filter, thereby routing harmonic currents to ground and consuming power, thereby reducing the amplitude of harmonics in the grid 200. As another example, harmonics may be controlled by controlling the dispatch of power-supplying grid components 222 (e.g., generators) in particular areas of the grid 200. For example, the dispatch of grid components 222 may represent the power each power-delivery grid component 222 provides to grid 200 at a particular point in time. By controlling different grid components 222 at different locations within the grid, specific and different amounts of power can be delivered to grid 200, thereby reducing harmonics within the grid. In this case, the predefined function for each specific grid component 222 may include, for example, a set of harmonic amplitudes or trigger values above which the grid component 222 can decrease (or increase) its power delivery to match a specific amount, thereby reducing the amplitude of harmonics within grid 200 (or a specific region of the grid).

[0060] In some examples, the power flow characteristics may indicate the short circuit ratio, fault level, and / or system strength of the power grid. The fault level at a particular location in the grid is proportional to the fault current (i.e., the current flowing during the fault) and voltage. The system strength at a particular location indicates the magnitude of the change in voltage after the fault and is proportional to the fault level. The short circuit ratio can be thought of as the fault level divided by the generator's rated power output measured at the generator's connection point. For example, the grid component 222 may supply reactive power to support voltage in weak areas of the grid (i.e., areas of low system strength). In this case, the predefined function may include, for example, a system strength trigger value below which the grid component supplies reactive power to the grid to support voltage, thereby increasing system strength.

[0061] Thus, one or more grid components 222 may provide ancillary services to power grid 200 .

[0062] In some examples, grid component 222 may be provided by a device that consumes / supplies power from / to the grid according to a predefined function 550. For example, grid component 222 may take the form of a grid battery or a home battery 222. For example, grid-connected grid battery 222 may consume power from and / or supply power to power grid 200 (e.g., by charging and discharging, respectively) according to predefined function 550. In some examples, providing auxiliary services to grid 200 may be the only or primary function of grid component 222.

[0063] In some examples, grid component 222 may include a modulator 218 and one or more associated power units 219. For example, each power unit 219 may be configured to consume power from and / or supply power to power grid 200, and an associated modulator 218 may be configured to modulate (e.g., decrease or increase) the consumption and / or supply, such that one or more power units 219 consume power from and / or supply power to power grid 200 according to a predefined function. For example, one or more power generating units 219 may be connected to grid 200 via modulator 218. For example, wind farm 216 may include multiple turbines 219, and modulator 218 may modulate the total power output of the wind farm to grid 200. As another example, household 213 may include multiple appliances 219, and modulator 218 may modulate the total power consumed by the household. For example, this may be offered as a service operated by a utility company or other party. Thus, in some examples, grid component 222 or portions thereof may have a purpose other than providing auxiliary services to grid 220, but may contribute to providing auxiliary services to the grid as needed.

[0064] 1 includes, in step 102, obtaining measurement data indicative of one or more measurements v of characteristics of power flow in power grid 200. For example, the measurement data may be obtained from one or more measurement devices 220 or derived from the output of one or more measurement devices 220. For example, a phasor measurement unit may measure the frequency, voltage, reactive power, phase angle, one or more oscillations, and one or more harmonics of electricity flowing in the power grid, and these measurements (e.g., voltage, current, etc.) may be used to derive, for example, the short circuit ratio, fault level, and / or system strength of the power grid, as described above.

[0065] In some examples, acquiring measurement data may include, in the controller 205, acquiring multiple measurements of a power flow characteristic value, each acquired at multiple different locations within the power grid, and combining the multiple measurements to determine the acquired power flow characteristic value. Combining multiple measurements may enable a more accurate and / or reliable measurement of the power flow characteristic value, for example, compared to using a single value. For example, if one of the values is erroneous, this is mitigated by combining it with other values. Alternatively, or additionally, combining multiple measurements may enable a more rapid determination of the power flow characteristic value. For example, a power flow characteristic value, such as frequency, may be determined from multiple samples acquired during a sampling window, for example, to provide a value of the power flow characteristic value within a particular statistical confidence level. However, combining multiple measurements acquired at different locations may provide a particular statistical confidence level for the value and thus may shorten the length of the sampling window used to generate the value. This allows the value to be determined more quickly, i.e., with less latency, thereby improving responsiveness to grid component values. Alternatively, or additionally, combining multiple measurements may enable a power flow characteristic value to be determined that is representative of an area or the entire power grid. This may allow grid components to be provided with region-specific or national or synchronous regional power flow characteristic values, which may allow for increased granularity in controlling the grid components. In any event, measurement data is obtained that indicates one or more measurements of power flow characteristics in the power grid 200.

[0066] As previously mentioned, the method of FIG. 1 then includes, in step 104, modifying the obtained power flow characteristic values by inputting the obtained power flow characteristic values into a mapping function that maps a predefined function to a controller function to generate modified power flow characteristic values.

[0067] 3A-3C, according to an example, a predefined function 550 (FIG. 3A), a controller function 552 (FIG. 3B), and a mapping function 554 (FIG. 3C) are shown.

[0068] 3A , an example of a predefined function 550 is shown. As can be seen from this example, the predefined function 550 defines the power P that the grid component 222 supplies to or consumes from the power grid 200 as a function of the power flow characteristic value v. In this example, a positive value of power P corresponds to supplying power to the grid 200, and a negative value of power P corresponds to consuming power from the grid 200. A value B may correspond to a nominal value of the power flow characteristic value v. At this value, the power P is zero. This may correspond to the grid component 222 neither supplying nor consuming power to the grid 220 (or, for example, neither increasing nor decreasing the current state of power consumption or supply of the power units 119 of the grid component 220). The predefined function 550 has a dead band centered on the value B, extending from a lower trigger value A to an upper trigger value C of the power flow characteristic value v. That is, when the power flow characteristic value v is in the range from the lower trigger value A to the upper trigger value C, the power P is zero. When the value of the power flow characteristic value v exceeds the upper trigger value C, the power P decreases linearly with respect to the power flow characteristic value v. When the value of the power flow characteristic value v is below the lower trigger value A, the power P increases linearly with respect to the power flow characteristic value. For example, if the power flow characteristic value v is the grid frequency, the nominal value B may be 50 Hz and the dead band may be ±0.03 Hz, so that the upper trigger value C may be 50.03 Hz and the lower trigger value A may be 49.97 Hz. In some examples, the power P may take the form of a percentage of the maximum power that the grid component 222 can consume and / or provide.

[0069] However, it may be desirable for grid component 222 to instead implement controller function 552 shown in FIG. 3B . For example, it may be determined that the ability of grid 200 to withstand faster occurring changes in grid frequency would be improved by reducing the dead-band. Thus, in this example, controller function 552 is similar to predefined function 550, except that the size of the dead-band has been reduced. Specifically, controller function 552 has the same dead-band centered around value B as predefined function 550, but the dead-band of controller function 552 instead extends from a lower trigger value A′ (higher than lower trigger value A of predefined function 550) to an upper trigger value C′ (lower than upper trigger value C of predefined function 550) of power flow characteristic value v. In controller function 552, when the value of the power flow characteristic value v exceeds the upper trigger value C', the power P decreases linearly with increasing power flow characteristic value v, and when the value of the power flow characteristic value v is below the lower trigger value A', the power P increases linearly with decreasing power flow characteristic value. For example, if the power flow characteristic value v is the grid frequency, the nominal value B may be 50 Hz and the dead band may be ±0.015 Hz, so that the upper trigger value C' may be 50.015 Hz and the lower trigger value A may be 49.985 Hz.

[0070] 3C, a mapping function 554 is shown that maps predefined function 550 to controller function 552. Specifically, for a given input measured power flow characteristic value v, mapping function 554 outputs a modified power flow characteristic value v'. Specifically, for a given measured power flow characteristic value v, the modified power flow characteristic value v', when input to predefined function 550, causes predefined function 550 to output the power P that controller function 552 would output for the given measured power flow characteristic value v. By way of example, as can be seen in FIG. 3C, the mapping function maps trigger points A' and C' to trigger points A and C, respectively. Thus, when the measured power flow characteristic value v is at trigger point C' (or A'), the modified power flow characteristic value v' is at trigger point C (or A, respectively).

[0071] 1 includes, at step 106, transmitting modified power flow characteristic values v′ to one or more grid components 222, thereby controlling the one or more grid components 222 to consume power from and / or supply power to the power grid 200 according to controller function 552. As an example, if the measured power flow characteristic value v has a value of C′, then the modified power flow characteristic value v′ output by mapping function 554 may have a value of C. This modified power flow characteristic value C may be transmitted to grid component 222, which may then be input to predefined function 550, e.g., as described above, such that it may be determined that trigger value C is met and therefore grid component 222 should begin consuming power P from grid 200. Similarly, as another example, if the measured power flow characteristic value v has a value of A′, then the modified power flow characteristic value v′ output by mapping function 554 may have a value of A. This modified power flow characteristic value A may be sent to grid component 222, which may then input it into predefined function 550, e.g., as described above, so that it may be determined that trigger value A is met and therefore grid component 222 should begin supplying power P to grid 200. Thus, grid component 222 is controlled to consume power from and / or supply power to power grid 200 according to controller function 552, without necessarily modifying or reprogramming predefined function 550 in grid component 222.

[0072] As mentioned above, in some examples, the predefined function 550 may define a first trigger point (A or C) for the power flow characteristic value v at which each grid component 222 is triggered to consume power from or supply power to the power grid 200. The controller function 552 may define a second trigger point (A' or C') for the power flow characteristic value v that is different from the first trigger point (A or C). Sending the modified power flow characteristic value v' to one or more grid components 222 may trigger one or more grid components 222 to consume power from and / or supply power to the power grid when the obtained power flow characteristic value v is at the second trigger point (A' or C'). For example, the first trigger point (A or C) may be a deviation of ±0.03 Hz from the nominal grid frequency B, and the second (e.g., desired) trigger point (A' or C') may be a deviation of ±0.015 Hz. In this case, the mapping function can simply be "multiply the measured frequency deviation by 2," which can be expressed as an equation: v'=2(v).

[0073] In some examples, the controller function 552 and / or the mapping function 554 may be relatively simple, for example, following the examples above. In some examples, the controller function 552 and / or the mapping function 554 may be arbitrarily complex, for example, including linear and non-linear functions. Generally, in some examples, the mapping function may take the form v' = F(v), where F is any function that maps the predefined function 550 to the desired controller function 552.

[0074] In some examples, the controller function 552 may be constructed according to a grid operator's service specifications, such as a dynamic control service specification. For example, the power flow characteristic value may be the deviation of the grid frequency from the nominal frequency, and the controller function 552 may have a dead band in the range of ±0.015 Hz (i.e., supplying / consuming 0% of the grid component's power supply / consumption capacity), a first linear increase in the power consumed by the grid component 222 from 0% to a maximum of 5% of the grid component's consumption capacity between +0.015 Hz and +0.2 Hz, a first linear increase in the power consumed by the grid component 222 from 0% to a maximum of 5% of the grid component's consumption capacity between -0.015 Hz and -0.2 Hz, and a second linear increase in the power consumed by the grid component 222 from 0% to a maximum of 5% of the grid component's supply capacity between -0.015 Hz and -0.2 Hz. A corresponding first linear increase in power provided by grid component 222, a second increase (e.g., linear increase) in power consumed by grid component 222 from 5% to 100% of grid component 222 consumption capacity between +0.02 Hz and +0.5 Hz, and a corresponding second increase (e.g., linear increase) in power provided by grid component 222 from 5% to 100% of grid component 222 supply capacity between -0.02 Hz and -0.5 Hz. For example, other controller functions may be used as and when different service specifications are published.

[0075] As mentioned above, in some instances it may be desirable to implement controller function 552 instead of predefined function 550, for example, as a result of a change in grid operator policy. However, in some instances, changes in the obtained power flow characteristic values may be in response to other events.

[0076] For example, in some examples, changes to the obtained power flow characteristic values may be in response to detected and / or predicted changes in grid conditions of the power grid. This may allow the response provided by grid component 222 to be modified during or before a change in grid conditions, such as a frequency event or a drop in inertia. For example, a minimum value for the event may be predicted, and the response of grid component 222 may be triggered by a modified grid characteristic value before a nadir occurs. The change in grid conditions may be detected or predicted by controller 250 or another entity.

[0077] In some examples, grid conditions may include one or more of the following: grid inertia, short-circuit ratio, fault level, and / or system strength; and / or frequency, voltage, current, reactive power, one or more oscillations, one or more harmonics, and / or phase angle of electricity flowing within the grid. Grid inertia is a measure of the amount of kinetic energy stored in the grid and affects the rate at which the grid's operating frequency changes in response to changes in the balance of power supply and consumption within the grid. A change in any one or more of these grid conditions may mean that one or more controller functions are more optimal in response to changes in power flow characteristics than a predefined function. For example, if a change in grid inertia is detected, deadbands may be reduced and / or a more aggressive controller function compared to a predefined function may be preferred to provide a faster response to changes in the power balance within the grid.

[0078] For example, referring to FIG. 4, there is a plot illustrating changes in grid conditions for power grid 200 according to an example. Specifically, in this example, the plot is of grid frequency f versus time t. Between times t1 and t2, the grid frequency is at its nominal value f0. However, at time t2, the grid frequency drops sharply and flattens to a new value at time t4 (the event minimum). For example, such an event may be caused by a generator 206 ceasing operation due to a fault. The change in grid condition (in this case, the drop in grid frequency to the value at time t4) may be detected by detecting the drop in frequency between times t2 and t4. In some examples, the change in grid condition may be predicted by analyzing the drop in frequency between t2 and t3 and predicting or forecasting that the frequency will continue to drop to the value at t4. For example, the prediction may be achieved by fitting a polynomial function to the frequency as a function of time and extrapolating the function to future times. For example, a change in the power flow characteristic value may be triggered in response to a prediction of time t3 at which the frequency will continue to decrease, so that grid components may supply power to grid 200 sooner than they would otherwise (thus helping to return the grid frequency to its nominal value). Thus, a more effective response to changing grid conditions may be provided.

[0079] In some examples, the method may include dynamically varying the modification of the obtained power flow characteristic value v in response to one or more detected or predicted changes in grid conditions of the power grid. This may allow the modified response provided by the grid component 222 to vary in response to evolving conditions in the grid. This may provide a more appropriate response to a power flow characteristic event. The detected or predicted grid condition changes may be, for example, the same as those mentioned above. Dynamically varying the modification may include, for example, at a first time point, modifying the obtained power flow characteristic value v by inputting the obtained power flow characteristic value to a first mapping function that maps a predefined function to a first controller function to generate a first modified power flow characteristic value, and at a second, later time point (e.g., in response to one or more detected or predicted changes in grid conditions), modifying the obtained power flow characteristic value v by inputting the obtained power flow characteristic value to a second mapping function that maps the predefined function to a second controller function to generate a second modified power flow characteristic value. For example, the second controller function may have a smaller deadband and / or an increased slope of power P as a function of power flow characteristic value v outside the deadband compared to the first controller function. In any case, dynamically varying the modifications may enable providing more detailed and / or more appropriate responses to changing grid conditions.

[0080] As mentioned above, in some examples, the grid conditions may include one or more oscillations in electricity flowing through the power grid. For example, the one or more oscillations may be inter-area oscillations, such as oscillations in power or frequency between different areas of the grid 200. As another example, the one or more oscillations may result from one or more auxiliary service units being locked in a feedback loop, such that, for example, rather than canceling a frequency deviation from a nominal value as designed, the one or more auxiliary service units contribute to the deviation in the form of such oscillations. For example, the oscillations may occur at frequencies on the order of 1 Hz or a few Hz, or, for example, 0.5 Hz. Referring to FIG. 5, a plot of grid frequency f versus time t is shown. Between times t1 and t2, grid frequency f is at its nominal value f0. However, at time t2, the grid frequency begins to oscillate. Between times t2 and t3, for example, the period, frequency, and / or phase of the oscillations may be determined.

[0081] In some examples, dynamically varying the modifications may include varying the modifications to dampen one or more oscillations. This may be useful, for example, to dampen or eliminate grid frequency oscillations that may occur between different portions of the grid or that may occur due to responsive auxiliary service units being locked in a feedback loop. For example, dynamically varying the modifications may include changing the modified power flow characteristic values to change the power that one or more grid components 222 supply to or consume from the grid 200 out of phase with the oscillations. For example, at time t4, the grid frequency oscillations may be at a valley (i.e., a minimum), so the power flow characteristic values may be modified such that one or more grid components 222 supply power to the grid at this time. However, at time t5, the grid frequency oscillations may be at a peak (i.e., a maximum), so the power flow characteristic values may be modified such that one or more grid components 222 consume power from the grid at this time. In this manner, the oscillations may be dampened.

[0082] In some examples, the dynamic variation may take into account a latency or delay between transmitting the modified power flow characteristic value and one or more grid components 222 supplying and / or consuming power in response. For example, if the oscillations in the measured power flow characteristic value have a period of 1 second and the time it takes for the modified power flow characteristic value to be transmitted to the grid components that supply or consume power to the grid 200 according to the received value is 0.5 seconds, dynamically varying the modification of the power flow characteristic value may include oscillating the modified power flow characteristic value with a phase shift of 0.5 seconds compared to the measured oscillation, thereby ensuring that the controlled power consumption / delivery is actually out of phase with the oscillation and therefore damping the measured oscillation.

[0083] In some examples, the obtained power flow characteristic values may be modified (or actually dynamically changed) in response to reaching one or more points in a time schedule. This may allow the functions by which grid components are controlled to consume / supply power to depend on time, e.g., time of day or time of year. This may provide a simple way to account for differences in grid conditions that may occur at those different times. For example, power consumption may be known to peak at certain times of the day and / or at certain times of the year. Accordingly, the controller functions by which grid components consume / supply power to the grid may be different for those different times. For example, during peak consumption times, the dead band may be reduced.

[0084] In some examples, only the modified power flow characteristic value is transmitted from the controller 205 to one or more grid components 222. However, in some examples, one or more additional signals may be transmitted in addition to the modified power flow characteristic value.

[0085] In some examples, the predefined function 550 is fixed in each of one or more grid components 222. For example, the predefined function or parameters (e.g., trigger values) characterizing the predefined function 550 stored in the grid component 222 may not be changeable. In some examples, the predefined function of the grid component 222 can only be changed by manually reprogramming the grid component 222 with a new predefined function. For example, during manufacture or installation of the grid component 222, the predefined function 550 may be preprogrammed into the memory of the grid component 222, and the predefined function 550 may be immutable, unchangeable, or changeable only by, for example, manual reprogramming of the grid component 222. In these cases, changing the power flow characteristic values in the manner described above and transmitting them to one or more grid components 222 may enable the grid components to consume / supply power according to a different function (i.e., controller function 552) and / or may enable the grid components to consume / supply power according to a controller function without having to manually reprogram the grid components 222 with controller functions 552 (and retest the grid components 222 for conformance to the specifications of the reprogrammed function) to replace the predefined function 550. As described, this may allow for increased flexibility and / or cost efficiency in providing responses in response to changes in power flow characteristics.

[0086] However, in some examples, the predefined function stored in each grid component 222 may not necessarily be fixed and, in some examples, may include one or more parameters that are variable. In such examples, the method may include, in addition to the modified power flow characteristic values, sending to one or more grid components 222 a reparameterization signal configured to cause each of the one or more grid components 222 to modify one or more parameters of the predefined function 550 configured for the grid component 222 to consume power from and / or supply power to the power grid 200. This may enable control of the power consumption / supply of the grid component 222 by causing the grid component 222 to modify one or more parameters of the predefined function 550 itself, in addition to the control of the power consumption / supply of the grid component 222 provided by modifying the power flow characteristic values.

[0087] In some examples, in addition to changing the power flow characteristic values, it may be useful to change certain parameters of the predefined function via a reparameterization signal because, in some cases, it may not be possible to control certain parameters solely by changing the power flow characteristic. For example, one or more parameters may define the aggressiveness of the response, e.g., the amount of power P that the grid component 222 provides to or consumes from the grid 200, or the percentage of total available power. For example, a signal may increase or decrease the maximum power consumption / supply (or maximum percentage of total available power) included in the predefined function 550. Changing the maximum power consumption / supply specified by the predefined function using a reparameterization signal is useful because, in some cases, this may not be achievable solely by changing the power flow characteristic values. As another example, one or more parameters may define the mode of power consumption / supply by the grid component 222, e.g., specifying the phase angle and therefore the percentage of reactive power that the grid component 222 provides / consumes. Again, using a reparameterization signal to change the mode of power consumption / supply may be useful because in some cases this may not be achievable by simply changing the power flow characteristic values, and therefore in these cases may provide a more appropriate and / or granular response to changes in the power flow characteristic values compared to, for example, using only the modified power flow characteristic values.

[0088] In yet another example, the reparameterization signal may be used to change certain other parameters of the predefined function 550. For example, the one or more parameters may be one or more trigger points of the predefined function 550. For example, the reparameterization signal may reparameterize, for example, to decrease or increase the deadband of the predefined function. In some cases, it may be useful to change such parameters via the reparameterization signal in addition to controlling such parameters via a changed power flow characteristic. For example, it may be desirable to control multiple grid components 222 according to a particular controller function 552 (e.g., to provide a coordinated response to changes in power flow characteristic values), but each of the multiple grid components 222 may have a different predefined function 550. In this case, the grid components 222 may be controlled using respective multiple mapping functions 554 and transmitting respective multiple changed power flow characteristic value streams to each grid component 222. However, it may be desirable to limit the number of different changed power flow characteristic value streams transmitted, for example, to reduce communication overhead and therefore improve communication efficiency. In this case, a reparameterization signal may be initially transmitted to one or more grid components 222, and the predefined function 550 may be uniformed (e.g., made the same) (in some examples only temporarily) across two or more grid components 222. These two or more grid components 222 may then be controlled according to the controller function 552 based on the same modified power flow characteristic values. This may reduce the number of streams of different modified power flow characteristic values that need to be transmitted, thus improving communication efficiency.As another example, a reparameterization signal may be used to reparameterize a predefined function in advance, e.g., before a grid condition change (e.g., a frequency event) occurs, and the change in the power flow characteristic may be used to further control the grid component 222 to consume / supply power according to the controller function in response to the grid condition change (e.g., the occurrence of a frequency event). This may enable providing an effective response to dynamic changes in grid conditions. As another example, a reparameterization signal may be used to reparameterize one parameter of a predefined function, and the change in the power flow characteristic value may be used to effectively control another parameter. For example, the amount of power consumed and / or provided by the grid component 222 according to the predefined function may be changed via the reparameterization signal, but the rate at which the power consumption / supply occurs (e.g., how narrow the dead band is, how steep the slope of the power consumption / supply as a function of the power flow characteristic value, or the general functional form of the power consumption / supply as a function of the power flow characteristic value) may be controlled via the change in the power flow characteristic value. Because the latter can be particularly time-consuming and resource-intensive to change by manual reprogramming, controlling these parameters through changes in power flow characteristic values may offer certain improvements in speed and efficiency in implementing control according to the controller function.

[0089] In some examples, each grid component 222 may have (e.g., store) only one predefined function 550. However, in other examples, one or more grid components 222 may each have multiple selectable predefined functions by which the respective grid component 222 may be configured to consume power from and / or supply power to the power grid 220.

[0090] For example, the multiple predefined functions may differ from one another in any one or more of a variety of different ways. For example, as described above, each predefined function may be parameterized by one or more parameters, and the predefined functions may differ from one another by one or more parameters varying among the predefined functions. For example, as also described above, the one or more parameters may include one or more of the aggressiveness of the predefined function, the slope of one or more portions of the predefined function, one or more trigger points of the predefined function, the mode of consumption / provision of power by grid component 222, and / or the delay applied by the grid component before power is provided / consumed by grid component 222.

[0091] In these cases, the method may include transmitting to one or more grid components 222, in addition to the modified power flow characteristic value, a selection signal configured to cause each of the one or more grid components 222 to select a predefined function from among a plurality of predefined functions, whereby each grid component is configured to consume power from and / or supply power to the power grid according to the selected predefined function. For example, a particular grid component 222 may operate according to a first predefined function from among a plurality of selectable predefined functions. Grid component 222 receives a selection signal specifying that grid component 222 should operate according to a second predefined function from among the plurality of selectable predefined functions. Upon receiving the selection signal, the grid component obtains and operates according to the second predefined function. For example, if low inertia is detected, measured, or predicted on the power grid, the selection signal may cause one or more of grid components 222 to respectively select a predefined function that provides a more aggressive response to changes in grid frequency. Other criteria may also be used. This may allow one to adjust the response provided by grid component 222 not only by changing the power flow characteristics, but also by having the grid component select a particular function from among multiple predefined functions.

[0092] In some examples, the above methods may be applied to only one grid component 222. However, in other examples, the methods may be applied to multiple grid components 222. This may allow the multiple grid components 222 to provide a coordinated response to changes in power flow characteristics. This may allow the multiple grid components 222 to provide a larger, and therefore more effective, response to changes in power flow characteristics.

[0093] Referring to Figure 6, a portion of a power grid 200' is shown. For clarity, only grid component 222 is displayed in Figure 6, but it is understood that power grid 200' shown in Figure 6 may be the same as or similar to power grid 200 described above in connection with Figure 2, for example. In the example of Figure 6, grid 200' includes multiple (four in this example) grid components 222a, 222b, 222c, and 222d.

[0094] In some examples, the method may include selecting a first group 600a of one or more 222a, 222b of the plurality of grid components 222a-222d and transmitting modified power flow characteristic values to each grid component 222a, 222b in the selected first group 600a, thereby increasing granularity of response to changes in the power flow characteristic values provided by the grid components 222. For example, as described in more detail below, the grid components 222 may be selected for the first group based on the region in which the grid component is located, the type of grid component 222, and / or the current operational status of the grid component 222.

[0095] In some examples, all of the grid components 222 in the first group 600a may have the same predefined function 550. In this case, the same modified power flow characteristic value may be transmitted to each of the grid components 222a, 222b in the selected first group 600a. In this case, transmitting the modified power flow characteristic value may include broadcasting the modified power flow characteristic value to the first group 600a. For example, if all of the grid components 222 in the first group 600a are in the same region, the modified power flow characteristic value may be broadcast to that region. In that case, all of the grid components 222 in that region may be controlled to consume / supply power according to the controller function 552. However, in some examples, one or more of the grid components in the first group 600a may have a predefined function 550 that is different from the predefined function 550 of one or more other grid components in the first group 600a. In this case, different modified power flow characteristic values may be transmitted to different grid components 222 of the first group 600a (according to respective different mapping functions 554 that map respective different predefined functions 550 to the controller function 552) to control each grid component of the first group 600a according to the same controller function 552. In this case, for example, transmitting the modified power flow characteristic values may include transmitting the modified power flow characteristic values individually to each grid component 222 of the first group 600a. In some examples, the method may include selecting one or more 222c, 222d of the second group 600b of grid components from among the plurality of grid components 222. In these examples, the method may include transmitting a second modified power flow characteristic value to each grid component 222c, 222d of the second group 600b of grid components. For example, the second modified power flow characteristic value may be different from the first modified power flow characteristic value transmitted to the first group 600a.For example, a first modified power flow characteristic value may be obtained by inputting the obtained power flow characteristic value into a first mapping function 554 that maps the predefined function 550 to a first controller function 552, thereby controlling a first group 600a of grid components 222a, 222b to consume power from and / or supply power to the power grid 200′ in accordance with the first controller function 552. Meanwhile, for example, a second modified power flow characteristic value may be obtained by inputting the obtained power flow characteristic value into a second mapping function (not shown) that maps the predefined function 550 to a second controller function (not shown) different from the first controller function 552, thereby controlling a second group 600b of grid components 222c, 222d to consume power from and / or supply power to the power grid in accordance with the second controller function (not shown). This may allow different groups of grid components 222 to operate according to different controller functions 552, which may allow for further refinement of the granularity with which responses to changes in power flow characteristic values may be provided. As described for the first group 600a above, the grid components 222 in the second group 600b may all have the same predefined function (which may in some examples be the same as the predefined function for the grid components 222 in the first group 600a) or may have different predefined functions 550 from one another. Thus, transmitting the second modified power flow characteristic value may be performed by broadcasting the same second modified power flow characteristic value to all grid components 222 in the second group 600b, or by transmitting different second modified power flow characteristic values to different ones of the grid components according to their predefined functions 550, as desired, for example.Similarly, in some examples, the grid components of the first group 600a may have the same predefined function as the grid components of the second group 600b, or may have a different predefined function than the grid components of the second group 600b. In the latter case, modifying the second modified power flow characteristic values may include inputting the resulting power flow characteristic values to a second mapping function (not shown) that maps a different predefined function (not shown) to a second controller function (not shown). In some examples, selecting one or more grid components of the first group 600a and / or selecting one or more grid components of the second group 600b may be based on the region in which the grid components are located. This may provide a particular response to changes in the power flow characteristic values in a particular region, or a different response may be provided in different regions (e.g., different grid regions / locations and / or different geographic regions / areas / locations). For example, different regions or areas of the grid 200′ may have different inertias. For example, in areas of grid 200′ with low inertia, grid frequency may change relatively quickly in response to a particular change in the power consumption / supply balance. Therefore, for grid components 222 in areas of grid 200′ with low inertia, the underlying controller function 552 from which modified frequency values are derived may have a relatively small deadband of frequency to cause the grid components 222 to react relatively quickly to measured frequency changes. As another example, a fault, such as an unexpected disconnection of a generator, may occur in a particular area of the grid. Therefore, for grid components 222 in areas of grid 200′ where the fault occurs, the controller function may define a relatively aggressive response (e.g., a relatively large change in power for a particular change in frequency) to cause these grid components to respond aggressively to the fault. For example, reactive power does not typically travel long distances within a grid.Therefore, responding to a reactive power or voltage sag is best done by controlling grid components 222 in the same area as the reactive power or voltage sag to provide an effective response.

[0096] In some examples, there may be multiple grid components 222a, 222b in the first group 600a, and the grid components selected for the first group may be located in the same area (e.g., grid area or geographic area) as each other. Similarly, there may be multiple grid components 222c, 222d in the second group 600b, and the grid components selected for the second group 600b may be located in the same area (e.g., grid area or geographic area) as each other. This may allow for the provision of coordinated responses from multiple grid components 222 in a particular area, or different coordinated responses in different areas.

[0097] In some examples, the first group 600a and / or the second group 600b of grid components may be selected based on at least one power flow condition in the region in which the grid components of the respective groups are located. This may enable specific response(s) to be provided in the specific region(s) based on the power flow conditions in the specific region(s). For example, as described above, the power flow conditions in a specific region may include one or more of the inertia of the region and the reactive power of the region. This may enable providing a more optimal and / or detailed response. As another example, the power flow conditions may include an event propagation time, such as an estimate or prediction of the time it takes for the effects of an event (such as the loss of a generator) to propagate through a region of the grid. For example, propagation may be faster in a strong region of the grid with low inertia and slower in a weak region of the grid with high inertia. This may enable, for example, selecting grid components to provide a response taking propagation time into account. For example, in a region with a relatively small propagation time, grid components with a relatively fast response capability may be selected. This may enable providing an optimal and / or effective response.

[0098] In some examples, the first group 600a and / or the second group 600b of grid components may be selected based on the area in which the grid components of the respective groups are located, where a response to a change in grid conditions in the power grid is determined to be necessary or likely to be effective. This may allow the grid components 222 to provide a response in the area where a response is determined to be necessary or likely to be effective. For example, as described above, grid components 222 in the same area as the fault (and / or areas with low inertia or reactive power) may be selected to provide a modified response, which may be more effective than providing a response in an area farther away from the fault. As another example, grid components 222 in an area where the response is likely to propagate effectively throughout the grid 200′ may be selected to provide a response. For example, a grid area with low inductance may allow reactive power to propagate relatively effectively.

[0099] In some examples, the first group 600a and / or the second group 600b of grid components may be selected based on the type of grid component. For example, the type of grid component may include one or more of: whether the grid component consumes or provides power; the power provision / consumption capacity of the grid component; the power provision / consumption function of the grid component, such as a response speed; the power consumption / provision mode of the grid component; the delay before power is consumed / provided by the grid component; the operating status of the grid component; one or more impact characteristics of the grid component (e.g., a response propagation time indicating an estimate or prediction of the time it takes for a change in power provision / consumption to propagate throughout the grid, with propagation being faster for grid components located in strong regions of the grid with low inertia); or any other characteristic of the grid component. For example, groups may be selected that include grid components of the same or similar type to each other, which may provide a coordinated response from the group of power units. As another example, the groups may be selected to include a mix of grid components of various types, such as some grid components with low provision / consumption capacity but with low delays to provide a relatively small but rapid initial response and some grid components with high provision / consumption capacity but with high delays to provide a relatively large follow-up response. In either case, a more optimal and / or detailed response may be provided.

[0100] As mentioned above, in some examples, power consumed from and / or supplied to the power grid by one or more grid components may be reactive power, which may enable, for example, providing a response to voltage deviations.

[0101] As previously mentioned, in some examples, at least controller function 552 may include a dead-band for a power flow characteristic such that one or more grid components 222 are controlled to consume power from and / or supply power to the grid only when the obtained power flow characteristic value v is outside the dead-band. This may allow the dead-band to be implemented (or modified) by providing modified power flow characteristic values to grid components 222, which may provide a stable response. This may also be provided for grid components 222 for which the predefined function 550 does not necessarily include a dead-band.

[0102] Referring to FIG. 7, a system 700 is shown that includes a device 205. The device 205 may be configured to perform a method according to any of the examples described above in connection with FIGS. 1-6. For example, the device 205 may be the controller 205 described above in connection with FIGS. 1-6 and / or perform any of the functions of the examples of the controller 205 described above in connection with FIGS. 1-6. In this example, the system 700 includes a grid component 222. For example, the grid component 222 may be configured to perform any one or more functions of any one of the examples of the grid component 222 described above in connection with FIGS. 1-6. As also discussed above, in some examples, the system may include multiple grid components 222, which may be grouped into separate groups and / or located in different areas of the grid 200, for example, as described above in connection with FIGS. 1-6. In this example, the system 700 includes a measurement device 220. In some examples, there may be multiple measurement devices 220 located in different areas of the grid, for example, as described above in connection with FIGS. 1-6.

[0103] In this example, device 205 (hereinafter controller 205) includes an input interface 718, a memory 714, a processor 712, and an output interface 716. Memory 714 may store a computer program including instructions that, when executed by the processor, cause controller 205 to perform a method according to any one of the examples described above in connection with Figures 1-6. Additionally, a computer-readable medium may be provided that stores instructions that, when executed by a computer (such as controller 205), cause the computer to perform a method according to any one of the examples described above in connection with Figures 1-6.

[0104] Input interface 718 is configured to receive measurement data indicative of one or more measurements of power flow characteristics in power grid 200 from measurement device 220. The measurement data may be communicated via wired or wireless means. Input interface 718 provides the measurement data to processor 712, which enables processor 712 to obtain power flow characteristic values.

[0105] The memory 714 may store predefined functions 550 for one or more grid components 222, one or more controller functions 552 that are desired to control the one or more grid components 222, and / or one or more mapping functions 554, each mapping a predefined function 550 to a controller function 552.

[0106] The processor 712, in combination with the memory 714, may modify the obtained power flow characteristic values by inputting the obtained power flow characteristic values into a mapping function 554 that maps a predefined function 550 to a controller function 552 to generate modified power flow characteristic values. For example, the mapping function 554 may be retrieved from the memory 714. In some examples, the processor 712 may determine a predefined function 550 to be used by the selected one or more grid components 222, determine a controller function 552 for controlling the selected one or more grid components, and determine a mapping function 554 that maps the determined predefined function 550 to the determined controller function 552 (e.g., by generating a mapping function from the predefined function 550 and the controller function 552, or by retrieving an appropriate mapping 554 function from the memory 714, for example). In either case, the processor 712 may provide the modified power flow characteristic values to the output interface 716.

[0107] The output interface 716 may be configured to transmit the modified power flow characteristic values to one or more grid components 222, thereby controlling the one or more grid components 222 to consume power from and / or supply power to the power grid 200 in accordance with the controller function 554. For example, the output interface 716 may be configured to transmit the modified power flow characteristic values to one or more grid components 222 via wired or wireless means. For example, the output interface 716 may be configured to transmit the modified (or possibly unchanged) power flow characteristic values to one or more grid components 222 via a communications network, such as the Internet 710. For example, each of the one or more grid components 222 may subscribe to the controller 205's data stream and may receive real-time or near-real-time power flow characteristic values from the controller 205 via this stream. When the controller 205 modifies the power flow characteristic values in the manner described above, the data stream includes the modified power flow characteristic values, so that the one or more grid components 222 receive those modified power flow characteristic values. Other means may be used to provide power flow characteristics from controller 205 to grid components 222. In addition to modified power flow characteristics, output interface 716 may transmit other signals determined by processor 712 to one or more grid components 222, such as reparameterization signals and / or selection signals, as described above.

[0108] In this example, grid component 222 includes input interface 818, memory 814, processor 812, and electricity consumers and / or suppliers 816. Input interface 318 is configured to receive power flow characteristics (as well as additional signals, in some examples) from controller 205, for example, in the manner described above. Memory 314 may store a predefined function 550 (or, in some examples, multiple selectable predefined functions 550) for grid component 222 to consume / supply power to grid 200. The predefined function(s) 550 are preprogrammed into grid component 222, for example, during grid component installation and / or registration of grid component 222 as part of an ancillary service. For example, when grid component 222 is registered, memory 714 or other storage of controller 205 may be updated with an identifier for grid component 222 to associate with the grid component's predefined function(s) 550 (and other information about the grid component, such as, for example, the grid component's location, type, supply / consumption capabilities, etc.). For example, other information may include the maximum capabilities of grid component 222, such as the maximum supply / consumption capacity of grid component 222 (or the maximum capacity made available as part of ancillary services), the maximum rate at which grid component 222 can change its power consumption and / or supply (or the maximum rate at which it can be made available as part of ancillary services), etc. Controller 205 may be configured to limit controller function 552 and / or mapping function 554 to prevent grid component 222 from exceeding these maximum values. This may help ensure that grid components do not need to be tested and certified for use with a new controller function 552 each time a new controller function 552 is used.

[0109] The processor 812 may retrieve the predefined function 550 from the memory 314, input the received (modified) power flow characteristic value into the predefined function 550, and obtain an output of the function, e.g., power P, that the grid component 222 consumes from or provides to the power grid 200. The processor 312 may control the power consumers and / or providers 316 to consume or provide power to the grid 200 according to the output of the function 550.

[0110] Thus, one or more grid components 222 may consume power from and / or supply power to the power grid according to controller function 552 .

[0111] In some examples, the input interface 818 of the grid component 222 may receive a local measurement of the power flow characteristic value in addition to the modified power flow characteristic value. For example, the grid component may include or be associated with a measurement device (not shown in FIG. 7 ) that measures the power flow characteristic value at or near the grid component. In some examples, if the modified power flow characteristic value is not received by the grid component 222 due to a communication issue, such as an internet connection issue, the grid component 222 may instead use the local measurement of the power flow characteristic value. This may provide a failover / fail-safe capability for the grid component to continue operating in at least some functionality even if the modified power flow characteristic value is not received for some reason.

[0112] In some examples, each grid component 222 may consume power from and / or supply power to the power grid 200 according to a predefined function that takes only one power flow characteristic value as an input. However, in other examples, the consumption and / or supply of power from and / or to the power grid 200 by the grid component 222 may be based on received values of multiple different power flow characteristics. For example, in some examples, the predefined function 550 may be a multidimensional function that takes as input values for each of multiple different power flow characteristics. As another example, there may be multiple predefined functions 550 according to which a particular grid component 222 is configured to consume power from and / or supply power to the power grid 200. For example, for a particular grid component 222, a first predefined function (or a first dimension of a multidimensional predefined function) may receive as input a received value of a first power flow characteristic, and a second predefined function (or a second dimension of a multidimensional predefined function) may receive as input a received value of a second power flow characteristic. For example, the first power flow characteristic may be grid frequency and the second power flow characteristic may be grid inertia (although it is understood that any number of power flow characteristics may be used). For example, if grid component 222 is a generator, the first predefined function / dimension may include a frequency trigger value below which generator 222 supplies power to power grid 200, and the second predefined function / dimension may include an inertia trigger value below which grid component 222 supplies power to power grid 200. For example, if either or both of the trigger values are met, grid component 222 may supply power to the power grid (although it is understood that, as noted above, each predefined function or multi-dimensional predefined function may take any functional form). In such cases, or otherwise, values of the multiple power flow characteristic values may be received by the grid component and used as inputs for the dimensions of the respective predefined function or multi-dimensional predefined function. In such cases, or otherwise, the values of each of the multiple power flow characteristics may be changed by the controller.For example, the value of each respective power flow characteristic may be changed by inputting the acquired value of the respective power flow characteristic into a mapping function that maps a respective predefined function to a respective controller function. As another example, the predefined functions, the controller function, and the mapping function may each be multi-dimensional. In these examples, the value of each respective power flow characteristic may be changed by inputting the acquired value of the respective power flow characteristic into a respective dimension of the mapping function that maps the predefined function to the controller function. In some examples, each value of multiple power flow characteristics may be changed. However, in other examples, only the values of one or more of the multiple power flow characteristics may be changed.

[0113] Thus, in some examples, each grid component 222 may be configured to receive values of each of a plurality of power flow characteristics from the controller and consume power from and / or supply power to power grid 200 according to at least one predefined function that takes the received values of the plurality of power flow characteristics as inputs. In these cases, obtaining measurement data according to step 102 may include obtaining data indicative of one or more measurements of each of the characteristics of the plurality of power flows in the power flow grid. Modifying the obtained power flow characteristic values according to step 104 may include modifying the obtained value of each of the plurality of power flow characteristics by inputting the obtained value of each of the plurality of power flow characteristics to at least one mapping function that maps the at least one predefined function to at least one controller function to generate modified values of each of the plurality of power flow characteristics. Transmitting the modified power flow characteristic values as in step 106 may include transmitting the modified values of the power flow characteristics to one or more grid components, thereby controlling one or more grid components 222 to consume power from and / or supply power to power grid 200 according to at least one controller function. In the above example, the modified power flow characteristic values are transmitted to one or more grid components 222, thereby controlling one or more grid components 222 to consume power from and / or supply power to power grid 200 according to controller function 552.

[0114] However, in some examples, the method need not necessarily include transmitting the modified power flow characteristic value to one or more grid components 222. For example, a method for providing a modified power flow characteristic value v' may be provided, and this modified power flow characteristic value v' may have other uses. For example, with reference to FIG. 8, a method for providing a modified power flow characteristic value v' is shown. For example, the method may be performed by a first entity (e.g., see apparatus 900 in FIG. 9), which in some examples may be controller 205 according to any one of the examples described above in connection with FIGS. 1-7, or in other examples may be any entity, such as a general-purpose computer.

[0115] The method includes, at step 802, obtaining measurement data indicative of one or more measurements of characteristics of power flow in the power grid 200. For example, the measurement data and / or the grid 200 may be the same as or similar to those described above in connection with FIGS. 1-7. One or more grid components 222 are configured to consume power from and / or supply power to the power grid according to a first function based on the respective received power flow characteristic values v. In some examples, the first function may be a predefined function 550 according to any one of the examples described above in connection with FIGS. 1-7.

[0116] The method, at step 804, includes determining a second function, different from the first function, for controlling one or more grid components 222 to consume power from and / or supply power to the power grid. For example, the second function may be controller function 552 according to any one of the examples described above in connection with FIGS. 1-7. For example, as described above for controller function 552, the second function may be provided or specified by a grid operator, and determining the second function may include, for example, obtaining the second function from the grid operator. As another example, the second function may be determined based on a detected or predicted change in grid conditions of the power grid, a particular point in time on a time schedule that has arrived, a group to which one or more grid components belong, a particular area in which the one or more grid components are located, and / or grid conditions in the particular area. For example, different second functions may be associated with different grid conditions, times, groups, and / or regions, and determining the second function may include matching the detected or predicted grid conditions, the current time, the group to which one or more grid components 222 belong, and / or the region in which one or more grid components are located to the associated second function.

[0117] In step 806, the method includes modifying the obtained power flow characteristic value v by inputting the obtained power flow characteristic value v to a mapping function that maps the first function to a second function to generate a modified power flow characteristic value v′. For example, the mapping function may be mapping function 554 according to any one of the examples described above in connection with FIGS. 1-7.

[0118] The method includes outputting the modified power flow characteristic values at step 808. The output modified power flow characteristic values may be used in different ways (which may or may not include transmitting the output modified values to one or more grid components 222 to control the one or more grid components according to the second function). For example, the method may include providing the modified power flow characteristic values to one or more components of a model of the power grid 200 to simulate power flow behavior within the power grid that would result if the modified power flow characteristic values were transmitted to one or more grid components 222. This may allow a grid operator to simulate how the grid 200 would react when the modified values are transmitted to particular grid components. For example, the model may include a “digital twin” of the power grid 200 and may model the behavior of the grid 200. One or more components of the model may include one or more grid component models that may model the behavior of grid components 222 within the grid 200. The modified power flow characteristics may be provided as inputs to one or more grid component models to model the resulting power flow behavior within the grid, which can aid in designing a controller function 554 that provides the most optimal response to changes in power flow characteristics or grid conditions of the grid 200, for example.

[0119] In some examples, as described above, values of multiple power flow characteristics may be used, and there may be a respective plurality of first functions (or the first function may have dimensions of the respective plurality of power flow characteristic values). Thus, in some examples, obtaining measurement data according to step 802 may include obtaining measurement data indicative of one or more measurements of each of a plurality of characteristics of power flow in power grid 200. Determining a second function according to step 804 may include determining at least one second function different from the at least one first function for controlling one or more grid components 222 to consume power from and / or supply power to power grid 200. Modifying the obtained power flow characteristic values according to step 806 may include modifying the obtained values of the plurality of power flow characteristics by inputting the obtained values of the plurality of power flow characteristics into at least one mapping function that maps the at least one first function to the at least one second function to generate modified values of the plurality of power flow characteristics. Outputting the modified power flow characteristics according to step 806 may include outputting modified values of a plurality of power flow characteristics. Referring to FIG. 9 , an apparatus 900 according to an example is shown. The apparatus may be configured to perform a method according to any one of the examples described above in connection with FIG. 8 . The apparatus 900 includes a processor 902, a memory 904, an input interface 906, and an output interface 908. The memory 904 may store a computer program that, when executed by the processor 902, causes the processor to perform a method according to any of the examples described above in connection with FIG. 8 . In some examples, a model of the power grid 200 may also be executed by the processor 902 and the memory 904. In some examples, the model of the power grid may be executed by another device (not shown). In some examples, the input interface 906 may receive measurement data, for example, from a measurement device (not shown in FIG. 9 ) or from the output of another device (not shown) that executes the model of the power grid 200.In some examples, the output interface 908 may output the modified power flow characteristic values, for example to another device (not shown), or for example to one or more grid components (not shown in FIG. 9).

[0120] The above examples are to be understood as illustrative examples of the present invention. It is to be understood that any feature described in connection with any one embodiment may be used alone or in combination with other features described, and may also be used in combination with one or more features of any other embodiment, or in any combination of any other embodiment. Furthermore, equivalents and modifications not described above may be employed without departing from the scope of the present invention, as defined in the appended claims.

Claims

1. 1. A method of controlling one or more grid components of an electric power grid, each grid component configured to consume power from and / or supply power to the electric power grid, each grid component configured to receive a respective power flow characteristic value from a controller and to consume power from and / or supply power to the electric power grid according to a respective predefined function, the predefined function receiving the received power flow characteristic value as an input, the method comprising: obtaining measurement data indicative of one or more measurements of characteristics of power flow in the power grid; modifying the obtained power flow characteristic values by inputting the obtained power flow characteristic values into a mapping function that maps the predefined function to a controller function to generate modified power flow characteristic values; transmitting the modified power flow characteristic value to the one or more grid components, thereby controlling the one or more grid components to consume power from and / or supply power to the power grid in accordance with the controller function.

2. 2. The method of claim 1, wherein the predefined function defines a first trigger point for the power flow characteristic value at which the respective grid component is triggered to consume power from and / or supply power to the power grid, the controller function defines a second trigger point for the power flow characteristic value that is different from the first trigger point, and wherein sending the modified power flow characteristic value to the one or more grid components triggers the one or more grid components to consume power from and / or supply power to the power grid when the obtained power flow characteristic value is at the second trigger point.

3. The method of claim 1 or claim 2, wherein modifying the obtained power flow characteristic values is in response to detected or predicted changes in grid conditions of the power network.

4. 10. The method of any one of the preceding claims, wherein the method includes dynamically varying the modifications of the obtained power flow characteristic values in response to one or more detected or predicted changes in grid conditions of the power grid.

5. 5. The method of claim 3 or claim 4, wherein the grid conditions include the inertia, short circuit ratio, fault level and / or system strength of the power grid, and / or the frequency, voltage, current, reactive power, one or more oscillations, one or more harmonics, and / or phase angle of electricity flowing within the power grid.

6. 5. The method of claim 4, wherein the grid conditions include one or more oscillations in electricity flowing within the power grid, and wherein dynamically varying the modification includes varying the modification to dampen one or more of the oscillations.

7. 10. A method according to any one of the preceding claims, wherein modifying the obtained power flow characteristic values is in response to reaching a point in time in a time schedule, and / or the method comprises dynamically varying the modification of the obtained power flow characteristic values in response to reaching one or more points in time in a time schedule.

8. 10. The method of any one of the preceding claims, comprising transmitting to the one or more grid components, in addition to the modified power flow characteristic value, a reparameterization signal configured to cause each of the one or more grid components to modify one or more parameters of the predefined function in accordance with the predefined function, the grid components being configured to consume power from and / or supply power to the power grid.

9. wherein each of the one or more grid components has a plurality of selectable predefined functions according to which the respective grid component is configurable to consume power from and / or supply power to the power grid, and the method further comprises:

10. The method of any one of the preceding claims, comprising transmitting to the one or more grid components, in addition to the modified power flow characteristic value, a selection signal configured to cause each of the one or more grid components to respectively select a predefined function from the plurality of predefined functions, whereby each of the grid components is configured to consume power from and / or supply power to the power grid in accordance with the selected predefined function.

10. 10. A method according to any one of the preceding claims, wherein there are a plurality of said grid components.

11. The method comprises: selecting a first group of one or more of the plurality of grid components; and transmitting the modified power flow characteristic value to each grid component in the selected first group.

12. The method comprises: selecting a second group of one or more of the plurality of grid components; 12. The method of claim 11, comprising: transmitting a second modified power flow characteristic value to each grid component of the second group of grid components, the second modified power flow characteristic value being obtained by inputting the obtained power flow characteristic value into a second mapping function that maps the predefined function to a second controller function, thereby controlling the second group of grid components to consume power from and / or supply power to the power grid in accordance with the second controller function.

13. 13. The method of claim 11 or 12, wherein selecting the first group of one or more grid components and / or selecting the second group of one or more grid components is based on an area in which the grid components are located.

14. 14. The method of claim 13, wherein there are multiple grid components in the first group, and the grid components selected to belong to the first group are located in the same area as each other, and / or there are multiple grid components in the second group, and the grid components selected to belong to the second group are located in the same area as each other.

15. 15. The method of claim 13 or 14, wherein the first group and / or the second group of grid components are selected based on at least one power flow condition in the region in which the grid components of the respective group are located.

16. 16. The method of claim 15, wherein the grid components of the first group and / or the second group are selected based on the region in which the grid components of the respective groups are located being a region in which a response to changes in grid conditions of the power grid is determined to be necessary or likely to be effective.

17. Obtaining the one or more power flow characteristic values in the controller comprises: obtaining a plurality of measurements of power flow characteristics obtained at respective plurality of different locations within the power grid; and combining the measurements to determine the obtained power flow characteristic value.

18. 10. A method according to any one of the preceding claims, wherein the power flow characteristics are indicative of one or more of the short circuit ratio, fault level and / or system strength of the power grid, and / or frequency, voltage, reactive power, one or more oscillations, one or more harmonics and / or phase angle of electricity flowing within the power grid.

19. 10. The method of any one of the preceding claims, wherein the power consumed from and / or supplied to the power grid by the one or more grid components is reactive power.

20. 10. The method of any one of the preceding claims, wherein at least the controller function includes a dead-band for power flow characteristic values, such that the one or more grid components are controlled to consume power from and / or supply power to the power grid only if the obtained power flow characteristic values are outside the dead-band.

21. each grid component is configured to receive respective values of a plurality of power flow characteristics from a controller and to consume power from and / or supply power to the power grid according to a respective at least one predefined function, the at least one predefined function receiving the received values of the plurality of power flow characteristics as inputs; obtaining the measurement data includes obtaining data indicative of one or more measurements of each of the plurality of characteristics of power flow in the power flow grid; modifying the obtained power flow characteristic values includes modifying the obtained value of each of the plurality of power flow characteristics by inputting the obtained value of each of the plurality of power flow characteristics into at least one mapping function that maps the at least one predefined function to at least one controller function to generate modified values of each of the plurality of power flow characteristics; 10. The method of any one of the preceding claims, wherein transmitting the modified power flow characteristic values comprises transmitting the modified values of the plurality of power flow characteristics to the one or more grid components to thereby control the one or more grid components to consume power from and / or supply power to the power grid in accordance with the at least one controller function.

22. 1. A method of providing a modified power flow characteristic value, the method comprising, at a first entity: obtaining measurement data indicative of one or more measurements of characteristics of power flow in an electric power grid, wherein one or more grid components are each configured to consume power from and / or supply power to the electric power grid according to a first function based on the received power flow characteristic values; determining a second function, different from the first function, for controlling the one or more grid components to consume power from and / or supply power to the power grid; modifying the obtained power flow characteristic values by inputting the obtained power flow characteristic values into a mapping function that maps the first function to the second function to generate modified power flow characteristic values; and outputting the modified power flow characteristic value.

23. The method comprises:

23. The method of claim 22, comprising providing the modified power flow characteristic values to one or more components of a model of the power grid, thereby simulating power flow behavior within the grid resulting from transmitting the modified power flow characteristic values to the one or more grid components.

24. obtaining the measurement data includes obtaining measurement data indicative of one or more measurements of each of a plurality of characteristics of power flow in an electric power grid, wherein one or more grid components are each configured to consume power from and / or supply power to the electric power grid according to at least one first function based on the received values of the plurality of power flow characteristics; determining the second function includes determining at least one second function different from the at least one first function for controlling the one or more grid components to consume power from and / or supply power to the power grid; modifying the obtained power flow characteristic values includes modifying the obtained values of the plurality of power flow characteristics by inputting the obtained values of the plurality of power flow characteristics into at least one mapping function that maps the at least one first function to the at least one second function to generate modified values of the plurality of power flow characteristics; outputting the modified power flow characteristics includes outputting the modified values of the plurality of power flow characteristics.

24. The method of claim 22 or claim 23.

25. An apparatus configured to perform the method of any one of claims 1 to 21 or the method of any one of claims 22 to 24.

26. A computer program comprising instructions which, when executed by a computer, cause the computer to carry out the method according to any one of claims 1 to 21 or the method according to any one of claims 22 to 24.

27. 26. A system comprising the apparatus of claim 25 and the one or more grid components.

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