Method of controlling participation of loads in an electric grid flexibility scheme

Abstract

A method of controlling participation of one or more loads in an electric grid flexibility scheme is disclosed. The method comprises halting participation of a load in the flexibility scheme in response to determining, by a processing system, that the load has failed to communicate a status update to the processing system within a first predefined period. Also disclosed is a corresponding energy flexibility management system, and a computer-implemented method of controlling participation of one or more loads in an electric grid flexibility scheme.

Description

[0001] METHOD OF CONTROLLING PARTICIPATION OF LOADS IN AN ELECTRIC GRID FLEXIBILITY SCHEME

[0002] FIELD OF INVENTION

[0003] The present disclosure is in the field of electric grid flexibility management systems, and relates in particular to a method of controlling participation of one or more loads in an electric grid flexibility scheme. The disclosure also relates to an energy flexibility management system.

[0004] BACKGROUND TO INVENTION

[0005] Electrical energy distribution systems, which may for example comprise electricity generation, electricity transportation and transformation (and may collectively be referred to herein as the ‘electrical grid’), may need to be adapted to continuously match supply to demand. Energy system flexibility may refer to an ability to adjust supply and / or demand to achieve a necessary balance within such electrical energy distribution systems, and to maintain flows of electrical energy through the grid to within safe limits. A flexible electrical grid is capable of managing volatility in supply and / or demand to achieve a sustainable balance, providing many benefits.

[0006] In a practical situation, instantaneous electricity supply and electricity demand do not exactly match one another, and this may have detrimental effects on the supply of electrical energy.

[0007] For example, when the electrical grid is in a balanced condition, an alternating current frequency of electrical power transferred via the grid may remain at a nominal frequency, e.g. typically 50 Hz or 60 Hz. However, an imbalance between supply and demand may result in a deviation from the nominal system frequency. If demand, e.g. load, exceeds supply then the AC frequency in the grid may drop below the nominal frequency. If supply exceeds demand then the AC frequency in the grid may increase above the nominal frequency.

[0008] Exact balancing of instantaneous supply and demand in an electrical grid may be difficult to achieve in practice, and therefore minor deviations between the nominal frequency and the actual AC frequency of the grid may be tolerable, e.g. between 49.9 Hz and 50.1 Hz. To balance the electrical grid, short-term power balancing reserves may be implemented by the Transmission System Operator (TSO) of the electrical grid to increase or decrease a power supply demand from the electrical grid in relation to the AC frequency of the electrical grid.

[0009] One such example of a power balancing reserve is a Frequency Containment Reserve (FCR), which may also be known in the art as a primary reserve. An FCR may be configured to intervene automatically and with low latency to restore a balance between supply and demand and thus maintain the AC frequency of the electrical grid at the nominal frequency.

[0010] Loads participating in a FCR scheme may increase or decrease their demand at short notice, for example in response to requests from the TSO or DSO indicating variations in the AC frequency of the electrical supply. In such schemes, providers of flexibility may be financially rewarded.

[0011] Notably, use of an FCR may require real-time responses from loads, and a low- latency response to a request to adapt a level of demand may be of paramount importance to the successful operation of the FCR. Existing schemes may require substantial amounts of data relating to operation of loads to be provided with low latency to a flexibility management system, such as a system operating an FCR.

[0012] Such FCR schemes (known in the art as FCR regulation) may require a higher frequency of status updates from the enrolled loads than in typical ‘Smart Charging’ systems. There are, however, situations wherein loads enrolled in such an FCR scheme may temporarily or permanently stop satisfying requirements to provide status updates. For example, the loads may either stop responding to status queries or may not react fast enough to the commands sent from the FCR regulation system.

[0013] As such, it is therefore desirable to provide a reliable and low-complexity method and system for handling loads that may fail to satisfy requirements of an electric grid flexibility scheme to provide status updates in a timely manner.

[0014] It is therefore an aim of at least one embodiment of at least one aspect of the present disclosure to obviate or at least mitigate at least one of the above identified shortcomings of the prior art.

[0015] SUMMARY OF INVENTION

[0016] The present disclosure is in the field of methods of electric grid flexibility management systems, and relates in particular to a method of controlling participation of one or more loads in an electric grid flexibility scheme. The disclosure also relates to an electric grid flexibility management system.

[0017] According to a first aspect of the disclosure, there is provided a method of controlling participation of one or more loads in an electric grid flexibility scheme. The method comprises halting participation of a load in the flexibility scheme in response to determining, by a processing system, that the load has failed to communicate a status update to the processing system within a first predefined period.

[0018] Halting participation of a load in an electric grid flexibility scheme may be known in the art as ‘detaining’ the load.

[0019] Advantageously, by implementing such detention, a regulation algorithm of the electric grid flexibility scheme, which may be implemented on the processing system, may more accurately predict a power consumption of loads. This is because the algorithm may only use loads that are operational at the time. Advantageously, detention may also prevent said algorithm from sending commands to loads that are unlikely to react to the command, thereby avoiding inducing too heavy a load on OEMs’ APIs (e.g. an Original Equipment Manufacturer of one or more features of the load).

[0020] That is, electric grid flexibility schemes (such as FOR regulation) may require a high frequency of updates and a precision in following a high volume of commands. There are situations where enrolled loads stopped satisfying those requirements, either by failing to respond to a status query or by not reacting fast enough to commands sent from the regulation system. The disclosed method introduces a concept of detention for loads which do not perform. For example, and as described in more detail below, the load may be detained if at least one of the following conditions was met: the load did not react to a start charging or stop charging command within a specified time; a status update from the load did not contain a power reading if a charging process was in the middle of starting or stopping; and / or a new status update from the load was not received by the processing system within a specified time, i.e. the first predefined period.

[0021] Detaining a load means that it ceases to be included in a pool of assets controlled in the electric grid flexibility scheme. There’s also a way for a load to be released from detention if the load starts producing updates again in a timely fashion and a specified time has passed, as described in more detail below.

[0022] Each one or more load may comprise an electric vehicle and an electric vehicle charger. The / each status update may comprise data indicating a charging status and / or power consumption of the load.

[0023] A power consumption of the load may refer to an instantaneous, predicted, calculated or otherwise determined charging power of the load. That is, the load may comprises a circuit for measuring one of more characteristics of electrical power consumed by the load, and for reporting such characteristics as a status update to the processing system. That is, the load and / or the processing system may comprise means, such as processing means, to determine the charging power of the load.

[0024] The method may comprise a further step of restoring participation of the load in the flexibility scheme in response to determining, by the processing system, that participation in the flexibility scheme by the load has been halted for at least a second predefined period and that the load has communicated a status update to the processing system within a third predefined period.

[0025] In response to determining, by the processing system, that the load has communicated a status update to the processing system within the first predefined period, a further determination may be made, by the processing system, of whether the load is in a state of transition between charging states.

[0026] As a non-limiting example, such charging states may comprise: a paused charging state; a low-power charging state; a high-power charging state; a full-power charging state.

[0027] In response to determining, by the processing system, that the load is not in a state of transition between charging states, a further determination may be made, by the processing system, of whether the communicated status update corresponds to the desired load status.

[0028] In response to determining, by the processing system, that the load is in a state of transition between charging states, a further determination may be made, by the processing system, of whether the communicated status update comprises a power reading.

[0029] The method may comprise halting participation of the load in the flexibility scheme in response to determining, by the processing system, that the communicated status update does not correspond to the desired load status.

[0030] The method may comprise halting participation of the load in the flexibility scheme in response to determining, by the processing system, that the communicated status update does not comprises the power reading. In response to determining, by the processing system, that the communicated status update comprises the power reading, a further determination may be made, by the processing system, of whether the load is configured to react within a further predefined period to a charge operation command.

[0031] The method may comprise halting participation of the load in the flexibility scheme in response to determining, by the processing system, that the load is not configured to react within the further predefined period to a charge operation command.

[0032] The method may comprise controlling participation of a plurality of loads in the electric grid flexibility scheme. The method may further comprise halting participation of each load of the plurality of loads in the flexibility scheme in response to determining, by a processing system, that the respective load has failed to communicate a status update to the processing system within a first predefined period.

[0033] The electric grid flexibility scheme may comprises a Frequency Containment Reserve (FCR) scheme.

[0034] According to a second aspect of the disclosure, there is provided an electric grid flexibility management system. The electric grid flexibility management system comprises an electrical energy distribution system. The electric grid flexibility management system a plurality of loads configured to receive energy from the electrical energy distribution system. The electric grid flexibility management system comprises a processing system in communication with the electrical energy distribution system and the plurality of loads. The processing system is configured to halt participation of a load in the flexibility scheme in response to determining, by the processing system, that the load has failed to communicate a status update to the processing system within a first predefined period.

[0035] The electrical energy distribution system may be configured to implement a scheme to adapt the provision of electrical power to the one or more loads to contain a supply frequency of the electrical power to within a targeted frequency range.

[0036] The processing system may comprise a user equipment configured to selectively enable participation in the scheme at least one of the plurality of loads.

[0037] The user equipment may comprise a communications device, such as a personal communications device, such as a cellular telephone, smartphone, tablet device or the like.

[0038] According to a third aspect of the disclosure, there is provided a computer- implemented method of controlling participation of one or more loads one or more loads in an electric grid flexibility scheme. The method comprises halting participation of a load in the flexibility scheme in response to determining, by a processing system, that the load has failed to communicate a status update to the processing system within a first predefined period.

[0039] The above summary is intended to be merely exemplary and non-limiting. The disclosure includes one or more corresponding aspects, embodiments or features in isolation or in various combinations whether or not specifically stated (including claimed) in that combination or in isolation. It should be understood that features defined above in accordance with any aspect of the present disclosure or below relating to any specific embodiment of the disclosure may be utilized, either alone or in combination with any other defined feature, in any other aspect or embodiment or to form a further aspect or embodiment of the disclosure.

[0040] BRIEF DESCRIPTION OF DRAWINGS

[0041] These and other aspects of the present disclosure will now be described, by way of example only, with reference to the accompanying drawings, wherein:

[0042] Figure 1 depicts an example of an energy flexibility management system, according to an embodiment of the disclosure;

[0043] Figure 2 depicts an example graph showing a simulation of the states of vehicles during an FCR regulation period, according to an embodiment of the disclosure; and

[0044] Figure s depicts a flow chart of a method of controlling participation of one or more loads in an electric grid flexibility scheme, according to an embodiment of the disclosure.

[0045] DETAILED DESCRIPTION OF DRAWINGS

[0046] Figure 1 depicts an example of an energy flexibility management system 100, according to an embodiment of the disclosure.

[0047] The energy flexibility management system 100 comprises an electrical energy distribution system 105. The electrical energy distribution system 105 may comprise local and regional energy distribution networks, which may be operated and / or managed by a Distribution System Operator (DSO). The electrical energy distribution system 105 may also comprise means for transmission of electricity from generation plants via the electrical grid 130, e.g. as managed by a Transmission System Operator (TSO).

[0048] The example electrical energy distribution system 105 is configured to provide electrical energy to a load, which is the depicted example is an energy storage system 110.

[0049] In the example, only a single energy storage system 110 is depicted for simplicity of illustration, but it will be appreciated that many more than a single energy storage system 110 may be implemented in practice.

[0050] The example energy storage system 110 comprises a charger 115. In the depicted example, the charger 115 is for an electric vehicle 120, which is also depicted.

[0051] The charger 115 is configured to receive electrical energy from the electrical energy distribution system 105. The electric vehicle 120 is configured to receive electrical energy from the charger 115, e.g. to charge an internal battery of the electric vehicle 120.

[0052] In some embodiments, the electric vehicle 120 may additionally be configured to provide electrical energy to the electrical energy distribution system 105, via the charger 115.

[0053] Also depicted is a processing system 125 in communication with the electrical energy distribution system 105 and the energy storage system 110. The processing system 125 may, for example, comprise one or more servers configured to halt participation of a load, e.g. energy storage system 110, in the flexibility scheme in response to determining, by a processing system 125, that the load has failed to communicate a status update to the processing system 125 within a first predefined period.

[0054] The processing system 125 may comprise, for example, one or more servers 135. In an example, the one or more servers 135 may comprise an OEM-server associated with a manufacturer, e.g. OEM, of the electric vehicle 120. Such an OEM- server may communicate with the electric vehicle 120 and / or the charger 115. Such communication may be over wired and / or wireless communication.

[0055] In examples, the processing system 125 may comprise, for example, a further- server associated with a tool for management of the energy flexibility management system 105 of the electric vehicle 120. Such a further server may, for example administer participation of the energy storage system 110 in a flexibility scheme, such as by providing the energy storage system 110 as part of a Frequency Containment Reserve (FCR). It will be appreciated that such a configuration of the processing system 125 is provided as an example, and in other embodiments such functionality may be implemented on a single device / server and / or may be implemented over two or more such servers which may be remote from one another.

[0056] In examples, the processing system 125 may comprises a user equipment 140. The user equipment 140 may be, for example, a cellular telephone, tablet device or other smart / connected device.

[0057] The user equipment 140 may run a program, e.g. an application or “App” for administering and / or selectively enabling participation in a flexibility scheme by the energy storage system 110. The user equipment 140 may be in communication with the one or more servers 135 and / or the electrical energy distribution system 105 may be and configured to indicate a halting of participation of the energy storage system 110 in the flexibility scheme in response to determining, by the processing system 125, that the the energy storage system 110 has failed to communicate a status update to the processing system 125 within a first predefined period. Although not depicted in Figure 1 , in some embodiments the user equipment 140 may be in communication with the electric vehicle 120 and / or the charger 115.

[0058] In use, the processing system 125 may be configured to transmit power consumption data of the energy storage device 110 to the electrical energy distribution system 105, thereby enabling implementation of a flexibility scheme such as use of an FCR, by the electrical energy distribution system 105, as described in more detail below

[0059] Electric vehicles are, in general terms, an emerging technology. The high electrical power usage associated with charging electric vehicles, together with the relatively high storage capacity of such vehicles, makes them good candidates for participation in electrical grid flexibility programs.

[0060] For example, electric vehicles (and more generally charging systems such as the energy storage system 110 comprising a charger 115 and an electric vehicle 120) are particularly suitable for contributing to a Frequency Containment Reserve.

[0061] As described above, use of an FCR may require high frequency, low latency status updates from the enrolled loads. There are, however, situations wherein loads enrolled in such an FCR scheme may temporarily or permanently stop satisfying requirements to provide status updates. As such, the disclosed method and systems directly addresses this problem. That is, the disclosed method and systems provide a reliable and low-complexity way of handling loads that may fail to satisfy requirement of an electric grid flexibility scheme to provide status updates in a timely manner, as described in more detail below with reference to Figures 2 and 3.

[0062] Figure 2 depicts an example graph showing a simulation of the states of vehicles during an FCR regulation period, according to an embodiment of the disclosure. It can be seen that the number of detained cars rises when an overall number of cars charging also increases.

[0063] Figure 3 depicts a flow diagram for a method of controlling participation of one or more loads in an electric grid flexibility scheme, which may be an FCR scheme. The example of Figure 3 relates to vehicles, and in particular electric vehicles, referred to as cars. It will be appreciated that the disclosed method may more generally apply to other vehicle types, and more generally to energy storage systems, e.g. energy storage system 110. The method of Figure 3 may be implemented, at least in part, on the processing system 125 of Figure 1.

[0064] At a first step 305, a status update, referred to a “new update” from the car is received by the processing system, e.g. processing system 125. The status update may comprise data indicating a charging status and / or power consumption of the load.

[0065] At a next step 310, a determination is made, by the processing system 125, of whether the car has communicated the status update to the processing system 125 within a first predefined period. In the depicted example, the first predefined period is 150 seconds, although it will be appreciated that this is for purposes of example only and other durations of first predefined period may be used.

[0066] If it is determined at step 310 that the car has failed to communicate the status update to the processing system 125 within the first predefined period, then at a step 315 the car is detained, i.e. participation of the car in the flexibility scheme is halted.

[0067] If the car has been detained at step 315, then at a step 320 it is determined, by the processing system 125, whether detention (e.g. a halting of participation in the flexibility scheme by the car) has continued for at least a second predefined period. In the depicted example, the second predefined period is 20 seconds, although it will be appreciated that this is for purposes of example only and other durations of first predefined period may be used.

[0068] If it is determined at step 320 that the car has not yet been detained for the second predefined period then the car remains detained at step 335. In some embodiments, for a detained car the determination at step 320 may subsequently be repeated. If it is determined at step 320 that the car has been detained for the second predefined period, then at a step 325 it is determined whether the car has communicated a status update to the processing system 125 within a third predefined period. The third predefined period may be the same as the first predefined period. That is, continuing with the above example, at step 325 it may be determined whether the car has communicated a status update to the processing system 125 within the last 150 seconds. If at step 325 it is determined that the car has communicated the status update to the processing system 125 within the third predefined period, then the car is released from detention at a step 330. If at step 325 it is determined that the car has not communicated the status update to the processing system 125 within the third predefined period, then the car is held in detention at step 335.

[0069] If, at step 310, it is determined, by the processing system 125, that the car has communicated a status update to the processing system 125 within the first predefined period, then at a step 340 a further determination is made, by the processing system 125, of whether the car is in a state of transition between charging states.

[0070] A state of transition between charging states may refer to a state of transition between any of: a paused charging state; a low-power charging state; a high-power charging state; a full-power charging state.

[0071] If, at step 340, it is determined from the status update that the car is not in transition between states, then at a step 345 the processing system 125 makes a determination of whether the received status update corresponds to a desired car state, e.g. corresponds to the correct or expected state. If at step 345 it is determined that the received status update corresponds to a desired car state then the car is allowed to continue to participate in the flexibility scheme at step 360. If at step 345 it is determined that the received status update does not correspond to the desired car state then the car is detained at step 315. Step 320 may follow such a detention, as described above.

[0072] If, at step 340, it is determined from the status update that the car is in transition between states, then at a 350 a further determination is made by the processing system 125 of whether the received status update comprises a power reading, e g. an indication of an amount of electrical power being used by the car.

[0073] If it is determined that the received status update does not comprise a power reading, then the car is detained at step 315. Step 320 may follow such a detention, as described above. If at step 350 it is determined that the received status update does comprise a power reading, then a further determination is made at step 355, by the processing system 125, of whether the car has reacted, or is configured to react, to a charge operation command within a further predefined period. In the depicted example, the further predefined period is 30 seconds, although it will be appreciated that this is for purposes of example only and other durations of first predefined period may be used.

[0074] A charge operation command may, for example, comprise a command to continue operation in a charging state, to stop or start charging, or to transition between states such as a paused charging state, a low-power charging state, a high- power charging states and / or a full-power charging state.

[0075] If, at step 355, it is determined that the car has reacted, or has been configured to react, to the charge operation command within the further predefined period then the car is allowed to continue to participate in the flexibility scheme at step 360.

[0076] If, at step 355, it is determined that the car has not reacted, or has not been configured to react, to the charge operation command within the further predefined period then the car is detained at step 315. Step 320 may follow such a detention, as described above.

[0077] Although the disclosure has been described in terms of particular embodiments as set forth above, it should be understood that these embodiments are illustrative only and that the claims are not limited to those embodiments. Those skilled in the art will be able to make modifications and alternatives in view of the disclosure, which are contemplated as falling within the scope of the appended claims. Each feature disclosed or illustrated in the present specification may be incorporated in any embodiments, whether alone or in any appropriate combination with any other feature disclosed or illustrated herein.

Claims

CLAIMS:

1. A method of controlling participation of one or more loads in an electric grid flexibility scheme, the method comprising: halting participation of a load in the flexibility scheme in response to determining, by a processing system, that the load has failed to communicate a status update to the processing system within a first predefined period.

2. The method of claim 1 , wherein each one or more load comprises an electric vehicle and an electric vehicle charger.

3. The method of claim 1 or 2, wherein the status update comprises data indicating a charging status and / or power consumption of the load.

4. The method of any preceding claim, comprising a further step of: restoring participation of the load in the flexibility scheme in response to determining, by the processing system, that participation in the flexibility scheme by the load has been halted for at least a second predefined period and that the load has communicated a status update to the processing system within a third predefined period.

5. The method of any preceding claim, wherein in response to determining, by the processing system, that the load has communicated a status update to the processing system within the first predefined period, a further determination is made, by the processing system, of whether the load is in a state of transition between charging states.

6. The method of claim 5, wherein: in response to determining, by the processing system, that the load is not in a state of transition between charging states, a further determination is made, by the processing system, of whether the communicated status update corresponds to the desired load status; and in response to determining, by the processing system, that the load is in a state of transition between charging states, a further determination is made,by the processing system, of whether the communicated status update comprises a power reading.

7. The method of claim 6, comprising halting participation of the load in the flexibility scheme in response to determining, by the processing system, that the communicated status update does not correspond to the desired load status.

8. The method of claim 6 or 7, comprising halting participation of the load in the flexibility scheme in response to determining, by the processing system, that the communicated status update does not comprises the power reading.

9. The method of any of claims 6 to 8, wherein: in response to determining, by the processing system, that the communicated status update comprises the power reading, a further determination is made, by the processing system, of whether the load is configured to react within a further predefined period to a charge operation command.

10. The method of claim 9, comprising halting participation of the load in the flexibility scheme in response to determining, by the processing system, that the load is not configured to react within the further predefined period to a charge operation command.11 . The method of any preceding claim, comprising: controlling participation of a plurality of loads in the electric grid flexibility scheme, the method further comprising halting participation of each load of the plurality of loads in the flexibility scheme in response to determining, by a processing system, that the respective load has failed to communicate a status update to the processing system within a first predefined period.

12. The method of any preceding claim, wherein the electric grid flexibility scheme is a Frequency Containment Reserve (FCR) scheme.

13. An energy flexibility management system comprising: an electrical energy distribution system;a plurality of loads configured to receive energy from the electrical energy distribution system; and a processing system in communication with the electrical energy distribution system and the plurality of loads, wherein the processing system is configured to: halt participation of a load in the flexibility scheme in response to determining, by the processing system, that the load has failed to communicate a status update to the processing system within a first predefined period.

14. The energy flexibility management system of claim 13, wherein the electrical energy distribution system is configured to implement a scheme to adapt the provision of electrical power to the one or more loads to contain a supply frequency of the electrical power to within a targeted frequency range.

15. The energy flexibility management system of claim 13 or 14, wherein the processing system comprises a user equipment configured to selectively enable participation in the scheme at least one of the plurality of loads.

16. A computer-implemented method of controlling participation of one or more loads one or more loads in an electric grid flexibility scheme, the method comprising: halting participation of a load in the flexibility scheme in response to determining, by a processing system, that the load has failed to communicate a status update to the processing system within a first predefined period.

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