Method for adapting the power of a battery

Abstract

The present invention relates to a method for adapting the power of an electrical storage device (1) comprising a plurality of cells (6) through which an electric current is able to flow and each provided with an active part (16) and with an electrical connection element (18), the power-adapting method comprising a first step of determining a temperature of the electrical connection element (18) of at least one cell (6) and a second step of adjusting the power of the electrical storage device (1) based on the temperature determined during the first step, the first step comprising a sub-step of determining a temperature of the active part (16) of the cell (6), a sub-step of determining the current in the electrical storage device (1) and a sub-step of estimating the temperature of the electrical connection element using the values determined in the previous sub-steps and a temperature model.

Description

[0001] DESCRIPTION

[0002] Title: Battery Power Adaptation Method

[0003] The present invention relates to the field of automotive vehicle batteries, and more particularly to the field of methods for adapting the power of these batteries.

[0004] It is now common practice to equip electric, internal combustion, or hybrid vehicles with battery systems that provide electrical power to the various components of the vehicle. These battery systems are generally composed of several cells, which are themselves arranged in modules that form the battery system. During vehicle operation, battery systems can generate a significant amount of heat and therefore be subject to temperature increases that can, in some cases, cause damage or even destruction. Pouch cells are electrochemical cells comprising an active part made up of stacked layers of materials, including an anode and a cathode, within which redox reactions take place, necessary for charging and discharging the cell.The active part of the cell is enclosed within a flexible casing that provides insulation between this active part and the environment outside the cell. The cell has at least one electrical connection element, for example, an electrically conductive connecting tab, which extends from the active part, through the flexible casing, and to the outside of the casing. The electrical connection element allows for electrical connections between the cell and another cell and / or another module of the battery system. The cell is sealed at the electrical connection element by a sealing agent, or gasket, such as an adhesive.

[0005] In the case of these "pouch" type cells, the passage of current within the battery system causes an increase in the temperature of the electrical connection element and, through thermal conduction, an increase in the temperature of the sealing element, which can lead to a deterioration in the sealing element's effectiveness, for example, by melting the adhesive. There is then a risk of leakage of the contents of the flexible casing. The present invention addresses this issue by proposing a method for adapting the power of a battery system, which limits overheating that could damage the cell's sealing element by controlling the temperature at its electrical connection element.

[0006] The main object of the present invention is a method for adapting the power of an electrical storage device in a vehicle, the electrical storage device comprising a plurality of cells, each provided with an active part and at least one electrical connection element extending at least partially inside the active part, the cells being configured to be electrically connected via their respective electrical connection elements and to carry an electric current flowing within the electrical storage device, the power adaptation method comprising:

[0007] - a first step of determining the temperature of the electrical connection element of at least one of the cells of the electrical storage device, and - a second step of adjusting the power supplied or received by the electrical storage device according to the temperature determined during the first step,

[0008] the first step including:

[0009] - a sub-step for determining the temperature of the active part of a cell,

[0010] - a sub-step for determining the electric current flowing within the electrical storage device,

[0011] - a substep of estimating the temperature of the electrical connection element using the electric current and temperature values ​​determined in the previous substeps, and a predetermined temperature model.

[0012] The power adaptation method according to the invention is used to regulate electrical power supplied to or received by an electrical storage device, in particular a battery in a motor vehicle. The electrical storage device is then configured to supply the energy required to start the vehicle.

[0013] The electrical storage device comprises a plurality of cells, for example, "pocket" type cells as described in the introduction, which consist of an active part enclosed in a flexible casing with an electrical disconnect element protruding from it. The casing is sealed at the electrical connection element using a sealing means. The cells can be arranged in series to form a single electrical current flow branch. Alternatively, the cells can be distributed across several parallel electrical current flow branches, with a plurality of cells connected in series on each branch.

[0014] The power adaptation method according to the invention prevents overheating of the electrical connection elements, which could damage their sealing means. To this end, the power adaptation method comprises a first step that determines the temperature of the electrical connection element, and a second step that adapts the supplied or received electrical power, and therefore the temperature of the electrical connection element.

[0015] Advantageously, the adaptation method does not require the installation of a temperature sensor on the cell's electrical connection element, thus reducing costs and space requirements within the electrical storage device. Instead, the step of determining the temperature of the electrical connection element involves determining the temperature of the cell's active part. This determination can be performed using commonly used measuring instruments already present in the electrical storage device, for example, to ensure the proper progress of chemical reactions within the active part. Similarly, the step of determining the current involves determining the current itself using measuring instruments already present in the electrical storage device, for example, to determine its state of charge.The current measurement devices are advantageously located at one end of a current flow branch that forms part of the electrical storage device. The "determination" substep here means that the temperature, or current respectively, is either measured in situ using a dedicated sensor or calculated using remote measurements. Such a current flow branch is a current transmission line to or from a single cell, a plurality of cells connected in series, a single cell connected to a plurality of cells connected in parallel, or several cells connected in parallel. The second adjustment step can, in particular, allow for the adjustment of electrical power supplied by the storage device, notably to supply current to an inverter upstream of an electric traction motor in a motor vehicle.The second adjustment step can also allow for an adjustment of electrical power received by the storage device, including charging power from a charging station or mechanical energy recovery from braking of the motor vehicle.

[0016] Advantageously, during the second stage, the power supplied to and / or received by the electrical storage device is reduced when the temperature determined during the first stage exceeds a predetermined threshold value. This limitation of the electrical storage device's power results in a reduction of the temperature to which the electrical connection element is subjected, thereby limiting the temperature of the sealing element and consequently the risk of damage to the sealing element. The power limitation is proportional to the temperature determined for the electrical connection element; thus, the higher the determined temperature, the greater the power limitation. Conversely, the power supplied to and / or received by the electrical storage device can be maintained or even increased when the temperature determined during the first stage is below the threshold value.

[0017] In this case, the power is not reduced because the temperature to which the connecting element is subjected does not pose a risk of damage to the sealing means. In some embodiments, the power of the electrical storage device is maintained or increased when the temperature determined during the first step is below a second predetermined threshold value, distinct from the threshold value above which the power of the electrical storage device is reduced and which corresponds to a first threshold value in such an embodiment.

[0018] The power adaptation method according to the invention makes it possible to implement hysteresis within the electrical storage device, so as to ensure its optimal operation. Where applicable, each threshold value is associated with a temperature model.

[0019] The limitation of the power supplied and / or received by the electrical storage device can be gradual, that is, in successive increments. Alternatively, it can be proportional to the temperature of the electrical connection element, so that the higher this temperature, the greater the power limitation. The threshold value (or, where applicable, the first and / or second threshold values) is obtained from tests and / or modeling performed on the electrical storage device.

[0020] According to an optional feature of the invention, the temperature threshold value is a function of an operating mode of the electrical storage device chosen from a vehicle traction mode and an electrical storage device charging mode.

[0021] The threshold value (or where applicable the first threshold value, respectively second threshold value) of the temperature is a function of an operating mode of the electrical storage device chosen from among a vehicle traction mode and a charging mode of the electrical storage device.

[0022] In other words, the temperature threshold value (or, where applicable, the first and second threshold values) varies depending on the operating mode of the electrical storage device. This operating mode can correspond to a vehicle traction mode, which contributes to the vehicle's propulsion, or to a charging mode, which includes, for example, regenerative braking or charging from an external electrical grid. For instance, a first threshold value will be chosen for traction mode and a second threshold value for charging from an external electrical grid, with the first threshold value being higher than the second. This is because, in charging mode, the vehicle is stationary. Heat exchange between the battery and the environment is less than during traction mode, i.e., while driving.In charging mode, it may be preferable to lower the threshold for safety reasons (long charging time with high power). In towing mode, one can temporarily favor dynamic or sporty vehicle use without reducing electric power.

[0023] According to an optional feature of the invention, during the first step, the substep of determining the temperature of the active part is carried out at the level of different cells, the first step further comprising a substep of selecting a maximum temperature among the respective temperatures of the different cells. The selection substep makes it possible to determine, among the cells for which the temperature of the electrical connection element is determined, the one which has the highest temperature.The temperature retained is, for example, that corresponding to the electrical connection element of the first cell of a given module of the electrical storage device in the direction of current flow in that module, the current flow branch comprising several modules connected in series each receiving several cells connected in series, or that corresponding to the connection element of the last cell of said module in the direction of current flow in that module, because these two cells are subjected both to the heating of their own connection element and to that of an electrical connection terminal of the module.

[0024] According to an optional feature of the invention, the temperature model used in the first step includes a heating constant for the electrical connection element under consideration and a heat transfer constant between the electrical connection element under consideration and the active part whose temperature has been determined. The constants are predetermined coefficients known for a given type of electrical storage device.

[0025] According to an optional feature of the invention, each cell includes an envelope defining a housing for the active part, the substep of determining the temperature of the active part being carried out using a temperature sensor positioned on the envelope.

[0026] The temperature sensor is therefore positioned on a cell, at a distance from its electrical connection point (and at a distance from the electrical connection point whose temperature is to be determined, whether or not it belongs to the same cell). The temperature sensor is, for example, a thermistor present in the electrical storage device to measure the temperature of at least one active part of a cell.

[0027] According to an optional feature of the invention, the current determination substep is carried out using a current sensor positioned at the input of the electrical storage device.

[0028] The current sensor is, for example, located within the electrical storage device upstream of the cells, or outside a housing that defines the storage device. If the cells are arranged in parallel branches within the storage device, the current sensor is positioned, for example, upstream of a division of the parallel branches. It is then assumed that the current is distributed equally among the different branches (referred to above as current flow branches).

[0029] The invention further relates to a control system for an electrical storage device for the implementation of a power adaptation method as previously mentioned, comprising an electrical storage device for a vehicle, the electrical storage device comprising a plurality of cells each provided with an active part and at least one electrical connection element extending at least partly inside the active part, the cells being configured to be electrically assembled via their respective electrical connection elements and through which an electric current flows within the electrical storage device, the control system comprising means for determining the temperature of an electrical connection element and means for adjusting the power supplied and / or received by the electrical storage device.The control system is, for example, a battery management system, also known by the English name battery management system or BML.

[0030] The means of determining the temperature of an electrical connection element cover both means of determining the temperature of the active part of a cell and means of determining the electric current flowing within the electrical storage device.

[0031] According to an optional feature of the invention, the means for determining the temperature of an electrical connection element include means for determining the temperature of the active part of a cell comprising at least one temperature sensor positioned on the envelope.

[0032] According to an optional feature of the invention, the means for determining the temperature of an electrical connection element include means for determining the electric current comprising at least one current sensor positioned at the input of the electrical storage device.

[0033] The means for determining the temperature of an electrical connection element further include at least one computer equipped with at least one memory, the memory storing a predetermined temperature model, and the computer being configured to estimate the temperature of the electrical connection element using the electrical current and temperature values ​​of the active part of a cell, and the temperature model. The power adjustment means are configured to reduce the power supplied to and / or received by the electrical storage device based on the values ​​measured by the means for determining the temperature of the electrical connection element and the temperature model. The means for determining the temperature of the electrical connection element and the power adjustment means may, for example, share the same computer within the control system.

[0034] Other features, details and advantages of the invention will become clearer upon reading the following description on the one hand, and the illustrative and non-limiting examples of embodiments given with reference to the accompanying drawings on the other hand, in which:

[0035] [Fig. 1] illustrates, schematically, a battery comprising a plurality of modules, each containing a plurality of cells;

[0036] [Fig. 2] illustrates, schematically, a portion of a cell from figure 1, and in particular its connection element to a neighboring module;

[0037] [Fig. 3] illustrates, schematically, a portion of the battery in Figure 1 equipped with a control system.

[0038] The features, variations, and different embodiments of the invention may be combined in various ways, provided they are not incompatible or mutually exclusive. In particular, variations of the invention may include only a selection of features, described hereafter in isolation from the other features described, if this selection of features is sufficient to confer a technical advantage and / or to differentiate the invention from prior art.

[0039] In the figures, elements common to several figures retain the same reference numeral. Figures 1 to 3 thus schematically illustrate an electrical storage device 1 according to the invention. This electrical storage device 1 is intended to equip a motor vehicle, in particular for the purpose of electrically powering an electric traction motor to propel the vehicle. The electrical storage device 1 is, for example, an electric battery of the vehicle. The electrical storage device 1 comprises a housing 2 within which modules 4 are arranged. The housing 2 of the electrical storage device 1 contains four modules 4, although this number is not a limitation of the invention. The modules 4 form housings for electrical cells 6 of the electrical storage device 1.For illustrative purposes, only three cells 6 are shown here in a first module 4, but each module 4 comprises, for example, but not limited to, between 16 and 46 cells 6. In each module 4, the cells 6 are connected in series, but in other embodiments the cells 6 could be connected in parallel. As shown, the individual modules 4 are connected to each other in series by a current flow branch 8, as illustrated in Figure 1. This current flow branch 8 has an input point 10 within the housing 2 of the electrical storage device 1, as well as an output point 12 from said housing 2. The current flow branch 8 allows the flow of an electric current within the electrical storage device 1. According to variants not shown, the individual modules 4 are connected to each other in series and in parallel, so as to define at least two current flow branches.In the embodiment shown in Figure 1, the cells 6 are arranged in series on the circulation branch 8, as are the modules 4 within which they are arranged.

[0040] As can be seen in Figure 2, each cell 6 has an envelope 14 or pocket that encloses an active part 16 of the cell 6. This active part 16 includes, in particular, at least one positive electrode or cathode, at least one negative electrode or anode, as well as an electrolyte and a separator arranged between the electrodes. The active part 16 is, for example, in the form of layers between which redox reactions take place, allowing the cell 6 to be charged and discharged.

[0041] Cell 6 also includes an electrical connection element 18. This electrical connection element 18 is a metal tab. It is designed to electrically connect the active part 16 of cell 6 to an adjacent cell 6 of the same module 4 or to a connection terminal 24 of said module 4 for connection to a nearby electrical storage device 1. The electrical connection element 18 extends partly within the enclosure 14 and partly outside of it. It is therefore understood that the enclosure 14 has an opening 20 through which the electrical connection element 18 passes. To ensure the sealing of cell 6, in particular by preventing electrolyte leakage through the opening 20, cell 6 includes a sealing means 22. The sealing means 22, or sealing gasket, is thus positioned within the opening 20 around the electrical connection element 18.The sealing method is, for example, glue.

[0042] Notably, for the first cell 6 and the last cell 6 of a given module 4 in the direction of current flow from one cell 6 to the other, the electrical connection element 18 further enables an electrical connection to a connection terminal 24 of the module 4.

[0043] As can be seen in Figures 1 and 3, the electrical storage device 1 has a current determination means 26. This current determination means 26 is configured to measure or calculate the current flowing within the electrical storage device 1, for example within the circulation branch 8. The current determination means 26 is used in particular to determine a state of charge of the cells 6 of the energy storage device 1.

[0044] The current determination means 26 is, for example, a current sensor 26. In the embodiments shown in Figures 1 and 3, the current sensor 26 is located on the circulation branch 8. More precisely, the current sensor 26 is located on the circulation branch 8 upstream of the entry point 10 within the housing 2 of the electrical storage device 1. In other embodiments, the current sensor 26 could be located at another point on the circulation branch 8. If there are N current circulation branches 8 in the device 1, with N greater than or equal to 2, the current determination means 26 may include a current sensor located upstream of a branching node. The current flowing in the circulation branch 8 is then i(t) / N, where i(t) is the current measured by the current sensor.

[0045] In addition to the current-determining means 26, the energy storage device 1 includes at least one temperature-determining means 28 for the active part 16 of one of the cells 6. This temperature-determining means 28 for the active part 16 is configured to measure or calculate the temperature within the active part 16 of the cell. The temperature-determining means 28 for the active part 16 is used, in particular, to ensure the proper progress of the redox reactions taking place within this active part 16. The temperature-determining means 28 for the active part 16 is, for example, a temperature sensor 28 such as a thermistor. As illustrated in Figure 2, the temperature-determining means 28 for the active part 16 is positioned here on the casing 14 of the cell 6.

[0046] The electrical storage device 1 may have a plurality of temperature determination means 28. The electrical storage device 1 includes, for example, three to four temperature determination means 28 per module 4. It is understood here that only some of the cells 6 are equipped with the temperature determination means 28.

[0047] To prevent overheating of the cells 6, and more specifically of their electrical connection elements 18, which could damage the sealing means 22, this application proposes a method for adapting the power of the electrical storage device 1. This power adaptation method aims to limit the power delivered by the electrical storage device 1 and consequently the heating of the electrical connection elements 18 of the cells 6. The power adaptation method is implemented, for example, within a control system that includes the electrical storage device 1, this control system being illustrated in Figure 3. The control system is, for example, a battery management system (BML).

[0048] The power adaptation method according to the invention includes a first step of determining the temperature of the electrical connection element 18. This first step aims to determine the temperature of the electrical connection element 18 at a contact area of ​​this electrical connection element 18 with the sealing means 22. The first step of determining the temperature of the electrical connection element 18 is implemented using means for determining the temperature of the electrical connection element 18, as will now be described.

[0049] The first step in determining the temperature of the electrical connection element 18 is based on, on the one hand, determining the temperature of the active part 16 of one of the cells 6 of the electrical storage device 1, and on the other hand, determining an electric current flowing within the electrical storage device 1. The determination of the temperature of the active part 16 and the determination of the electric current flowing within the electrical storage device 1 thus constitute two sub-steps of the first step in determining the temperature of the electrical connection element 18, these two sub-steps being able to be carried out simultaneously within the electrical storage device 1.

[0050] The substep of determining the temperature of the active part 16 is carried out using the temperature determination means 28 of the active part 16 (for example, a thermistor, as described above), while the substep of determining an electric current flowing within the electrical storage device 1, in particular within the circulation branch 8, is carried out using the current determination means 26 (for example, a current sensor, as described above). Thus, the temperature determination means 28 of the active part 16 and the current determination means 26 belong to the temperature determination means of the electrical connection element 18.

[0051] Once the temperature of the active part 16 and the value of the electric current have been determined, the temperature of the electrical connection element 18 is determined using the following mathematical formula:

[0052] estimated temperature (t)

[0053]

[0054] — K2(estimated temp (t — At) — measured temp (t — At))] In which:

[0055] "estimated temp (t)" is the temperature of the electrical connection element 18 estimated at a time t;

[0056] "At" is the time step of the control system that implements the power adaptation method;

[0057] "K r " is a first constant corresponding to a heating constant by Joule effect of the electrical connection element 18, this first constant being able to be weighted according to the number of circulation branches 8 of the current within the electrical storage device 1;

[0058] "K2" is a second constant corresponding to a heat transfer constant between the electrical connection element 18 considered, and the active part 16 at which a temperature has been determined, this active part 16 being able to be that of another cell of the same branch; is a current value determined by the current determination means 26;

[0059] "Measured temp" is the temperature determined by the temperature determination means 28 of the active part 16.

[0060] When at least part of the cells are arranged in parallel, the current i(t- t) determined by the current determination means 26 does not correspond to the current flowing in the electrical connection element 18 considered.

[0061] In this case, the first constant K radvantageously incorporates a multiplicative coefficient representative of the current distribution in the different cells arranged in parallel. Alternatively, the value of " is used

[0062]

[0063] » the current value as determined by the current determination method 26 multiplied by a multiplicative coefficient depending on the distribution of the current in the different cells arranged in parallel.

[0064] Put another way, during the first determination of the temperature of the electrical connection element 18, the temperature of the electrical connection element 18 is estimated on the one hand using the values ​​of electric current and temperature of the active part 16 determined, and on the other hand using a predetermined temperature model.

[0065] The means for determining the temperature of the electrical connection element 18 therefore also include a calculator 30, equipped with a memory storing said predetermined temperature model, and a processor configured to implement said estimation using said current and temperature values ​​of the active part 16. The calculator 30 is integrated into the control system, which in addition to this calculator 30 also includes the means for determining the current 26 and the means for determining the temperature 28 of the active part 16. The calculator 30, the means for determining the current 26 and the means for determining the temperature 28 of the active part 16 can, for example, form a control unit incorporated into the control system.As can be seen in Figure 3, the control system's computer 30 receives the temperature value determined for the active part 16 and the estimated value for the electric current flowing in the electrical storage device 1. This reception of values ​​is illustrated in Figure 3 by dashed arrows. It should be noted that when the electrical storage device 1 includes a single means for determining the temperature 28 of the active part 16, the measured temperature or "measured temp" corresponds to the temperature value determined by said temperature-determining means 28. Conversely, when there are multiple temperature-determining means 28 positioned on several different cells 6, the first step in determining the temperature of the electrical connection element 18 includes a selection substep.This selection substep allows more precisely the choice, as measured temperature or "measured temp", of the highest temperature value among all the temperatures recorded by the multiple temperature determination means 28 positioned within the electrical storage device 1. Due to the connection to the connection terminal 24 of a given module 4 of the first and last cells 6 of said module 4, which increases the heating of their electrical connection element 18, the highest measured temperature or "measured temp" generally corresponds to the temperature determined by the temperature determination means 28 of the active part 16 of one or the other of these first and last cells 6.

[0066] To obtain the first heating constant and the second heat transfer constant, the power matching method includes, for example, a preliminary calibration step. This preliminary calibration step occurs before the first step of determining the temperature of the electrical connection element 18. The preliminary step is carried out, for example, on a test bench. During the preliminary calibration step, a temperature measuring device is installed at the electrical connection element 18 of one of the cells 6 of the electrical storage device 1. This measuring device records the temperature evolution of the electrical connection element 18.From the temperature evolution of the electrical connection element 18, the temperature of the active part 16 determined by the temperature measurement device 28, and the determination of the electric current flowing within the electrical storage device, particularly the circulation branch 8, it is possible to determine, using the aforementioned mathematical formula, firstly, a heating value for the electrical connection element 18, which corresponds to the first constant, and secondly, a heat transfer value between the electrical connection element 18 and the active part 16, which corresponds to the second constant. Once the two constants have been estimated, the measurement device is removed prior to the implementation of the first step of determining the temperature of the electrical connection element 18.

[0067] Once the first step is complete, that is, when the temperature of the connection element 18 is determined, the power adaptation method continues with a second step of adjusting the power supplied to and / or received by the electrical storage device 1. This second step, which notably implements means for adjusting the power of the electrical storage device 1, will now be described in detail. The second step is implemented using the control system's computer 30.

[0068] The second power adjustment step of the electrical storage device 1 depends on the temperature of the connecting element 18, determined during the first step. Thus, during the second step, the temperature of the connecting element 18 obtained during the first step is compared by the control system to a temperature threshold value. This temperature threshold value is, for example, stored in a memory of the control system's computer 30. It should be noted that the threshold value varies depending on the operating mode of the electrical storage device 1; for example, the threshold value will differ depending on whether the electrical storage device 1 is used in traction mode or in charging mode within a motor vehicle. It is understood here that the temperature threshold value is linked to an average power consumption of the electrical storage device 1.

[0069] When the temperature of the electrical connection element 18 determined during the first step is below the threshold value, this means that there is no risk of damage to the sealing means 22 of the cell 6. Therefore, the power of the storage device 1 can, as appropriate, remain unchanged or be increased.

[0070] On the contrary, when the temperature of the electrical connection element 18 determined during the first step is above the threshold value, there is a risk of overheating of the electrical connection element 18 and therefore a risk of damage to the sealing means 22. Therefore, the adjustment means of the control system implement a reduction of the power of the electrical storage device 1. Such a reduction of power is applied until the temperature determined for the electrical connection element 18 is below the threshold value, i.e. until the heat of the electrical connection element dissipates.

[0071] The limitation of the power supplied and / or received by the electrical storage device is merged with the other power limitations of the electrical storage device for the control of the electrical machine(s) in traction mode and of the charger or charging infrastructure in charging mode.

[0072] As shown in Figure 3, the control system's computer 30 is capable of sending limiting information for the input power of the storage device 1 and / or for the output power of the storage device 1. This power limiting information is illustrated in Figure 3 by dashed arrows. It should be noted that while in Figure 3 the information is shown, for illustrative purposes, sent directly by the control system, in practice this power limiting information may be transmitted through any other computer in the vehicle capable of limiting the power supplied to and / or received by the electrical storage device 1.

[0073] It should be noted that in practice, the power adaptation method can use two distinct threshold values, respectively forming a threshold above which power is limited and a threshold below which power is not limited or is no longer limited. Thus, it is possible to implement power control based on hysteresis within the electrical storage device 1.

[0074] For example, when a motor vehicle equipped with an electrical storage device 1 is accelerating and the control system detects that the temperature of the electrical connection element 18 exceeds the threshold value, the control system implements a power reduction for the electrical storage device 1, which in turn reduces the vehicle's acceleration. In other words, the vehicle's acceleration is limited. For example, the vehicle's speed may be reduced from 130 km / h to 110 km / h. This power reduction for the motor vehicle 1 is applied as long as the temperature of the electrical connection element 18 remains above the threshold value.

[0075] It should be noted that the greater the difference between the determined temperature of the electrical connection element 18 and the threshold value, the greater the power reduction of the electrical storage device 1. An appropriate power reduction is determined, for example, based on a table that associates a power reduction coefficient with each temperature value that can be determined for the electrical connection element 18. This allows for a gradual limitation of the power supplied and / or received by the electrical storage device 1, thus preventing sudden power drops that could be disruptive to a driver of a vehicle equipped with the electrical storage device 1.

[0076] The present invention thus proposes a method for adapting the power of an electrical storage device comprising cells, this method being designed to limit overheating that could damage the cell's sealing system. The power adaptation method is based on monitoring the temperature of an electrical connection element of the cell. The power adaptation method uses sensors already present in the electrical storage device and therefore does not require the use of an additional sensor specific to the electrical connection element.

[0077] The present invention is not limited to the means and configurations described and illustrated herein, and also extends to any equivalent means and configuration as well as any technically operative combination of such means.

Claims

DEMANDS 1. Method for adapting the power of an electrical storage device (1) of a vehicle, the electrical storage device (1) comprising a plurality of cells (6), each having an active part (16) and at least one electrical connection element (18) extending at least partially within the active part (16), the cells (6) being configured to be electrically connected via their respective electrical connection elements (18) and to carry an electric current flowing within the electrical storage device (1), the power adaptation method comprising: - a first step of determining the temperature of the electrical connection element (18) of at least one of the cells (6) of the electrical storage device (1), and - a second step of adjusting the power supplied and / or received by the electrical storage device (1) as a function of the temperature determined during the first step, the first step including: - a sub-step for determining the temperature of the active part (16) of a cell (6); a substep for determining an electric current flowing within the electrical storage device (1); and - a substep of estimating the temperature of the electrical connection element using the electrical current and temperature values ​​determined in the previous substeps, and a predetermined temperature model.

2. Power adaptation method according to the preceding claim, wherein in the second step, the power supplied and / or received by the electrical storage device (1) is reduced when the temperature determined in the first step exceeds a predetermined threshold value.

3. Power adaptation method according to the preceding claim, wherein the temperature threshold value is a function of an operating mode of the electrical storage device (1) chosen from a vehicle traction mode and a charging mode of the electrical storage device (1).

4. Power adaptation method according to any one of the preceding claims, wherein in the first step, the substep of determining a temperature of the active part (16) is carried out at the level of different cells (6), the first step further comprising a substep of selecting a maximum temperature among the respective temperatures of the different cells (6).

5. Power adaptation method according to any one of the preceding claims, wherein the temperature model used in the first step includes a heating constant of the electrical connection element (18) considered and a heat transfer constant between the electrical connection element (18) considered and the active part (16) whose temperature has been determined.

6. Power adaptation method according to any one of the preceding claims, wherein each cell (6) comprises an envelope (14) defining a housing for the active part (16), the substep of determining the temperature of the active part (16) being carried out using a temperature sensor (28) positioned on the envelope (14).

7. Power adaptation method according to any one of the preceding claims, wherein the current determination substep is carried out using a current sensor (26) positioned at the input of the electrical storage device (1)- 8.Control system for an electrical storage device (1) for implementing a power adaptation method according to any one of the preceding claims, comprising an electrical storage device (1) of a vehicle, the electrical storage device having a plurality of cells (6) each having an active part (16) and at least one electrical connection element (18) extending at least partly inside the active part (16), the cells (6) being configured to be electrically assembled via their respective electrical connection elements (18) and through which an electric current flows within the electrical storage device (1), the control system comprising means for determining the temperature of one of the electrical connection elements (18) and means for adjusting a power supplied and / or received by the electrical storage device (1).

9. Electrical storage device control system (1) according to the preceding claim in combination with claim 6, wherein the means for determining the temperature of the electrical connection element (18) include means for determining a temperature of the active part (16) of a cell (6) comprising at least one temperature sensor (28) positioned on the envelope (14).

10. Control system for electrical storage device (1) according to any one of claims 8 and 9 in combination with claim 7, wherein the means for determining the temperature of the electrical connection element (18) include means for determining the electric current comprising at least one current sensor (26) positioned at the input of the electrical storage device (1).

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