FR3063581A1 - METHOD FOR CHARGING AN ELECTRIC BATTERY OF A MOTOR VEHICLE - Google Patents

Abstract

The invention relates to such a method, comprising the following steps: a1) acquisition of a data representative of a duration provided by a user for the electric charge of the electric battery by a charging terminal, a2) acquisition of a data item representative of an autonomy of operation of the motor vehicle desired by the user, b) determination, of a corresponding electric power of charge, among the electric powers that can be delivered by the charging terminal, to the smallest electrical power such as the motor vehicle has, at the end of the charging time, a range of autonomy equal to or greater than the said autonomy desired by the user, and c) control of the charging terminal to deliver the determined charging electric power to step b).

Description

Technical field to which the invention relates

The present invention relates generally to the field of electric batteries of motor vehicles with electric or hybrid traction.

It relates more particularly to a method of charging an electric battery of a motor vehicle, connected to a charging station external to the motor vehicle, the charging method comprising the following steps:

a1) acquisition of data representative of a charging time supplied by a user for the electric charge of the electric battery by the charging station,

b) determination, as a function of the charging time, of an electrical charging power to be applied to the electric battery, and

c) control of the charging station so that it delivers the electric charging power determined in step b).

Technological background

Motor vehicles with electric propulsion, comprising an electric traction motor powered by an electric battery, are more and more widespread. Some of these vehicles are fitted with sockets which allow the electric battery to be charged (or recharged) before using these vehicles.

The electrical power under which the electric battery is charged directly influences the time required to fully charge this battery. For a full charge of the battery, this duration can vary in practice from a few tens of minutes to several hours, depending on the electric charge power.

However, this electric charging power also has a notable influence on the aging of the electric battery: the greater the electric charging power, the faster the aging of the battery.

Document KR 100388417 then discloses a method for charging an electric battery of a vehicle during which:

- a user sets a charging time for the electric battery,

- an electric charge power is determined as a function of this charge duration, so as to be as small as possible, in order to minimize the aging of the battery, and this while making it possible to fully charge the electric battery during the charge duration set by the user, and

- the electric battery is charged under this electric power.

Even so, we see that electric batteries age quickly, especially because this process often leads to charging the battery much more than necessary, at the expense of its lifespan.

Furthermore, in this process, the user does not know whether the charging time he has set will effectively allow the battery to be fully charged (in the case where this charging time is relatively short and / or in the case where the level of battery charge is very low). Thus, the charging of the battery begins without the user knowing whether this charging, which can be long, will allow the electric battery to be fully or only partially charged. And the user therefore cannot know whether he can reach his destination directly or whether he will have to recharge en route.

Object of the invention

In order to remedy the problem of premature aging of the electric battery mentioned above, a charging method according to the invention is proposed as defined in the introduction:

- further comprising a step a2) of acquiring data representative of the operating autonomy of the motor vehicle desired by the user, and in which

the electric charge power determined at the end of step b) is, among the electric powers that can be delivered by the charging station, the smallest electric power such as the motor vehicle has, at the end of the charge duration, autonomy equal to or greater than said autonomy desired by the user.

The range available to the motor vehicle depends directly on the level of charge of the electric battery.

Taking into account (in step b)) the autonomy desired by the user, which in practice does not systematically correspond to the total charge level of the electric battery, allows, compared to a process which would systematically target a total charge of this battery, to reduce the electric charge power, and this while satisfying the need for autonomy and the charge duration indicated by the user.

This reduction in the electric charge power advantageously increases the life of the electric battery.

The reduction of the final charge level of the battery (to adjust it optimally to the needs indicated by the user), also increases the service life of the electric battery.

It also makes it possible to maximize an electrical power which, during charging, remains available on an electrical network supplying the charging station. This remaining available electric power can then advantageously be used for, for example, charging the batteries of other electric vehicles.

Preferably, step a2) is executed after step a1).

Other non-limiting and advantageous characteristics of the process according to the invention are as follows:

- step b) includes a step b2) which includes a determination of the autonomy which the vehicle will have after said charging time, for said electric charging power;

- it is provided, when the maximum electric power that can be delivered by the charging station is too small for the autonomy, which the motor vehicle will have after the charging time, to be greater than or equal to the desired autonomy, at l step b), to determine that the electric charge power to be applied to the electric battery is equal to this maximum electric power, and in step d2), to develop a message for the user indicating that the desired autonomy cannot be reached at the end of the charging time, and indicating the range, determined in step b2), which the motor vehicle will actually have after said charging time;

- step b2) further comprises a determination, for at least one other charging duration, of a range which the motor vehicle will have, for said electrical charging power, after said other duration;

- The method further comprising a step d1) of developing a message to the user indicating the range, determined in step b2), which will be available to the motor vehicle after said other period;

- step b) is implemented by means of an autonomous sub-method for determining a total charge time, necessary to fully charge the electric battery from a given initial charge level;

- step b) includes the following steps:

b1) generation of a range of distinct given charge levels, between 0% and 100%, this range notably comprising the current charge level of the electric battery, and

F) determination, by means of said sub-process, for each of said given charge levels, of the corresponding total charge duration;

in step b2), a charge level which will be reached at the end of the charge time is calculated, as a function of said given charge levels and of the corresponding total charge durations determined in step F), said autonomy, which will be available to the motor vehicle after the charging time, being determined according to the level of charge thus calculated;

- the autonomy which will be reached after said other duration is determined, in step b2), as a function of said given charge levels and of the corresponding total charge durations which have been determined in step F);

- step F) is executed several times successively, each of these executions being followed by an execution of steps b2) then d1);

- said total charge durations are determined by executing said sub-process several times successively, each time for one of said given charge levels, according to a determined time sequence;

step b2) comprises a selection of a first charge level, corresponding to that of said given charge levels for which the difference between the total charge time of the electric battery from its current charge level, and the total charge duration associated with this level, is the closest, by higher value, to said charge duration acquired in step a1);

- the charge level which will be reached at the end of said charge duration is determined as a function of said first charge level;

step b2) comprises a selection of a second charge level, corresponding to that of said given charge levels for which the difference between the total charge time of the electric battery from its current charge level, and the total charge duration associated with this level, is the closest, by lower value, to said charge duration acquired in step a1);

- the charge level which will be reached at the end of said charge duration is determined as a function of said second charge level.

Detailed description of an exemplary embodiment

The description which follows with reference to the accompanying drawings, given by way of nonlimiting examples, will make it clear what the invention consists of and how it can be carried out.

In the accompanying drawings:

FIG. 1 schematically represents a part of an electric motor vehicle connected to a charging station for the implementation of a charging method according to the invention,

FIG. 2 schematically represents the main steps of the charging method implemented in the motor vehicle of FIG. 1,

FIG. 3 schematically represents, in more detail, one of the steps of the method of FIG. 2, in the form of a flow diagram,

FIG. 4 represents in more detail, in the form of a block diagram, other steps of the method of FIG. 2,

FIGS. 5A to 5D represent the evolution over time of different quantities determined during the process of FIG. 2, and

- Figure 6 schematically shows the detail of one of the functional blocks of Figure 4.

In Figure 1, there is partially shown a motor vehicle 1 with electric propulsion, seen from above. This vehicle 1 comprises an electric traction motor (not shown) powered by an electric battery 10.

So this is an exclusive electric vehicle. Alternatively, it could be a hybrid vehicle or an electric vehicle equipped with a range extender (commonly known by its term "range extender").

In the configuration shown in FIG. 1, the vehicle 1 is parked near a charging station 2, that is to say of a structure:

- Having means of connection to the electric vehicle 1, here an electric cord 2B provided with an electric plug, and

- suitable for delivering to the vehicle 1 an electric power allowing to charge (or recharge) the battery 10.

The electrical cord 2B of the charging station 2 is connected to a socket 10C of the vehicle 1, the charging station 2 then being electrically connected to the battery 10. It can be provided that the battery 10 is, as here, connected to the charging station 2 by means of a protection device 10B comprising for example a controlled switch and / or a fuse device.

The electric power delivered to the vehicle 1 by the charging station 2 can be adjusted between a minimum electric power Pmin and a maximum electric power Pmax, and this either continuously or discretely, that is to say in stages. In the latter case, the electric power delivered by the charging station 2 is selected from a list of electric powers P ^ Pmin, ..., Pj, ..., P _Q = Pmax which can be delivered by the charging station 2 , Q in number, each identified for example by an index j between 1 and Q.

The vehicle here comprises an electronic control unit 11, comprising in particular a processor and a memory.

This control unit 11 is adapted to receive, from the charging station 2, data relating to the electrical powers that can be delivered by this terminal. These data specify in particular whether the electrical power delivered is continuously adjustable, or else in stages. They also include data P_charge_poss (Figure 4) indicating:

- the minimum Pmin and maximum Pmax electrical powers, and

- when the electrical power delivered is adjustable in stages, the (discrete) set of powers Ρ _Ί , ..., Pj, ..., P _Q can be delivered.

The control unit 11 is also adapted to control the charging terminal 2 so that the latter delivers a given electrical charging power P_target (FIG. 4), specified by the control unit 11.

The control unit 11 is also suitable for receiving data relating to the operation of the battery 10, in particular from sensors fitted to the vehicle 1. This data is in particular representative of a charge level (or "State of Charge" - state of charge -, according to the Anglo-Saxon name) SOC_actuel of battery 10, or at least include information making it possible to determine this level of charge SOC_actuel.

The charge level represents, here in the form of a percentage, the electric charge accumulated in the battery 10. It is therefore between 0%, when the battery 10 is completely discharged, and 100%, when the battery is fully charged . The data relating to the operation of the battery 10 can also include, inter alia, data relating to the temperature of the battery 10.

The control unit 11 is also configured to exchange data with a man-machine interface 12. The man-machine interface 12 makes it possible to display or send messages to a user, and to receive messages. data or instructions from it. The human machine interface 12 can for example comprise a touch screen, or a system comprising a microphone and a loudspeaker, in which case messages intended for the user are emitted in the form of sound. The human-machine interface 12 can be integrated directly into the vehicle 1, or can be part of a portable electronic device separate from the vehicle, such as a portable telephone. Alternatively, the man-machine interface could also be integrated into the charging station.

Alternatively, instead of being part of the motor vehicle, the control unit could be included in the portable electronic device mentioned above. In this case, the portable electronic device receives from the motor vehicle the aforementioned data relating to the operation of the electric battery.

In another variant, instead of part of the motor vehicle, the control unit could be included in the charging station, the charging station then receiving from the motor vehicle the above-mentioned data relating to the operation of the electric battery.

In Figure 2, there is shown the main steps of a method of charging the battery 10 of the motor vehicle 1, according to the invention.

This process includes the following steps, implemented by the electronic control unit 11:

a1) acquisition of data representative of a charging time T_ch supplied by the user for the electric charge of the battery 10 by the charging station 2,

b) determination, as a function of the charging time T_ch, of the electrical charging power P_target to be applied to the battery 10, and

c) control of the charging station 2 so that it delivers the electric charging power P_target determined in step b).

In practice, the data representative of the charging time T_ch is supplied by the user via the man-machine interface 12, then acquired by the control unit.

This data here corresponds to a departure time h_dep desired by the user (from which the charging time T_ch is deducted). Typically, this can be the time you leave for work the next morning. As a variant, this data could of course correspond directly to the charging time itself. It could also be automatically calculated, depending on the habits of the user (and in particular his usual time of departure from work).

Remarkably,

the method further comprises a step a2) of acquiring data representative of the operating autonomy of the motor vehicle desired by the user, Auton_souhait, and

the electric charge power P_target determined at the end of step b) is, among the electric powers that can be delivered by the charging station, the smallest electric power such as the motor vehicle 1 has, at the end of the duration of charge T_ch, with an Auton_dep autonomy equal to or greater than said Auton_souhait autonomy desired by the user.

The Auton_dep range available to the motor vehicle 1 after the charge time T_ch depends directly on the charge level SOC_dep of the electric battery reached at the end of this period.

Taking into account the autonomy, or equivalently the level of charge, desired by the user makes it possible to adjust the electric charge power to the minimum compatible with the needs indicated by it. This reduction in the electrical charge power increases the service life of the electric battery in a particularly advantageous manner, in particular with respect to an approach which would systematically aim for a complete charge of the battery.

Here, said data representative of the autonomy Auton_souhait desired by the user corresponds directly to this autonomy, that is to say that it corresponds to a distance that the user wishes to be able to cover, once the battery 10 is charged, without having to stop to recharge it.

As a variant, this data could correspond to the SOC_souhait charge level, corresponding to the autonomy desired by the user (in practice the driver of the vehicle), or even to a duration of autonomous operation of the vehicle 1 desired by the user.

In practice, the data representative of the desired autonomy is indicated by the user via the man-machine interface 12, to then be acquired by the control unit 11. It could alternatively be automatically calculated, according to the habits of the user (and in particular the distance between his home and his workplace).

In the example embodiment shown in the figures, it is directly the value of the electric charge power P_target which is determined in step b). However, as the intensity of the electric charge current directly conditions the value of this power, it is understood that the adjustment of the electric charge power could be achieved by adapting the intensity of this electric current, according to criteria identical to those indicated above for the determination of the electrical load power.

Here, step b) of the method more specifically comprises a step b2) (shown diagrammatically in FIG. 4) which includes a determination of the Auton_dep range which the vehicle will have after said charging time T_ch, for said electrical charging power P_target.

Evaluating the Auton_dep range that the vehicle 1 will actually have, after charging the battery 10, makes it possible to verify that the electric power of charge P_target is sufficient for the vehicle to have the Auton_dependent range desired by the user.

During this process, if the charge time T_ch that the user wishes to devote to the charge is very short, it may happen that the charge level SOC_souhait, corresponding to the autonomy desired by the user, cannot be reached even if the charging station 2 delivers its maximum electrical power Pmax.

Also, it is provided here, when the maximum electric power Pmax that can be delivered by the charging station 2 is too small for the autonomy Auton_dep, which the motor vehicle will have after the charging time T_ch, to be greater than or equal to l desired autonomy Auton_souhait,

- in step b), to determine that the electric charge power P_target to be applied to the electric battery is equal to this maximum electric power Pmax, and

- in a step d2), to elaborate a message intended for the user indicating that the desired autonomy Auton_souhait cannot be reached at the end of the charging time T_ch, and indicating the autonomy Auton_dep, determined at step b2), which the motor vehicle 1 will effectively dispose of after said charging time.

This message is then displayed, or sent, by the human-machine interface

12. Here, this message indicates not only the Auton_dep range which the vehicle will have, but also the corresponding SOC_dep charge level, reached at the end of the charge time T_ch.

The user thus has information as to the autonomy which the vehicle 1 will actually have, taking into account the charging time T_ch indicated. This information is particularly useful because it allows the user to knowingly choose the compromise that best suits him between a short charging time and a long autonomy.

Step b2) of the method further comprises a determination, for at least one other charging time time_laps_i (with i between A and M), of a range Auton_dans_i_min which the motor vehicle will have, for said electrical charging power P_target , after said other duration.

The method further comprising a step d1) of developing a message intended for the user indicating the autonomy, determined in step b2), which will be reached at the end of said other duration time_laps_i. This message is also displayed, or sent, by the man-machine interface 12. Again, it indicates not only the Auton_dans_i_min autonomy which the vehicle will have after said other charging time, but also the corresponding SOC_dans_i_min charge level.

The user thus has access to additional information relating to the evolution of the autonomy available to the vehicle 1, as a function of the time elapsed since the start of the charging of the battery 10. This information enables him to estimate even more finely if the charging time he indicated corresponds best to his expectations, in terms of autonomy and charging time. They can thus lead the user to review the charge duration that he had initially indicated, to, according to his needs, lengthen or shorten it.

Furthermore, when the electric charge power P_target determined in step b) allows, at the end of the charge time T_ch, to reach the desired autonomy Auton_souhait, it is provided here, during a step dO) , develop a message for the user indicating that the desired autonomy will be reached.

Step b)

Step b) of the charging method according to the invention can now be described in more detail, with reference to FIG. 3.

Here, in step b), the electric charge power P_target is firstly initialized to a value corresponding to the smallest electric power Pmin (not zero) that can be delivered by the charge terminal 2.

If this minimum electric power Pmin is too small for the autonomy Auton_dep, which will be available to vehicle 1 after the charging time T_ch, to be greater than the desired autonomy Auton_souhait, then, the electric power for charging P_target is not increased to not, until it becomes just large enough for the SOC_dep autonomy to reach, or possibly slightly exceeds, the desired SOC_dependent autonomy.

More specifically, step b) here begins with a step bO), during which the control unit 11 determines, as a function of the aforementioned data received from the charging station 2, whether the electric power delivered by the terminal is continuously adjustable, or in steps.

When the electric power delivered by the charging station 2 is adjustable in stages, step b) continues (arrow fl1 in FIG. 3) by a set of steps bOO), b01), b02), etc. , which will be described first.

When the electric power delivered by the charging station 2 is continuously adjustable, step b) continues (arrow fl1 'in FIG. 3) by a set of steps bOO'), b01 '), b02'), etc. ..., analogous to steps bOO), b01), b02) and which will be described in a second step.

During step bOO), which follows step bO) when the electrical power delivered by the terminal is adjustable in stages, the control unit 11 receives the data P_charg_poss from the charging station. Recall that this data then specifies the (discrete) set of electrical powers Pi = Pmin,

Pj,, P _Q = Pmax which can be supplied by charging station 2.

Step bOO) is followed by step b01), during which the electric charge power P_target is initialized to the value corresponding to the smallest electric power Pmin = P1 that can be delivered by the charge terminal 2, in accordance to the following formula F1:

P_target = Pmin (F1)

In the next step b02), the control unit 11 compares:

- Auton_dep autonomy which vehicle 1 will have after the charging time T_ch, for said electrical charging power P_ch, with

- the desired autonomy Auton_souhait.

When step b02) shows that the autonomy Auton_dep, which will be available to vehicle 1 after the charging time T_ch, is greater than or equal to the desired autonomy Auton_souhait, then, the electric charging power P_target retains its value determined previously , and step b) ends to be followed (arrow fl2 in FIG. 3)) by steps dO) and d1) described above, and by step c) of controlling the charging station 2.

When step b02) on the contrary shows that the autonomy Auton_dep, which will be available to vehicle 1 after the charging time T_ch, is less than the desired autonomy Auton_souhait, the process then continues with a step b03) (arrow fI3 in Figure 3).

During step b03), the control unit 11 increases the value of the electric charge power P_target. For this, among the electrical powers Pi, ..., Pj, ..., P _Q , which can be delivered by the charging terminal 2, the control unit 11 selects the electrical power P _{j +} i immediately greater than the power electrical power Pj previously assigned to the electrical load power P_target:

PJarget = P _{j + 1} (F2)

For example, in a case where the electrical powers which can be delivered by the charging station 2 are respectively equal to Pi = 10 kilowatts (kW), P ₂ = 20 kW, P ₃ = 30 kW, P ₄ = 40 kW and P ₅ = P _Q = 50 kW, when the electrical power Pj, previously assigned to the charging electrical power PJarget, is P ₃ = 30 kW, then, in step b03), the electrical power P ₄ = 40 kW is attributed to the electrical load power PJarget.

Step b03) is followed by step b04), during which the control unit 11 determines whether the electric charge power PJarget (the value of which has just been increased in step b03)) is equal at the maximum electrical power Pmax = P _{Q which} can be supplied by charging station 2.

When the charge electric power PJarget is different from the maximum electric power Pmax (in this case less than this maximum power), the process resumes at step b02) (arrow fl4).

Whereas when the electric charge power P_target is equal to the maximum electric power Pmax, step b04) is followed by a step b05) analogous to step b02 described above.

More precisely, when the control unit 11 determines, during step b05, that the autonomy Auton_dep, which will be available to the vehicle 1 after the charging time T_ch, is greater than or equal to the desired autonomy Auton_souhait, then step b) ends to be followed (arrow fl6) of step dO) (elaboration of the message indicating that the vehicle will actually have the desired autonomy) and of step d1) described above.

When step b05) shows on the contrary that the autonomy Auton_dep, which will be available to vehicle 1 after the charging time T_ch, is less than the desired autonomy Auton_souhait, then, step b) ends by being followed ( arrow fl7) of step d2) (elaboration of the message indicating that the vehicle will not have the desired autonomy, and also indicating the autonomy Auton_dep which it will actually have) and of step d1) described above.

After step b05), whether the Auton_dep autonomy is greater or not than the desired autonomy, step b) is followed by step c) of control of the charging station 2, the electrical power of charge P_target then being equal to the maximum electrical power Pmax.

The series of steps implemented during step b), when the electric power delivered by the charging station 2 is continuously adjustable, is now described. In this case, step b) includes, after step bO) steps b00 ’), b01’), b02 ’), b03’), b04 ’) and b05’) (Figure 3).

The steps b01 ’), b02’) and b05 ’) are each identical, respectively to step b01), to step b02), and step b05) described above.

Steps bOO '), b03'), and b04 ') are similar, respectively, in step bOO), in step b03) and in step b04) described above, but with respect to the latter the slight differences in implementation indicated below.

More precisely, in step bOO ′), the control unit 11 receives from the charging station the data P_charg_poss, which then specifies only the minimum electrical powers Pmin and maximum Pmax which can be delivered by the charging station 2, at place to indicate a whole discrete set of electrical powers that can be delivered.

Furthermore, when step b02 ') continues with step b03'), the electric charge power P_target is increased, in step b03 '), by adding to it a positive elementary electric power δ, according to the formula Following F3:

P_target (t) = P_target (t-1) + δ (F3) where the variable t designates time steps.

The value of the elementary electric power δ is chosen to satisfy a compromise between, on the one hand, a progressive increase in the electric power of charge, and, on the other hand, the fact of reaching an electric power, sufficient to obtain the desired autonomy, in a limited number of iterations of the set of steps b02 '), b03') and b04 '). In practice, the value of the elementary electric power δ may for example be between 0.5 kWetIOkW.

Finally, in step b04 '), the control unit tests whether the electric charge power P_target determined in step b03') is greater than or equal to the maximum electric power Pmax (instead, as is the case in step b03), to simply test if these two powers are equal to each other).

In a variant of the charging method described above, provision may be made for the control unit to control the charging terminal so that it delivers said electrical charging power P_target from step b01), or bOT) (the power electric charge being equal, at this stage, to the minimum electric power). In this case, in the remainder of the process, each time the value of the electric charge power is modified, the control unit transmits this value to the charging station and commands it to deliver this updated value.

It is understood from the description of step b) above that a determination of the autonomy Auton_dep, which will be reached at the end of the charging time T_ch, for the charging power P_target, is carried out during the step b02) or in parallel with it (and, in a comparable manner, during step b02 ') or in parallel with it).

Determination of the autonomy which the motor vehicle will have after the charging time T ch

The way of determining the autonomy which the motor vehicle will have can now be described, with reference to FIGS. 4 to 6.

In a particularly remarkable manner, the autonomy Auton_dep, which the motor vehicle will have after the charging time T_ch, is determined here by means of an autonomous sub-process, which is also used to determine a total charging time T_charge_compl, necessary to fully charge the battery 10 from a given initial SOC charge level.

More specifically, step b) here comprises the following steps (FIG. 4): b1) generation of a range of charge levels SOC_1, SOC_2,

..., SOC_N_state separate data, between 0% and 100%, this range including in particular the current SOC_actical level of battery 10, and

F) determination, by means of said sub-process, for each of said charge levels SOC_1, SOC_2, ..., SOC_N_state given, of the total charge duration T_charge_compl_1, T_charge_compl_2, ..., T_charge_compl_ N_state corresponding.

In step b2), the charge level SOC_dep, which will be reached at the end of the charge duration T_ch, is then calculated as a function of said charge levels SOC_1, SOC_2, ..., SOC_N_state and as a function of charge durations total corresponding T_charge_compl_1, T_charge_compl_2, ..., T_charge_compl_ N_state, previously determined in step F).

Auton_dep autonomy, which will have the motor vehicle 1 after the charging time T_ch, is then determined according to the SOC_dep charge level thus calculated.

The autonomous sub-method for determining the total charge time, necessary to fully charge the battery from a given initial charge level, is generally implemented by default in an electrically propelled motor vehicle. It is then already available, as a calculation function, in the vehicle control or electronic calculation unit.

Implementing this calculation function generally requires adjusting the values of different parameters relating to the operation of the vehicle and the electric battery, and carrying out measurements making it possible to map mutual dependencies between these parameters.

This sub-process is described here as autonomous, with respect to the charging process itself, in the sense that the sub-process is used as it is, without modifying it (in the manner of a black box ), intervening only at the level of the input variable SOC of the sub-process.

Using this sub-process already implemented, without modifying it, then makes it possible to rely on the adjustments and measures mentioned above, which have already been carried out, which considerably simplifies the implementation of the charging process.

In addition, thanks to this arrangement, the charging process remains fully functional (without having to adjust its operating parameters for this) even if the calculation function mentioned above is updated, following for example a replacement. of the electric battery.

The steps for implementing this determination technique are now described in more detail.

Part of these steps is shown schematically in Figure 4, in the form of a block diagram.

The BL3 functional block groups together all of the steps shown in FIG. 3, which have already been described.

The operations making it possible to determine the charge level SOC_dep, which will be reached at the end of the charge duration T_ch, correspond to the functional blocks, or otherwise formulated in steps, b1), F) and b2).

Step b1)

Step b1) includes a first step b11) which consists in generating a kind of synchronization signal which varies in stages, at regular time intervals.

More precisely here, during this step b11), the control unit 11 generates a SOC_select signal which successively has distinct integer values.

The SOC_select signal is periodic, and successively presents, during each period, the integer values 1, 2, 3, ..., then N_state. The positive integer N_state is equal to the number of given charge levels involved in determining the SOC_dep charge level.

The evolution of the SOC_select signal as a function of time t, expressed here in seconds, is shown diagrammatically in FIG. 5A, in a case where

N_state = 10.

As can be seen in this figure, the SOC_select signal has each of said integer values for a given duration t_ss, equal to approximately 2 seconds for the example shown.

The SOC_select signal is generated so as to present the value 1 when the charge of the electric battery begins, the start of this charge being indicated by the passage from 0 to 1 of a Boolean variable Charge_active (Figure 3).

Step b1) also includes a step b12), during which the SOC signal is generated, at the rate imposed by the SOC_select signal. The signal SOC presents over time values corresponding successively to said charge levels SOC_1,, SOC_N_state given.

More precisely :

SOC = SOC_1 = SOC_actual when SOC_select = 1

SOC = SOC_2 when SOC_select = 2

SOC = SOC_3 when SOC_select = 3

SOC = SOC_N_state when SOC_select = N_state.

The values of the charge levels SOC_2, ..., SOC_N_state are pre-established constants while the value of the charge level SOC_1 is a variable.

The evolution of the SOC signal, in response to the SOC_select signal of FIG. 5A, is represented diagrammatically in FIG. 5B as a function of the time t (expressed in seconds), in solid line. In FIG. 5B, the values of the SOC signal are expressed as a percentage. For the case represents, the preset values of the load levels SOC_2, SOC_3, ..., SOC_N_state are the following:

SOC_2 = 30%

SOC_3 = 50%

SOC_4 = 70%

SOC_5 = 80%

SOC_6 = 85%

SOC_7 = 90%

SOC_8 = 95%

SOC_9 = 97.5%

SOC_10 = 100%.

Etaee_F)

Step F) is implemented here by supplying, at the input of the autonomous subprocess for determining the total charge time of the battery 10, the signal SOC produced in step b1).

In response to the signal SOC, this sub-process then generates a signal T_charge_compl which successively presents, for each of the charge levels SOC_1, SOC_2, SOC_N_state mentioned above, the total charge duration T_charge_compl_1, T_charge_compl_2, T_charge_compl_N_state corresponding, that is ie the charging time required to fully charge the electric battery, under the charging power P_target, from this given charge level.

Thus, as can be seen in FIG. 5C, the signal T_charge_compl (drawn in solid lines) is periodic, synchronous with the signal SOC_select, and, during each period, presents values corresponding successively to the total charge durations T_charge_compl_1, T_charge_compl_2, T_charge_compl_ N_state.

The values of the signal T_charge_compl indicated in FIG. 5C are, as well as that of the signal T_ch_compl_SOC_actual (drawn in dashes), expressed in minutes.

Step b2)

Step b2) here comprises a step, or functional block b21), which receives the SOC_select and T_charge_compl signals as input, and outputs, a T_ch_compl_SOC_actuel signal, the value of which corresponds to the time required to fully charge the electric battery, from its current SOC_current charge level (i.e. from the actual charge level of the battery at the time of calculation t).

The value of the signal T_ch_compl_SOC_actuel is updated at each period of the signal SOC_select, at the moment when the signal SOC_select changes value to take the value 1 (the value of the signal T_charge_compl then corresponds to the total duration of charge of the battery, from the current SOC_current charge level). The value of the signal T_ch_compl_SOC_actuel is moreover kept constant between two such instants.

Sci, to determine the value of the signal T_ch_compl as indicated above, the control unit executes the following formula F4, at each calculation step:

T_ch_compl_SOC_actuel (t) _ fT_charge_compl (t) if [Soc_Select (t) = 1 AND Soc_Select (t - 1) # = 1] ”(T_ch_compl_SOC_actuel (t -1) otherwise '

The instant t corresponds to the current calculation step, and the instant t-1 corresponds to the calculation step which immediately precedes it.

Here, step b2) also includes a step b22) (FIGS. 4 and 6) during which the control unit determines, for several distinct durations time_laps_A, time_laps_B, time_laps_M:

- the level of charge SOG_dans_A_min, SOC_dans_B_min, SOC_dans_M_min which will be reached at the end of this period (under the load power P_target), and the autonomy SOG_dans_A_min, SOG_dans_B_min, SOG_dans_M_min, which will be available to the motor vehicle 1.

Each of these load levels SOG_dans_A_min, SOG_dans_B_min, ..., SOG_dans_M_min is determined here separately, during a dedicated sub-step b2_A), b2_B), ..., b2_M).

One of the durations time_laps_A, time_laps_B, ..., time_laps_M mentioned above, here the duration time_laps_B, is equal to the duration of charge T_ch supplied by the user for the battery charge 10. The other durations time_laps_A and time_laps_G , ..., time_laps_i, time_laps_M are spread out above, and below the charge time T_ch.

The different substeps b2_A), b2_B), ..., b2_M) are identical here, except that they are each executed for a different value of duration (of charge). Also, only the sub-step b2_i) will be described below.

The signals SOG_dans_i_min and Auton_dans_i_min generated in step b2_i) each have a value which is "refreshed", that is to say updated, once per period.

This update is carried out at the moment when the difference ecc_T between:

- the total charge time of the electric battery from its current charge level, T_ch_compl_SOC_actuel, and

- the signal T_charge_compl becomes greater than the timejapsj duration, which is identified by the passage from 0 to 1 of a Boolean variable Condit_rafraich (t).

The value of the Condit_rafraich (t) variable is calculated by the control unit (at each calculation step) in accordance with the following formula F5:

'1 if {ecc_T (t)> timejapsj AND ecc_T (t-1) <timejapsj}

Condit_rafraich (t) = (F5) otherwise where ecc_T (t) = T_ch_compl_SOG_actuel (t) - T_charge_compl (t).

When the Condit_rafraich variable goes from 0 to 1, the value of the SOC_dansJ_min signal is recalculated according to the method described below.

First of all, the control unit selects a first charge level SOC_Str_act, corresponding to that of said charge levels SOC_1, SOC_2, SOC_N_state given for which the difference between:

- the total charge time of the battery from its current charge level, T_ch_compl_SOC_actuel, and

- the total charge duration T_charge_compl_1, T_charge_compl_2, T_charge_compl_ N_state from the charge level (fictitious) considered, is the closest, by higher value, to the duration timejapsj.

Here, the control unit also selects a second charge level SOC_Str_prec, corresponding to that of said charge levels SOC_1, SOC_2, SOG_N_state given for which the difference between:

- the total charge time of the battery from its current charge level, T_ch_compl_SOC_actuel, and

- the total charge duration T_charge_compl_1, T_charge_compl_2, T_charge_compl_ N_state from the (fictitious) charge level considered, is the closest, by lower value, to the duration timejapsj.

The charge level which will be reached at the end of the timejapsj (charge) duration is then determined according to the first and second charge levels SOC_Str_act and SOC_Str_prec thus selected.

More precisely, the charge level SOC_dansJ_min is determined here by interpolation between the first and second charge levels SOC_Str_act and SOC_Str_prec.

This interpolation, here linear, is carried out as a function of time, so as to estimate the level of charge which will be reached at the end of the time timejapsj, knowing that it has been determined that:

- at the end of the term

T_ch_comp! _SOC_actuel - T_charge_compl (SOC_Str_act), (greater than time_laps_i, and whose value has already been calculated), the first SOC_Str_act charge level is reached, and

- only at the end of the term

T_ch_compl_SOC_actuel - T_charge_compl (SOC_Str_prec) (lower than timejapsj, and whose value has already been calculated), the second SOC_Str_prec load level is reached.

To determine the value of the SOC_dans_i_min charge level as explained above, the control unit calculates this charge level here, at each calculation step, in accordance with formulas F6 to F11 below.

if Condit refreshed = 1, ... ... (ecc T (t) delta t (t) =, ,, ..

~ ^v '(delta t (t - 1) if Refresh condition = 0 (F6), _o ... i ecc T (t - 1) delta t Soc prec (t) = t.' .. ..

- ^rv '(delta t Soc prec (t - 1) if Condit_rafraich = 1 if Condit refresh = 0 (F7)

SOC_Str_act (t) = f SOC (t) (SOC_Str_act (t -1)

SOC_Str_prec (t) { _SO c_Str_prec ( _t _ i) if Condit_rafraich = 1 if Condit_rafraich = 0 if Condit_rafraich = 1 if Condit refresh = 0 (F8) (F9)

SOC_dans_i_min (t) (= SOC_Str_prec (t) [SOC_Str_act (t) - SOC_Str_prec (t)] [timejapsj - delta_t_Soc_prec (t)] and if Condit refresh deltaj (t) - delta_t_Soc_prec (t) (F10)

SOC_dans_i_min (t - 1) if Condit_rafraich = 0 and

SOC in i min = (100% if T_ch_compl_SOC_actuel <timejapsj (F11) (SOC_dans_i_min otherwise

The interpolation operation, between the first and second charge levels SOC_Str_act and SOC_Str_prec, corresponds to the formula F10.

The signals indicated above present, at the start of the process, initial values, which can for example be equal to delta_t (0) = 2 minutes, delta_t_SOC_prec (0) = 1 minute, SOC_Str_act (0) = 0%, SOC_Str_prec (0 ) = 0%, and SOC_in_i_min * (0) = 0%. The influence of these initial values disappears from the first change to 1 of the Condit_rafraich variable.

In step b2_i), once the charge level SOC_in_i_min has been calculated, the control unit determines the range which the motor vehicle will have after a charge of duration time_laps_i.

For this, the control unit converts the SOC_dans_i_min charge level here, according to a proportionality rule, to obtain the corresponding Auton_dans_i_min autonomy.

More precisely, the control unit here determines, at each instant, the value of the signal Auton_dans_i_min, in accordance with the following formula F12:

SOC_to_kWh

Auton in i min = SOC in i min—- (F12) - - Consom_moy

The SOC_to_kWh parameter is equal to the amount of energy (in kilowatt hours, for example) delivered by the electric battery when its charge level drops by 1%. The value of this parameter is adapted here as a function of physical parameters characteristic of the battery such as its age and / or its temperature.

The Consom_moy parameter, whose value is expressed for example in kilowatt-hours per kilometer, represents the average energy consumption of the motor vehicle per unit of distance traveled. This average energy consumption is evaluated here for the last X kilometers, for example for the last 200 kilometers, traveled by the vehicle (sliding average).

By way of illustration, a numerical example of calculation of the charge level SOC_dans_i_min, using the formulas F6 to F11, is now described with reference to FIGS. 5B to 5D. In this example, the time_laps_i duration is 10 minutes.

In FIG. 5B, the current SOC_current charge level of the battery 10 is shown in dotted lines, as a function of time t, at the start of a battery charging phase.

The signal SOC_dans_i_min is also represented in FIG. 5B, at the same times, in long dashes.

The evolution of the Boolean variable Condit_rafraich, for this example of time sequence and for the duration time_laps_i = 10 minutes, is plotted in Figure 5D as a function of time t (expressed in seconds).

As can be seen in this figure, this sequence has three instants t0, t1 and t2 of refreshment of the signal SOC_dans_i_min.

For the moment t2, for example:

- the total charge time of the battery from its current charge level, T_ch_compl_SOC_actuel (t2), is worth approximately 58 minutes (Figure 5C),

- at time t2 - 1, the signal T_charge_compl is worth approximately 51 minutes (it then corresponds to the total charge time of the battery since the charge level (fictitious) SOC_4 = 70%),

- while at time t2, the signal T_charge_compl is worth approximately 43 minutes, (it then corresponds to the total charge time of the battery since the charge level (fictitious) SOC_5 = 80%).

As ecc_T (t2-l) "58-51 = 7 minutes is less than the time_laps_i duration (10 minutes, in this example), and as ecc_T (t2)" 58 - 43 = 15 minutes is greater than the time_laps_i duration, at at time t2, the Condit_rafraich variable switches from 0 and 1, and the value of the SOC_dans_i_min signal is updated (recalculated).

We then have:

delta_t (t2) = ecc_T (t2) "15 minutes delta_t_SOC_prec (t2) = ecc_T (t2 - 1)" 7 minutes

SOC_Str_act (t2) = SOC (Î2) = SOC_5 = 80%

SOC_Str_prec (t2) = SOC (t2 - 1) = SOC_4 = 70% [80% - 70%)] [10 - 7]

SOC_dans_i_min (î2) "70% + --- _r _ _? - "74% then

SOC_dans_i_min (t2) = SOC_dans_i_min (t2) ~ 74%, as can be seen in Figure 5B.

As already indicated, during step b2), the control unit determines:

- the charge level SOC_dep = SOC_dans_B_min, which will be reached at the end of the charge time T_ch provided by the user, but also

- the charge levels which will be reached respectively at the end of the times time_laps_A, time_laps_C, time_laps_D, etc ...

Here, each time the value of one of these charge levels is updated, what happens once in each period of the SOC_select signal, step d1) is repeated, so as to update, on on the basis of this refreshed value, the message displayed or transmitted by the man-machine interface 12 intended for the user.

As we have seen, in the embodiment described above, the total charge durations T_charge_compl_1, T_charge_compl_2, ... are determined one after the other (by means of the aforementioned sub-process) according to a sequence determined time, to form the signal T_charge_compl. The T_charge_compl signal is then used to deduce the SOC_dep charge level.

In other embodiments, instead of implementing such a sequential approach, provision could be made, for example, for the different total charge durations T_charge_compl_1, T_charge_compl_2, ..., to be calculated in parallel, then for the first, and possibly the second charge level SOC_Str_act and SOC_Str_prec mentioned above are then selected directly on the basis of this set of total charge durations.

Furthermore, in a simplified embodiment, the interpolation operation described above could be omitted. In this case, provision could be made, for example, to determine that the charge level SOÇ_dep, which will be reached at the end of said charge duration, is approximately equal to the first charge level SOC_Str_act, or to the second charge level SOC_Str_prec. This simplifies the determination of the SOC_dep charge level, but makes it less precise in return.

Claims (10)

1. Method for charging an electric battery (10) of a motor vehicle (1), connected to a charging terminal (2) external to the motor vehicle (1), the charging method comprising the following steps: a1) acquisition of data representative of a charging time (T_ch) supplied by a user for the electrical charging of the electric battery (10) by the charging station (2), b) determination, as a function of the charging time (T_ch), of an electrical charging power (P_target) to be applied to the electric battery (10), and c) control of the charging station (2) so that it delivers the electric charging power (P_target) determined in step b), characterized in that: - The method further comprises a step a2) of acquiring data representative of the operating autonomy of the motor vehicle desired by the user (Auton_souhait), and in that - the electric charging power (P_target) determined at the end of step b) is, among the electric powers that can be delivered by the charging station (2), the smallest electric power such as the motor vehicle (1) has , at the end of the charging time (T_ch), a range (Auton_dep) equal to or greater than said range (Auton_souhait) desired by the user. 2. Method according to claim 1, in which step b) comprises a step b2) which comprises a determination of the range (Auton_dep) which the vehicle (1) will have after said charging time (T_ch), for said power electric charge (P_target). 3. Method according to claim 2 wherein it is provided, when the maximum electric power (Pmax) that can be delivered by the charging station (2) is too small for the range (Auton_dep), which will have the vehicle (1 ) automobile after the charging time (T_ch), either greater than or equal to the desired autonomy (Auton_souhait), - in step b), to determine that the electric charge power (P_target) to be applied to the electric battery (10) is equal to this maximum electric power (Pmax), and - in a step d2), to elaborate a message intended for the user indicating that the desired autonomy (Aunton_souhait) cannot be reached at the end of the charging time (T_ch), and indicating the autonomy (Auton_dep ), determined in step b2), which the motor vehicle (1) will actually have after said charging time (T_ch). 4. Method according to one of claims 2 and 3, wherein step b2) further comprises a determination, for at least one other charging time (time_laps_A, ... time_laps_i, ..., time_laps_M), d 'an autonomy (Auton_dans_A_min, ..., Auton_dans_i_min, ..., Auton_dans_M_min) which will be available to the motor vehicle (1), for said electric charge power (P_target), after said other duration (time_laps_A, ... time_laps_i,. .., time_laps_M), the method further comprising a step d1) of developing a message for the user indicating the autonomy (Auton_dans_A_min, ..., Auton_dans_i_min, ..., Auton_dans_M_min), determined at step b2), which will be available to the motor vehicle (1) after said other period. 5. Method according to one of claims 2 to 4, - in which step b) is implemented by means of an autonomous sub-method for determining a total charge duration (T_charge_compl_1, T_charge_compl_2, ..., T_charge_compl_ N_state), necessary to fully charge the electric battery from a given initial charge level (SOC_1, SOC_2, ..., SOC_N_state), step b) comprising the following steps: b1) generation of a range of distinct given charge levels (SOC_1, SOC_2, ..., SOC_N_state), between 0% and 100%, this range notably comprising the current charge level (SOC_actual) of the battery (10 ) electric, F) determination, by means of said sub-process, for each of said given charge levels, of the corresponding total charge duration (T_charge_compl_1, T_charge_compl_2, ..., T_charge_compl_ N_state), - And in which, in step b2), a charge level (SOC_dep) which will be reached at the end of the charge duration (T_ch) is calculated, as a function of said given charge levels (SOC_1, SOC_2, ... , SOC_N_state) and corresponding total charge times (T_charge_compl_1, T_charge_comp! _2, ..., T_charge_compl_ N_state) determined in step F), said autonomy (Auton_dep), which will be available to the motor vehicle (1) after the duration of charge (T_ch), being determined as a function of the charge level (SOC_dep) thus calculated. 6. Method according to claims 4 and 5, wherein the autonomy (Auton_dans_A_min, ..., Auton_dans_i_min, ..., Auton_dans_M_min) which will be reached after said other duration (time_laps_A, ... time_laps_i, ..., time_laps_M ) is determined, in step b2), as a function of said charge levels (SOC_1, SOC_2, ..., SOC_N_state) given and of the corresponding total charge durations (T_charge_compl_1, T_charge_compl_2, ..., T_charge_compl_ N_state) which have been determined in step F). 7. Method according to claims 4 and 5 or according to claim 6, wherein step F) is executed several times successively, and wherein each of these executions is followed by an execution of steps b2) then d1). 8. Method according to one of claims 5 to 7, wherein said total charge durations (T_charge_compl_1, T_charge_compl_2, T_charge_compl_ N_state) are determined by executing said sub-process several times successively, each time for one of said levels of given charge (SOC_1, SOC_2, ..., SOC_N_state), according to a determined temporal sequence. 9. Method according to one of claims 5 to 8, - in which step b2) includes a selection of a first charge level (SOC_Str_act), corresponding to that of said charge levels (SOC_1, SOC_2, ..., SOC_N_state) given for which the difference between: - the total charge time of the electric battery from its current charge level (T_ch_compl_SOC_actuel), and - the total charge duration (T_charge_compl_1, T_charge_compl_2, ..., T_charge_compl_ N_state) associated with this level (SOC_Str_act), is the closest, by higher value, to said charge duration (T_ch), acquired in step a1 ), - And in which the charge level (SOC_dep) which will be reached at the end of said charge duration (T_ch) is determined according to the first charge level (SOC_Str_act) thus selected. 10. Method according to one of claims 5 to 9, - in which step b2) includes a selection of a second charge level (SOC_Str_prec), corresponding to that of said charge levels (SOG_1, SOC_2, SOC_N_state) given for which the difference between: - the total charge time of the electric battery from its current charge level (T_ch_compl_SOC_actuel), and 5 - the total charging time (T_charge_compl_1, T_charge_compl_2, T_charge_compl_ N_state) associated with this level (SOG_Str_act), is the closest, by lower value, to said duration of charge (T_ch), acquired in step a1), - And in which the charge level (SOC_dep) which will be reached at the end of said charge duration (T_ch) is determined according to the second charge level (SOG_Str_prec) thus selected. 1/5