METHOD FOR CORRECTING AN ELECTRIC CHARGE CURRENT PROFILE INJECTED AT THE INPUT OF AN ELECTRIC OR HYBRID MOTOR VEHICLE

Abstract

The invention relates to a method, implemented by a calculation system (4) embedded in an electric or hybrid vehicle, for correcting an electric charging current profile (3) injected into the input of an electric battery (2) of the vehicle, the calculation system (4) comprising a memory (10) storing a predefined electrothermal model (12), the predefined electrothermal model and the electric battery (2) each providing first and second electrical voltage (18A, 18B) and temperature (20A, 20B) values ​​as output respectively; the method comprising the following steps: - a calculation of a voltage error (E1) and a temperature error (E2); - a calculation of a first electric charging current profile (P1) and a second electric charging current profile (P2); and - an application to the input of the electric battery (2) of a corrected electric charging current profile (P3). Figure 1

Description

Title of the invention: METHOD FOR CORRECTING AN ELECTRIC CURRENT PROFILE OF A CHARGE INJECTED AT THE INPUT OF AN ELECTRIC OR HYBRID MOTOR VEHICLE

[0001] The invention relates to a method for correcting an electric charging current profile injected into the input of an electric battery of an electric or hybrid motor vehicle. The electric battery (also called a battery pack) is a traction battery of the electric or hybrid vehicle, in particular a lithium-ion battery. In the present invention, the term "electric charging current profile" means the evolution over a predefined period of time of an electric charging intensity and / or voltage.

[0002] The invention further relates to a corresponding calculation system and computer program.

[0003] The invention belongs to the field of electric storage batteries for electric or hybrid vehicles.

[0004] Charging systems for electric and hybrid vehicles have evolved considerably to meet the growing demand for electric mobility. With varying charging levels, ranging from standard home charging to DC fast charging, drivers now have several options for charging their vehicles. Electric charging networks in particular have expanded significantly, although interoperability remains a challenge. Home electric charging has become more accessible, supported by government incentives, and emerging technologies, such as wireless charging, are gaining popularity. Charging optimization, smart charging, and continued infrastructure expansion are helping to advance the adoption of electric vehicles, marking an important step in the transition to more sustainable mobility.

[0005] An electric battery conventionally comprises a set of electrical energy storage modules connected in series, each electrical energy storage module comprising several electrical energy storage cells. The increase in the power of electric chargers, which has increased in a fairly short time from approximately 100 kW to approximately 400 kW, results in electrical charging rates ranging from 1.5 C to 10 C at each electrical energy storage cell. These charging rates should not be neglected, and various limitations may arise.

[0006] Currently, a variety of electrical current profiles dedicated to charging electric vehicles is available. Among them is the "constant current-constant voltage" type of charging, which represents a standard charging method involving an initial constant current phase followed by a constant voltage phase. Another electric current charging profile is the multi-stage charging, characterized by several distinct charging phases, often adapted to optimize battery performance. Finally, there is also the pulse profile, an approach where the charge is applied in successive pulses, offering an alternative method for battery management. These various profiles, generally applied in an open loop at the input of the electric battery, reflect the ongoing efforts to adapt charging methods to the specific needs of electric or hybrid vehicle batteries, seeking to maximize the efficiency and sustainability of these energy systems.

[0007] However, a disadvantage of such an open-loop application strategy of an electric charging current profile at the input of the vehicle's electric battery is a lack of control and a limited understanding of the operation of the battery. In addition, due to temperature constraints and thermal gradients, the electric battery is likely to degrade over time, depending on the different phases of electric recharging. A risk of thermal runaway of the electric battery is also possible. Thermal runaway of an electric battery, in particular a lithium-ion battery, is a well-known phenomenon during which a rise in temperature within one or more cells of the battery leads to a series of chain reactions during which different internal constituents of the cell(s) are decomposed.If the heat removed is less than the heat produced, these reactions follow one another and the system becomes self-sustaining until a sudden rise in temperature becomes uncontrollable. Due to its tightness, the cell builds up pressure until it opens, releasing the electrolyte in the form of flammable gases, generally leading to a fire with the release of toxic fumes due to the presence of fluorinated compounds. This poses safety and security problems.

[0008] The aim of the invention is to overcome the drawbacks of the prior art by proposing a method for correcting an electric charging current profile injected into the input of an electric battery of an electric or hybrid motor vehicle, which allows a user of the vehicle to be able to charge the latter in record time while preventing the electric battery from deteriorating over time due to temperature constraints and thermal gradients.

[0009] To do this, the invention thus relates, in its broadest acceptance, to a method, implemented by a calculation system on board an electric or hybrid motor vehicle, for correcting an electric current profile of charge injected into the input of an electric battery of the vehicle, the calculation system being connected to the electric battery and comprising an electric voltage corrector, a temperature corrector, and a memory storing a predefined electrothermal model, the electric or hybrid vehicle comprising, in addition to the electric battery, means for determining the profile of the electric charging current injected into the input of the electric battery, said means for determining the profile of the electric charging current being connected to the calculation system, the predefined electrothermal model receiving as input the profile of the electric charging current determined by the determination means, the predefined electrothermal model and the electric battery each providing as output respectively first and second values ​​of electric voltage and temperature; the process comprising the following steps: - a calculation, from the first and second electrical voltage values ​​provided at the output of the predefined electrothermal model and the electric battery, of a voltage error; - a calculation, from the first and second temperature values ​​provided at the output of the predefined electrothermal model and the electric battery, of a temperature error; - a calculation, by the electrical voltage corrector and from said calculated voltage error, of a first electrical charging current profile; - a calculation, by the temperature corrector and from said calculated temperature error, of a second electric charging current profile; and - an application at the input of the electric battery, from the electric charging current profile determined by the determination means, from the first calculated electric charging current profile and from the second calculated electric charging current profile, of a corrected electric charging current profile, said corrected electric charging current profile taking into account the electric voltage and temperature limits specific to the electric battery.

[0010] The correction method according to the invention makes it possible to adapt in real time the profile of the electric charging current injected into the input of an electric battery of the vehicle, taking into account the temperature limits and thermal gradients relating to the electric battery. This allows better supervision of the electric battery, as well as a better level of safety and security by limiting potential thermal runaways of the battery. The service life of the electric battery is thus advantageously improved, and the correction method according to the invention allows a user of the vehicle to be able to charge the latter in record time while preventing the electric battery from deteriorating over time due to temperature constraints and thermal gradients.

[0011] Preferably, the step of applying a corrected electric charging current profile to the input of the electric battery comprises a first sub-step of comparing the electric charging current profile determined by the determination means with the first calculated electric charging current profile, said first comparison sub-step providing as output a first corrected electric charging current profile; a second sub-step of comparing the electric charging current profile determined by the determination means with the second calculated electric charging current profile, said second comparison sub-step providing as output a second corrected electric charging current profile;and a third substep of applying to the input of the electric battery, as a corrected electric charging current profile, one of the first corrected electric charging current profile and the second corrected electric charging current profile.;

[0012] Preferably, during the third sub-step, the corrected electric charging current profile which is applied to the input of the electric battery is the minimum profile among the first corrected electric charging current profile and the second corrected electric charging current profile.

[0013] By "minimum profile" is meant in the present invention the electric charging current profile which represents the lowest level of electric current from the electric voltage corrector and the temperature corrector.

[0014] Another subject of the invention relates to a computer program product comprising program code instructions for executing the steps of a method according to the invention, when said program operates on a calculation system embedded in an electric or hybrid motor vehicle.

[0015] The program product can be loaded into the memory of the on-board calculation system within the motor vehicle, serving as a computer.

[0016] The invention also relates to a calculation system embedded in an electric or hybrid motor vehicle, the calculation system comprising an electrical voltage corrector, a temperature corrector, and a memory storing a computer program product and a predefined electrothermal model, the calculation system being able to be connected to an electric battery of the vehicle and to means for determining an electric charging current profile injected at the input of the electric battery, the predefined electrothermal model being able to receive as input an electric charging current profile determined by the determination means, the predefined electrothermal model and the electric battery being able to each provide as output respectively first and second electric voltage and temperature values, in which the computer program product is as described above,for implementing the steps of a method according to the invention.,

[0017] Preferably, the calculation system further comprises a first subtractor of which the non-inverting input is connected to the output of the electrothermal model and the inverting input is connected to the output of the electric battery, and the output of which is connected to the input of the electric voltage corrector; a second subtractor the non-inverting input of which is connected to the output of the electrothermal model and the inverting input is connected to the output of the electric battery, and the output of which is connected to the input of the temperature corrector; a third subtractor the non-inverting input of which is capable of being connected to the output of the means for determining an electric charging current profile and the inverting input is connected to the output of the electric voltage corrector; a fourth subtractor the non-inverting input of which is capable of being connected to the output of the means for determining an electric charging current profile and the inverting input is connected to the output of the temperature corrector;and a minimization module configured to provide a minimum output value from among two input values, the two inputs of the minimization module being respectively connected to the output of the third subtractor and to the output of the fourth subtractor, the output of the minimization module being connected to the input of the electric battery. ;

[0018] The invention also relates to an electric or hybrid motor vehicle comprising an electric battery and an on-board calculation system according to the invention, the on-board calculation system being connected to the electric battery.

[0019] The invention will be further detailed by the description of non-limiting embodiments, and on the basis of the following appended figures in which: - [Fig.l] schematically illustrates an assembly comprising an electric battery of an electric or hybrid vehicle, and a computing system on board the vehicle and connected to the electric battery; and - [Fig.2] is a flowchart representing a method, implemented by the calculation system of [Fig.l], of correcting a profile of electric charging current injected into the input of the electric battery of [Fig.l], according to the present invention.

[0020] Referring to [Fig. 2] the present invention relates to a method for correcting an electric charging current profile injected into the input of an electric battery of an electric or hybrid vehicle. The electric battery is a traction battery of the electric or hybrid vehicle, in particular a lithium-ion battery. In [Fig. 1] is shown an assembly 1 comprising an electric battery 2 and a calculation system 4 installed in an electric or hybrid vehicle (not shown). The calculation system 4 is connected to the electric battery 2. The electric or hybrid vehicle comprises, in addition to the electric battery 2, means for determining the electric charging current profile 3 injected into the input of the electric battery 2, such determination means not being shown in the figures for reasons of clarity.The means for determining the profile of the electric charging current 3 injected into the input of the electric battery 2 are connected to the calculation system 4.

[0021] The calculation system 4 comprises an electrical voltage corrector 6, a temperature corrector 8, and a memory 10 storing a predefined electrothermal model 12. The memory 10 also stores a computer program product (not shown). Preferably, as illustrated in [Fig.l], the calculation system 4 further comprises four subtractors 14A-14D and a minimization module 16.

[0022] The predefined electrothermal model 12 receives as input the electric charging current profile 3 determined by the determination means. The predefined electrothermal model 12 and the electric battery 2 each provide as output respectively first and second values ​​of electric voltage 18A, 18B and temperature 20A, 20B. The non-inverting input 14A1 of a first subtractor 14A is connected to the output of the electrothermal model 12 and the inverting input 14A2 of the first subtractor 14A is connected to the output of the electric battery 2. The output of the first subtractor 14A is connected to the input of the electric voltage corrector 6. The non-inverting input 14B1 of a second subtractor 14B is connected to the output of the electrothermal model 12 and the inverting input 14B2 of the second subtractor 14B is connected to the output of the electric battery 2. The output of the second subtractor 14B is connected to the input of the temperature corrector 8.The non-inverting input 14C1 of a third subtractor 14C is connected to the output of the means for determining an electric load current profile 3 and the inverting input 14C2 of the third subtractor 14C is connected to the output of the electric voltage corrector 6. The output of the third subtractor 14C is connected to an input of the minimization module 16. The non-inverting input 14D1 of a fourth subtractor 14D is connected to the output of the means for determining an electric load current profile 3 and the inverting input 14D2 of the fourth subtractor 14D is connected to the output of the temperature corrector 8. The output of the fourth subtractor 14D is connected to another input of the minimization module 16. The minimization module 16 is configured to provide a minimum value as output among its two input values. The output of the minimization module 16 is connected to the input of the electric battery 2.

[0023] As illustrated in [Fig.2], the method for correcting a profile of electric charging current 3 injected at the input of the electric battery 2 comprises a first step 22 during which the first subtractor 14A calculates a voltage error El, from the first and second electric voltage values ​​18A, 18B provided at the output of the predefined electrothermal model 12 and of the electric battery 2.

[0024] The method comprises a parallel or following step 24 during which the second subtractor 14B calculates a temperature error E2, from the first and second temperature values ​​20A, 20B provided at the output of the predefined electrothermal model 12 and of the electric battery 2.

[0025] The method comprises a following step 26 during which the electrical voltage corrector 6 calculates a first electrical load current profile PI, from the calculated voltage error El.

[0026] The method comprises a parallel or subsequent step 28 during which the temperature corrector 8 calculates a second electric load current profile P2, from the calculated temperature error E2.

[0027] The method comprises a following step 30 during which the calculation system 4 applies to the input of the electric battery 2, from the electric charging current profile 3 determined by the determination means, the first calculated electric charging current profile PI and the second calculated electric charging current profile P2, a corrected electric charging current profile P3. The corrected electric charging current profile P3 takes into account the electrical voltage and temperature limits specific to the electric battery 2. This step 30 of applying the corrected electric charging current profile P3 comprises a first sub-step 30A during which the third subtractor 14C compares the electric charging current profile 3 determined by the determination means with the first electric charging current profile PI calculated during step 26,and outputs a first corrected electric charging current profile P4; a second substep 30B during which the fourth subtractor 14D compares the electric charging current profile 3 determined by the determination means with the second electric charging current profile P2 calculated during step 28, and outputs a second corrected electric charging current profile P5; and a third substep 30C during which the minimization module 16 determines a minimum profile from among the first corrected electric charging current profile P4 and the second corrected electric charging current profile P5, then applies this minimum profile as the corrected electric charging current profile P3 to the input of the electric battery 2.

[0028] Another subject of the invention relates to a computer program product comprising program code instructions for executing the steps of a method as described above, when said program operates on a calculation system embedded in an electric or hybrid motor vehicle.

[0029] The invention also relates to an electric or hybrid motor vehicle comprising the assembly 1 as described previously.

Claims

Claims

1. Method, implemented by a calculation system (4) embedded in an electric or hybrid motor vehicle, for correcting an electric charging current profile (3) injected into the input of an electric battery (2) of the vehicle, the calculation system (4) being connected to the electric battery (2) and comprising an electric voltage corrector (6), a temperature corrector (8), and a memory (10) storing a predefined electrothermal model (12), the electric or hybrid vehicle comprising, in addition to the electric battery (2), means for determining the electric charging current profile (3) injected into the input of the electric battery (2), said means for determining the electric charging current profile (3) being connected to the calculation system (4), the predefined electrothermal model (12) receiving as input the electric charging current profile (3) determined by the determination means,the predefined electrothermal model (12) and the electric battery (2) each providing as output respectively first and second values ​​of electric voltage (18A, 18B) and temperature (20A, 20B);, the method being characterized in that it comprises the following steps: - a calculation (22), from the first and second electrical voltage values ​​(18A, 18B) provided at the output of the predefined electrothermal model (12) and the electric battery (2), of a voltage error (El); - a calculation (24), from the first and second temperature values ​​(20A, 20B) provided at the output of the predefined electrothermal model (12) and the electric battery (2), of a temperature error (E2); - a calculation (26), by the electrical voltage corrector (6) and from said calculated voltage error (El), of a first electrical charging current profile (PI); - a calculation (28), by the temperature corrector (8) and from said calculated temperature error (E2), of a second electric charging current profile (P2); and - an application (30) at the input of the electric battery (2), from the electric charging current profile (3) determined by the determination means, the first calculated electric charging current profile (PI) and the second calculated electric charging current profile (P2), of a corrected electric charging current profile (P3), said corrected electric charging current profile (P3) taking into account the electric voltage and temperature limits specific to the electric battery (2).

2. Method according to claim 1, in which the step (30) of applying to the input of the electric battery (2) a corrected electric charging current profile (P3) comprises a first sub-step (30A) of comparing the electric charging current profile (3) determined by the determination means with the first calculated electric charging current profile (PI), said first comparison sub-step (30A) providing as output a first corrected electric charging current profile (P4); a second sub-step (30B) of comparing the electric charging current profile (3) determined by the determination means with the second calculated electric charging current profile (P2), said second comparison sub-step (30B) providing as output a second corrected electric charging current profile (P5);and a third sub-step (30C) consisting of applying at the input of the electric battery (2), as a corrected electric charging current profile (P3), one of the first corrected electric charging current profile (P4) and the second corrected electric charging current profile (P5).;

3. The method of claim 2, wherein, in the third substep (30C), the corrected electric charging current profile (P3) which is applied to the input of the electric battery (2) is the minimum profile among the first corrected electric charging current profile (P4) and the second corrected electric charging current profile (P5).

4. Computer program product comprising program code instructions for executing the steps of a method according to any one of claims 1 to 3, when said program operates on a calculation system (4) embedded in an electric or hybrid motor vehicle.

5. Calculation system (4) embedded in an electric or hybrid motor vehicle, the calculation system (4) comprising an electrical voltage corrector (6), a temperature corrector (8), and a memory (10) storing a computer program product and a predefined electrothermal model (12), the calculation system (4) being able to be connected to an electric battery (2) of the vehicle and to means for determining a profile of electric charging current (3) injected at the input of the electric battery (2), the predefined electrothermal model (12) being able to receive as input a current profile electric charge (3) determined by the determination means, the predefined electrothermal model (12) and the electric battery (2) each being capable of providing at output respectively first and second values ​​of electric voltage (18A, 18B) and temperature (20A, 20B), characterized in that the computer program product is in accordance with claim 4, for implementing the steps of a method according to any one of claims 1 to 3.

6. An on-board calculation system (4) according to claim 5, wherein the calculation system (4) further comprises a first subtractor (14A) whose non-inverting input (14A1) is connected to the output of the electrothermal model (12) and whose inverting input (14A2) is connected to the output of the electric battery (2), and whose output is connected to the input of the electric voltage corrector (6); a second subtractor (14B) whose non-inverting input (14B1) is connected to the output of the electrothermal model (12) and whose inverting input (14B2) is connected to the output of the electric battery (2), and whose output is connected to the input of the temperature corrector (8); a third subtractor (14C) whose non-inverting input (14C1) is capable of being connected to the output of the means for determining an electric charging current profile (3) and the inverting input (14C2) is connected to the output of the electric voltage corrector (6);a fourth subtractor (14D) whose non-inverting input (14D1) is capable of being connected to the output of the means for determining a charging electric current profile (3) and the inverting input (14D2) is connected to the output of the temperature corrector (8); and a minimization module (16) configured to provide a minimum output value from among two input values, the two inputs of the minimization module (16) being respectively connected to the output of the third subtractor (14C) and to the output of the fourth subtractor (14D), the output of the minimization module (16) being connected to the input of the electric battery (2).;

7. Electric or hybrid motor vehicle comprising an electric battery (2) and an on-board computing system (4) according to claim 5 or 6, the on-board computing system (4) being connected to the electric battery (2).

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