Method for controlling an electric battery

Abstract

A method for controlling an electric battery equipped with a battery management system, the electric battery comprising at least two branches connected in parallel, each branch comprising at least one energy storage module, the branches being electrically connected to a junction box through which the battery current flows, each branch being equipped with at least one protective fuse suitable for interrupting the passage of an electric current in the event of an overcurrent in said branch, the method comprising: - a determination of the absence or presence of a branch current, and of the absence or presence of a junction current, - a verification of consistency between the branch current and the junction current, an anomaly of the fuse on said branch being considered in the event of inconsistency, - a modification of the operation of the battery management system according to the fuse anomaly, the other branch supplying current.Figure for the abridged version: Fig. 1.

Description

Title of the invention: Method for controlling an electric battery. FIELD OF THE INVENTION

[0001] The present invention relates to a method for controlling an electric battery comprising at least two branches connected in parallel, each branch comprising at least one energy storage module, and preferably at least two energy storage modules mounted in series, each branch being equipped with at least one protective fuse, the method enabling the detection of a fuse anomaly and the modification of the operation of a battery management system according to the fuse anomaly. STATE OF THE ART

[0002] Electric batteries allow for the storage of electrical energy in chemical form and its controlled release as direct current. To achieve the high power levels required for applications such as vehicle mobility, electric batteries are made up of assemblies of electrochemical storage elements called cells. These elements have a relatively low nominal voltage, typically 3.7 V, and are electrically connected in series and / or parallel to achieve voltage and energy levels compatible with the intended applications. To facilitate the assembly and maintenance of large batteries, and also to ensure the safety of these operations, a battery is often divided into sub-assemblies called modules. These battery modules generally have a non-hazardous voltage (less than 60 V) and dimensions and weight that allow for easy handling.These modules can be connected in series to adapt the desired voltage level and form a complete battery, thus creating a branch. These branches can then be connected in parallel to increase the energy level carried by the battery and therefore achieve sufficient autonomy for the intended application.

[0003] For large batteries, this type of architecture is repeated, and branches are connected in parallel to increase the onboard capacity, as described in patent EP3273567B1. In this example, the two polarities of a branch are connected to a junction box, which contains the safety devices. This configuration has the disadvantage of using several junction boxes and an additional central unit, resulting in higher costs and a larger overall size, which is unacceptable for embedded applications.

[0004] It is therefore preferable to use architectures with modules connected in The cables are connected in series to form branches, which are themselves connected in parallel to form a module matrix. To ensure the safety of these installations, each branch is equipped with at least one suitable protective fuse to interrupt the flow of electrical current in the event of an overcurrent in that branch. Typically, fuses can be placed on at least the positive and negative terminals of each branch, so as to protect the parallel cables and prevent a general fault in the event of a fault on a single branch.

[0005] These battery architectures are much smaller and much less expensive, but they have a significant drawback: if one of the fuses blows, fewer cells are connected to the junction box. At constant power, the current flowing through the remaining cells therefore increases and can potentially reach dangerous levels. For example, with three branches of modules connected in parallel, blowing a fuse removes one branch from the electrical circuit. Two branches of modules then remain to supply or absorb current, meaning one-third fewer modules. Each remaining branch must therefore supply or absorb 50% more current to compensate for the missing branch. Exceeding the permitted current limits by 50%, especially during charging, can damage the battery cells and ultimately cause a fire in the battery.

[0006] It is therefore necessary to ensure that the battery modules are not subjected to excessive currents or voltages, even if the fuse is open. Patent application EP3576214 Al proposes a system for detecting a poor battery connection by monitoring voltage and detecting excessive resistance, by comparing the cell voltages to the overall battery voltage. This system is highly dependent on the measurement accuracy of the cell voltage sensors and the voltage of a complete battery. For high-voltage batteries (e.g., 800V), a measurement error of 1% already corresponds to twice the maximum voltage of a lithium-ion cell.

[0007] Furthermore, systems such as the one proposed by patent application EP3576214 A1 suggest disconnecting the battery if an anomaly is detected. An electric vehicle powered by the battery is therefore taken out of service in the event of an anomaly. However, the high power and capacity required for the electric propulsion of a vehicle necessitate a battery composed of numerous cells, increasing the risk of anomalies. The battery may then lack the reliability to fulfill its function of powering an electric vehicle.

[0008] There is therefore a need for a method of controlling an electric battery that makes it possible to ensure a power supply to the load powered by the battery, while ensuring that the electrical safety margins of the battery modules are preserved, even in the event of an anomaly such as a blown fuse. Description of the invention

[0009] A method for controlling an electric battery equipped with a battery management system is proposed, the electric battery comprising at least two branches connected in parallel, each branch comprising at least one energy storage module, the branches being electrically connected to a junction box through which the battery current flows, each branch being equipped with at least one protective fuse suitable for interrupting the flow of electric current in the event of an overcurrent in said branch, the method comprising: - a determination of the absence or presence of a branch current flowing in a branch, and of the absence or presence of a junction current corresponding to the sum of the currents flowing in the branches, - a consistency check between the absence or presence of a branch current and the absence or presence of a junction current, with a fuse anomaly on said branch being considered in case of inconsistency, - a modification of the operation of the battery management system depending on the fuse anomaly, in which the other branch continues to supply current.

[0010] The control method according to the invention simply detects the absence or presence of a branch current and therefore does not require a precise or complex measuring device, unlike methods requiring precise current measurement. Furthermore, even if a fuse on a branch fails, the battery continues to supply electricity.

[0011] Advantageously, but optionally, the method may include at least one of the following features, taken alone or in any combination: - each branch includes at least two energy storage modules mounted in series; - the modification of the operation of the battery management system includes a reduction of a junction current limit; - the reduction of the junction current limit is a function of a factor corresponding to the branch's share in the battery's current supply; - the determination of the absence or presence of a branch current flowing in a branch includes the measurement of the intensity of the branch current using a voltage across a conductive part of an energy storage module of said branch, said conductive part forming a portion of a power circuit through which at least a part of the branch current passes; - The voltage across a conductive part of a module is determined from one measurement point among measurement points used by an electronic board of the module to determine internal voltages said modules, and from another measurement point corresponding to a power connection terminal of the module; - the conductive part of a module is a busbar, or busbar; - the determination of the absence or presence of a branch current flowing in a branch includes a measurement of the branch current, and the comparison with at least one threshold, the absence or presence of a branch current being determined according to a result of the comparison; - the determination of the absence or presence of a branch current flowing in a branch is based on a plurality of current measurements in the branch at different points of said branch, the absence or presence of a branch current being determined from a value derived from the plurality of current measurements.

[0012] The invention also relates to an electric battery equipped with a battery management system, the electric battery comprising at least two parallel-connected branches, each branch comprising at least one energy storage module or storage modules in series, the branches being electrically connected to a junction box through which the battery current flows, each branch being equipped with at least one protective fuse suitable for interrupting the flow of electric current in the event of an overcurrent in said branch, the battery management system being configured to implement: - a consistency check between the absence or presence of a branch current and the absence or presence of a junction current, with a fuse anomaly on said branch being considered in case of inconsistency, - a modification of the operation of the battery management system according to the fuse anomaly, in which the other branch continues to supply current, in accordance with the method according to the invention.

[0013] The invention also relates to an electrically powered vehicle comprising the electric battery according to the invention. DESCRIPTION OF THE FIGURES

[0014] Other features, objectives and advantages of the invention will become apparent from the following description, which is purely illustrative and not limiting, and which should be read in conjunction with the accompanying drawings on which:

[0015] [Fig.1] Fig.1 schematically illustrates the configuration of a battery powering a machine, in an example with three branches, according to a possible embodiment of the invention;

[0016] [Fig.2] Fig.2 shows an example of an energy storage module according to one possible embodiment of the invention;

[0017] [Fig. 3] [Fig. 3] illustrates a detail of a front face of a module, showing the bus bar connecting two measurement points;

[0018] [Fig.4] Fig.4 is a diagram schematically illustrating steps of the method according to a possible embodiment of the invention.

[0019] Throughout the figures, similar elements bear identical references. DETAILED DESCRIPTION

[0020] With reference to [Fig. 1], an electric battery 1 comprises at least two branches 2 connected in parallel, and in this simplified example comprises three branches 2. Additional branches 2 may be provided depending on the intended applications. Preferably, in order to ensure a large capacity of the battery 1, the battery 1 typically comprises more than 10 parallel branches 2. Each branch 2 comprises at least one energy storage module 4, and preferably several energy storage modules 4 connected in series, such as, for example, three modules 4 per branch 2 in [Fig. 1]. Preferably, each branch 2 comprises the same number of modules 4. Connecting branches 2 in parallel increases the power or energy of the electric battery 1.

[0021] As mentioned above, each module 4 is an assembly of electrochemical storage elements in a housing. Typically, the nominal voltage across a module is between 30 V and 100 V, and is, for example, 60 V. Connecting several modules 4 in series in a branch 2 increases the voltage across branch 2. French patent application FR3089067 describes an example of a module that can be used. A module 4 is generally equipped with control electronics, allowing, for example, the measurement of the temperature or voltage across the module 4.

[0022] The branches 2 are electrically connected to a junction box 6 through which the current from the battery 1 flows. More specifically, a power circuit 10 connects the parallel branches 2 to power connectors 12 of the junction box 6. Other power connectors 14 of the junction box 6 are connected to the machine 16 that the battery 1 supplies with electricity, in this example of a battery 1 discharge configuration. In a battery charging configuration, a power supply is, of course, connected to the power connectors 14 of the junction box in order to recharge the energy storage modules 4. Preferably, the machine 16 powered by the battery 1 is an electric vehicle, the battery providing the propulsion power for said vehicle.

[0023] The junction box 6 may include components adapted to perform various battery interfacing functions. The junction box 6 may include a current sensor 18 on at least one supply channel 20, allowing current measurement on said supply channel 20. Current measurement is understood to mean A measurement used to determine the characteristics of an electric current. Typically, a current measurement is a representative measurement of the current intensity, and can be a direct measurement of this intensity, or it can be a measurement of a voltage proportional to the current intensity.

[0024] As in the illustrated example, the junction box 6 may include switches 22, optionally coupled in series with fuses 24, for example on each of the two supply paths 20. The junction box 6 may include an isolation monitor 26 between the two supply paths 20, and for example a pre-charge circuit in parallel with a switch 22 on one supply path 20.

[0025] Each branch 2 is provided with at least one protective fuse 30 suitable for interrupting the flow of electric current in the event of overcurrent in said branch 2. Preferably, each branch 2 includes at least one fuse 30 at each end of said branch 2. Typically, and as illustrated, a fuse 30 can be associated with each module 4 of the branch 2.

[0026] Battery 1 is equipped with a battery management system, more commonly referred to by the acronym BMS. The BMS is designated as the master to distinguish it from other BMSs that may be associated with each module 2, designated as slave BMSs because they are subordinate to the master BMS. These module 4 BMSs are the management circuits mentioned above. Hereafter, the term BMS refers to the master BMS. The BMS 32 is connected to each of the modules 4 by communication channels 34 over which signals such as measurements or commands are transmitted. The BMS 32 is also connected to the junction box 6 by communication channels 36 over which signals such as measurements or commands are transmitted. The BMS 32 can also be connected to the machine 16 by a communication channel 38, serving as a communication interface between battery 1 and the machine 16.The BMS 32 is a control unit that includes a processor and memory, and is capable of communication.

[0027] Each branch 2 is equipped with at least one current sensor, allowing a measurement of the branch current on said branch, i.e., the current flowing from one end of branch 2 to the other. Typically, the current sensor is integrated into a module 4. Preferably, each module 4 is equipped with such a current sensor, in order to standardize the modules. However, only one current measurement per branch 4 is required. The current sensor measures a voltage across a conductive part of an energy storage module 4, this voltage being representative of the branch current flowing in branch 2 of battery 1. Preferably, the conductive part of the energy storage module 4 across which the voltage is measured includes a portion of a power circuit through which all or part of the branch current flows. Preferably, at least 50%, and preferably even At least 75% of the branch current flows through the portion of a power circuit across which the voltage is measured. Such a portion of a power circuit typically has a resistance greater than 150 microohms, and preferably greater than 300 pQ. Preferably, this portion of the power circuit is a busbar, that is, a conductor connecting several electrical circuits at separate points, in this case connecting several modules 4 together.

[0028] With reference to [Fig. 2], each module 4 comprises a casing, or box, including a plurality of walls, typically a housing 40 having a substantially parallelepiped shape and two covers 41, 42 hermetically sealing the housing 40, together defining a sealed enclosure. The term "sealed" here means impermeability to any type of fluid, such as water and / or air, whether in their movement from the outside to the inside of the enclosure, or from the inside to the outside of the enclosure. An assembly of cells is arranged within the enclosure, each cell comprising an electrochemical accumulator. Such electric batteries have, for example, been described in patent application WO 2020 / 109714.

[0029] Each module 4 includes connection terminals 43, 44 configured to be coupled to power connectors linking the modules 4 together, in particular for connecting modules 4 of the same branch 2 in series. More specifically, each module 4 includes a first terminal 43, which corresponds, for example, to the negative terminal, and a second terminal 44, which corresponds, for example, to the negative "+" terminal. When connecting the modules 4 in series, the first terminal 43 of a module 4 is connected to the second terminal 44 of a preceding module 4, and the second terminal 44 of said module 4 is connected to the first terminal 43 of a subsequent module 4. The modules 4 at the ends of a branch 2 have a terminal 43, 44 connected to a power circuit 10. Typically, these connection terminals 43, 44 protrude from a cover 41 designated as forming the front face.

[0030] In order to measure at least one of the following: the voltage delivered by each cell or group of cells and the temperature of each cell or group of cells, several sensors are arranged inside the housing 40. Each sensor is configured to emit a signal, preferably electrical, based on voltage and / or temperature values ​​recorded at one or more cells. This signal must then be collected for processing outside the enclosure.

[0031] With reference to [Fig. 1], in order to transmit this signal emitted by the sensor from the inside to the outside of the enclosure, an electronic board 45 is advantageously mounted on an external surface of a wall of the housing 40, preferably a wall of one of the two covers 41, 42, as shown in [Fig. 1]. As shown in [Fig. 1], connectors 46, preferably of the electrical type, are advantageously connected to the electronic board 45, so as to transmit a signal from the electronic board. The electronic board 45 connects to another element of the electric battery, typically the battery management system 32. Another connector, not shown, typically links the electronic board 45 to the inside of the housing 40, including the internal sensors. The electronic board 45 is equipped with processing means such as an electronic chip, for example the MAX17852 or MAX17853 chip from Maxim Integrated or the MC33771 chip from NXP, which are specifically developed for battery monitoring.

[0032] As mentioned previously, internal sensors are configured to measure voltages between sets of cells. These voltage measurements are taken between measurement points at different potentials, representing the gradual increase in voltage within the cell assembly of module 4. The resulting plurality of voltage measurements is used, in particular, to verify that the voltage across each cell or group of cells remains within ranges that do not damage the cells. Indeed, due to the electrochemical nature of the cells, a voltage that is too low can cause problems, particularly during charging, while a voltage that is too high poses a risk of fire.

[0033] Among the measurement points of a module 4, one measurement point corresponds to an extreme voltage, that is, the lowest or highest potential among those used by the sensors, and which corresponds to the measurement at one end of the cell assembly. With reference to [Fig. 3], this end of the cell assembly is electrically connected by a conductive part to a connection terminal 43, 44 forming the power connection at the output of the module 4. The current of the module 4, and therefore of the branch 2 to which said module 4 belongs, flows in this conductive part, which thus forms a portion of the power circuit and generally takes the form of a busbar 48.

[0034] In the illustrated example, a screw-type fastener 49 on the busbar 48 corresponds to the first measuring point with the lowest potential. A wire attached to the fastener 49 allows, for example, the lowest potential to be measured. The busbar 48 connects this measuring point to the second connection terminal 43. This connection terminal 43 forms the second measuring point, allowing a potential to be measured that is slightly different from that of the first measuring point. The difference between the potentials arises from the branch current flowing in the busbar 48. The voltage measurement based on these two measuring points is therefore representative of the branch current intensity.

[0035] Such an approach makes it possible to use one of the measurement points already used for voltage monitoring in module 4. The second measurement point is preferably a connection terminal 43, 44, which is both easily accessible and separated by a conductive part of module 4 forming a portion of the circuit. power.

[0036] The first and second measurement points can be connected to the external electronic board 45, which can deduce the potential differences, even small ones, between the two measurement points, and thus derive a current measurement. It is also possible to use two voltage measurements, one involving the first measurement point and the other involving the second measurement point (for example, with respect to a common reference), and to determine, as a voltage measurement representative of the branch current, the difference between these voltage measurements. An operational amplifier can be used to record the measurements, such as the one found in the MAX17852 from Maxim Integrated or the MC33771 from NXP.

[0037] Unlike prior art systems, the current measurement is not performed across a calibrated precision resistor of only a few pQ, connected in series with the entire circuit, thus requiring a lower branch module different from the other modules. Conventionally, this precision resistor (or "shunt") is made of a specific material to maintain its resistance value under all conditions, for example, a copper-magnesium-nickel alloy. Such prior art current measurements must indeed be precise for applications such as accurately estimating the state of charge of battery 1, which is calculated by integration and therefore requires high accuracy.

[0038] In the present invention, it is not necessary for the branch current measurement to be very precise, as it only aims to detect the presence or absence of branch current circulation, as described in the method below.

[0039] The method is intended to be implemented continuously and iteratively. With reference to [Fig. 3], in a first step 1, the absence or presence of a branch current flowing in a branch 2 is determined. Determining the absence or presence of a branch current flowing in branch 2 typically involves measuring the branch current intensity using a sensor that measures a voltage across a conductive part of an energy storage module 4 of said branch 2, as explained above. Typically, such a current measurement is then compared to a threshold, and the absence or presence of a branch current is determined based on the result of the comparison.

[0040] For example, it is possible to compare the current measurement to a load threshold representative of a charging current, for example, greater than 250 mA if the measurement is in current or greater than 62.5 mV if the measurement is in voltage. If the current measurement is greater than this load threshold, this means that a charging current is flowing in branch 2. If the current measurement is less than this load threshold, this means either that no branch current is flowing, or that a discharging current is flowing. It is It is therefore possible to compare the current measurement to a discharge threshold representative of a discharge current, for example, less than -250 mA if the measurement is current or less than -62.5 mV if the measurement is voltage. If the current measurement is below this discharge threshold, it means that a discharge current is flowing in branch 2. If the current measurement is above this discharge threshold, it means either that no branch current is flowing or that a charging current is flowing. Thus, the presence or absence of a branch current is determined if the current measurement is between the charging threshold and the discharge threshold. To simplify, it is possible to compare an absolute value of the current measurement to a threshold, below which the absence of current in branch 2 is determined.

[0041] It is possible that several current measurements may be available, particularly when several current sensors are available on the same branch 2, at different points on the branch, for example with one current sensor per electricity storage module 4. In this case, the absence or presence of a branch current is determined from a value derived from the plurality of current measurements. Typically, an average of the current measurements can be determined, and it is this average that is used as the current measurement when comparing to at least one threshold.

[0042] Simply determining the absence or presence of a branch current flowing in a branch is not sufficient to determine a fault in fuse 30 on that branch 2, such as an open fuse 30. The absence of branch current may also be normal when there is no power exchange between battery 1 and the machine 16 to which said battery 1 is connected (for example, a vehicle or a power supply). It is therefore necessary to verify the consistency between the absence or presence of a branch current and the absence or presence of a junction current flowing in the junction box 6, corresponding to the sum of the currents flowing in the branches 2. To do this, the absence or presence of the junction current is determined, for example, by means of the current sensor 18 located in the junction box.Similar to branch current, the current measurement is compared to a threshold, and the absence or presence of a junction current is determined based on the result of the comparison.

[0043] The consistency between the absence or presence of a branch current and the absence or presence of a junction current means that an absence of a branch current must correspond to an absence of a junction current, and vice versa, and that the presence of a branch current must correspond to the presence of a junction current. In the event of an inconsistency, particularly in the event of an absence of a branch current and the presence of a junction current, the fuse 30 on said branch 2 is considered to have a fault. A fault in fuse 30 is typically due to that fuse 30 is open, for example, due to excessive current on branch 2. It is possible that the absence or presence of a branch current, like the absence or presence of a junction current, can each be represented by an indicator, for example, a high or low voltage value, or even a numerical value. In this case, the comparison simply involves comparing indicators, for example, numerically or using logic gates.

[0044] Following the detection of a fault in fuse 30 on branch 2, the operation of the battery management system, or BMS 32, is modified according to the fuse fault (step S3), in which the other branch continues to supply current. The modification of the operation of the battery management system 32 takes into account the unavailability of branch 2 on which the fault was detected, without, however, interrupting the power supply to the machine 16, or the charging of battery 1. Preferably, the modification of the operation of the battery management system 32 includes a reduction of a junction current limit. This reduction is advantageously a function of a current limit associated with branch 2 affected by the fuse fault.Preferably, the battery management system 32 adapts at least one maximum permissible current threshold according to the number of branches 2 not affected by a fuse anomaly.

[0045] Typically, the junction current limit is information transmitted to the machine or vehicle 16, which can then control the current drawn from the battery according to this junction current limit. It is also possible to provide a safety procedure for the battery if the junction current exceeds the junction current limit, for example, because the machine 16 does not take into account the junction current limit information. The safety procedure may include disconnecting the battery, for example, by opening at least one switch 22 on a power supply channel 20, or by causing a battery fault, with a fault information sent to the machine 16.

[0046] By way of example, in [Fig. 1], the battery comprises three parallel branches 2. The battery management system 32 is configured to limit the maximum current flowing through the junction box, for obvious safety reasons. If the fuse 30 on one branch 2 blows, that branch 2 can no longer supply its share of current. The total current must therefore be supplied by the two remaining branches 2, which then have to supply 50% more current than before, in order to compensate for the missing branch. This 50% increase in current can exceed the permissible limit for a branch 2 and lead to damage to the battery, or even cause a fire in battery 1. Of course, the effect of the unavailability of one branch is less critical when there are many branches 2. For example, the loss of one branch 2 out of ten branches 2 does not imply that a 10% increase in the current of the remaining branches 2. However, even a small increase can have consequences, especially since battery 1 is generally configured to respond to power peaks. Since a safety margin results in overcapacity in modules 4, and therefore in increased costs, weight, and size, it is preferable to keep this margin as low as possible. Thus, even a minor current shift to the remaining branches 2 can be enough to over-stress the modules of the remaining branches.

[0047] Thus, according to the invention, upon detecting the fuse 30 anomaly, an permissible current threshold is reduced proportionally to the share of branch 2 affected in the current distribution. Let Vi be the maximum permissible junction current when all branches 2 are connected and delivering current.With n identical branches (n>2) in operation, the detection of a fuse fault on one branch results in a reduction of the maximum junction current threshold Vj by a factor of (nl) / n. With preferably similar branches 2, the current limit will thus be reduced by one-third for three branches 2, and by 10% for ten branches 2. The remaining branches 2 are therefore not subjected to a higher maximum load than before. However, it is possible to use other reduction factors, allowing for example a reduction in safety margins, assuming that the fault is not expected to persist and that fuse 30 will be replaced promptly.

[0048] The proposed method therefore does not involve shutting down battery 1, but instead provides for a degraded operating mode in which the maximum permissible power is reduced by reducing the maximum permissible junction current. The method is thus particularly suited to supplying power to an electric vehicle, which cannot tolerate any interruption in power supply. It should be noted that while the examples below only mentioned a single blown fuse 30 affecting one branch 2, it is possible that several successive branches may be affected. In this case, the method is repeated and detects each fault in fuse 30, resulting in a successive adaptation of the operation of the battery management system 32. The method is therefore suitable for dealing with the occurrence of several successive blown fuses 30, increasing the ability of battery 1 to maintain power supply despite multiple failures.Of course, if there are no more available branches 2, battery 1 is shut down. It is possible to anticipate that the BMS will send information about the detected fuse 30 fault to machine 16, preferably identifying the branch 2 affected by the fault.

[0049] The invention is not limited to the embodiment described and shown in the accompanying figures. Modifications remain possible, particularly with regard to the constitution of the various technical features or by substitution of equivalents. techniques, without, however, leaving the scope of protection of the invention.

Claims

Demands

1. A method for controlling an electric battery (1) equipped with a battery management system (32), the electric battery (1) comprising at least two branches (2) connected in parallel, each branch (2) comprising at least one energy storage module (4), the branches (2) being electrically connected to a junction box through which the battery current (1) flows, each branch (2) being equipped with at least one protective fuse (30) suitable for interrupting the flow of an electric current in the event of an overcurrent in said branch (2), characterized in that the method comprises: - determining the absence or presence of a branch current flowing in a branch, and the absence or presence of a junction current corresponding to the sum of the currents flowing in the branches (2), - verifying the consistency between the absence or presence of a branch current and the absence or presence of a junction current,an anomaly in the fuse on said branch (2) being considered in case of inconsistency, - a modification of the operation of the battery management system (32) depending on the fuse anomaly, in which the other branch (2) continues to supply current.

2. A method according to claim 1, wherein the modification of the operation of the battery management system includes a reduction of a junction current limit.

3. A method according to the preceding claim, wherein the reduction of the junction current limit is a function of a factor corresponding to the share of branch (2) in the current supply of battery (1).

4. A method according to any one of the preceding claims, wherein the determination of the absence or presence of a branch current flowing in a branch (2) comprises measuring the intensity of the branch current using a voltage across a conductive part of an energy storage module (4) of said branch (2), said conductive part forming a portion of a power circuit through which at least a portion of the branch current passes.

5. A method according to the preceding claim, wherein the voltage across a conductive part of a module (4) is determined from one measurement point among several measurement points used by an electronic card (45) of the module (4) to determine internal voltages said modules, and from another measurement point corresponding to a power connection terminal (43, 44) of the module (4).

6. A method according to any one of claims 4 or 5, wherein the conductive part of a module is an omnibus bar (48), or bus-bar.

7. A method according to any one of the preceding claims, wherein the determination of the absence or presence of a branch current flowing in a branch comprises a measurement of the branch current, and the comparison with at least one threshold, the absence or presence of a branch current being determined as a function of a result of the comparison.

8. A method according to any one of the preceding claims, wherein the determination of the absence or presence of a branch current flowing in a branch is based on a plurality of current measurements in the branch at different points of said branch, the absence or presence of a branch current being determined from a value derived from the plurality of current measurements.

9. Electric battery (1) equipped with a battery management system (32), the electric battery (1) comprising at least two branches (2) connected in parallel, each branch (2) comprising at least one energy storage module (4), the branches being electrically connected to a junction box through which the battery current flows, each branch being equipped with at least one protective fuse suitable for interrupting the flow of electric current in the event of an overcurrent in said branch, characterized in that the battery management system is configured to implement: - a consistency check between the absence or presence of a branch current and the absence or presence of a junction current, a fuse anomaly on said branch being considered in the event of inconsistency, - a modification of the operation of the battery management system according to the fuse anomaly,in which the other branch continues to supply current, in accordance with the method described in any one of the preceding claims.

10. Electrically powered vehicle comprising the electric battery of the Claim 9.

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