AU2017259177B2

AU2017259177B2 - Method, computer program, system, and equipment for optimizing the functioning of an electrical current transmission network

Info

Publication number: AU2017259177B2
Application number: AU2017259177A
Authority: AU
Inventors: David GAME; Olivier GRABETTE; Patrick PANCIATICI
Original assignee: RTE Reseau de Transport dElectricite SA
Current assignee: RTE Reseau de Transport dElectricite SA
Priority date: 2016-05-04
Filing date: 2017-05-02
Publication date: 2021-11-25
Anticipated expiration: 2037-05-02
Also published as: ZA201807023B; JP2019515624A; MA44867A; UA126752C2; FR3051055B1; AU2017259177A1; JP6987079B2; WO2017191402A1; MX2018013345A; EP3453095A1; FR3051055A1; CA3021619A1

Abstract

This method of optimizing the functioning of an electrical current transmission network comprises the command of conversion controllers by sending (108) energy storage or release commands in or from energy storage units connected to the ends of at least one electrical line in the network. The method provides for the activation (106, 108) of a virtual transmission of quantity Q of electrical current from a first assembly E1 of line ends toward a second assembly E2 of line ends while jointly addressing the related conversion controllers; at least one first command to store a quantity of energy corresponding to the quantity Q of electrical current, in a first assembly S1 of storage unit(s) connected to the first assembly E1; at least one second command to release the same quantity of energy from a second assembly S2 of storage units connected to the second assembly E2. These two commands are then executed (110) together by the related conversion controller.

Description

METHOD, COMPUTER PROGRAM, SYSTEM, AND EQUIPMENT FOR OPTIMIZING THE FUNCTIONING OF AN ELECTRICAL CURRENT TRANSMISSION NETWORK

This invention relates to a method for optimizing the functioning of an electrical current transmission network. It also relates to a corresponding computer program and a system as well as equipment for optimized transmission of electrical current implementing such a method. It relates more precisely to a method for optimizing that applies for the management of a network comprising at least one electrical line, a plurality of energy storage units connected to a plurality of ends of said at least one electrical line and controllers for converting stored energy into electric current or reciprocally between each storage unit and the line end(s) to which it is connected, this method comprising the following steps: - maintaining up to date in memory of filling information of each one of the storage units supplied by the conversion controllers, - commanding of the conversion controllers, by sending energy storage or release commands in or from the storage units. Such a method is generally implemented in order to provide at any time a certain balance between supply and demand in production and in consumption of electrical current. In particular, when the network is supplied with electrical current by production sites with renewable energy sources such as wind or solar panel farms, which by definition are highly dependent on climatic conditions, storage units can be provided on these production sites. A temporary surplus of electrical energy obtained by favorable climatic conditions can thus be stored locally if the demand for electrical current is not at this level. Likewise a temporary lack of electrical energy produced due to unfavorable climatic conditions can be offset on the site by a discharge of the storage unit or units in case of demand that is higher than production. In sum, the storage units are then used to offset the ups and down in production according to consumption constraints. Such teaching is for example detailed in patent applications US 2014/0163754 Al and WO 2014/072278 Al. With regards to the consumption loads of electrical current, storage units for UPS (Uninterruptible Power Supply) can also be provided in order to offset certain untimely variations in the supply with electrical current by the electrical current transmission network. The method for optimizing then aims to provide a stable alternating current that is devoid of outages or micro-outages, whatever happens over the network. Such teaching is for example detailed in patent application CA 2 869 910 Al. Unfortunately, these methods are not designed to handle the sporadic risks of congestion of a network. These risks are increased when the network is supplied by production sites with renewable energy sources and supply consumption sites such as terminals for recharging electric vehicles. In particular, in the case of an electrical current transmission network that tends to increasingly operate at the limit of the capacity in particular because it is sized as best possible to be used at the maximum of its capacities, this can lead to damaging electrical lines, untimely disconnections, service outages. In general, no solutions are considered other than building new electrical lines or reinforcing the existing lines in order to create new transmission capacities. In addition to the associated costs, the impact on the territories that are passed through is often hard to accept by the local population when it entails high voltage electrical lines. To a lesser degree, it is possible to resolve at least partially the problems of congestion: - by redirecting the flows: but this supposes that alternative paths that are not overloaded are available in the network and the gains are limited, or - by increasing the effectiveness or the efficiency of existing lines, for example by integrating reactive power generating elements of which the deficit limits the capacity to transit the active power, i.e. the power that is actually useful, or for example by developing dynamic measurements of the temperature of the lines in order to operate them closer to their physical limits: but the gains are then really limited. It can thus be desired to design a method for optimizing the functioning of an electrical current transmission network, in particular able to handle the sporadic risks of congestion, at least cost and least impact, while still providing a genuine increase in the temporary capacity of the network during high production or demand for electrical current. In a first aspect, a method for optimizing the functioning of an electrical current transmission network is proposed, the network comprising at least one electrical line, a plurality of energy storage units connected to a plurality of ends of said at least one electrical line, and controllers for converting stored energy into electric current or reciprocally between each storage unit and the line end(s) to which it is connected, the method for optimizing comprising the following steps: - maintaining up to date in memory of filling information of each one of the storage units supplied by the conversion controllers, - commanding of the conversion controllers, by sending energy storage or release commands in or from the storage units, further comprising the following steps: - selecting a first assembly S1 of at least one storage unit connected to a first assembly El of at least one line end, - selecting a second assembly S2 of at least one storage unit connected to a second assembly E2 of at least one line end, - based on the filling information maintained up to date in memory, activation of a virtual transmission of quantity Q of electrical current from the first assembly El toward the second assembly E2 by jointly sending to the related conversion controllers: • at least one first command to store a quantity of energy, corresponding to the quantity Q of electrical current, in the first assembly S1, and * at least one second command to release the same quantity of energy, corresponding to the same quantity Q of electrical current, from the second assembly S2, and - jointly executing in parallel and at the same time the storage and release commands of said same quantity of energy by the related conversion controllers. Thus, thanks to such a method, it is possible to use the storage capacities distributed in the network to simulate, at a given moment of high supply or demand for electrical current, a transmission of electrical current between the assemblies El and E2 that is greater than what it actually is. The storage units solicited can then be rebalanced when the supply or demand is not as high. In other terms, the storage units are used to prevent or absorb temporary congestions of the network without having any impact on the supply/demand balance for electrical current and in an entirely transparent manner in the flows transmitted. The joint storing and releasing of the same quantity Q of electrical current make it possible to induce flows in the opposite direction of the planned or observed congestions in order to offset them. Virtual lines are thus temporarily created, their length can be as long as desired.

There is indeed no operating constraint over the distance separating the assemblies El and E2. Compared to the solution of building or reinforcing the existing lines, the impact on the territories that are passed through is practically zero for comparable efficiency. Optionally, the storage and release commands sent during the activation of the virtual transmission of the quantity Q of electrical current are executed by the related conversion controllers for a zero total energy balance of the storage units of the assemblies S1 and S2, to the nearest energy efficiency losses. Also optionally, a reference filling is predetermined for each one of the storage units, the method further comprising, following the step of activation of the virtual transmission, a step of reconstitution according to which the conversion controllers of the storage units that have been solicited during the virtual transmission command their energy storage or release, from or toward said at least one electrical line of the network in the opposite direction to that ordered during the activated virtual transmission, so as to reach their reference filling. Also optionally, the step of reconstitution is executed in such a way as to never solicit an exceeding of the maximum electrical current transmission capacity of said at least one electrical line. Also optionally, each electrical line has a maximum electrical current transmission capacity and the virtual transmission of the quantity Q of electrical current is activated when at least one electrical line located between the assemblies El and E2 is solicited to temporarily transmit a quantity of electrical current that exceeds its maximum capacity by a quantity greater than or equal to the quantity Q. Also optionally: - a main direction of congestion of at least one electrical line in the network is determined, and - the selections of the first and second assemblies S1, S2 are made so as to direct the virtual transmission in this main direction of congestion. In a second aspect, there is provided a method for optimizing the functioning of an electrical current transmission network, the network comprising at least one electrical line, a plurality of energy storage units connected to a plurality of ends of said at least one electrical line, and controllers for converting stored energy into electric current or reciprocally between each storage unit and the line end(s) to which it is connected, the method for optimizing comprising the following steps:

- maintaining up to date in memory of filling information of each one of the storage units supplied by the conversion controllers, - commanding of the conversion controllers, by sending energy storage or release commands in or from the storage units, wherein the method further comprises the following steps: - selecting a first assembly S1 of at least one storage unit connected to a first assembly El of at least one line end, - selecting a second assembly S2 of at least one storage unit connected to a second assembly E2 of at least one line end, - based on the filling information maintained up to date in memory, activating a virtual transmission of quantity Q of electrical current from the first assembly El toward the second assembly E2 by jointly sending to the related conversion controllers: • at least one first command to store a quantity of energy, corresponding to the quantity Q of electrical current, in the first assembly S1, and * at least one second command to release the same quantity of energy, corresponding to the same quantity Q of electrical current, from the second assembly S2, and - jointly executing in parallel and at the same time the storage and release commands of said same quantity of energy by the related conversion controllers; wherein a reference filling is predetermined for each one of the storage units, the method further comprising, following the step of activation of the virtual transmission, a step of reconstitution according to which the conversion controllers of the storage units that have been solicited during the virtual transmission command their energy storage or release, from or toward said at least one electrical line of the network in the opposite direction to that ordered during the activated virtual transmission, so as to reach their reference filling; and wherein, each electrical line having a maximum electrical current transmission capacity, the virtual transmission of the quantity Q of electrical current is activated when at least one electrical line located between the assemblies El and E2 is solicited to temporarily transmit a quantity of electrical current that exceeds its maximum capacity by a quantity greater than or equal to the quantity Q, i.e. in case of potential congestion detection, and the reconstitution is activated when required and when no congestion is detected.

In a third aspect, a computer program is also proposed that can be downloaded from a communications network and/or recorded on a medium that can be read by a computer and/or that can be executed by a processor, including instructions for the execution of the steps of a method for optimizing according to aspects of the invention, when said program is executed on a computer. In a fourth aspect, there is provided a system for optimizing the functioning of an electrical current transmission network is also proposed, the network comprising at least one electrical line, a plurality of energy storage units connected to a plurality of ends of said at least one electrical line, and controllers for converting stored energy into electric current or reciprocally between each storage unit and the line end(s) to which it is connected, the system for optimizing comprising: - a memory maintaining up to date filling information on each one of the storage units, - a command unit, with a read/write connection to the memory and exchanging with the conversion controllers, programmed to send energy storage or release commands in or from the storage units, the command unit being furthermore programmed to: - select a first assembly S1 of at least one storage unit connected to a first assembly El of at least one line end, - select a second assembly S2 of at least one storage unit connected to a second assembly E2 of at least one line end, - based on the filling information maintained up to date in memory, activate a virtual transmission of quantity Q of electrical current from the first assembly El toward the second assembly E2 while jointly sending to the related conversion controllers: • at least one first command to store a quantity of energy, corresponding to the quantity Q of electrical current, in the first assembly S1, and * at least one second command to release the same quantity of energy, corresponding to the same quantity Q of electrical current, from the second assembly S2, and * an instruction for jointly executing in parallel and at the same time said storage and release commands of said same quantity of energy by the related conversion controllers. In a fifth aspect, there is provided a system for optimizing the functioning of an electrical current transmission network, the network comprising at least one electrical line, a plurality of energy storage units connected to a plurality of ends of said at least one electrical line, and controllers for converting stored energy into electrical current and reciprocally between each storage unit and the line end(s) to which it is connected, the system for optimizing comprising: - a memory maintaining up to date filling information on each one of the storage units, - a command unit, with a read/write connection to the memory and exchanging with the conversion controllers, programmed to send energy storage or release commands in or from the storage units, wherein the command unit is furthermore programmed to: - select a first assembly S1 of at least one storage unit connected to a first assembly El of at least one line end, - select a second assembly S2 of at least one storage unit connected to a second assembly E2 of at least one line end, - based on the filling information maintained up to date in memory, activate a virtual transmission of quantity Q of electrical current from the first assembly El toward the second assembly E2 while jointly sending to the related conversion controllers: • at least one first command to store a quantity of energy, corresponding to the quantity Q of electrical current, in the first assembly S1, * at least one second command to release the same quantity of energy, corresponding to the same quantity Q of electrical current, from the second assembly S2, and • an instruction for jointly executing in parallel and at the same time the storage and release commands of said same quantity of energy by the related conversion controllers; wherein a reference filling is predetermined for each one of the storage units, the command unit is further programmed to, following activation of the virtual transmission, activate a reconstitution according to which the conversion controllers of the storage units that have been solicited during the virtual transmission command their energy storage or release, from or toward said at least one electrical line of the network in the opposite direction to that ordered during the activated virtual transmission, so as to reach their reference filling; and wherein, each electrical line having a maximum electrical current transmission capacity, the virtual transmission of the quantity Q of electrical current is activated when at least one electrical line located between the assemblies El and E2 is solicited to temporarily transmit a quantity of electrical current that exceeds its maximum capacity by a quantity greater than or equal to the quantity Q, i.e. in case of potential congestion detection, and the reconstitution is activated when required and when no congestion is detected. Also proposed is an equipment for optimized transmission of electrical current comprising: - an electrical current transmission network comprising: • at least one electrical line, * a plurality of energy storage units connected to a plurality of ends of said at least one electrical line, and * controllers for converting stored energy into electrical current or reciprocally between each storage unit and the line end(s) to which it is connected, - a system for optimizing according to the fourth aspect of the invention, and - a telecommunications network for an exchange of the filling information and storage/release commands between the command unit of the system for optimizing and the conversion controllers of the electrical current transmissionnetwork. In another aspect, an equipment for optimized transmission of electrical current is provided, comprising: - an electrical current transmission network comprising: • at least one electrical line, * a plurality of energy storage units connected to a plurality of ends of said at least one electrical line, and * controllers for converting stored energy into electrical current or reciprocally between each storage unit and the line end(s) to which it is connected, - a system for optimizing according to the fifth aspect of the invention, and - a telecommunications network for an exchange of the filling information and storage/release commands between the command unit of the system for optimizing and the conversion controllers of the electrical current transmissionnetwork.

Optionally, the storage units can be arranged inside electrical substations for connecting electrical lines of the electrical current transmission network. The invention shall be better understood using the following description, given solely as an example and given in reference to the appended drawings wherein: - figure 1 diagrammatically shows the general structure of an equipment for optimized transmission of electrical current, according to an embodiment of the invention, - figure 2 shows an example of a topology of an electrical current transmission network of the equipment of figure 1, - figures 3A and 3B show virtual transmission and reconstitution scenarios, executed on an electrical line in accordance with a method for optimizing the functioning of an electrical current transmission network according to the invention, - figure 4 shows the successive steps of a method for optimizing the functioning of an electrical current transmission network, according to a first embodiment of the invention allowing for the execution of the scenarios of figures 3A and 3B, - figures 5A and 5B show virtual transmission and reconstitution scenarios, executed over portions of an electrical network in accordance with a method for optimizing the functioning of an electrical current transmission network according to the invention, - figure 6 shows the successive steps of a method for optimizing the functioning of an electrical current transmission network, according to a second embodiment of the invention allowing for the execution of the scenarios of figures 5A and 5B, - figures 7A and 7B show two other virtual transmission scenarios, that can be executed over a portion of an electrical network in accordance with a method for optimizing of figure 6, - figure 8 shows a scenario changing over time of any virtual transmissions and reconstitutions, executed over a portion of an electrical network in accordance with a method for optimizing the functioning of an electrical current transmission network according to the invention, and - figure 9 shows the successive steps of a method for optimizing the functioning of an electrical current transmission network, according to a third embodiment of the invention allowing for the execution of the scenario of figure 8. The equipment diagrammatically shown in figure 1 comprises an electrical current transmission network 10, a system 12 for optimizing the operation of the network 10 and a telecommunications network 14 for exchanging data between the system for optimizing 12 and some elements of the network 10. The network 10 comprises several electrical substations that form some of its nodes. Each electrical substation is electrically connected to at least one end of an electrical line, each line being itself a transport line or a distribution line of high, medium or low voltage electrical current. In particular, the high voltage lines of the network 10 extend from one electrical substation to another. In this particular non-limiting example, the network 10 comprises four electrical substations 16, 18, 20 and 22, each one being defined, by the IEC (International Electrotechnical Commission), as "a part of an electrical network, confined to a given area, mainly including ends of transmission or distribution lines, electrical switchgear and control gear, buildings and, possibly, transformers". An electrical substation is therefore an element of the electrical current transmission network used for both transporting and distributing electricity. It makes it possible to raise the electrical voltage for its transmission at high voltage, and to lower it again for the purpose of the consumption thereof by users (private individuals or industry). The relative arrangement of the four electrical substations 16, 18, 20 and 22 can be of any arrangement and does not correspond to the illustration wherein they are aligned for convenience. They form the four vertices of any quadrilateral of which each side can measure several kilometers or tens or hundreds of kilometers. The network 10 is also for example a subnetwork of any network that is more substantial and complete, in particular with national coverage. In this particular non-limiting example also, the network 10 comprises an electrical line Li extending between the substation 16 and the substation 18, an electrical line L2 extending between the substation 18 and the substation 20, an electrical line L3 extending between the substation 20 and the substation 22, an electrical line L4 extending between the substation 22 and the substation 16 and an electrical line L5 extending between the substation 18 and the substation 22. The network 10 comprises furthermore a plurality of energy storage units connected to at least one portion of the ends of the electrical lines L1, L2, L3, L4 and L5. These storage units comprise for example electrochemical batteries, supercapacitors, flywheels, pumped-storage power hydraulic stations, or others. In the example of figure 1, they are distributed in the electrical substations. In this case, their impact on the territories passed through by the electrical lines L1, L2, L3, L4 and L5 is zero. A storage unit 24 is thus installed inside the electrical substation 16. It is connected to the ends of lines L and L4 which arrive in this electrical substation. A conventional conversion device 26 makes it possible to convert the energy stored in the unit 24 into electrical current intended to be transmitted by at least one of the electrical lines Li and L4. Reciprocally, it makes it possible to convert electrical current transmitted by at least one of the electrical lines Li and L4 into energy to be stored in the unit 24. This conversion device 26 is itself commanded by a conversion controller 28 which serves as an interface with the system for optimizing 12: more precisely, the controller 28 is able to provide filling information of the storage unit 24 to the system for optimizing 12; it is furthermore able to control energy conversions in one direction or the other according to storage commands (for a conversion of electrical current transmitted by at least one of the electrical lines Li and L4 into energy to be stored in the unit 24) or release commands (for a conversion of energy stored in the unit 24 into electrical current to be transmitted by at least one of the electrical lines Li and L4) that it receives from the system for optimizing 12. Likewise, a storage unit 30 is installed inside the electrical substation 18. It is connected to the ends of lines L1, L2 and L5 which arrive in this electrical substation. A conversion device 32 makes it possible to convert the energy stored in the unit 30 into electrical current intended to be transmitted by at least one of the electrical lines L1, L2 and L5. Reciprocally, it makes it possible to convert electrical current transmitted by at least one of the electrical lines L1, L2 and L5 into energy to be stored in the unit 30. This conversion device 32 is itself commanded by a conversion controller 34 which serves as an interface with the system for optimizing 12: more precisely, the controller 34 is able to provide filling information of the storage unit 30 and to control energy conversions in one direction or the other according to the storage or release commands that it receives from the system for optimizing 12. Likewise, a storage unit 36 is installed inside the electrical substation 20. It is connected to the ends of lines L2 and L3 which arrive in this electrical substation. A conversion device 38 makes it possible to convert the energy stored in the unit 36 into electrical current intended to be transmitted by at least one of the electrical lines L2 and L3. Reciprocally, it makes it possible to convert electrical current transmitted by at least one of the electrical lines L2 and L3 into energy to be stored in the unit 36. This conversion device 38 is itself commanded by a conversion controller 40 which serves as an interface with the system for optimizing 12: more precisely, the controller 40 is able to provide filling information of the storage unit 36 and to control energy conversions in one direction or the other according to the storage or release commands that it receives from the system for optimizing 12. Likewise, a storage unit 42 is installed inside the electrical substation 22. It is connected to the ends of lines L3, L4 and L5 which arrive in this electrical substation. A conversion device 44 makes it possible to convert the energy stored in the unit 42 into electrical current intended to be transmitted by at least one of the electrical lines L3, L4 and L5. Reciprocally, it makes it possible to convert electrical current transmitted by at least one of the electrical lines L3, L4 and L5 into energy to be stored in the unit 42. This conversion device 44 is itself commanded by a conversion controller 46 which serves as an interface with the system for optimizing 12: more precisely, the controller 46 is able to provide filling information of the storage unit 42 and to control energy conversions in one direction or the other according to the storage or release commands that it receives from the system for optimizing 12. The system for optimizing 12 is for example implemented in a computer device such as a conventional computer and then comprises at least one processing unit 48 associated for reading/writing with at least one memory 50 (for example a RAM memory) for the storage of data files and computer programs. The processing unit 48 comprises an interface 52 for connection to the telecommunications network 14. It further comprises at least one calculator 54, for example a microprocessor, able to process data supplied by the interface 52 or stored in memory 50 and to issue commands for the network 10, in particular for conversion controllers 28, 34, 40 and 46. In this, the calculator 54 fulfils a function of a command unit. The memory 50 is partitioned into a first zone 56 for storing processing data and a second zone 58 for storing computer programs. This partition is purely functional, chosen for a clear presentation of the system for optimizing 12, but does not necessary reflect the actual organization of the memory 50. The first storage zone 56 thus comprises in particular the updated filling information of each one of the storage units 24, 30, 36, 42 such as it is regularly supplied by each one of the conversion controllers 28, 34, 40, 46 of each one of the electrical substations 16, 18, 20, 22 to the system for optimizing 12.

The second storage zone 58 functionally comprises one or several computer programs. Alternatively, the functions carried out by this or these program(s) can be at least partially micro-programmed or micro-wired in dedicated integrated circuits. Thus, alternatively, the computer device implementing the processing unit 48 and its memory 50 could be replaced with an electronic device comprised solely of digital circuits (without a computer program) for carrying out the same functions. The computer program or programs of the second storage zone 58 have instruction lines for sending energy storage or release commands in or from storage units 24, 30, 36 and 42. More precisely and in accordance with this invention, these instructions lines are defined in such a way as to allow the command unit 54 to: - select a first assembly S1 of at least one storage unit connected to a first assembly El of at least one line end, - select a second assembly S2 of at least one storage unit connected to a second assembly E2 of at least one line end, - based on the filling information maintained up to date in memory 50, activate a virtual transmission of quantity Q of electrical current from the first assembly El toward the second assembly E2 while jointly sending to the related conversion controllers: • at least one first command to store a quantity of energy, corresponding to the quantity Q of electrical current, in the first assembly S1, and * at least one second command to release the same quantity of energy, corresponding to the quantity Q of electrical current, from the second assembly S2. The command unit 54 can furthermore be programmed to activate such a virtual transmission of a quantity Q of electrical current when at least one electrical line located between the assemblies El and E2 is solicited to temporarily transmit a quantity of electrical current that exceeds its maximum capacity by a quantity greater than or equal to the quantity Q, for example due to at least one production site of electrical current connected to the network 10 in a situation of temporary overproduction or due to at least one consumption site of electrical current connected to the network 10 in a situation of temporary overconsumption. A zone or a site in "overproduction" is a zone or a site that has a surplus of energy that exceeds the

removal capacities of the electrical lines that connect it to the rest of the network. A zone or a site in "overconsumption" is a zone or a site that has a deficit in energy that exceeds the supply capacities of the electrical lines that connect it to the rest of the network. In other terms, the virtual transmission is activated in case of temporary congestion of a portion of the network 10 and is carried out using a joint solicitation in storage/release of the assemblies S1 and S2 of storage units. The more precise functioning of the command unit 54 programmed as indicated hereinabove will be detailed according to different possible scenarios in reference to figures 3A, 3B to 9. Note that all of the information coming from the network 10 (including in particular the filling information of the storage units 24, 30, 36, 42) and all of the storage/release commands coming from the command unit 54 are exchanged between the command unit 54 of the system for optimizing 12 and the related elements of the electrical substations 16, 18, 20, 22 of the network 10 (in particular the conversion controllers 28, 34, 40, 46) by the intermediary of the telecommunications network 14. Further knowing that the equipment of figure 1 is in a manner known per se managed by at least one remote surveillance site connected to each one of the electrical substations 16, 18, 20, 22, the system for optimizing can be implemented in one of these remote sites. Alternatively, it can also be installed inside one of the electrical substations. Figure 2 shows a non-limiting example of configuration and possible topology for the network 10. The electrical substation 16 is for example connected to a production site of electricity using wind turbines while the electrical substation 22 is connected to a production site of electricity using photovoltaic panels. These two sites are able to generate temporary overproductions. The electrical substations 18 and 20 are connected to consumption sites of electricity, for example urban zones. These zones are able to generate temporary overconsumptions. Of course, the network 10 is particularly simple and is produced by way of example solely for the purpose of allowing for a quick understanding of the invention. Generally, an electrical current transmission network, including the transport and/or distribution thereof, is much more complex. In particular, it comprises electrical substations which are not directly connected to a production site or to a consumption site but to one or more other electrical substations. Figures 3A and 3B show a scenario for optimizing a single electrical line L of an electrical current transmission network. This electrical line L receives electrical current at a first end and supplies electrical current at its second end. Its two ends are respectively connected to two storage units. It is exposed to proven or simulated intermittent congestions as "N-1", i.e. conditionally to an assumed failure of one of the structure of the network considered, and immediate or anticipated according to the forecasts of changes in the solicitations of the network in production or in consumption. It has a maximum electrical current transmission capacity noted as Pmax.

In figure 3A, the line L is confronted at an instant TA with a transmission request for a quantity Pmax + Q of electrical current thus exceeding its maximum capacity by the quantity Q. In accordance with the invention, the command unit 54 therefore activates a virtual transmission consisting in: - considering that the assembly El is comprised of the end of line L upstream of the transmission and that the assembly S1 to be selected is comprised of the storage unit connected to El, - considering that the assembly E2 is comprised of the end of line L downstream of the transmission and that the assembly S2 to be selected is comprised of the storage unit connected to E2, - checking that the storage unit S1 can store an additional quantity of energy corresponding to the quantity Q of electrical current, - checking that the storage unit S2 has a stored quantity of energy corresponding to a quantity of electrical current greater than or equal to Q, then - jointly and respectively sending to the conversion controllers managing the two storage units S1 and S2 a first storage command of the quantity of energy corresponding to the quantity Q of electrical current in the storage unit S1 and a second release command of the quantity of energy corresponding to the quantity Q of electrical current from the storage unit S2. This activation concludes with executing jointly storage and release commands by the related conversion controllers. These commands are executed symmetrically and at the same time for zero total energy balance of the storage units S1 and S2, to the nearest energy efficiency losses. These losses are more preferably less than 10%. Consequently, everything happens as if the quantity Pmax + Q of electrical current was transmitted from the end El to the end E2 although only the quantity Pmax actually transits in the line L. Thus the actual line L of capacity Pmax reinforced by the storage units S1 and S2, renders the same service as a line with capacity Pmax + Q with complete transparency for the distribution network. The storage units can easily be sized in energy and power capacities in order to absorb all of the temporary congestions to which the line L is able to be confronted. However, for economic reasons linked to a comparison of investment costs in storage and costs resulting from residual congestions, it can be decided to size the storage units only for absorbing a portion of the temporary congestions. Note that the length of the line L has no influence on the virtual transmission capacity linked to the presence and to the operation of the storage units, in such a way that virtual transmissions with very great distances can be considered. Note also that a reference filling is advantageously predetermined for each one of the storage units S1 and S2. For example, if the direction of congestion is equiprobable (which is not the case in figures 3A and 3B where the end El is always producing and the end E2 is always consuming), the reference condition is the filling to half-capacity of the two storage units. If the congestion always occurs in the same direction of transmission, then the reference condition for the upstream storage unit S1 will be the lowest load level possible, and the reference condition for the downstream storage unit S2 will be the highest load level possible. For intermediate situations, the reference condition is defined as a monotonous statistical function that interpolates the two preceding cases. The configuration of this function is chosen in such a way as to obtain the best storage performance in simulation. This configuration is within the scope of those skilled in the art. The temporary virtual transmission of figure 3A generates a storage imbalance in relation to the reference condition that needs to be corrected by taking advantage of low transmission periods. Thus, at an instant TB shown in figure 3B where the demand for the transmission of electrical current on the line L is of value P less than Pmax - Q, a reconstitution of the reference condition is carried out at the ends of the line L. The conversion controllers of the storage units S1 and S2 solicited during the preceding virtual transmission command their energy storage or release so as to reach their reference filling. In the example shown, everything happens as if the quantity P of electrical current was transmitted from the end El to the end E2 while the quantity P + Q actually transits in the line L in order to reconstitute the reference condition of the storage units S1 and S2. Of course, this reconstitution is executed in such a way as to never solicit an exceeding of the maximum capacity Pmax of the line L. It can be executed autonomously by the related conversion controllers or commanded by the command unit 54. It is possible only if the line L does not always function as the capacity limit. In order to process this scenario in accordance with figures 3A and 3B, the command unit 54 and optionally the conversion controllers of the equipment can be programmed to execute in a loop the successive steps of the method shown in figure 4. During a step 100, the system for optimizing 12 receives various remote signaling and measuring data coming from the network 10, more precisely from electrical substations, or from a remote surveillance site. This data comprises in particular the filling information for each one of the storage units supplied by the conversion controllers and any possible real or simulated, imminent or upcoming congestion information. This in particular allows the command unit 54 to update the data of the first storage zone 56. The step 100 is followed by a first test 102 during which the command unit 54 determines if one of the lines of the network 10, noted as L, is in a situation of potential congestion. If yes, the test 102 is followed by a step 104 of selecting: - a storage unit S1 connected to the end El of the line L located upstream of the potential congestion, and - a storage unit S2 connected to the end E2 of the line L located downstream of the potential congestion. The method then passes to a second test 106 during which the filling information of the storage units selected in the step 104 is analyzed by the command unit 54 in order to determine if the desired storing and releasing in order to absorb the potential congestion can be carried out. In other terms, are the margins for maneuver sufficient in the storage units S1 and S2 in order to carry out the virtual transmission of a quantity Q of electrical current by the line L in overload? If yes, the test 106 is followed by a step 108 of activation of this virtual transmission from the end El toward the end E2 while jointly sending to the related conversion controllers: - a first storage command of a quantity of energy, corresponding to the quantity Q of electrical current, in the storage unit S1, and - a second release command of the same quantity of energy, corresponding to the quantity Q of electrical current, from the storage unit S2.

Then, the commands are executed in parallel by the related conversion controllers during a step 110, then the method returns to the step 100. If no congestion is detected in the test step 102, the method moves to a third test 112 during which the command unit 54 determines if a reconstitution of the reference condition of at least one portion of the storage units of the network 10 is required, particularly following a virtual transmission carried out previously. If yes, the test 112 is followed by a step 114 during which the conversion controllers of the storage units concerned by this reconstitution command their energy storage or release so as to reach their reference filling, this being carried out within the limit of the maximum electrical current transmission capacity of the electrical line or lines solicited for the reconstitution. The step of reconstitution 114 continues until the reference fillings are obtained or until the reconstitution is no longer possible, for example due to another congestion. It is followed by a return to the step 100. Finally, if a virtual transmission is not considered to be possible during the test 106 or if a reconstitution is not detected as being necessary during the test 112, the method also returns to the step 100. Figures 5A and 5B show a scenario for optimizing portions of an electrical current transmission network that can simultaneously involve several close and distant lines. This is a generalization of the scenario of figures 3A and 3B. A first zone Z1 is for example a producer of electrical current and exposed to temporary overproductions. A second zone Z2 is for example a consumer of electrical current and exposed to temporary overconsumptions. An intermediate zone Z, through which the two zones Z1 and Z2 are connected, comprises its own connections to production and/or consumption sites and is assumed to be balanced. Electrical lines LL1 with a maximum global capacity Pimax make it possible to connect the first zone Z1 to the intermediate zone Z. They are exposed to temporary congestions due to the potential overproductions of the first zone Z1. Electrical lines LL2 with a maximum global capacity P2 ,max that make it possible to connect the second zone Z2 to the intermediate zone Z. They are exposed to temporary congestions due to the potential overconsumptions of the second zone Z2. As hereinabove, these temporary congestions can be real or simulated, immediate or anticipated. The zone Z1 comprises a first assembly S1 of storage units connected to a first assembly El of line ends (which can be either the ends of lines LL1 connected to the first zone Z1, or other ends of lines of the first zone Z1). The zone Z2 comprises a second assembly S2 of storage units connected to a second assembly E2 of line ends (which either be the ends of lines LL2 connected to the second zone Z2, or other ends of lines of the second zone Z2). In figure 5A, the electrical current transmission network is confronted at an instant TA with a potential congestion: - either because the zone Z1 is in overproduction P 1 = Pimax + Q, independently of the state of the zone Z2, - or because the zone Z2 is in overconsumption P 2 = P2,max + Q, independently of the state of the zone Z1, - or for the two preceding reasons simultaneously, and in this case Q is noted as the greater of the two congestions. In accordance with the invention, the command unit 54 therefore activates a virtual transmission consisting in: - selecting the assembly S1 of storage units of the zone Z1, - selecting the assembly S2 of storage units of the zone Z2, - checking that the storage units of the assembly S1 can globally store an additional quantity of energy corresponding to the quantity Q of electrical current desired, - checking that the storage units of the assembly S2 globally have a stored quantity of energy corresponding to a quantity of electrical current greater than or equal to Q, then - if only the zone Z1 is in overproduction, checking that the required releasing in the assembly S2 for the energy neutrality would not congest the zone Z2, - if only the zone Z2 is in overconsumption, checking that the required storage in the assembly S1 for the energy neutrality would not congest the zone Z1, - jointly and respectively sending to the conversion controllers managing the two assemblies S1 and S2 of storage units at least one first storage command of the quantity of energy corresponding to the quantity Q of electrical current in the assembly S1 and at least one second release command of the quantity of energy corresponding to the quantity Q of electrical current from the assembly S2. This activation concludes by jointly executing together storage and release commands by the related conversion controllers.

Consequently, everything happens as if the quantity P1 of electrical current was transmitted from the zone Z1 to the zone Z and the quantity P2 from the zone Z to the zone Z2 while only the quantities P1 - Q and P 2 - Q actually transit respectively in the lines LL1 and LL2. The storage units of assemblies S1 and S2 can easily be sized in energy and power capacities to absorb all or a portion (according to the aforementioned economic reasons) of the temporary congestions with which the lines LL1 and LL2 are able to be confronted. Note that in the case where the production P1 is less than Q, a portion of the production P of the intermediate zone Z can be directed toward the assembly S1. As hereinabove, reference fillings are advantageously predetermined for all of the storage units of assemblies S1 and S2. The general reference condition is defined in such a way as to obtain the best storage performance in simulation according to an a priori statistical knowledge of the congestions. Such a configuration is again within the scope of those skilled in the art. The temporary virtual transmission of figure 5A generates a storage imbalance as compared to the reference condition that needs to be corrected by taking advantage of low transmission periods. Thus, at an instant TB shown in figure 5B where the requests for the transmission of electrical current on the lines LL1 and LL2 are of values P'1 and P' 2 respectively less than Pmax - Q and P 2 max - Q, a reconstitution of the general reference condition is carried out at the ends of the assemblies El and E2. The conversion controllers of the assemblies S1 and S2 of storage units solicited during the preceding virtual transmission commanding their energy storage or release for the purpose of reaching the reference fillings. In the example shown, everything happens as if the quantities P'1 and P' 2 of electrical current were respectively transmitted from the zone Z1 to the zone Z and from the zone Z to the zone Z2 while the quantity P'1 +

Q actually transits in the lines LL1 and the quantity P' 2 + Q in the lines LL2 in order to reconstitute the reference condition of the storage units of assemblies S1 and S2. Of course, this reconstitution is executed in such a way as to never solicit an exceeding of the maximum capacities Pmax and P 2 ,max of the lines LL1 and LL2. It can be executed autonomously by the related conversion controllers or commanded by the command unit 54. It is possible only if the lines LL1 and LL2 do not always function at the capacity limit. In order to process this scenario in accordance with figures 5A and 5B, the command unit 54 and possibly the conversion controllers of the equipment can be programmed to execute in a loop the successive steps of the method shown in figure 6. During a step 200, the system for optimizing 12 receives various remote signaling and measuring data coming from the network 10, more precisely from electrical substations, or from a remote surveillance site. This data comprises in particular the filling information for each one of the storage units supplied by the conversion controllers and any real or simulated, imminent or upcoming congestion information. This in particular allows the command unit 54 to update the data of the first storage zone 56. The step 200 is followed by a first test 202 during which the command unit 54 determines if at least one of the zones of the network 10 is affected by a situation of potential congestion. If yes, the test 202 is followed by a second test 204 during which the command unit 54 determines if a virtual transit can improve the situation of the affected zone without placing another in a critical situation. If yes, the test 204 is followed by a step 206 of selecting: - an assembly S1 of storage units connected to an assembly El of line ends located upstream of the potential congestion, and - an assembly S2 of storage units connected to an assembly E2 of line ends located downstream of the potential congestion. The method then passes to a third test 208 during which the filling information of the storage units selected in the step 206 is analyzed by the command unit 54 in order to determine if the desired storage or release in order to absorb the potential congestion can be carried out. In other terms, are the margins for maneuver sufficient in the storage units of the assemblies S1 and S2 in order to carry out the virtual transmission of a quantity Q of electrical current by the zone with overload? If yes, the test 208 is followed by a step 210 of activating this virtual transmission from the assembly El toward the assembly E2 while jointly sending to the related conversion controllers: - at least one first command to store a quantity of energy, corresponding to the quantity Q of electrical current, in the storage units of the assembly S1, and - at least one second command to release the same quantity of energy, corresponding to the quantity Q of electrical current, from the storage units of the assembly S2.

Then, the commands are executed in parallel by the related conversion controllers during a step 212, then the method returns to the step 200. If no congestion is detected in the test step 202, the method moves to a fourth test 214 during which the command unit 54 determines if a reconstitution of the reference condition of at least one portion of the storage units of the network 10 is required, particularly following a virtual transmission carried out previously. If yes, the test 214 is followed by a step 216 during which the conversion controllers of the storage units concerned by this reconstitution command their energy storage or release so as to reach their reference filling, this being carried out within the limit of the maximum electrical current transmission capacity of the electrical lines solicited for the reconstitution. The step of reconstitution 216 continues until the reference fillings are obtained or until the reconstitution is no longer possible, for example due to another congestion. It is followed by a return to the step 200. Finally, if a virtual transmission is not considered to be possible during the test 208 or if a reconstitution is not detected as being necessary during the test 214, the method also returns to the step 200. Figures 7A and 7B show two other virtual transmission scenarios that can be processed by execution of the method of figure 6. According to these scenarios, any network whatsoever for the transmission of electrical current can be affected by variable intermittent congestions, in particular according to variable transmission main directions. This network is then provided with multiple storage units distributed into a large number of its nodes, in particular at the precise locations where the congestions are most likely. According to the main direction of a congestion, which can be determined in the step 202, the command unit 54 selects the best possible assemblies El, S1 and E2, S2 in the step 206 to direct the virtual transmission desired in the correct main direction shown by the texturized arrow with dots, i.e. in the direction of the congestion. In the case of figure 7A, it is for example a virtual transmission from South to North that is desired. In the case of figure 7B, it is for example a virtual transmission from West to East that is desired. By executing in a loop the method of figure 6, it is moreover possible to modify the main direction of the virtual transmission at any time, via a simple command, by simply changing the composition of the assemblies El, S1 and E2, S2. It is thus possible to direct the virtual transmission like a weather vane, according to the needs of the network. Figure 8 shows another scenario of virtual transmissions and reconstitutions that can be executed at the same time and change over time independently from one another, without requiring having main directions. Also note that the assemblies El and E2 do not necessarily form connected geometrical figures due to the complexity of the distribution of the congestions to be treated. This scenario thus represents a generalization of the preceding scenarios. As hereinabove, the storage units are multiplied at the most sensitive points of the network in order to handle all or a portion (according to the aforementioned economic reasons) of the possible congestion situations. At an instant T1, two virtual transmissions (represented by two texturized arrows with dots) in accordance with the scenario of figure 3A are for example executed while a reconstitution (represented by a texturized arrow with horizontal hatching) in accordance with the scenario of figure 3B is also executed. The situation then changes in such a way that at an instant T2, two other virtual transmissions (represented by two texturized arrows with dots) in accordance with the scenario of figure 3A are executed while two other reconstitutions (represented by two texturized arrows with horizontal hatching) in accordance with the scenario of figure 3B are also executed. Note that in particular a storage unit solicited for a virtual transmission at the instant T1 can be at least partially reconstituted by another virtual transmission at the instant T2. Likewise, at a given instant, the same storage unit can be solicited in virtual transmission and reconstitution, one even able incidentally at least partially to offset the other. A general method for optimizing such as the one shown in figure 9, executing as an overlayer of at least any one of the methods of figures 4 and 6, makes it possible to process this more complex scenario. This general method can itself also be executed by the command unit 54 and possibly the conversion controllers of the equipment. During a first step 300, the system for optimizing 12 receives various remote signaling and measuring data coming from the network 10, more precisely from electrical substations, or from a remote surveillance site. This data comprises in particular the filling information for each one of the storage units supplied by the conversion controllers and any real or simulated, imminent or upcoming congestion information. This in particular allows the command unit 54 to update the data of the first storage zone 56. In this step can be included the steps 100 and 200 of the two methods described hereinabove. During a following step 302, a computer program implanting a method of optimizing under constraints is executed, integrating all of the needs in virtual transmissions and reconstitutions of the network at an instant T and the forecasts for needs at future instants. Such a program for optimizing is for example an adaptation of a known mathematical optimization program, of the "Optimal Power Flow" type, such as implemented in the Eurostag (registered trademark) software distributed by the company TRACTEBEL Engineering. In this step 302, and even in the program for optimizing, can be included the steps 102, 104, 106, 108 and 112 or 202, 204, 206, 208, 210 and 214 of the two methods described hereinabove, but the program for optimizing can also be adapted in another way to include the general principles of the invention. Finally, during a step 304, the instructions and commands established at the preceding step are executed, including in particular the storage and release commands intervening in the operations of virtual transmissions and reconstitutions that are decided: for example the steps 110 and 114 of the method of figure 4, or the steps 212 and 216 of the method of figure 6. The general method for optimizing then returns to the step 300 at the end of the current period It clearly appears that equipment such as that described hereinabove, implementing one of the methods described hereinabove, makes it possible to sporadically and transparently increase the transmission capacities of the electrical lines of an electrical current transmission network without the need of resizing or reinforcing it. Note moreover that the invention is not limited to the embodiments described hereinabove. In particular, the use described hereinabove of the storage units for virtual transmissions of electrical current with a zero total energy balance do not oppose the conventional additional use of a net storage or release movement of these units. These two storage or release processes can be superimposed, the first consisting in creating a virtual transmission carrying out a zero energy balance and the second a net storage or release. It is simply suitable to provide these two uses in order to consequently size the storage units. In particular, the power capacity of the storage units must be coherent with the maximum power of virtual transmission that can be considered and their capacity in energy must be coherent with the maximum duration that can be considered for a virtual transmission. It will appear more generally to those skilled in the art that various modifications can be made to the embodiments described hereinabove, in light of the teaching that has just been disclosed. In the claims that follow, the terms used must not be interpreted as limiting the claims to the embodiments disclosed in this description, but must be interpreted so as to include therein all of the equivalents that the claims aim to cover due to their formulation and of which the projection is within the scope of those skilled in the art by applying their general knowledge to the implementation of the teaching that has just been disclosed.

Claims

1. A method for optimizing the functioning of an electrical current transmission network, the network comprising at least one electrical line, a plurality of energy storage units connected to a plurality of ends of said at least one electrical line, and controllers for converting stored energy into electric current and reciprocally between each storage unit and the line end(s) to which it is connected, the method for optimizing comprising the following steps: - maintaining up to date in memory of filling information of each one of the storage units supplied by the conversion controllers, - commanding of the conversion controllers, by sending energy storage or release commands in or from the storage units, wherein the method further comprises the following steps: - selecting a first assembly S1 of at least one storage unit connected to a first assembly El of at least one line end, - selecting a second assembly S2 of at least one storage unit connected to a second assembly E2 of at least one line end, - based on the filling information maintained up to date in memory, activating a virtual transmission of quantity Q of electrical current from the first assembly El toward the second assembly E2 by jointly sending to the related conversion controllers: • at least one first command to store a quantity of energy, corresponding to the quantity Q of electrical current, in the first assembly S1, and • at least one second command to release the same quantity of energy, corresponding to the same quantity Q of electrical current, from the second assembly S2, and - jointly executing in parallel and at the same time the storage and release commands of said same quantity of energy by the related conversion controllers; wherein a reference filling is predetermined for each one of the storage units, the method further comprising, following the step of activation of the virtual transmission, a step of reconstitution according to which the conversion controllers of the storage units that have been solicited during the virtual transmission command their energy storage or release, from or toward said at least one electrical line of the network in the opposite direction to that ordered during the activated virtual transmission, so as to reach their reference filling; and wherein, each electrical line having a maximum electrical current transmission capacity, the virtual transmission of the quantity Q of electrical current is activated when at least one electrical line located between the assemblies El and E2 is solicited to temporarily transmit a quantity of electrical current that exceeds its maximum capacity by a quantity greater than or equal to the quantity Q, i.e. in case of potential congestion detection, and the reconstitution is activated when required and when no congestion is detected.

2. The method for optimizing according to claim 1, wherein the storage and release commands sent during the activation of the virtual transmission of the quantity Q of electrical current are executed by the related conversion controllers for a zero total energy balance of the storage units of the assemblies S1 and S2, to the nearest energy efficiency losses.

3. The method for optimizing according to claim 1 or 2, wherein the step of reconstitution is executed in such a way as to never solicit an exceeding of the maximum electrical current transmission capacity of said at least one electrical line of the network.

4. The method for optimizing according to any one of the preceding claims, wherein the reference filling is predetermined for each of the storage units at least according to the following rules: - if the risk for exceeding the maximum electrical current transmission capacity, or congestion, of the network is equiprobable, then the reference filling is the filling to half-capacity of each concerned storage unit, - if the congestion always occurs in the same direction of transmission, then the reference filling for each upstream storage unit will be the lowest load level possible, and the reference filling for each downstream storage unit will be the highest load level possible, and - for any intermediate situation, the reference filling is defined as a monotonous statistical function that interpolates the two preceding rules.

5. The method for optimizing according to any one of the preceding claims, wherein: - a main direction of congestion of at least one electrical line in the network is determined, and - the selections of the first and second assemblies S1, S2 are made so as to direct the virtual transmission in this main direction of congestion.

6. A computer program that can be downloaded from a communications network and/or recorded on a medium that can be read by a computer and/or that can be executed by a processor, wherein it comprises instructions for the execution of the steps of a method for optimizing according to any one of the preceding claims, when said program is executed on a computer.

7. A system for optimizing the functioning of an electrical current transmission network, the network comprising at least one electrical line, a plurality of energy storage units connected to a plurality of ends of said at least one electrical line, and controllers for converting stored energy into electrical current and reciprocally between each storage unit and the line end(s) to which it is connected, the system for optimizing comprising: - a memory maintaining up to date filling information on each one of the storage units, - a command unit, with a read/write connection to the memory and exchanging with the conversion controllers, programmed to send energy storage or release commands in or from the storage units, wherein the command unit is furthermore programmed to: - select a first assembly S1 of at least one storage unit connected to a first assembly El of at least one line end, - select a second assembly S2 of at least one storage unit connected to a second assembly E2 of at least one line end, - based on the filling information maintained up to date in memory, activate a virtual transmission of quantity Q of electrical current from the first assembly El toward the second assembly E2 while jointly sending to the related conversion controllers: • at least one first command to store a quantity of energy, corresponding to the quantity Q of electrical current, in the first assembly S1, * at least one second command to release the same quantity of energy, corresponding to the same quantity Q of electrical current, from the second assembly S2, and * an instruction for jointly executing in parallel and at the same time the storage and release commands of said same quantity of energy by the related conversion controllers; wherein a reference filling is predetermined for each one of the storage units, the command unit is further programmed to, following activation of the virtual transmission, activate a reconstitution according to which the conversion controllers of the storage units that have been solicited during the virtual transmission command their energy storage or release, from or toward said at least one electrical line of the network in the opposite direction to that ordered during the activated virtual transmission, so as to reach their reference filling; and wherein, each electrical line having a maximum electrical current transmission capacity, the virtual transmission of the quantity Q of electrical current is activated when at least one electrical line located between the assemblies El and E2 is solicited to temporarily transmit a quantity of electrical current that exceeds its maximum capacity by a quantity greater than or equal to the quantity Q, i.e. in case of potential congestion detection, and the reconstitution is activated when required and when no congestion is detected.

8. An equipment for optimized transmission of electrical current comprising: - an electrical current transmission network comprising: • at least one electrical line, • a plurality of energy storage units connected to a plurality of ends of said at least one electrical line, and * controllers for converting stored energy into electrical current or reciprocally between each storage unit and the line end(s) to which it is connected, - a system for optimizing according to claim 7, and

- a telecommunications network for an exchange of the filling information and storage/release commands between the command unit of the system for optimizing and the conversion controllers of the electrical current transmission network.

9. The equipment according to claim 8, wherein the storage units are arranged inside electrical substations for connecting electrical lines of the electrical current transmission network.