ESTIMATION OF INFORMATION RELATED TO A CELLULAR BATTERY

Abstract

A method is used to estimate at least one piece of information about a cellular battery in a system comprising N cells suitable for storing electrical energy, with N > 1, each having a current state of charge, a current resistive health state, and a current capacity health state. This method includes a step (10⁻⁴⁰) in which a first piece of information is estimated, representing the total energy available in the cellular battery as a function of the current resistive health states, current capacity health states, and current states of charge, and a time interval during which the cellular battery is allowed to discharge under a chosen discharge current and at a reference temperature. Fig. 3

Description

Title of the invention: ESTIMATION OF INFORMATION RELATED TO A CELLULAR BATTERY Technical field of the invention

[0001] The invention relates to cellular batteries, and more specifically to the estimation of information relating to such batteries. State of the art

[0002] Certain batteries, which may be used, for example, in vehicles, possibly automobiles, comprise at least two electrical energy storage cells, possibly electrochemical (for example, lithium-ion (or Li-ion), Ni-MH, or Ni-Cd). It should be noted that in the case of a vehicle, the cellular battery may be a so-called "main" (or traction) battery because it is responsible for supplying electrical current to the vehicle's on-board electrical system, via a converter, and to an electric drive unit of the vehicle's powertrain. However, in the case of a vehicle, the cellular battery may also be a so-called "service" battery when it is of the very low voltage type (typically between 12 V and 48 V) and is responsible for supplying electrical current to the vehicle's on-board electrical system in the absence of a main battery (and therefore an electric drive unit), or in place of or in addition to a main vehicle battery.

[0003] In what follows and what precedes, "on-board network" means an electrical power supply network to which electrical (or electronic) equipment (or components) consuming electrical energy are coupled.

[0004] As those skilled in the art know, current cellular batteries are subject to the management of certain parameters to ensure optimal use, with a minimized risk of failure and incidents, for example, for the safety and peace of mind of vehicle users. This management aims, in particular, to enable cellular battery diagnostics, which in turn allow for optimized use, reduced repair costs, and the anticipation of major malfunctions.

[0005] Among the parameters managed, we can mention in particular the energy available in the cellular battery and the cellular battery's state of health (or SOHE), which are used, for example, to estimate a vehicle's range as accurately as possible so as not to overestimate or underestimate performance. It should be noted that the estimated available energy is used to estimate the state of health (or SOHE).

[0006] Currently, at least four solutions have been proposed for estimating the energy available.

[0007] A first solution consists of estimating the energy available in the cellular battery by taking into account the cell which is the most limiting at the moment considered and using maps previously made up from characterizations of new cells and giving the energy available as a function of the state of charge (or SOC (“State Of Charge”)) and the internal temperature of each cell of the cellular battery.

[0008] This first solution provides estimates of available energy that are too pessimistic because it considers the cell with the smallest electrical energy storage capacity in the battery (and therefore the lowest State of Health Capacity (SOHC) of all the cells), or the cell with the lowest state of charge in the battery, or the cell with the lowest internal temperature. Furthermore, the estimates are approximate because they are based on maps obtained during cell characterizations that are not necessarily representative of those equipping the battery in question, and are less precise in the event of cell production variability.

[0009] A second solution consists of estimating the energy available in the cellular battery by taking into account only the estimated capacities of each of the cells of the cellular battery, and therefore their respective SOHCs.

[0010] This second solution provides estimates of available energy which are not very precise, and even less precise as we get closer to the end of the life of the cells because we do not take into account the resistive health states (or SOHR (“State Of Health of Resistance”)) of each of the cells even though they increase with their aging and therefore their impact on energy dissipation increases.

[0011] A third solution consists of estimating the energy available in the cell battery using a durability model that has been calibrated offline, for example, at a location other than a vehicle manufacturer (which generally handles the assembly of cells according to requirements). Each offline-calibrated durability model requires a significant characterization plan for the accelerated aging of cells under different conditions, but this plan is not capable of accounting for a sudden energy loss in a cell at the end of its life due to usage that falls outside the limits of the experimental design initially tested during the trials.

[0012] A fourth solution consists of estimating the energy available in the cellular battery using a "black box" (or artificial intelligence) learning method that uses an offline database, for example, one located remotely from a vehicle. These learning methods require very large databases, do not offer true real-time responsiveness, and monopolize a lot of bandwidth of wireless communication networks, and give inaccurate estimates when the cellular battery is used outside the limits of the learning.

[0013] The invention therefore aims in particular to improve the situation. Presentation of the invention

[0014] In particular, it proposes for this purpose a method for estimating information(s) intended to be implemented in a system comprising a cellular battery having N cells suitable for storing electrical energy, with N > 1, and each having a current state of charge, a current resistive health state and a current capacity health state.

[0015] This information estimation method is characterized by the fact that it includes a step in which a first information representative of a total energy available in the cellular battery is estimated as a function of the current resistive health states, current capacity health states and current charge states, and of a time interval during which the cellular battery is allowed to be discharged under a chosen discharge current and at a reference temperature.

[0016] This consideration of the parameters which define the actual state in which each of the cells of the cellular battery is located makes it possible to have in the system a particularly precise and reliable estimate of the first information (representative of the total energy available in the cellular battery).

[0017] The information estimation method according to the invention may include other features which may be taken separately or in combination, and in particular:

[0018] - in its step, the first piece of information can be estimated as a further function of initial electrical energy storage capacities of each of the cells and initial maximum charge states of each of the cells;

[0019] - in its step, the first piece of information can be estimated as a further function of theoretical models chosen and representative respectively of equivalent resistances of each of the cells;

[0020] - in its step, the first piece of information can be estimated as a further function of open-circuit voltage sums of each of the cells for state-of-charge values ​​between a maximum state of charge and a state of charge at the end of the time interval;

[0021] - in its step the time interval can be chosen as a function of a voltage minimum limiting value of a cell below which discharge of the cellular battery is prohibited under the chosen discharge current and / or minimum state of charge of a cell below which discharge of the cellular battery is prohibited under the chosen discharge current;

[0022] - in the presence of the last option, in its step one can determine a first in a theoretical time interval as a function of the minimum limiting voltage, the current electrical energy storage capacities of each of the cells, the chosen discharge current, the chosen theoretical models representing respectively the equivalent resistances of each of the cells, and the initial charge states of each of the cells, and a second theoretical time interval as a function of the minimum charge state, the chosen discharge current, the current electrical energy storage capacities and the initial charge states, then we can choose the time interval by taking the smallest of these first and second theoretical time intervals;

[0023] - in its step one can estimate a second piece of information representative of a state of Cell battery energy health based on initial information and useful energy at the beginning of the cell battery's life.

[0024] The invention also proposes a computer program product comprising a set of instructions which, when executed by processing means, is suitable for implementing a method for estimating information of the type presented above to estimate at least one piece of information relating to a cellular battery of a system comprising N cells suitable for storing electrical energy, with N > 1.

[0025] The invention also proposes an information estimation device intended to equip a system comprising a cellular battery having N cells suitable for storing electrical energy, with N > 1, and each having a current state of charge, a current resistive health state and a current capacity health state.

[0026] This information estimation device is characterized by the fact that it comprises at least one processor and at least one memory arranged to perform the operations of estimating a first information representative of a total energy available in the cellular battery as a function of the current resistive health states, current capacity health states and current charge states, and of a time interval during which a discharge of the cellular battery is allowed under a chosen discharge current and at a reference temperature.

[0027] The invention also proposes a system, possibly a vehicle, comprising, on the one hand, a cellular battery comprising N cells suitable for storing electrical energy, with N > 1, and each having a current state of charge, a current resistive health state and a current capacity health state, and, on the other hand, an information estimation device of the type presented above. Brief description of the figures

[0028] Other features and advantages of the invention will become apparent from an examination of the detailed description below, and the accompanying drawings, in which:

[0029] [Fig. 1] schematically and functionally illustrates an example of the realization of a vehicle comprising a powertrain with an electric motor powered by a cellular battery, and an information estimation device according to the invention,

[0030] [Fig.2] schematically and functionally illustrates an example of the realization of a battery calculator comprising a device for estimating information(s) according to the invention, and

[0031] [Fig.3] schematically illustrates an example of an algorithm implementing a method for estimating information(s) according to the invention. Detailed description of the invention

[0032] The invention aims in particular to propose a method for estimating information(s), and an associated information estimation device DEI, intended to allow an accurate and reliable estimation of at least one piece of information relating to a cellular battery BC of a system V comprising N cells CE.

[0033] In what follows, system V is considered, by way of non-limiting example, to be a motor vehicle, such as a car, as illustrated in [Fig. 1]. However, the invention is not limited to this type of system. It relates to any type of system comprising at least one rechargeable cellular battery (regardless of the type). Thus, it relates, for example, to land vehicles (commercial vehicles, motorhomes, minibuses, coaches, trucks, motorcycles, road maintenance vehicles, construction equipment, agricultural machinery, recreational vehicles (snowmobiles, go-karts), and tracked vehicles, for example), boats and aircraft, but also to any fixed or stationary system, such as an electrical power supply installation and, more generally, any electronic device (possibly high-consumption), any building or any installation (including industrial installations).As an illustrative example, the BC cellular battery of the V system can be connected to a renewable energy source (in particular photovoltaic or wind).

[0034] Furthermore, in what follows, by way of non-limiting example, system V (here a vehicle) is considered to comprise a powertrain (or PWM) of the all-electric type (and therefore whose propulsion is provided exclusively by at least one electric motor MME). But the PWM could be of the hybrid type (thermal and electric) or purely thermal.

[0035] Furthermore, in what follows, by way of non-limiting example, the cellular battery BC is considered to be a main (or traction) battery. However, the cellular battery that is the subject of the information estimation(s) could be a service battery (possibly rechargeable via a converter powered by electrical energy from a main battery).

[0036] Figure 1 schematically represents a system V (here a vehicle) comprising an electric powertrain, an on-board network RB, a power group comprising a service battery BS and (here) an electric power generator GE associated with a cellular battery BC, and an information estimation device DEI according to the invention.

[0037] The RB on-board network is an electrical power supply network to which electrical (or electronic) equipment (or components) that consume electrical energy are coupled.

[0038] The auxiliary battery BS is responsible for supplying electrical power to the vehicle's electrical system RB, supplementing that supplied by the electrical power generator GE powered by the cellular battery BC, and sometimes replacing this electrical power generator GE (particularly when the engine is asleep and the electrical power generator GE is inactive). For example, this auxiliary battery BS may be configured as a very low voltage type battery (typically 12 V, 24 V, or 48 V). It is rechargeable at least by the electrical power generator GE. In the following, by way of non-limiting example, the auxiliary battery BS is assumed to be a 12 V lithium-ion type.

[0039] The transmission system has a powertrain which, in this case, is purely electric, and therefore includes, in particular, an electric drive machine MME, a drive shaft AM, and a transmission shaft AT. Here, "electric drive machine" means an electric machine arranged to supply or recover torque to move the system V (here, a vehicle). The operation of the powertrain is supervised by a control unit CS.

[0040] The electric drive unit MME (here an electric motor) is coupled to the cell battery BC to receive electrical power and, optionally, to supply electrical power to this cell battery BC during a regenerative braking phase. It is coupled to the motor shaft AM to provide it with torque by rotational drive. This motor shaft AM is coupled to a reduction gear RD, which is also coupled to the transmission shaft AT, itself coupled to a first set of wheels Tl, preferably via a differential DI.

[0041] This first train Tl is here located in the front part PVV of the vehicle V. But in a variant this first train Tl could be the one which is here referenced T2 and which is located in the rear part PRV of the vehicle V.

[0042] The drive machine MME is, here, also coupled to the electric power generator GE which is also indirectly coupled to the service battery BS, in particular to recharge it with electrical energy from the cellular battery BC and converted.

[0043] This electrical power generator (EPG) is a current converter electrically coupled to the charging connector CN of vehicle V, by way of example. It is also responsible here for supplying the on-board network RB with electrical power from the cellular battery BC, converted when the powertrain is running or when the powertrain is running. is asleep but vehicle V is in a phase of recharging its cellular battery BC, in addition to ensuring the recharging of the service battery BS.

[0044] In the example illustrated non-limitingly on [Fig.1] the BC cellular battery is suitable not only for charging in mode 2 or 3, but also for charging in mode 4.

[0045] For example, the BC cellular battery may comprise electrochemical energy storage cells CE, possibly of the lithium-ion (or Li-ion) or Ni-MH or Ni-Cd type. Also, for example, the BC cellular battery may be of the low-voltage type (typically 450 V by way of illustration). But it could also be of the medium-voltage or high-voltage type.

[0046] It should be noted, as illustrated (though not exhaustively) in [Fig. 1], that the CE cells can be part of MC modules which are coupled together, for example in series, within the BC cell battery. Here, "MC module" means a group of at least one CE cell. When an MC module comprises several CE cells, these cells (CE) can be coupled together in series and / or in parallel.

[0047] It should be noted that the BC cellular battery is associated with a BB battery housing which includes, in particular, means for measuring voltage, current and internal temperature (not shown) and a CB battery calculator. This CB battery calculator centralizes the current measurements, voltage measurements and internal temperature measurements (in particular those relating individually to each of the N CE cells), and estimates parameters of the BC cellular battery based on these measurements, and in particular its internal resistance, its minimum voltage and its current state of charge (or SOC).

[0048] It should also be noted that in the example illustrated, but not limited to, in [Fig. 1], the vehicle V also includes a distribution box BD to which the auxiliary battery BS, the electric power generator GE, and the on-board network RB are coupled. This distribution box BD is responsible for distributing into the on-board network RB the electrical power that is produced by the electric power generator GE or stored in the auxiliary battery BS, to power the electrical components (or equipment) coupled to the on-board network RB, according to power demands received (in particular from the powertrain control unit CS).

[0049] As mentioned above, the invention proposes in particular a method for estimating information(s) intended to allow an accurate and reliable estimation of at least one piece of information ibn relating to a cell battery BC of a vehicle V comprising N CE cells (i), with N > 1. In what follows, "i" is an index which designates each of the CE cells, and therefore which takes values ​​between 1 and N.

[0050] This method (of estimating information) can be implemented at least partially by the information estimation device DEI (illustrated in Figures 1 and 2) which includes for this purpose at least one PR1 processor, for example a digital signal processor (or DSP), and at least one MD memory. This information estimation device DEI can therefore be implemented in the form of a combination of electrical or electronic circuits or components (or "hardware") and software modules (or "software").

[0051] The MD memory is random access memory (RAM) for storing instructions for the implementation by the PR1 processor of at least part of the information estimation process. The PR1 processor may comprise integrated (or printed) circuits, or several integrated (or printed) circuits connected by wired or wireless connections. An integrated (or printed) circuit is defined as any type of device capable of performing at least one electrical or electronic operation.

[0052] In the example illustrated, but not limited to, in Figures 1 and 2, the information estimation device (DEI) is part of the battery control unit (CB) (and therefore of the battery housing (BB). However, this is not mandatory. The information estimation device (DEI) could comprise its own dedicated control unit, which could then be coupled to the battery control unit (CB).

[0053] As illustrated non-limitingly in [Fig.3], the method (for estimating information(s)), according to the invention, includes a step 10-40 which is implemented in the vehicle V whenever an estimation of at least one first piece of information ibl (n = 1), representative of the total energy Etotref available in the cellular battery BC, is requested, for example by the battery computer CB.

[0054] This step 10-40 includes a substep 30 in which the information estimation device (IED) estimates the first information ibl as a function of the resistive health states SOHR; during each of the N CE cells, the capacity health states SOHC; during each of the N CE cells, the charge states SOC; during each of the N CE cells, and a time interval Atfin during which the cell battery BC is allowed to discharge under a chosen discharge current Idc and at a reference temperature Tref.

[0055] Thanks to this consideration of at least the parameters SOHR;, SOHC; and SOH; which define the real state in which each of the CE cells of the BC cellular battery is located (and not just the most limiting one), we now have in vehicle V, in real time, a particularly precise and reliable estimate of the first information ibl (representative of the total energy Etotref available in the BC cellular battery).

[0056] It will be understood that at least the PR1 processor and MD memory of the DEI estimation device are arranged to perform the operations consisting of estimating the first ibl information as a function of the resistive health states SOHR, the capacity health states SOHCi, the load states SOC, and the time interval Atfin during which a discharge of the cellular battery BC is allowed under the chosen discharge current Idc and at the reference temperature Tref.

[0057] For example, the reference temperature Tref can be equal to 25°C. But other values ​​can be used.

[0058] Also, for example, the discharge current Idc can be chosen to obtain a discharge rate equal to one-third of the total capacity (i.e., C / 3), particularly when the powertrain is all-electric. However, other values ​​of discharge current Idc can be used.

[0059] It should be noted that step 10-40 may also include a preliminary substep 10 in which all resistive health states (SOHR), capacitance health states (SOHC), and charge states (SOC) are estimated from voltage, current, and internal temperature measurements of each of the CE cells (i). It is recalled that each capacitance health state (SOHC) is estimated from the charge state (SOC), that each resistive health state (SOHR) is estimated from the charge state (SOC) and the associated internal temperature, and that each charge state (SOC) is itself estimated from previous estimates of the resistive health state (SOHR) and the charge state (SOC).

[0060]

[0061]

[0062]

[0063] SOHC capability; within a feedback loop. The resistive health states SOHR; and / or capacity health states SOHC; and / or charge states SOC; can be estimated by the information estimation device DEI or by the battery calculator CB. It should also be noted that step 10-40 may also include a preliminary substep 20 in which the time interval Atfin is chosen as a function of a minimum limiting voltage Ucutoff_min of a CE cell below which the discharge of the cellular battery BC is prohibited under the chosen discharge current Idc and / or a minimum state of charge SOCmin_seuii of a CE cell below which the discharge of the cellular battery BC is prohibited under the chosen discharge current Idc. In the presence of this last option in substep 20 of step 10-40 we can, for example, determine a first theoretical time interval and a second theoretical time interval 2\^oc. The first theoretical time interval is determined based on the voltage minimum limiting UcutOff_min, electrical energy storage capacities capa; during each of the CE cells, the chosen discharge current Idc, the chosen theoretical models (representing respectively the equivalent resistances R; of each of the CE cells), and the initial charge states SOCini>i of each of the CE cells.

[0064] For example, the equivalent resistance R can be given in a simplified way by the following equation:

[0065] nr> L / -ALinYh where ROi is the open-circuit resistance of the circuit which re- R^R 01 + Ri ^i-exp 01 4 presents the CE (i) cell, Ru is the internal resistance of the CE (i) cell, and Atfin (= tfin - tini) is the duration of the discharge between the initial time tini and the final time tfin.

[0066] It should be noted that the preceding equation can be replaced, as a first approximation, by the equation:

[0067] Ri = R0 i + Rj r

[0068] Also, for example, using for each of the CE cells the approximate equivalent resistance indicated above (Rj — R() j + R1 ,), the first theoretical time interval can be determined by means of the following equation:

[0069] u / 3600*capa. r > \ At t„„ = min (----[ SOCini , - OCV ( U„,tn + W[R . + R,.,] ) ] ).

[0070] The second theoretical time interval is determined as a function of the state of Minimum charge SOCminseuii, the chosen discharge current Idc, the electrical energy storage capacities capa; ongoing, and the initial charge states SOCinii. It is understood that reaching SOCmin_threshold at the end of discharge constitutes a constraint related to the durability of the BC cellular battery or the risk of not achieving minimum power performance.

[0071] For example, by aiming AtSOC 9uand a cell charge state SOC; reaches the minimum charge state SOCmin_seuii, the second theoretical time interval ^t^OC can be determined by means of the following equation: 100721 At^ = min ( ^Capa, ( SOC in . , - SOC min seull ) ) '

[0073] Then, in substep 20 of step 10-40, the time interval Atfin can be chosen by taking the smaller of the first and second theoretical time intervals (i.e. = min ( A C C AO-

[0074] It will also be noted that in substep 30 of step 10-40 the first information ibl can be estimated as a function also of initial electrical energy storage capacities capa; (at tini) of each of the CE cells and of the initial maximum charge states SOCmax>i of each of the CE cells.

[0075] It will also be noted that in sub-step 30 of step 10-40 the first information ibl can be estimated also as a function of theoretical models chosen and representative respectively of the equivalent resistances R;.

[0076] For example, for each of the CE cells, we can use the same theoretical model called "RC" which represents it within an RC circuit, and in which the voltage U across the terminals of a CE cell (i) is given by the following equation:

[0077] U; = OCV(SOCi) + Ru * Idc,

[0078]

[0079]

[0080]

[0081]

[0082]

[0083]

[0084]

[0085]

[0086]

[0087]

[0088]

[0089]

[0090] where OCV(SOCi) is the open-circuit voltage of the CE (i) cell in the presence of a state of charge SOC;. Note that the open-circuit voltage can be given by the following equation: OCV ( SOC, ) = OCV f SOC ini | ' oîl eM l état * initial charge of the CE cell (i) at the initial instant tini of the start of discharge. More complex theoretical models than the RC model can be used, such as a theoretical model in which each CE cell (i) uses a combination of at least two RC circuits mounted in parallel, instead of a single RC circuit. It should also be noted that in substep 30 of step 10-40, the first ibl information can be estimated based on sums of open-circuit voltages OCV for each of the CE cells for state-of-charge values ​​between a maximum state-of-charge SOCmax>i and a state-of-charge SOCfini at the end of the time interval At fin*. For example, the open-circuit voltage sums OCV of each of the CE (i) cells can be determined using the following integral: f SOCfin, i Also, for example, each final charge state SOCfin can be determined using the following equation: SOC to ., = Each integral can be calculated numerically. In one approach, the result of each integral can be found in a predetermined map that gives the open-circuit voltage (OCV) as a function of the state of load (SOC). In a second approach, the result of each integral can be found using the trapezoidal rule, or any equivalent method known to those skilled in the art. Given the options described above, the first ibl information can be determined using the following equation when it is equal to the total energy available for the Etotref discharge: j=N[ SOCfin. i ] ibl = £7, [ capaBOL*SOHCj ] SOCmax .OCV,(SOC) dSOC - V £ k;„Te.SOHR,*(R TfrfBOL .+RJjTref BOLi)(k)j. where capaB0L * SOHCi = capa;, SOHR; * (R0,TrefBOL,i + Ri.TrefBOLj) = (Ro,i + Ri,i), Te is the sampling period equivalent to the call frequency of the first information calculation function ibl in the information estimation device(s) DEI, and for example equal to 100 ms or 1 s, R0,TrefBOL,i is the open-circuit resistance of the circuit representing the CE cell (i) at the reference temperature Tref and at the beginning of the CE cell's life, and Ri,TrefBOL,i is the internal resistance of the CE cell (i) at the temperature reference Tref and at the beginning of the life of the CE cell (i).

[0091]

[0092]

[0093]

[0094]

[0095]

[0096]

[0097]

[0098]

[0099]

[0100]

[0101]

[0102]

[0103]

[0104]

[0105] This last equation of ibl follows from the fact that the total available energy Etot (for the current operating temperature of the BC cell battery) is given by the general equation: „ i = N f tfin j = N[ r tfin r tfin E„= E 1 = ,UJ aiU,dt= E i=KJ ^.OCV^dl-U J ,.j,,I(|c(R„ ,(tj+R,.,(9)dt]. which can be rewritten as follows: P SOCfin, i >- Atfin capa, J socini, ^(SOC) dSOC - Ide2 J 0 (R . + Rt s)dt WHERE dt Capa x dsoc, ^ic This last equation can in turn be rewritten as follows: capa, f then as follows: SOCfin. i . . OCVTSOC) dSOC - VTeE SOCmi, i ! üc 41fin Te , i - N f SOCfin, J Te Etot = E j _ । capaB0I "SOHCj J S0Cmi OCV / SOC) dSOC - Idc2Te. E SOHR^R ^,,+R; B0L i)(k) It will be understood that the transition from Etot to Etotref is done by replacing SOCini>i with SOC max>i in the integral because we are referring to the maximum energy at the beginning of the life of the CE cell (i), and (R0,BOL,i + Ri,BOL,i) with (Ro,Tref bol,i + Ri,Tref bol,i) because we are placing ourselves at the reference temperature Tref. It should also be noted, as illustrated non-limitingly in [Fig.3], that step 10-40 may include a substep 40 in which a second piece of information ib2 (n = 2) is estimated which is representative of the SOHE energy health state of the BC cell battery, as a function of the first piece of information ibl and an early life useful energy EtotBoL of the BC cell battery. For example, the second piece of information ib2 can be determined using the following equation when it is equal to the SOHE energy health state: ib2 = SOHE = lOof ^tot BOL Also, for example, when we want to take a production dispersion margin of N CE cells, the useful energy at the beginning of life EtotBoL can be chosen to be equal to (EtotBOL_avg - 3o), where EtotBOL_aVg is the average useful energy at the beginning of life and o is the standard deviation. It should also be noted, as illustrated (but not limited to) in [Fig. 2], that the CB battery computer (or the dedicated computer of the DEI information estimation device) may also include a mass memory MM1, notably for the temporary storage of voltage, current, and internal temperature measurements of the N CE cells and any intermediate data involved in all its calculations and processing. Furthermore, this CB battery calculator (or the dedicated calculator of the DEI information estimation device) may also include an IE input interface for receiving at least the voltage, current, and internal temperature measurements of the N CE cells for use in calculations or processing, possibly after shaping and / or demodulating and / or amplifying them, in a manner known per se, by means of a PR2 digital signal processor. In addition, this CB battery calculator (or the dedicated calculator of the DEI information estimation device) may also include an IS output interface, notably for delivering the first ibl information and the possible second ib2 information.

[0106] 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 type of electronic circuits (or hardware), such as for example the PR1 processor, is suitable for implementing the information estimation process described above to estimate at least one piece of information ibn relating to the cellular battery BC of the V system.

Claims

Demands

1. A method for estimating information about a cellular battery (CB) of a system (V) comprising N cells (CE) suitable for storing electrical energy, with N > 1, and each having a current state of charge, a current resistive health state and a current capacity health state, characterized in that it comprises a step (10-40) in which a first representative piece of information of a total energy available in said cellular battery (CB) is estimated as a function of said current resistive health states, current capacity health states and current states of charge, and of a time interval during which said cellular battery (CB) is allowed to be discharged under a chosen discharge current and at a reference temperature.

2. Method according to claim 1, characterized in that in said step (10-40) said first information is estimated further as a function of initial electrical energy storage capacities of each of said cells (CE) and initial maximum charge states of each of said cells (CE).

3. Method according to claim 1 or 2, characterized in that in said step (10-40) said first information is estimated further as a function of theoretical models chosen and representative respectively of equivalent resistances of each of said cells (CE).

4. A method according to any one of claims 1 to 3, characterized in that in said step (10-40) said first information is estimated further as a function of open-circuit voltage sums of each of said cells (CE) for state-of-charge values ​​between a maximum state-of-charge and a state-of-charge at the end of said time interval.

5. A method according to any one of claims 1 to 4, characterized in that in said step (10-40) said time interval is chosen as a function of a minimum limiting voltage of a cell (CE) below which said discharge of the cellular battery (BC) is prohibited under said chosen discharge current and / or of a minimum state of charge of a cell (CE) below which said discharge of the cellular battery (BC) is prohibited under said chosen discharge current.

6. The method according to claim 5, characterized in that in said step (10-40) a first theoretical time interval is determined as a function of said minimum limiting voltage, of the current electrical energy storage capacities of each of said cells (CE), of said chosen discharge current, chosen theoretical models representing respectively equivalent resistances of each of said cells (CE), and initial charge states of each of said cells (CE), and a second theoretical time interval as a function of said minimum charge state, said chosen discharge current, said current electrical energy storage capacities and said initial charge states, then said time interval is chosen by taking the smallest of said first and second theoretical time intervals.

7. A method according to any one of claims 1 to 6, characterized in that in said step (10-40) a second piece of information is estimated, representing a state of energy health of said cellular battery (BC) as a function of said first information and of a useful energy at the beginning of the life of said cellular battery (BC).

8. Product computer program comprising a set of instructions which, when executed by processing means, is suitable for implementing the information estimation method according to any one of claims 1 to 7 for estimating at least one piece of information relating to a cellular battery (BC) of a system (V) comprising N cells (CE) suitable for storing electrical energy, with N > 1.

9. Information estimation device (IED) for a system (V) comprising a cellular battery (CB) having N cells (CE) suitable for storing electrical energy, with N > 1, and each having a current state of charge, a current resistive health state and a current capacity health state, characterized in that it comprises at least one processor (PR1) and at least one memory (MD) arranged to perform the operations of estimating a first information representative of a total energy available in said cellular battery (CB) as a function of said current resistive health states, current capacity health states and current states of charge, and of a time interval during which said cellular battery (CB) is allowed to be discharged under a chosen discharge current and at a reference temperature.

10. System (V) comprising a cellular battery (BC) having N cells (CE) suitable for storing electrical energy, with N > 1, and each having a current state of charge, a current resistive health state and a current capacity health state, characterized in that it further comprises an information estimation device (IED) according to claim 9.

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