FREQUENCY REGULATION IN AN ELECTRICAL NETWORK, BY DISTRIBUTION OF POWER SUPPLIED BY / TO VEHICLE BATTERIES

Abstract

A power distribution method is implemented in an electrical network having a central operating frequency and to which are temporarily coupled vehicles each comprising a rechargeable power battery and capable of supplying this electrical network. This method comprises a step (10) in which the power batteries of at least some of the vehicles are used sequentially in an order chosen according to at least one chosen criterion and for respective individual electrical powers chosen, in order to achieve in the electrical network a total target electrical power depending on a frequency regulation law used in the latter. Figure 3

Description

Title of the invention: FREQUENCY REGULATION IN AN ELECTRICAL NETWORK, BY DISTRIBUTION OF POWER SUPPLIED BY / TO VEHICLE BATTERIES Technical field of the invention

[0001] The invention relates to electrical networks to which vehicles having rechargeable power batteries capable of supplying them can be temporarily coupled, and more precisely to the regulation of the frequency of such electrical networks by the use of these power batteries. State of the art

[0002] Certain vehicles, possibly of the automobile type, include a power battery which can, when temporarily coupled to an electrical network, either be recharged by the latter or be used to supply this electrical network.

[0003] As is known to those skilled in the art, an electrical network operates at a frequency which varies very slightly around a central operating frequency due to the differences occurring between the electrical power which is produced and the electrical power which is consumed.

[0004] In order to counteract these frequency variations within an electrical network, frequency regulation must be carried out. This generally consists of either supplying the electrical network with a reserve of electrical power, or removing electrical power from this electrical network, depending on the sign of the current frequency variation. It has therefore been proposed to use battery-powered vehicles, which are temporarily coupled to an electrical network, to participate in this frequency regulation. At least three methods have been proposed.

[0005] A first method consists of using tailor-made regulation laws which are not proportional to the frequency variations of the electricity network. Such a first method is only valid in a so-called island electricity network, and does not comply with the rules set by certain national or regional electricity transmission network operators.

[0006] A second method consists of using a decentralized strategy based on an operating point (or POP (“Preferred Operating Point”)). Such a second method simply applies an operating point (or POP) which depends only on the state of charge of the vehicle in question and the needs of its user, which is very limiting.

[0007] A third method consists of using a strategy minimizing the marginal loss of state of health (or SOH). Such a third method requires knowing the power demand profiles in advance, which is impossible in the context of global frequency regulation. In addition, minimizing the state of health does not necessarily lead to a global optimum.

[0008] The invention therefore aims in particular to improve the situation. Presentation of the invention

[0009] For this purpose, it proposes in particular a power distribution method intended to be implemented in an electrical network having a central operating frequency and to which vehicles are temporarily coupled, each comprising a power battery, rechargeable and capable of supplying this electrical network.

[0010] This power distribution method is characterized by the fact that it comprises a step in which the power batteries of at least some of the vehicles are used sequentially in an order chosen as a function of at least one chosen criterion and for respective individual electrical powers chosen, in order to achieve in the electrical network a total target electrical power depending on a frequency regulation law used in this electrical network.

[0011] Thanks to this use of a few vehicles one after the other, in a chosen order and with respective chosen individual electrical powers, the disadvantages of a decentralized strategy imposing a sub-optimal operating point are avoided, which makes it possible to reduce energy losses, the operating time of chargers and charging stations, and the degradation of power batteries.

[0012] The power distribution method according to the invention may include other characteristics which may be taken separately or in combination, and in particular:

[0013] - in its step, the target total electrical power can be proportional to a variation of operating frequency relative to the central operating frequency in the electrical network;

[0014] - in its step, each criterion can be chosen from a random draw, states of current charging of the power batteries increasing or decreasing, current health status of the power batteries increasing or decreasing, increasing or decreasing number of kilometers traveled by the vehicles since their entry into service, increasing or decreasing number of kilometers traveled by the vehicles during their last driving phase, and vehicle flexibility rates, each defined by (1 - (energy to be taken from or injected into the electricity network / duration of taking or injection)), increasing or decreasing;

[0015] - in the presence of the last option, in its step, when the chosen criterion is current charge states of the power batteries increasing or decreasing, the order chosen may be according to decreasing current load states in the presence of a negative variation in operating frequency relative to the central operating frequency, or the order chosen may be according to increasing current load states in the presence of a positive variation in operating frequency relative to the central operating frequency in the electrical network;

[0016] - in its step, each vehicle can be assigned a priority level of use depending on the current state of health of its power battery, the level of priority of use being higher the higher the current state of health, and, when a vehicle has been preselected according to the chosen criterion, it can be chosen when its assigned level of priority of use is higher than a chosen threshold or when its assigned level of priority of use is lower than or equal to this chosen threshold and there is no preselected alternative vehicle;

[0017] - in its step, when two vehicles must be used respectively for a first individual electrical power and a second individual electrical power much smaller than this first individual electrical power, we can use these two vehicles for the same individual electrical power equal to half of a sum of these first and second individual electrical powers.

[0018] The invention also proposes a computer program product comprising a set of instructions which, when executed by processing means, is capable of implementing a power distribution method of the type presented above, in an electrical network having a central operating frequency and to which are temporarily coupled vehicles each comprising a power battery, rechargeable and capable of supplying the electrical network, to carry out frequency regulation in the latter.

[0019] The invention also proposes a power distribution device intended to equip an electrical network having a central operating frequency and to which are temporarily coupled vehicles each comprising a power battery, rechargeable and capable of supplying this electrical network.

[0020] This power distribution device is characterized by the fact that it comprises at least one processor and at least one memory arranged to carry out the operations consisting of triggering use of the power batteries of at least some of the vehicles sequentially according to an order chosen as a function of at least one chosen criterion and for respective individual electrical powers chosen, in order to reach in the electrical network a total target electrical power depending on a frequency regulation law used in this electrical network.

[0021] The invention also proposes an electrical network, on the one hand, having a central operating frequency and to which vehicles can be temporarily coupled. each comprising a power battery, rechargeable and suitable for supplying this electrical network, and, on the other hand, comprising a power distribution device of the type presented above.

[0022] For example, the operating center frequency may be 50 Hz. Brief description of the figures

[0023] Other characteristics and advantages of the invention will appear on examining the detailed description below, and the appended drawings, in which:

[0024] [Fig. 1] schematically and functionally illustrates an exemplary embodiment of an electrical network, to which are connected charging terminals to which are coupled vehicles with rechargeable power batteries, and associated with a network calculator, and a power distribution device according to the invention,

[0025] [Fig.2] schematically and functionally illustrates an exemplary embodiment of a network calculator comprising an exemplary embodiment of a power distribution device according to the invention, and

[0026] [Fig.3] schematically illustrates an example of an algorithm implementing a power distribution method according to the invention. Detailed description of the invention

[0027] The invention aims in particular to propose a power distribution method, and an associated power distribution device DR, intended to allow the distribution of electrical power between an electrical network RE (having a central operating frequency fcf) and vehicles Vn, temporarily coupled to the latter (RE) and each comprising a rechargeable power battery BP, to regulate the operating frequency ff of this electrical network RE.

[0028] In the following, it is considered, by way of non-limiting example, that the vehicles Vn are of the automobile type. These are, for example, cars. But the invention is not limited to this type of vehicle. It relates in fact to any type of vehicle comprising a powertrain transmission chain (or GMP) comprising at least one electric motor associated with a power battery rechargeable via an electrical network. Thus, it relates to land vehicles (utility vehicles, camper vans, minibuses, coaches, trucks, motorcycles, road machinery, construction machinery, agricultural machinery, leisure machinery (snowmobile, kart), tracked vehicles, trains and trams, for example), aircraft and boats.

[0029] It should be noted that the GMPs of Vn vehicles can be all-electric (and therefore the drive is provided exclusively by at least one electric motor), or hybrid (electric and thermal or non-thermal (but not electric)).

[0030] [Fig.l] schematically shows an electrical network RE associated with a network calculator CR and to which charging stations BR are connected. to which vehicles Vn are coupled (here n = 1 to 7 as a purely illustrative example), and a power distribution device DR according to the invention. It will be noted that the network calculator CR can be responsible for ensuring at least part of the supervision of the electrical network RE, and in particular its frequency regulation.

[0031] The electrical network RE comprises in particular an electricity transmission infrastructure supplied by at least one main electrical power source (not illustrated), and to which are connected (directly or indirectly) fixed equipment or installations consuming electrical energy and connection interfaces, such as for example the BR charging stations (for Vn vehicles) and electrical sockets.

[0032] For example, the central operating frequency fcf of the electrical network RE can be equal to 50 Hz. But it can take other values.

[0033] Each vehicle Vn comprises at least one power (or "traction" or "main") battery BP which can, when it (Vn) is temporarily coupled to the electrical network RE (here via a charging station BR), either be recharged by this electrical network RE, or be used to supply this electrical network RE.

[0034] Each power battery BP is responsible for powering at least one electric motor of the GMP of its vehicle Vn. It may, for example, comprise electrical energy storage cells, possibly electrochemical (for example of the lithium-ion (or Li-ion) or Ni-Mh or Ni-Cd type). Also for example, each rechargeable battery BP may be of the low voltage type (typically 450 V for illustration purposes). But it could be of the medium voltage or high voltage type.

[0035] As mentioned above, the invention proposes in particular a power distribution method intended to allow the distribution of power between the electrical network RE and vehicles Vn temporarily coupled to the latter (RE) to carry out frequency regulation in the electrical network RE.

[0036] This method (of power distribution) can be implemented at least partially by the power distribution device DR (illustrated at least partially in FIGS. 1 and 2) which comprises for this purpose at least one processor PR1, for example a digital signal processor (or DSP ("Digital Signal Processor")), and at least one memory MD. This power distribution device DR can therefore be produced in the form of a combination of electrical or electronic circuits or components (or "hardware") and software modules (or "software"). For example, it can be a microcontroller.

[0037] The memory MD is RAM in order to store instructions for the implementation by the processor PR1 of at least part of the power distribution method. The processor PR1 may comprise integrated (or printed) circuits, or several integrated (or printed) circuits connected by wired or wireless connections. by integrated (or printed) circuit means any type of device capable of carrying out at least one electrical or electronic operation.

[0038] In the example illustrated non-limitingly in Figures 1 and 2, the power distribution device DR is part of the network computer CR. But this is not obligatory. Indeed, the power distribution device DR could comprise its own dedicated computer, which is then coupled to the network computer CR, for example.

[0039] As illustrated non-limitingly in [Fig. 3], the method (of power distribution), according to the invention, comprises a step 10 which is implemented each time that variations in operating frequency vf appear in the electrical network RE. Here, the term "variation in operating frequency vf" means the difference between the operating frequency ff in progress in the electrical network RE at a given instant and the central operating frequency fcf, i.e. vf = ff - fcf. It will be understood that this variation in operating frequency vf can be negative or positive.

[0040] In step 10 of the method, the power batteries BP of at least some of the vehicles Vn are used (for example, the power distribution device DR triggers use of the) in a sequential manner according to an order which is chosen as a function of at least one chosen criterion and for respective chosen individual electrical powers. These chosen individual electrical powers form a power distribution (or distribution) which makes it possible to achieve in the electrical network RE a target total electrical power which is a function of a frequency regulation law used in this electrical network RE.

[0041] It will be noted that the target total electrical power is determined as a function of the operating frequency variation vf detected (or predicted) in the electrical network RE and the frequency regulation law. It can, for example, be determined by the network calculator CR. Furthermore, the frequency regulation law used in the electrical network RE is predefined, and known to the network calculator CR. It can vary from one electrical network to another.

[0042] For example, one can start by determining the vehicles Vn that one will use, then one can determine the order of use of these vehicles Vn, then one can determine the respective individual electrical powers chosen from the power batteries BP of these vehicles Vn. Alternatively, one can start by determining the vehicles Vn that one will use, then one can determine at the same time the order of use of these vehicles Vn and the respective individual electrical powers chosen from the power batteries BP of these vehicles Vn.

[0043] By using a few vehicles Vn one after the other, in a chosen order and with respective individual electrical powers chosen, and therefore at their respective nominal operating points, the disadvantages of a decentralized strategy imposing a suboptimal operating point are avoided. In addition, this makes it possible to maximize the number of vehicles Vn used at maximum electrical power as well as the number of vehicles Vn used at zero electrical power. This results in reductions in energy losses, the operating time of chargers and charging stations BR, and the degradation of power batteries BP.

[0044] For example, in step 10 the target total electrical power can be proportional to the variation vf of the operating frequency ff with respect to the central operating frequency fcf in the electrical network RE. But other variation laws can be used.

[0045] Also for example, in step 10 each criterion can be chosen from:

[0046] - a random draw (or at random), and therefore independently of the current values of the parameters of the BP power batteries (such as for example the states of charge (or SOCs ("State Of Charge")) or the states of health (or SOHs) and of the Vn vehicles, and in this case the chosen Vn vehicles can be ordered in the sequence according to their respective drawing orders or according to another random drawing (or by lot),

[0047] - current states of charge (or SOCs) of the BP power batteries which are increasing or decreasing, and in this case the chosen vehicles Vn are ordered in the sequence according to their respective SOCs in an increasing or decreasing manner,

[0048] - current health states (or SOHs) of the BP power batteries which are increasing or decreasing, and in this case the chosen vehicles Vn are ordered in the sequence according to their respective SOHs in an increasing or decreasing manner,

[0049] - increasing or decreasing numbers of kilometers traveled by the vehicles Vn since their entry into service, and in this case the chosen vehicles Vn are ordered in the sequence according to their respective total number of kilometers traveled in an increasing or decreasing manner,

[0050] - increasing or decreasing numbers of kilometers traveled by vehicles Vn during their last rolling phase, and in this case the chosen vehicles Vn are ordered in the sequence according to their respective number of last kilometers traveled in an increasing or decreasing manner, and

[0051] - flexibility rates tfn of the vehicles Vn, each defined by (1 - (the energy at to be taken or injected into the RE electricity network using the vehicle Vn / the duration of taking or injection)), and which are increasing or decreasing, and in this case the chosen Vn vehicles are ordered in the sequence according to their rates respective tfn flexibility in an increasing or decreasing manner.

[0052] It should be noted that the list of criteria given above is not exhaustive. It should also be noted that several (at least two) criteria may possibly be used simultaneously.

[0053] Also for example, in step 10, when the chosen criterion is the second in the list given above (namely increasing or decreasing current charge states of the power batteries BP), the chosen order may be according to decreasing current charge states in the presence of a negative variation vf of the operating frequency ff relative to the central operating frequency fcf (i.e. when vf < 0 (or ff < fcf)), or the chosen order may be according to increasing current charge states in the presence of a positive variation vf of the operating frequency ff relative to the central operating frequency in the electrical network RE (i.e. when vf > 0 (or ff > fcf)).

[0054] Also for example, in step 10, one (for example the power distribution device DR) can assign to each of the vehicles Vn a level of priority of use which is a function of the current state of health (or SOH) of its power battery BP, this level of priority of use being all the higher as the current state of health is high. In this case, when a vehicle Vn has been preselected according to the (each) chosen criterion, one (for example the power distribution device DR) can choose it when its assigned level of priority of use is greater than a chosen threshold if, or when its assigned level of priority of use is less than or equal to this chosen threshold if and there is no preselected alternative vehicle Vn' (n' n).It will be understood that the objective here is to favor the use of Vn vehicles having a BP power battery whose state of health is good (or very good), in order to use as little as possible (and possibly not at all) Vn vehicles having a BP power battery whose state of health is average or poor.

[0055] Also for example, the threshold chosen if can be between 70% and 90%. As an illustrative example this threshold chosen if can be equal to 80%. But other values of threshold chosen if can be used.

[0056] Also for example, in step 10, when two vehicles Vn and Vn' (n' n) must be used respectively for a first individual electrical power peil and a second individual electrical power pei2 much smaller than this first individual electrical power peil, one (for example the power distribution device DR) can use these two vehicles Vn and Vn' for the same individual electrical power pei equal to half the sum of these first peil and second pei2 individual electrical powers (i.e. pei = (peil + pei2) / 2).

[0057] This option is intended to prevent a marginal vehicle Vn' from being chosen and used for a very low individual electrical power (here pei2), while another marginal vehicle Vn has also been chosen to be used for a very high individual electrical power (here peil), and possibly maximum among all the vehicles chosen.

[0058] It will also be noted, as illustrated non-limitingly in [Fig. 2], that the network calculator CR (or the calculator of the power distribution device DR) may also comprise a mass memory MME, in particular for storing each target total electrical power, each possible SOC and / or each possible SOH, as well as any intermediate data involved in all its calculations and processing. Furthermore, this network calculator CR (or the calculator of the power distribution device DR) may also comprise an input interface IE for receiving at least each target total electrical power, each possible SOC and / or each possible SOH, possibly after having shaped and / or demodulated and / or amplified them, in a manner known per se, by means of a digital signal processor PR2.In addition, this network calculator CR (or the calculator of the power distribution device DR) can also include an output interface IS, in particular to deliver a message containing the individual electrical powers chosen respectively for the vehicles Vn chosen.

[0059] It will also be noted that the invention also proposes a computer program product (or computer program) comprising a set of instructions which, when executed by processing means of the electronic circuit (or hardware) type, such as for example the processor PR1, is capable of implementing the power distribution method described above to carry out frequency regulation in the electrical network RE by distributing electrical power between the latter (RE) and vehicles Vn temporarily coupled to this electrical network RE.

Claims

Claims

1. Method for distributing power for an electrical network (RE) having a central operating frequency and to which are temporarily coupled vehicles (Vn) each comprising a power battery (BP), rechargeable and suitable for supplying said electrical network (RE), characterized in that it comprises a step (10) in which the power batteries (BP) of at least some of said vehicles (Vn) are used sequentially in an order chosen as a function of at least one chosen criterion and for respective individual electrical powers chosen, in order to reach in said electrical network (RE) a total target electrical power depending on a frequency regulation law used in the latter (RE).

2. Method according to claim 1, characterized in that in said step (10) said target total electrical power is proportional to a variation in operating frequency with respect to said central operating frequency in said electrical network (RE).

3. Method according to claim 1 or 2, characterized in that in said step (10) each criterion is chosen from a random draw, current charge states of said power batteries (BP) increasing or decreasing, current health states of said power batteries (BP) increasing or decreasing, increasing or decreasing numbers of kilometers traveled by said vehicles (Vn) since their entry into service, increasing or decreasing numbers of kilometers traveled by said vehicles (Vn) during their last driving phase, and flexibility rates of said vehicles (Vn), each defined by (1 - (energy to be taken from or injected into said electrical network (RE) / duration of taking or injection)), increasing or decreasing.

4. Method according to claim 3, characterized in that in said step (10) when said criterion is increasing or decreasing current charge states of said power batteries (BP), said chosen order is according to decreasing current charge states in the presence of a negative variation in operating frequency with respect to said central operating frequency, or said chosen order is according to increasing current charge states in the presence of a positive variation in operating frequency with respect to said central operating frequency in said electrical network (RE).

5. Method according to one of claims 1 to 4, characterized in that in said step (10) each of said vehicles (Vn) is assigned a usage priority level depending on the current health status of its power battery (BP), said usage priority level being higher the higher said current health status is, and, when a vehicle (Vn) has been preselected based on said chosen criterion, it is chosen when its assigned usage priority level is higher than a chosen threshold or when its assigned usage priority level is lower than or equal to said chosen threshold and there is no preselected alternative vehicle (Vn).

6. Method according to one of claims 1 to 5, characterized in that in said step (10) when two vehicles (Vn) are to be used respectively for a first individual electrical power and a second individual electrical power much smaller than said first individual electrical power, these two vehicles (Vn) are used for the same individual electrical power equal to half of a sum of said first and second individual electrical powers.

7. Computer program product comprising a set of instructions which, when executed by processing means, is capable of implementing the power distribution method according to one of claims 1 to 6, in an electrical network (RE) having a central operating frequency and to which are temporarily coupled vehicles (Vn) each comprising a power battery (BP), rechargeable and capable of supplying said electrical network (RE), to carry out frequency regulation in the latter (RE).

8. Power distribution device (DR) for an electrical network (RE) having a central operating frequency and to which are temporarily coupled vehicles (Vn) each comprising a power battery (BP), rechargeable and suitable for supplying said electrical network (RE), characterized in that it comprises at least one processor (PR1) and at least one memory (MD) arranged to carry out the operations consisting in triggering a use of the power batteries (BP) of at least some of said vehicles (Vn) sequentially according to an order chosen as a function of at least one chosen criterion and for respective individual electrical powers chosen, in order to reach in said electrical network (RE) a total target electrical power as a function of a frequency regulation law used in the latter (RE).

9. Electrical network (RE) having a central operating frequency and to which vehicles (Vn) can be temporarily coupled, each comprising a power battery (BP), rechargeable and capable of supplying said electrical network (RE), characterized in that it comprises a power distribution device (DR) according to claim 8.

10. Electrical network according to claim 9, characterized in that said central operating frequency is equal to 50 Hz.

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